Fecal Occult Blood Testing - which flavor of card?

February 25, 2011

Recnetly, there was discussion on the list about fecal occult blood testing.

I think the issue crosses clinical list and practice mgt lists - see below.

Several issues were brought up.

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

2. The issue of the cards outdating before being used up was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.Others mentioning getting free cards through Quest Labs, but then having to send them in through quest.

At first blush, it sounds like the Fecal immunochemical tests are becoming the standard, but there are several brands.

Is one cheaper than another?

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Here are the various testing techniques...

I know some aren't a fan of the wiki, but...

http://en.wikipedia.org/wiki/Fecal_occult_blood

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

, The USPSTF also has this:Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopy = colonoscopyfrom: http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend "high sensitivity fecal occult blood tests" meaning the FIT or the equivalent of the Hemocult II or SENSA.To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Recnetly, there was discussion on the list about fecal occult blood testing.

I think the issue crosses clinical list and practice mgt lists - see below.

Several issues were brought up.

1. Which is "best"? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

2. The issue of the cards outdating before being used up was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.Others mentioning getting free cards through Quest Labs, but then having to send them in through quest.

At first blush, it sounds like the Fecal immunochemical tests are becoming the standard, but there are several brands.

Is one cheaper than another?

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Here are the various testing techniques...

I know some aren't a fan of the wiki, but...

http://en.wikipedia.org/wiki/Fecal_occult_blood

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool

guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample

after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat

and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are

underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated

genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

, The USPSTF also has this:Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopy = colonoscopyfrom: http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend "high sensitivity fecal occult blood tests" meaning the FIT or the equivalent of the Hemocult II or SENSA.To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Recnetly, there was discussion on the list about fecal occult blood testing.

I think the issue crosses clinical list and practice mgt lists - see below.

Several issues were brought up.

1. Which is "best"? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

2. The issue of the cards outdating before being used up was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.Others mentioning getting free cards through Quest Labs, but then having to send them in through quest.

At first blush, it sounds like the Fecal immunochemical tests are becoming the standard, but there are several brands.

Is one cheaper than another?

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Here are the various testing techniques...

I know some aren't a fan of the wiki, but...

http://en.wikipedia.org/wiki/Fecal_occult_blood

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool

guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample

after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat

and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are

underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated

genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?).The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.SharonSharon McCoy MDRenaissance Family Medicine

10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?).The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.SharonSharon McCoy MDRenaissance Family Medicine

10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

It is interesting that the iFOB doesnâ€™t detect Upper GI

blood. I didnâ€™t know that. I use the iFOB almost exclusively and it

has improved compliance markedly. It is easier for the patients to do.

As far as losses, I get my supplies from the labs (LabCorp and

Quest) and they develop them and get paid for them. They supply them to

me for free. I have a couple of cash patients that I bought a kit for, I

canâ€™t remember the brand. I make the patient buy it up front.

It figured it would help motivate them to actually do it if they already paid

for it. But, Â½ expired before used so I actually lost money anyway.

Kathy Saradarian, MD

Branchville, NJ

www.qualityfamilypractice.com

Solo 4/03, Practicing since 9/90

Practice Partner 5/03

Low staffing

From:

[mailto: ] On Behalf Of Locke

Sent: Friday, February 25, 2011 2:50 AM

To:

Subject: Re: Fecal Occult Blood Testing - which

flavor of card?

Thanks, Carla.

This sort of implies using the old Guiac cards are passe --

malpractice?

Locke, MD

,

The USPSTF also has this:

Screening

Tests

The

relative sensitivity and specificity of the different colorectal screening

tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible

sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity:

Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible

sigmoidoscopy < colonoscopy

Specificity:

Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible

sigmoidoscopy = colonoscopy

from: http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

And they only recommend " high sensitivity fecal occult blood tests "

meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >;

Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PM

Subject: Fecal Occult Blood Testing - which

flavor of card?

Recnetly, there was discussion on

the list about fecal occult blood testing.

I think the issue crosses clinical

list and practice mgt lists - see below.

Several issues were brought up.

1. Which is " best " ? Which

could mean most sensitive or most specific.

This drives our clinical decision

making AND which cards we want to buy

2. The issue of the cards

outdating before being used up was mentioned -- wasteful from a practice

management standpoint -- But also raising the question of how to clinically

increase compliance of bringing the cards back in when they are sent out.

3. The issue of billing for the

testing was mentioned - many saying they didn't get paid or were paid very

little.

Others mentioning getting free cards through Quest Labs, but then having

to send them in through quest.

At first blush, it sounds like the

Fecal immunochemical tests are becoming the standard, but there are

several brands.

Is one cheaper than another?

=============================

Anyway, in regards to the testing

cards...found some interesting stuff out there.

Here are the various testing

techniques...

I know some aren't a fan of the

wiki, but...

http://en.wikipedia.org/wiki/Fecal_occult_blood

There are four methods in clinical use for testing

for occult blood

in feces. These

look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular

material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult

blood (gFOBT): - The stool

guaiac test involves smearing some feces on to some absorbent paper

that has been treated with a chemical. Hydrogen

peroxide is then dropped on to the paper; if trace amounts of blood are

present, the paper will change color in one or two seconds. This method

works as the heme

component in hemoglobin has a peroxidase-like

effect, rapidly breaking down hydrogen peroxide. In some settings such as

gastric or proximal upper intestinal bleeding the guaiac method may be

more sensitive than tests detecting globin because globin is broken down

in the upper intestine to a greater extent than is heme.[4] There are various commercially available

gFOBT tests which have been categorized as being of low or high

sensitivity, and only high sensitivity tests are now recommended in colon

cancer screening. Optimal clinical performance of the stool

guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing

(FIT), and immunochemical fecal occult blood test (iFOBT):

- Many commercial products rely on these methods, which chemically depend

on specific antibodies to detect globin. For colorectal

cancer screening, the FIT tests are superior than low sensitivity gFOBT.

Although FIT may be a consideration to replace gFOBT in colon cancer

screening,[6][7] high sensitivity gFOBT, such as Hemoccult

SENSA, remains an accepted option alongside FIT in recent guidelines,

being assessed as having similar overall performance characteristics to

FIT.[8] The number of fecal samples submitted for

FIT may affect the clinical sensitivity and specificity of the

methodology.[9] This methodology can be adapted for

automated test reading and to report quantitative results, which are

potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring

gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin

quantification: - HemoQuant, unlike gFOBT and FIT, permits

precise quantification of hemoglobin, and is analytically validated

with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically

converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin,

and the porphyrin content of both the original sample and of the sample

after hemoglobin conversion to porphyrin is quantified by comparative

fluorescence against a reference standard; the specificity for

hemoglobin is increased by subtracting the fluorescence of a sample blank

prepared with citric acid to correct for the potential confounding effect

of existing non-specific substances.[12] Precise quantification measurement has been

very useful in many clinical research applications.[13]

Fecal DNA test: -

The PreGen-Plus[14] test extracts human DNA from the stool

sample and tests it for alterations that have been associated with cancer.

The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as

well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay

(DIA).[citation needed]

Additional methods of looking for occult blood are

being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test

for fecal occult blood (gFOBT) sensitivity varies depending on the site

of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about

10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser

amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single

stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a

standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion

of sensitivity and sensitivity issues that relate particularly to the guaiac

method is found in the stool guaiac test

article.

Fecal Immunochemical Testing

(FIT) picks up as little as 0.3 ml but because it does not detect occult

blood from the stomach and upper small intestine the test threshold doesn't

cause undue false positives from normal upper intestinal blood leakage and it

is much more specific for bleeding from the colon or lower gastrointestinal

tract.[24] The detection rate

of the test decreases if the time from sample collection to laboratory

processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant

can be false

positive due to exogenous blood and various porphyrins. HemoQuant is

the most sensitive test for upper gastrointestinal bleeding and therefore may

be most appropriate fecal occult blood test to use in the evaluation of iron

deficiency [26] Advised to stop red

meat and aspirin for 3 days prior to specimen collection [27] False positives can

occur with myoglobin, catalase, or protohemes[13] and in certain

types of porphyria[citation needed]

The DNA based PreGen-Plus was four

times more sensitive than fecal blood testing, including detection of early

stage disease, when treatment is most effective.[28] Sensitivity

increased to 51.6% compared to 12.9%.[29] Additional clinical

trials of the PreGen-Plus method are underway to more fully characterize its

clinical performance.[30] Expanding the range

of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by

analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps

(HP) with microsatellite instability

(MSI)[32][33] and in proximal

colon tumours that have poorer differentiation, does not appear to appreciably

increase the sensitivity of the method because CTNNB1 mutations are infrequent

in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1

expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009

Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen

for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control,

Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology.

2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin

represent a major advance over guaiac-based fecal occult blood tests (GFOBTs)

for colorectal cancer screening. FITs specifically detect human hemoglobin in

stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase

the detection rates of cancer and advanced adenoma compared with

early-generation GFOBTs, and do so without the unacceptably high number of

colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to

use than GFOBTs, they improve rates of patient participation, and their cut-off

points for positive versus negative tests can be modified. A large, Dutch,

population-based, randomized controlled trial has compared the performance of a

GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT

detected two-and-a-half times as many cancers and advanced adenomas as did the

GFOBT, despite similar colonoscopy rates. The latest generation of FITs should

replace traditional GFOBTs in two-step (test then colonoscopy) screening for

colorectal cancer.

=============================

This article is getting outdated, but still had

some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

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February 25, 2011

I like the old Guiac test for in office use when pts c/o blood in stools, black stools. Helps me decide if they need to go to ER. For cancer screening, I use the Quest FIT cards. After my supplies runs out, I guess I will buy the Sensa cards. Or spilt a batch w someone. Â

Fri, Feb 25, 2011 at 3:13 AM, Locke wrote:

Â

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

-- M.D.www.elainemd.comOffice: Go in the directions of your dreams and live the life you've imagined.

This email transmission may contain protected and privileged, highly confidential medical, Personal and Health Information (PHI) and/or legal information. The information is intended only for the use of the individual or entity named above.

Â If you are not the intended recipient of this material, you may not use, publish, discuss, disseminate or otherwise distribute it. If you are not the intended recipient, or if you have received this transmission in error, please notify the sender immediately and confidentially destroy the information that email in error.

February 25, 2011

I like the old Guiac test for in office use when pts c/o blood in stools, black stools. Helps me decide if they need to go to ER. For cancer screening, I use the Quest FIT cards. After my supplies runs out, I guess I will buy the Sensa cards. Or spilt a batch w someone. Â

Fri, Feb 25, 2011 at 3:13 AM, Locke wrote:

Â

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject: Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

-- M.D.www.elainemd.comOffice: Go in the directions of your dreams and live the life you've imagined.

This email transmission may contain protected and privileged, highly confidential medical, Personal and Health Information (PHI) and/or legal information. The information is intended only for the use of the individual or entity named above.

Â If you are not the intended recipient of this material, you may not use, publish, discuss, disseminate or otherwise distribute it. If you are not the intended recipient, or if you have received this transmission in error, please notify the sender immediately and confidentially destroy the information that email in error.

February 25, 2011

OK Guys here it goes,

I would greatly apperciate any assistance in understanding what may be happening inside my own tush and bowels. First off don't assume I uderstand all good doctor lingo. I am an out of shape hockey coach and official approaching fifty years of age this July. As I have been coaching my son's team more and more on the weekends it is increasingly harder for me to also schedule in games to officiate to keep in shape as I used to.

Two seasons in a row now, as the season progresses it seems that I am getting more and more evidence of fresh red blood on my toilet paper, drips into the water and sometimes what appears to darker red mucus like clots although those are not regular and sporatic. By this time last season I was pretty upset and concerned. Understand I have a very decent GI but like many other struggling Americans we do not have any health insurance at the present time and so just as he and I were figuring this out, BOOM there went the coverage. I feel pretty embarressed saying all of this to all of you as YES I know I should probably eat the inflated charges of about $1K for a scope and just have it done anyway, but we literally don't have the funds as we struggle under mounds of debt, keep the lights on, pay the morgage and the office rent, feed the kids and fill the Jeeps... Cards maxed out as well... No CCHIT it is really like that

right now...

So I was wondering all along could what I am experiencing be at all related to the stress on my middle body raising blood pressure, hydration, colon health from continuingly growing amounts of stress combined with medications, when all of a sudden I read this from you folks and it makes me start to wonder about the effects of the combo of things in my personal life like extreme stress (the practice is only half of it, Amazing how nasty some selfish twisted people can make normal people's lives) and my out of shape sporatic hard skating and exercise...

Thanks so much in advance for your multiple curbside consults and good will....

To: Sent: Fri, February 25, 2011 6:13:39 AMSubject: Re: Fecal Occult Blood Testing - which flavor of card?

Sharon,

You bring up an interesting point about the newi tests being "too sensitive" -- in certain populations that have "normal" occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Locke MD

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have "normal upper intestinal blood leakage?"

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CA 92617PH: (949)387-5504 Fax: (949)281-2197 Toll free phone/fax: www.SharonMD.com

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopy = colonoscopy

from: http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htmAnd they only recommend "high sensitivity fecal occult blood tests" meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures Sent: Thu, February 24, 2011 11:42:21 PMSubject:

Fecal Occult Blood Testing - which flavor of card?

Recnetly, there was discussion on the list about fecal occult blood testing.

I think the issue crosses clinical list and practice mgt lists - see below.

Several issues were brought up.

1. Which is "best"? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

2. The issue of the cards outdating before being used up was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.Others mentioning getting free cards through Quest Labs, but then having to send them in through quest.

At first blush, it sounds like the Fecal immunochemical tests are becoming the standard, but there are several brands.

Is one cheaper than another?

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Here are the various testing techniques...

I know some aren't a fan of the wiki, but...

http://en.wikipedia.org/wiki/Fecal_occult_blood

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is

quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and

sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation

needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

February 25, 2011

..... this is not a normal sign of middle age or stress, you owe it to

yourself and your family to get it checked out. And if someone only charges you

1k and it includes the surgery suite and anesthesia that is a deal.

--

T. Ellsworth, MD

9377 E. Bell Road, Suite 175

sdale, AZ 85260

---- Bleiweiss wrote:

>

> OK Guys here it goes,

> Â Â Â I would greatly apperciate any assistance in understanding what may be

> happening inside my own tush and bowels. First off don't assume I uderstand

all

> good doctor lingo. I am an out of shape hockey coach and official approaching

> fifty years of age this July. As I have been coaching my son's team more and

> more on the weekends it is increasingly harder for me to also schedule in

games

> to officiate to keep in shape as I used to.

>

> Â Â Â Two seasons in a row now, as the season progresses it seems that I am

> getting more and more evidence of fresh red blood on my toilet paper, drips

into

> the water and sometimes what appears to darker red mucus like clots although

> those are not regular and sporatic. By this time last season I was pretty

upset

> and concerned. Understand I haveÂ a very decent GI but like many other

struggling

> Americans we do not have any health insurance at the present time and so just

as

> he and I were figuring this out, BOOM there went the coverage. I feel pretty

> embarressed saying all of this to all of you as YES I know I should probably

eat

> the inflated charges of about $1KÂ for a scope and just have it done anyway,

but

> we literally don't have the funds as we struggle under mounds of debt, keep

the

> lights on, pay the morgage and the office rent, feed the kids and fill the

> Jeeps... Cards maxed out as well... No CCHIT it is really like that right

now...

>

> Â Â Â So I was wondering all along could what I am experiencing be at all

health

> from continuingly growing amounts of stress combined with medications, when

all

> of a sudden I read this from you folks and it makes me start to wonder about

the

> effects of the combo of things in my personal life like extreme stress (the

> practice is only half of it, Amazing how nasty some selfish twisted people can

> make normal people's lives) and my out of shape sporatic hard skating and

> exercise...Â Â Â

>

> Thanks so much in advance for your multiple curbside consults and good

will....

>

> ________________________________

>

> To:

> Sent: Fri, February 25, 2011 6:13:39 AM

> Subject: Re: Fecal Occult Blood Testing - which flavor

of

> card?

>

> Â

> Sharon,

> You bring up an interesting point about the newi tests being " too sensitive "

--

> Â in certain populations that have " normal " occult blood.

> For example - will the new FIT testing overdiagnose problems in marathoners?

>

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/1\

54-original-article-marathon-induced-colitis.html

>

> Up to 20% of marathoners will have biochemical evidence of microscopic blood

in

> their stools upon post-race fecal occult blood testing

(â€œheme-positiveâ€).16

> Multiple cases and analyses of these cases suggest ischemia and reperfusion as

> the dominant mechanism for inducing colitis after a marathon.17-20 Shunting

and

> redirection of cardiac output to the skeletal muscles presumably leaves the

> gastrointestinal tract in a state of acutely diminished blood flow for the

> duration of the marathon.

>

> Additionally, marathoning appears to induce a systemic hypercoagulable state,

> more so than any other sport to which a comparison can be made,21-23 the

> magnitude of which is as great as that seen with pulmonary artery

> catheterization, 30% total body surface area thermal injury, and even

> experimental loss of 60% blood volume combined with mild traumatic brain

> injury.24-26 This hypercoagulable state may cause intravascular sludging and

> microvascular thrombotic events within the delicate capillary network within

the

> wall of the colon. Upon completing the race, reperfusion results in normal

> fibrinolysis and an acute inflammatory milieu is generated, resulting in

> colitis. Ischemia is prolonged and worsened by dehydration and volume

> contraction, problems exceedingly common among marathoners, even those with

> apparently appropriate volume and electrolyte replacement during the

race.10,12

>

> Â

> Locke MD

>

> On Fri, Feb 25, 2011 at 1:22 AM, Sharon McCoy

wrote:

>

> Â

> >Well , at least not worth wasting your patient's time and money on (or

> >maybe better to say, why not use the ones most likely to save lives?).

> >

> >The kits I have from Quest are Insure FIT (although they expire next month so

> >I've had them awhile and they may be using something else by now.....).

> >

> >Question, do we have " normal upper intestinal blood leakage? "

> >

> >Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because

it

> >does not detect occult blood from the stomach and upper small intestine the

test

> >threshold doesn't cause undue false positives from normal upper intestinal

blood

> >leakage....

> >>

> Thanks for educating us and Carla.

>

> Sharon

>

> Sharon McCoy MD

> Renaissance Family Medicine

> 10 McClintock Court; Irvine, CAÂ 92617

> PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â

> www.SharonMD.com

>

> Â

> >Thanks, Carla.

> >This sort of implies using the old Guiac cards are passe -- malpractice?

> > Locke, MD

> >

> >Â

> >>,

> >>The USPSTF also has this:

> >>Screening Tests

> >>The relative sensitivity and specificity of the different colorectal

screening

> >>tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible

> >>sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

> >>

> >>Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA

â‰ˆ

> >>flexible sigmoidoscopy < colonoscopy

> >>>Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II

<

> >>>flexible sigmoidoscopyÂ = colonoscopy

> >>>

> >from:Â

> >http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

> >

> >And they only recommend " high sensitivity fecal occult blood tests " meaning

the

> >FIT or the equivalent of the Hemocult II or SENSA.

> >

> ________________________________

>

> >To: practiceimprovement1 < >; Practice

> >Management Issues ; Clinical Procedures

> >

> >Sent: Thu, February 24, 2011 11:42:21 PM

> >Subject: Fecal Occult Blood Testing - which flavor of

> >card?

> >

> >Â

> >Recnetly, there was discussion on the list about fecal occult blood testing.

> >

> >I think the issue crosses clinical list and practice mgt lists - see below.

> >

> >Several issues were brought up.

> >

> >1. Which is " best " ? Which could mean most sensitive or most specific.

> >This drives our clinical decision making AND which cards we want to buy

> >

> >2. The issueÂ of the cards outdating before being used upÂ was mentioned --

> >wasteful from a practice management standpoint -- But also raising the

question

> >of how to clinically increase compliance of bringing the cards back in when

they

> >are sent out.

> >

> >3. The issue of billing for the testing was mentioned - many saying they

didn't

> >get paid or were paid very little.

> >OthersÂ mentioning getting free cards through Quest Labs, but then having to

send

> >them in through quest.

> >

> >At first blush, it sounds like the Fecal immunochemical testsÂ are becoming

the

> >standard, but there are several brands.

> >Is one cheaper than another?

> >

> >=============================

> >Anyway, in regards to the testing cards...found some interesting stuff out

> >there.

> >

> >Here are the various testing techniques...

> >

> >I know some aren't a fan of the wiki, but...

> >

> >http://en.wikipedia.org/wiki/Fecal_occult_blood

> >

> >There are four methods in clinical use for testing for occult blood in feces.

> >These look at different properties, such as heme, globin, and porphyrins in

> >blood or at DNA from cellular material such as from lesions of the intestinal

> >mucosa.

> > * Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test

> >involves smearing some feces on to some absorbent paper that has been treated

> >with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace

> >amounts of blood are present, the paper will change color in one or two

seconds.

> >This method works as the heme component in hemoglobin has a peroxidase-like

> >effect, rapidly breaking down hydrogen peroxide. In some settings such as

> >gastric or proximal upper intestinal bleeding the guaiac method may be more

> >sensitive than tests detecting globin because globin is broken down in the

upper

> >intestine to a greater extent than is heme.[4] There are various commercially

> >available gFOBT tests which have been categorized as being of low or high

> >sensitivity, and only high sensitivity tests are now recommended in colon

cancer

> >screening. Optimal clinical performance of the stool guaiac test depends on

> >preparatory dietary adjustment.[5]

> > * Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood

> >test (iFOBT): - Many commercial products rely on these methods, which

chemically

> >depend on specific antibodies to detect globin. For colorectal cancer

screening,

> >the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a

> >consideration to replace gFOBT in colon cancer screening,[6][7] high

sensitivity

> >gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in

> >recent guidelines, being assessed as having similar overall performance

> >characteristics to FIT.[8] The number of fecal samples submitted for FIT may

> >affect the clinical sensitivity and specificity of the methodology.[9] This

> >methodology can be adapted for automated test reading and to report

quantitative

> >results, which are potential factors in design of a widescale screening

> >strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions

> >such as ulcerative colitis.[11]

> > * Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits

> >precise quantification of hemoglobin, and is analytically validated with

gastric

> >juice and urine, as well as stool samples. The heme moiety of intact

hemoglobin

> >is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate

to

> >protoporphyrin, and the porphyrin content of both the original sample and of

the

> >sample after hemoglobin conversion to porphyrin is quantified by comparative

> >fluorescence against a reference standard; the specificity for hemoglobin is

> >increased by subtracting the fluorescence of a sample blank prepared with

citric

> >acid to correct for the potential confounding effect of existing non-specific

> >substances.[12] Precise quantification measurement has been very useful in

many

> >clinical research applications.[13]

> > * Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the

stool

> >sample and tests it for alterations that have been associated with cancer.

The

> >test looks at 23 individual DNA alterations, including 21 specific point

> >alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene

> >involved in microsatellite instability (MSI).[15][16] and a proprietary DNA

> >Integrity Assay (DIA).[citation needed]

> >Additional methods of looking for occult blood are being explored, including

> >transferrin dipstick[17] and stool cytology.[18]Clinical sensitivity and

> >specificity

> >Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending

on

> >the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood

loss

> >of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can

pick

> >up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity

of

> >a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%,

but

> >if a standard three tests are done as recommended the sensitivity rises to

> >92%.[23] Further discussion of sensitivity and sensitivity issues that relate

> >particularly to the guaiac method is found in the stool guaiac test article.

> >Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because

it

> >does not detect occult blood from the stomach and upper small intestine the

test

> >threshold doesn't cause undue false positives from normal upper intestinal

blood

> >leakage and it is much more specific for bleeding from the colon or lower

> >gastrointestinal tract.[24] The detection rate of the test decreases if the

time

> >from sample collection to laboratory processing is delayed.[25]

> >Fecal porphyrin quantification by HemoQuant can be false positive due to

> >exogenous blood and various porphyrins. HemoQuant is the most sensitive test

for

> >upper gastrointestinal bleeding and therefore may be most appropriate fecal

> >occult blood test to use in the evaluation of iron deficiency [26] Advised to

> >stop red meat and aspirin for 3 days prior to specimen collection [27] False

> >positives can occur with myoglobin, catalase, or protohemes[13] and in

certain

> >types of porphyria[citation needed]

> >The DNA based PreGen-Plus was four times more sensitive than fecal blood

> >testing, including detection of early stage disease, when treatment is most

> >effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29]

Additional

> >clinical trials of the PreGen-Plus method are underway to more fully

> >characterize its clinical performance.[30] Expanding the range of DNA testing

by

> >looking at additional known genetic markers, such as CTNNB1, or by analyzing

> >epigenetically methylated genes[31] such as MLH1 which is very common in

> >hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in

> >proximal colon tumours that have poorer differentiation, does not appear to

> >appreciably increase the sensitivity of the method because CTNNB1 mutations

are

> >infrequent in sporadic colorectal cancer, and because BAT26 alterations and

lack

> >of MLH1 expression show a high degree of overlap.[34]

> >==================================

> >http://www.ncbi.nlm.nih.gov/pubmed/19174764

> >Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

> >Which fecal occult blood test is best to screen for colorectal cancer?

> >Young GP, Cole SR.

> >Flinders Centre for Cancer Prevention and Control, Flinders University, Room

> >3D230, Bedford Park, Adelaide, SA 5042, Australia.

graeme.young@...

> >Comment on:

> > * Gastroenterology. 2008 Jul;135(1):82-90.

> >Abstract

> >Fecal immunochemical tests (FITs) for hemoglobin represent a major advance

over

> >guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer

screening.

> >FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs

only

> >detect heme. Studies show that FITs increase the detection rates of cancer

and

> >advanced adenoma compared with early-generation GFOBTs, and do so without the

> >unacceptably high number of colonoscopies that high-sensitivity GFOBTs

generate.

> >Also, FITs are simpler to use than GFOBTs, they improve rates of patient

> >participation, and their cut-off points for positive versus negative tests

can

> >be modified. A large, Dutch, population-based, randomized controlled trial

has

> >compared the performance of a GFOBT and a FIT on an intention-to-screen

basis.

> >This study found that the FIT detected two-and-a-half times as many cancers

and

> >advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The

> >latest generation of FITs should replace traditional GFOBTs in two-step (test

> >then colonoscopy) screening for colorectal cancer.

> >=============================

> >This article is getting outdated, but still had some interesting info...

>

>http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalI\

mmunoTest_updated.pdf

> >

> >==============================

> >

>

February 25, 2011

..... this is not a normal sign of middle age or stress, you owe it to

yourself and your family to get it checked out. And if someone only charges you

1k and it includes the surgery suite and anesthesia that is a deal.

--

T. Ellsworth, MD

9377 E. Bell Road, Suite 175

sdale, AZ 85260

---- Bleiweiss wrote:

>

> OK Guys here it goes,

> Â Â Â I would greatly apperciate any assistance in understanding what may be

> happening inside my own tush and bowels. First off don't assume I uderstand

all

> good doctor lingo. I am an out of shape hockey coach and official approaching

> fifty years of age this July. As I have been coaching my son's team more and

> more on the weekends it is increasingly harder for me to also schedule in

games

> to officiate to keep in shape as I used to.

>

> Â Â Â Two seasons in a row now, as the season progresses it seems that I am

> getting more and more evidence of fresh red blood on my toilet paper, drips

into

> the water and sometimes what appears to darker red mucus like clots although

> those are not regular and sporatic. By this time last season I was pretty

upset

> and concerned. Understand I haveÂ a very decent GI but like many other

struggling

> Americans we do not have any health insurance at the present time and so just

as

> he and I were figuring this out, BOOM there went the coverage. I feel pretty

> embarressed saying all of this to all of you as YES I know I should probably

eat

> the inflated charges of about $1KÂ for a scope and just have it done anyway,

but

> we literally don't have the funds as we struggle under mounds of debt, keep

the

> lights on, pay the morgage and the office rent, feed the kids and fill the

> Jeeps... Cards maxed out as well... No CCHIT it is really like that right

now...

>

> Â Â Â So I was wondering all along could what I am experiencing be at all

health

> from continuingly growing amounts of stress combined with medications, when

all

> of a sudden I read this from you folks and it makes me start to wonder about

the

> effects of the combo of things in my personal life like extreme stress (the

> practice is only half of it, Amazing how nasty some selfish twisted people can

> make normal people's lives) and my out of shape sporatic hard skating and

> exercise...Â Â Â

>

> Thanks so much in advance for your multiple curbside consults and good

will....

>

> ________________________________

>

> To:

> Sent: Fri, February 25, 2011 6:13:39 AM

> Subject: Re: Fecal Occult Blood Testing - which flavor

of

> card?

>

> Â

> Sharon,

> You bring up an interesting point about the newi tests being " too sensitive "

--

> Â in certain populations that have " normal " occult blood.

> For example - will the new FIT testing overdiagnose problems in marathoners?

>

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/1\

54-original-article-marathon-induced-colitis.html

>

> Up to 20% of marathoners will have biochemical evidence of microscopic blood

in

> their stools upon post-race fecal occult blood testing

(â€œheme-positiveâ€).16

> Multiple cases and analyses of these cases suggest ischemia and reperfusion as

> the dominant mechanism for inducing colitis after a marathon.17-20 Shunting

and

> redirection of cardiac output to the skeletal muscles presumably leaves the

> gastrointestinal tract in a state of acutely diminished blood flow for the

> duration of the marathon.

>

> Additionally, marathoning appears to induce a systemic hypercoagulable state,

> more so than any other sport to which a comparison can be made,21-23 the

> magnitude of which is as great as that seen with pulmonary artery

> catheterization, 30% total body surface area thermal injury, and even

> experimental loss of 60% blood volume combined with mild traumatic brain

> injury.24-26 This hypercoagulable state may cause intravascular sludging and

> microvascular thrombotic events within the delicate capillary network within

the

> wall of the colon. Upon completing the race, reperfusion results in normal

> fibrinolysis and an acute inflammatory milieu is generated, resulting in

> colitis. Ischemia is prolonged and worsened by dehydration and volume

> contraction, problems exceedingly common among marathoners, even those with

> apparently appropriate volume and electrolyte replacement during the

race.10,12

>

> Â

> Locke MD

>

> On Fri, Feb 25, 2011 at 1:22 AM, Sharon McCoy

wrote:

>

> Â

> >Well , at least not worth wasting your patient's time and money on (or

> >maybe better to say, why not use the ones most likely to save lives?).

> >

> >The kits I have from Quest are Insure FIT (although they expire next month so

> >I've had them awhile and they may be using something else by now.....).

> >

> >Question, do we have " normal upper intestinal blood leakage? "

> >

> >Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because

it

> >does not detect occult blood from the stomach and upper small intestine the

test

> >threshold doesn't cause undue false positives from normal upper intestinal

blood

> >leakage....

> >>

> Thanks for educating us and Carla.

>

> Sharon

>

> Sharon McCoy MD

> Renaissance Family Medicine

> 10 McClintock Court; Irvine, CAÂ 92617

> PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â

> www.SharonMD.com

>

> Â

> >Thanks, Carla.

> >This sort of implies using the old Guiac cards are passe -- malpractice?

> > Locke, MD

> >

> >Â

> >>,

> >>The USPSTF also has this:

> >>Screening Tests

> >>The relative sensitivity and specificity of the different colorectal

screening

> >>tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible

> >>sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

> >>

> >>Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA

â‰ˆ

> >>flexible sigmoidoscopy < colonoscopy

> >>>Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II

<

> >>>flexible sigmoidoscopyÂ = colonoscopy

> >>>

> >from:Â

> >http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

> >

> >And they only recommend " high sensitivity fecal occult blood tests " meaning

the

> >FIT or the equivalent of the Hemocult II or SENSA.

> >

> ________________________________

>

> >To: practiceimprovement1 < >; Practice

> >Management Issues ; Clinical Procedures

> >

> >Sent: Thu, February 24, 2011 11:42:21 PM

> >Subject: Fecal Occult Blood Testing - which flavor of

> >card?

> >

> >Â

> >Recnetly, there was discussion on the list about fecal occult blood testing.

> >

> >I think the issue crosses clinical list and practice mgt lists - see below.

> >

> >Several issues were brought up.

> >

> >1. Which is " best " ? Which could mean most sensitive or most specific.

> >This drives our clinical decision making AND which cards we want to buy

> >

> >2. The issueÂ of the cards outdating before being used upÂ was mentioned --

> >wasteful from a practice management standpoint -- But also raising the

question

> >of how to clinically increase compliance of bringing the cards back in when

they

> >are sent out.

> >

> >3. The issue of billing for the testing was mentioned - many saying they

didn't

> >get paid or were paid very little.

> >OthersÂ mentioning getting free cards through Quest Labs, but then having to

send

> >them in through quest.

> >

> >At first blush, it sounds like the Fecal immunochemical testsÂ are becoming

the

> >standard, but there are several brands.

> >Is one cheaper than another?

> >

> >=============================

> >Anyway, in regards to the testing cards...found some interesting stuff out

> >there.

> >

> >Here are the various testing techniques...

> >

> >I know some aren't a fan of the wiki, but...

> >

> >http://en.wikipedia.org/wiki/Fecal_occult_blood

> >

> >There are four methods in clinical use for testing for occult blood in feces.

> >These look at different properties, such as heme, globin, and porphyrins in

> >blood or at DNA from cellular material such as from lesions of the intestinal

> >mucosa.

> > * Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test

> >involves smearing some feces on to some absorbent paper that has been treated

> >with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace

> >amounts of blood are present, the paper will change color in one or two

seconds.

> >This method works as the heme component in hemoglobin has a peroxidase-like

> >effect, rapidly breaking down hydrogen peroxide. In some settings such as

> >gastric or proximal upper intestinal bleeding the guaiac method may be more

> >sensitive than tests detecting globin because globin is broken down in the

upper

> >intestine to a greater extent than is heme.[4] There are various commercially

> >available gFOBT tests which have been categorized as being of low or high

> >sensitivity, and only high sensitivity tests are now recommended in colon

cancer

> >screening. Optimal clinical performance of the stool guaiac test depends on

> >preparatory dietary adjustment.[5]

> > * Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood

> >test (iFOBT): - Many commercial products rely on these methods, which

chemically

> >depend on specific antibodies to detect globin. For colorectal cancer

screening,

> >the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a

> >consideration to replace gFOBT in colon cancer screening,[6][7] high

sensitivity

> >gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in

> >recent guidelines, being assessed as having similar overall performance

> >characteristics to FIT.[8] The number of fecal samples submitted for FIT may

> >affect the clinical sensitivity and specificity of the methodology.[9] This

> >methodology can be adapted for automated test reading and to report

quantitative

> >results, which are potential factors in design of a widescale screening

> >strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions

> >such as ulcerative colitis.[11]

> > * Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits

> >precise quantification of hemoglobin, and is analytically validated with

gastric

> >juice and urine, as well as stool samples. The heme moiety of intact

hemoglobin

> >is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate

to

> >protoporphyrin, and the porphyrin content of both the original sample and of

the

> >sample after hemoglobin conversion to porphyrin is quantified by comparative

> >fluorescence against a reference standard; the specificity for hemoglobin is

> >increased by subtracting the fluorescence of a sample blank prepared with

citric

> >acid to correct for the potential confounding effect of existing non-specific

> >substances.[12] Precise quantification measurement has been very useful in

many

> >clinical research applications.[13]

> > * Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the

stool

> >sample and tests it for alterations that have been associated with cancer.

The

> >test looks at 23 individual DNA alterations, including 21 specific point

> >alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene

> >involved in microsatellite instability (MSI).[15][16] and a proprietary DNA

> >Integrity Assay (DIA).[citation needed]

> >Additional methods of looking for occult blood are being explored, including

> >transferrin dipstick[17] and stool cytology.[18]Clinical sensitivity and

> >specificity

> >Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending

on

> >the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood

loss

> >of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can

pick

> >up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity

of

> >a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%,

but

> >if a standard three tests are done as recommended the sensitivity rises to

> >92%.[23] Further discussion of sensitivity and sensitivity issues that relate

> >particularly to the guaiac method is found in the stool guaiac test article.

> >Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because

it

> >does not detect occult blood from the stomach and upper small intestine the

test

> >threshold doesn't cause undue false positives from normal upper intestinal

blood

> >leakage and it is much more specific for bleeding from the colon or lower

> >gastrointestinal tract.[24] The detection rate of the test decreases if the

time

> >from sample collection to laboratory processing is delayed.[25]

> >Fecal porphyrin quantification by HemoQuant can be false positive due to

> >exogenous blood and various porphyrins. HemoQuant is the most sensitive test

for

> >upper gastrointestinal bleeding and therefore may be most appropriate fecal

> >occult blood test to use in the evaluation of iron deficiency [26] Advised to

> >stop red meat and aspirin for 3 days prior to specimen collection [27] False

> >positives can occur with myoglobin, catalase, or protohemes[13] and in

certain

> >types of porphyria[citation needed]

> >The DNA based PreGen-Plus was four times more sensitive than fecal blood

> >testing, including detection of early stage disease, when treatment is most

> >effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29]

Additional

> >clinical trials of the PreGen-Plus method are underway to more fully

> >characterize its clinical performance.[30] Expanding the range of DNA testing

by

> >looking at additional known genetic markers, such as CTNNB1, or by analyzing

> >epigenetically methylated genes[31] such as MLH1 which is very common in

> >hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in

> >proximal colon tumours that have poorer differentiation, does not appear to

> >appreciably increase the sensitivity of the method because CTNNB1 mutations

are

> >infrequent in sporadic colorectal cancer, and because BAT26 alterations and

lack

> >of MLH1 expression show a high degree of overlap.[34]

> >==================================

> >http://www.ncbi.nlm.nih.gov/pubmed/19174764

> >Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

> >Which fecal occult blood test is best to screen for colorectal cancer?

> >Young GP, Cole SR.

> >Flinders Centre for Cancer Prevention and Control, Flinders University, Room

> >3D230, Bedford Park, Adelaide, SA 5042, Australia.

graeme.young@...

> >Comment on:

> > * Gastroenterology. 2008 Jul;135(1):82-90.

> >Abstract

> >Fecal immunochemical tests (FITs) for hemoglobin represent a major advance

over

> >guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer

screening.

> >FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs

only

> >detect heme. Studies show that FITs increase the detection rates of cancer

and

> >advanced adenoma compared with early-generation GFOBTs, and do so without the

> >unacceptably high number of colonoscopies that high-sensitivity GFOBTs

generate.

> >Also, FITs are simpler to use than GFOBTs, they improve rates of patient

> >participation, and their cut-off points for positive versus negative tests

can

> >be modified. A large, Dutch, population-based, randomized controlled trial

has

> >compared the performance of a GFOBT and a FIT on an intention-to-screen

basis.

> >This study found that the FIT detected two-and-a-half times as many cancers

and

> >advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The

> >latest generation of FITs should replace traditional GFOBTs in two-step (test

> >then colonoscopy) screening for colorectal cancer.

> >=============================

> >This article is getting outdated, but still had some interesting info...

>

>http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalI\

mmunoTest_updated.pdf

> >

> >==============================

> >

>

February 25, 2011

..... this is not a normal sign of middle age or stress, you owe it to

yourself and your family to get it checked out. And if someone only charges you

1k and it includes the surgery suite and anesthesia that is a deal.

--

T. Ellsworth, MD

9377 E. Bell Road, Suite 175

sdale, AZ 85260

---- Bleiweiss wrote:

>

> OK Guys here it goes,

> Â Â Â I would greatly apperciate any assistance in understanding what may be

> happening inside my own tush and bowels. First off don't assume I uderstand

all

> good doctor lingo. I am an out of shape hockey coach and official approaching

> fifty years of age this July. As I have been coaching my son's team more and

> more on the weekends it is increasingly harder for me to also schedule in

games

> to officiate to keep in shape as I used to.

>

> Â Â Â Two seasons in a row now, as the season progresses it seems that I am

> getting more and more evidence of fresh red blood on my toilet paper, drips

into

> the water and sometimes what appears to darker red mucus like clots although

> those are not regular and sporatic. By this time last season I was pretty

upset

> and concerned. Understand I haveÂ a very decent GI but like many other

struggling

> Americans we do not have any health insurance at the present time and so just

as

> he and I were figuring this out, BOOM there went the coverage. I feel pretty

> embarressed saying all of this to all of you as YES I know I should probably

eat

> the inflated charges of about $1KÂ for a scope and just have it done anyway,

but

> we literally don't have the funds as we struggle under mounds of debt, keep

the

> lights on, pay the morgage and the office rent, feed the kids and fill the

> Jeeps... Cards maxed out as well... No CCHIT it is really like that right

now...

>

> Â Â Â So I was wondering all along could what I am experiencing be at all

health

> from continuingly growing amounts of stress combined with medications, when

all

> of a sudden I read this from you folks and it makes me start to wonder about

the

> effects of the combo of things in my personal life like extreme stress (the

> practice is only half of it, Amazing how nasty some selfish twisted people can

> make normal people's lives) and my out of shape sporatic hard skating and

> exercise...Â Â Â

>

> Thanks so much in advance for your multiple curbside consults and good

will....

>

> ________________________________

>

> To:

> Sent: Fri, February 25, 2011 6:13:39 AM

> Subject: Re: Fecal Occult Blood Testing - which flavor

of

> card?

>

> Â

> Sharon,

> You bring up an interesting point about the newi tests being " too sensitive "

--

> Â in certain populations that have " normal " occult blood.

> For example - will the new FIT testing overdiagnose problems in marathoners?

>

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/1\

54-original-article-marathon-induced-colitis.html

>

> Up to 20% of marathoners will have biochemical evidence of microscopic blood

in

> their stools upon post-race fecal occult blood testing

(â€œheme-positiveâ€).16

> Multiple cases and analyses of these cases suggest ischemia and reperfusion as

> the dominant mechanism for inducing colitis after a marathon.17-20 Shunting

and

> redirection of cardiac output to the skeletal muscles presumably leaves the

> gastrointestinal tract in a state of acutely diminished blood flow for the

> duration of the marathon.

>

> Additionally, marathoning appears to induce a systemic hypercoagulable state,

> more so than any other sport to which a comparison can be made,21-23 the

> magnitude of which is as great as that seen with pulmonary artery

> catheterization, 30% total body surface area thermal injury, and even

> experimental loss of 60% blood volume combined with mild traumatic brain

> injury.24-26 This hypercoagulable state may cause intravascular sludging and

> microvascular thrombotic events within the delicate capillary network within

the

> wall of the colon. Upon completing the race, reperfusion results in normal

> fibrinolysis and an acute inflammatory milieu is generated, resulting in

> colitis. Ischemia is prolonged and worsened by dehydration and volume

> contraction, problems exceedingly common among marathoners, even those with

> apparently appropriate volume and electrolyte replacement during the

race.10,12

>

> Â

> Locke MD

>

> On Fri, Feb 25, 2011 at 1:22 AM, Sharon McCoy

wrote:

>

> Â

> >Well , at least not worth wasting your patient's time and money on (or

> >maybe better to say, why not use the ones most likely to save lives?).

> >

> >The kits I have from Quest are Insure FIT (although they expire next month so

> >I've had them awhile and they may be using something else by now.....).

> >

> >Question, do we have " normal upper intestinal blood leakage? "

> >

> >Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because

it

> >does not detect occult blood from the stomach and upper small intestine the

test

> >threshold doesn't cause undue false positives from normal upper intestinal

blood

> >leakage....

> >>

> Thanks for educating us and Carla.

>

> Sharon

>

> Sharon McCoy MD

> Renaissance Family Medicine

> 10 McClintock Court; Irvine, CAÂ 92617

> PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â

> www.SharonMD.com

>

> Â

> >Thanks, Carla.

> >This sort of implies using the old Guiac cards are passe -- malpractice?

> > Locke, MD

> >

> >Â

> >>,

> >>The USPSTF also has this:

> >>Screening Tests

> >>The relative sensitivity and specificity of the different colorectal

screening

> >>tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible

> >>sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

> >>

> >>Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA

â‰ˆ

> >>flexible sigmoidoscopy < colonoscopy

> >>>Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II

<

> >>>flexible sigmoidoscopyÂ = colonoscopy

> >>>

> >from:Â

> >http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

> >

> >And they only recommend " high sensitivity fecal occult blood tests " meaning

the

> >FIT or the equivalent of the Hemocult II or SENSA.

> >

> ________________________________

>

> >To: practiceimprovement1 < >; Practice

> >Management Issues ; Clinical Procedures

> >

> >Sent: Thu, February 24, 2011 11:42:21 PM

> >Subject: Fecal Occult Blood Testing - which flavor of

> >card?

> >

> >Â

> >Recnetly, there was discussion on the list about fecal occult blood testing.

> >

> >I think the issue crosses clinical list and practice mgt lists - see below.

> >

> >Several issues were brought up.

> >

> >1. Which is " best " ? Which could mean most sensitive or most specific.

> >This drives our clinical decision making AND which cards we want to buy

> >

> >2. The issueÂ of the cards outdating before being used upÂ was mentioned --

> >wasteful from a practice management standpoint -- But also raising the

question

> >of how to clinically increase compliance of bringing the cards back in when

they

> >are sent out.

> >

> >3. The issue of billing for the testing was mentioned - many saying they

didn't

> >get paid or were paid very little.

> >OthersÂ mentioning getting free cards through Quest Labs, but then having to

send

> >them in through quest.

> >

> >At first blush, it sounds like the Fecal immunochemical testsÂ are becoming

the

> >standard, but there are several brands.

> >Is one cheaper than another?

> >

> >=============================

> >Anyway, in regards to the testing cards...found some interesting stuff out

> >there.

> >

> >Here are the various testing techniques...

> >

> >I know some aren't a fan of the wiki, but...

> >

> >http://en.wikipedia.org/wiki/Fecal_occult_blood

> >

> >There are four methods in clinical use for testing for occult blood in feces.

> >These look at different properties, such as heme, globin, and porphyrins in

> >blood or at DNA from cellular material such as from lesions of the intestinal

> >mucosa.

> > * Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test

> >involves smearing some feces on to some absorbent paper that has been treated

> >with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace

> >amounts of blood are present, the paper will change color in one or two

seconds.

> >This method works as the heme component in hemoglobin has a peroxidase-like

> >effect, rapidly breaking down hydrogen peroxide. In some settings such as

> >gastric or proximal upper intestinal bleeding the guaiac method may be more

> >sensitive than tests detecting globin because globin is broken down in the

upper

> >intestine to a greater extent than is heme.[4] There are various commercially

> >available gFOBT tests which have been categorized as being of low or high

> >sensitivity, and only high sensitivity tests are now recommended in colon

cancer

> >screening. Optimal clinical performance of the stool guaiac test depends on

> >preparatory dietary adjustment.[5]

> > * Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood

> >test (iFOBT): - Many commercial products rely on these methods, which

chemically

> >depend on specific antibodies to detect globin. For colorectal cancer

screening,

> >the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a

> >consideration to replace gFOBT in colon cancer screening,[6][7] high

sensitivity

> >gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in

> >recent guidelines, being assessed as having similar overall performance

> >characteristics to FIT.[8] The number of fecal samples submitted for FIT may

> >affect the clinical sensitivity and specificity of the methodology.[9] This

> >methodology can be adapted for automated test reading and to report

quantitative

> >results, which are potential factors in design of a widescale screening

> >strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions

> >such as ulcerative colitis.[11]

> > * Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits

> >precise quantification of hemoglobin, and is analytically validated with

gastric

> >juice and urine, as well as stool samples. The heme moiety of intact

hemoglobin

> >is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate

to

> >protoporphyrin, and the porphyrin content of both the original sample and of

the

> >sample after hemoglobin conversion to porphyrin is quantified by comparative

> >fluorescence against a reference standard; the specificity for hemoglobin is

> >increased by subtracting the fluorescence of a sample blank prepared with

citric

> >acid to correct for the potential confounding effect of existing non-specific

> >substances.[12] Precise quantification measurement has been very useful in

many

> >clinical research applications.[13]

> > * Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the

stool

> >sample and tests it for alterations that have been associated with cancer.

The

> >test looks at 23 individual DNA alterations, including 21 specific point

> >alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene

> >involved in microsatellite instability (MSI).[15][16] and a proprietary DNA

> >Integrity Assay (DIA).[citation needed]

> >Additional methods of looking for occult blood are being explored, including

> >transferrin dipstick[17] and stool cytology.[18]Clinical sensitivity and

> >specificity

> >Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending

on

> >the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood

loss

> >of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can

pick

> >up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity

of

> >a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%,

but

> >if a standard three tests are done as recommended the sensitivity rises to

> >92%.[23] Further discussion of sensitivity and sensitivity issues that relate

> >particularly to the guaiac method is found in the stool guaiac test article.

> >Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because

it

> >does not detect occult blood from the stomach and upper small intestine the

test

> >threshold doesn't cause undue false positives from normal upper intestinal

blood

> >leakage and it is much more specific for bleeding from the colon or lower

> >gastrointestinal tract.[24] The detection rate of the test decreases if the

time

> >from sample collection to laboratory processing is delayed.[25]

> >Fecal porphyrin quantification by HemoQuant can be false positive due to

> >exogenous blood and various porphyrins. HemoQuant is the most sensitive test

for

> >upper gastrointestinal bleeding and therefore may be most appropriate fecal

> >occult blood test to use in the evaluation of iron deficiency [26] Advised to

> >stop red meat and aspirin for 3 days prior to specimen collection [27] False

> >positives can occur with myoglobin, catalase, or protohemes[13] and in

certain

> >types of porphyria[citation needed]

> >The DNA based PreGen-Plus was four times more sensitive than fecal blood

> >testing, including detection of early stage disease, when treatment is most

> >effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29]

Additional

> >clinical trials of the PreGen-Plus method are underway to more fully

> >characterize its clinical performance.[30] Expanding the range of DNA testing

by

> >looking at additional known genetic markers, such as CTNNB1, or by analyzing

> >epigenetically methylated genes[31] such as MLH1 which is very common in

> >hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in

> >proximal colon tumours that have poorer differentiation, does not appear to

> >appreciably increase the sensitivity of the method because CTNNB1 mutations

are

> >infrequent in sporadic colorectal cancer, and because BAT26 alterations and

lack

> >of MLH1 expression show a high degree of overlap.[34]

> >==================================

> >http://www.ncbi.nlm.nih.gov/pubmed/19174764

> >Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

> >Which fecal occult blood test is best to screen for colorectal cancer?

> >Young GP, Cole SR.

> >Flinders Centre for Cancer Prevention and Control, Flinders University, Room

> >3D230, Bedford Park, Adelaide, SA 5042, Australia.

graeme.young@...

> >Comment on:

> > * Gastroenterology. 2008 Jul;135(1):82-90.

> >Abstract

> >Fecal immunochemical tests (FITs) for hemoglobin represent a major advance

over

> >guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer

screening.

> >FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs

only

> >detect heme. Studies show that FITs increase the detection rates of cancer

and

> >advanced adenoma compared with early-generation GFOBTs, and do so without the

> >unacceptably high number of colonoscopies that high-sensitivity GFOBTs

generate.

> >Also, FITs are simpler to use than GFOBTs, they improve rates of patient

> >participation, and their cut-off points for positive versus negative tests

can

> >be modified. A large, Dutch, population-based, randomized controlled trial

has

> >compared the performance of a GFOBT and a FIT on an intention-to-screen

basis.

> >This study found that the FIT detected two-and-a-half times as many cancers

and

> >advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The

> >latest generation of FITs should replace traditional GFOBTs in two-step (test

> >then colonoscopy) screening for colorectal cancer.

> >=============================

> >This article is getting outdated, but still had some interesting info...

>

>http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalI\

mmunoTest_updated.pdf

> >

> >==============================

> >

>

February 25, 2011

,Agree.I wonder about hemorrhoids? Even if you do have them though, you should get this checked out.....Sharon

February 25, 2011

,Agree.I wonder about hemorrhoids? Even if you do have them though, you should get this checked out.....Sharon

February 25, 2011

,Agree.I wonder about hemorrhoids? Even if you do have them though, you should get this checked out.....Sharon

February 25, 2011

We have a freestanding center that charges 750.00 cash.......which is still way Â too much ......Â Ah do you not have a PCP who canÂ coordinate your care and find youÂ this kind of help? cannot be your pcp.A PCP is an advocate someone who can advise and find you a way to get whatyou need.A good pCPÂ will beg for youÂ You should not have to

GoodÂ luckÂ Take care of yourslef

Â

OK Guys here it goes,

Â Â Â I would greatly apperciate any assistance in understanding what may be happening inside my own tush and bowels. First off don't assume I uderstand all good doctor lingo. I am an out of shape hockey coach and official approaching fifty years of age this July. As I have been coaching my son's team more and more on the weekends it is increasingly harder for me to also schedule in games to officiate to keep in shape as I used to.

Â

Â Â Â Two seasons in a row now, as the season progresses it seems that I am getting more and more evidence of fresh red blood on my toilet paper, drips into the water and sometimes what appears to darker red mucus like clots although those are not regular and sporatic. By this time last season I was pretty upset and concerned. Understand I haveÂ a very decent GI but like many other struggling Americans we do not have any health insurance at the present time and so just as he and I were figuring this out, BOOM there went the coverage. I feel pretty embarressed saying all of this to all of you as YES I know I should probably eat the inflated charges of about $1KÂ for a scope and just have it done anyway, but we literally don't have the funds as we struggle under mounds of debt, keep the lights on, pay the morgage and the office rent, feed the kids and fill the Jeeps... Cards maxed out as well... No CCHIT it is really like that

right now...

Â

Â Â Â So I was wondering all along could what I am experiencing be at all related to the stress on my middle body raising blood pressure, hydration, colon health from continuingly growing amounts of stress combined with medications, when all of a sudden I read this from you folks and it makes me start to wonder about the effects of the combo of things in my personal life like extreme stress (the practice is only half of it, Amazing how nasty some selfish twisted people can make normal people's lives) and my out of shape sporatic hard skating and exercise...Â Â Â

Â

Thanks so much in advance for your multiple curbside consults and good will....

Â

To:

Sent: Fri, February 25, 2011 6:13:39 AMSubject: Re: Fecal Occult Blood Testing - which flavor of card?

Â

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

And they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject:

Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is

quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and

sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation

needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

-- Â Â Â MDÂ Â Â Â Â Â ph Â Â fax impcenter.org

February 25, 2011

We have a freestanding center that charges 750.00 cash.......which is still way Â too much ......Â Ah do you not have a PCP who canÂ coordinate your care and find youÂ this kind of help? cannot be your pcp.A PCP is an advocate someone who can advise and find you a way to get whatyou need.A good pCPÂ will beg for youÂ You should not have to

GoodÂ luckÂ Take care of yourslef

Â

OK Guys here it goes,

Â Â Â I would greatly apperciate any assistance in understanding what may be happening inside my own tush and bowels. First off don't assume I uderstand all good doctor lingo. I am an out of shape hockey coach and official approaching fifty years of age this July. As I have been coaching my son's team more and more on the weekends it is increasingly harder for me to also schedule in games to officiate to keep in shape as I used to.

Â

Â Â Â Two seasons in a row now, as the season progresses it seems that I am getting more and more evidence of fresh red blood on my toilet paper, drips into the water and sometimes what appears to darker red mucus like clots although those are not regular and sporatic. By this time last season I was pretty upset and concerned. Understand I haveÂ a very decent GI but like many other struggling Americans we do not have any health insurance at the present time and so just as he and I were figuring this out, BOOM there went the coverage. I feel pretty embarressed saying all of this to all of you as YES I know I should probably eat the inflated charges of about $1KÂ for a scope and just have it done anyway, but we literally don't have the funds as we struggle under mounds of debt, keep the lights on, pay the morgage and the office rent, feed the kids and fill the Jeeps... Cards maxed out as well... No CCHIT it is really like that

right now...

Â

Â Â Â So I was wondering all along could what I am experiencing be at all related to the stress on my middle body raising blood pressure, hydration, colon health from continuingly growing amounts of stress combined with medications, when all of a sudden I read this from you folks and it makes me start to wonder about the effects of the combo of things in my personal life like extreme stress (the practice is only half of it, Amazing how nasty some selfish twisted people can make normal people's lives) and my out of shape sporatic hard skating and exercise...Â Â Â

Â

Thanks so much in advance for your multiple curbside consults and good will....

Â

To:

Sent: Fri, February 25, 2011 6:13:39 AMSubject: Re: Fecal Occult Blood Testing - which flavor of card?

Â

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

And they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject:

Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

Â

At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

Â

=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

Â

Here are the various testing techniques...

Â

I know some aren't a fan of the wiki, but...

Â

http://en.wikipedia.org/wiki/Fecal_occult_blood

Â

There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is

quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and

sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation

needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

-- Â Â Â MDÂ Â Â Â Â Â ph Â Â fax impcenter.org

February 25, 2011

We have a freestanding center that charges 750.00 cash.......which is still way Â too much ......Â Ah do you not have a PCP who canÂ coordinate your care and find youÂ this kind of help? cannot be your pcp.A PCP is an advocate someone who can advise and find you a way to get whatyou need.A good pCPÂ will beg for youÂ You should not have to

GoodÂ luckÂ Take care of yourslef

Â

OK Guys here it goes,

Â Â Â I would greatly apperciate any assistance in understanding what may be happening inside my own tush and bowels. First off don't assume I uderstand all good doctor lingo. I am an out of shape hockey coach and official approaching fifty years of age this July. As I have been coaching my son's team more and more on the weekends it is increasingly harder for me to also schedule in games to officiate to keep in shape as I used to.

Â

Â Â Â Two seasons in a row now, as the season progresses it seems that I am getting more and more evidence of fresh red blood on my toilet paper, drips into the water and sometimes what appears to darker red mucus like clots although those are not regular and sporatic. By this time last season I was pretty upset and concerned. Understand I haveÂ a very decent GI but like many other struggling Americans we do not have any health insurance at the present time and so just as he and I were figuring this out, BOOM there went the coverage. I feel pretty embarressed saying all of this to all of you as YES I know I should probably eat the inflated charges of about $1KÂ for a scope and just have it done anyway, but we literally don't have the funds as we struggle under mounds of debt, keep the lights on, pay the morgage and the office rent, feed the kids and fill the Jeeps... Cards maxed out as well... No CCHIT it is really like that

right now...

Â

Â Â Â So I was wondering all along could what I am experiencing be at all related to the stress on my middle body raising blood pressure, hydration, colon health from continuingly growing amounts of stress combined with medications, when all of a sudden I read this from you folks and it makes me start to wonder about the effects of the combo of things in my personal life like extreme stress (the practice is only half of it, Amazing how nasty some selfish twisted people can make normal people's lives) and my out of shape sporatic hard skating and exercise...Â Â Â

Â

Thanks so much in advance for your multiple curbside consults and good will....

Â

To:

Sent: Fri, February 25, 2011 6:13:39 AMSubject: Re: Fecal Occult Blood Testing - which flavor of card?

Â

Sharon,

You bring up an interesting point about the newi tests being " too sensitive " -- Â in certain populations that have " normal " occult blood.

For example - will the new FIT testing overdiagnose problems in marathoners?

Â

http://www.surgisphere.com/SurgRad/issues/volume-2/1-january-2011--pages-1-112/154-original-article-marathon-induced-colitis.html

Â

Up to 20% of marathoners will have biochemical evidence of microscopic blood in their stools upon post-race fecal occult blood testing (â€œheme-positiveâ€).16 Multiple cases and analyses of these cases suggest ischemia and reperfusion as the dominant mechanism for inducing colitis after a marathon.17-20 Shunting and redirection of cardiac output to the skeletal muscles presumably leaves the gastrointestinal tract in a state of acutely diminished blood flow for the duration of the marathon.

Additionally, marathoning appears to induce a systemic hypercoagulable state, more so than any other sport to which a comparison can be made,21-23 the magnitude of which is as great as that seen with pulmonary artery catheterization, 30% total body surface area thermal injury, and even experimental loss of 60% blood volume combined with mild traumatic brain injury.24-26 This hypercoagulable state may cause intravascular sludging and microvascular thrombotic events within the delicate capillary network within the wall of the colon. Upon completing the race, reperfusion results in normal fibrinolysis and an acute inflammatory milieu is generated, resulting in colitis. Ischemia is prolonged and worsened by dehydration and volume contraction, problems exceedingly common among marathoners, even those with apparently appropriate volume and electrolyte replacement during the race.10,12

Â

Locke MD

Â

Well , at least not worth wasting your patient's time and money on (or maybe better to say, why not use the ones most likely to save lives?). The kits I have from Quest are Insure FIT (although they expire next month so I've had them awhile and they may be using something else by now.....).

Question, do we have " normal upper intestinal blood leakage? "

Fecal Immunochemical TestingÂ (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage....

Thanks for educating us and Carla.

Sharon

Sharon McCoy MDRenaissance Family Medicine10 McClintock Court; Irvine, CAÂ 92617PH: (949)387-5504Â Â Fax: (949)281-2197Â Toll free phone/fax:Â www.SharonMD.com

Â

Thanks, Carla.

This sort of implies using the old Guiac cards are passe -- malpractice?

Locke, MD

Â

,

The USPSTF also has this:

Screening Tests

The relative sensitivity and specificity of the different colorectal screening tests with adequate data to assess cancer detectionâ€”colonoscopy, flexible sigmoidoscopy, and fecal testsâ€”can be depicted as follows:

Sensitivity: Hemoccult II < fecal immunochemical tests â‰¤ Hemoccult SENSA â‰ˆ flexible sigmoidoscopy < colonoscopy

Specificity: Hemoccult SENSA < fecal immunochemical tests â‰ˆ Hemoccult II < flexible sigmoidoscopyÂ = colonoscopy

from:Â http://www.uspreventiveservicestaskforce.org/uspstf08/colocancer/colors.htm

And they only recommend " high sensitivity fecal occult blood tests " meaning the FIT or the equivalent of the Hemocult II or SENSA.

To: practiceimprovement1 < >; Practice Management Issues ; Clinical Procedures

Sent: Thu, February 24, 2011 11:42:21 PMSubject:

Fecal Occult Blood Testing - which flavor of card?

Â

Recnetly, there was discussion on the list about fecal occult blood testing.

Â

I think the issue crosses clinical list and practice mgt lists - see below.

Â

Several issues were brought up.

Â

1. Which is " best " ? Which could mean most sensitive or most specific.

This drives our clinical decision making AND which cards we want to buy

Â

2. The issueÂ of the cards outdating before being used upÂ was mentioned -- wasteful from a practice management standpoint -- But also raising the question of how to clinically increase compliance of bringing the cards back in when they are sent out.

Â

3. The issue of billing for the testing was mentioned - many saying they didn't get paid or were paid very little.OthersÂ mentioning getting free cards through Quest Labs, but then having to send them in through quest.

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At first blush, it sounds like the Fecal immunochemical testsÂ are becoming the standard, but there are several brands.

Is one cheaper than another?

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=============================

Anyway, in regards to the testing cards...found some interesting stuff out there.

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Here are the various testing techniques...

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I know some aren't a fan of the wiki, but...

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http://en.wikipedia.org/wiki/Fecal_occult_blood

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There are four methods in clinical use for testing for occult blood in feces. These look at different properties, such as heme, globin, and porphyrins in blood or at DNA from cellular material such as from lesions of the intestinal mucosa.

Stool guaiac test for fecal occult blood (gFOBT): - The stool guaiac test involves smearing some feces on to some absorbent paper that has been treated with a chemical. Hydrogen peroxide is then dropped on to the paper; if trace amounts of blood are present, the paper will change color in one or two seconds. This method works as the heme component in hemoglobin has a peroxidase-like effect, rapidly breaking down hydrogen peroxide. In some settings such as gastric or proximal upper intestinal bleeding the guaiac method may be more sensitive than tests detecting globin because globin is broken down in the upper intestine to a greater extent than is heme.[4] There are various commercially available gFOBT tests which have been categorized as being of low or high sensitivity, and only high sensitivity tests are now recommended in colon cancer screening. Optimal clinical performance of the stool guaiac test depends on preparatory dietary adjustment.[5]

Fecal Immunochemical Testing (FIT), and immunochemical fecal occult blood test (iFOBT): - Many commercial products rely on these methods, which chemically depend on specific antibodies to detect globin. For colorectal cancer screening, the FIT tests are superior than low sensitivity gFOBT. Although FIT may be a consideration to replace gFOBT in colon cancer screening,[6][7] high sensitivity gFOBT, such as Hemoccult SENSA, remains an accepted option alongside FIT in recent guidelines, being assessed as having similar overall performance characteristics to FIT.[8] The number of fecal samples submitted for FIT may affect the clinical sensitivity and specificity of the methodology.[9] This methodology can be adapted for automated test reading and to report quantitative results, which are potential factors in design of a widescale screening strategy.[10] FOBT may have a role in monitoring gastrointestinal conditions such as ulcerative colitis.[11]

Fecal porphyrin quantification: - HemoQuant, unlike gFOBT and FIT, permits precise quantification of hemoglobin, and is analytically validated with gastric juice and urine, as well as stool samples. The heme moiety of intact hemoglobin is chemically converted by oxalic acid and ferrous oxalate or ferrous sulfate to protoporphyrin, and the porphyrin content of both the original sample and of the sample after hemoglobin conversion to porphyrin is

quantified by comparative fluorescence against a reference standard; the specificity for hemoglobin is increased by subtracting the fluorescence of a sample blank prepared with citric acid to correct for the potential confounding effect of existing non-specific substances.[12] Precise quantification measurement has been very useful in many clinical research applications.[13]

Fecal DNA test: - The PreGen-Plus[14] test extracts human DNA from the stool sample and tests it for alterations that have been associated with cancer. The test looks at 23 individual DNA alterations, including 21 specific point alterations in the APC, KRAS and p53 genes, as well as testing BAT26, a gene involved in microsatellite instability (MSI).[15][16] and a proprietary DNA Integrity Assay (DIA).[citation needed]

Additional methods of looking for occult blood are being explored, including transferrin dipstick[17] and stool cytology.[18]

Clinical sensitivity and specificity

Stool guaiac test for fecal occult blood (gFOBT) sensitivity varies depending on the site of bleeding. Moderately sensitive gFOBT can pick up a daily blood loss of about 10 ml (about two teaspoonfuls), and higher sensitivity gFOBT can pick up lesser amounts, sometimes becoming positive at about 2 ml. The sensitivity of a single stool guaiac test to pick up bleeding has been quoted at 10 to 30%, but if a standard three tests are done as recommended the sensitivity rises to 92%.[23] Further discussion of sensitivity and

sensitivity issues that relate particularly to the guaiac method is found in the stool guaiac test article.

Fecal Immunochemical Testing (FIT) picks up as little as 0.3 ml but because it does not detect occult blood from the stomach and upper small intestine the test threshold doesn't cause undue false positives from normal upper intestinal blood leakage and it is much more specific for bleeding from the colon or lower gastrointestinal tract.[24] The detection rate of the test decreases if the time from sample collection to laboratory processing is delayed.[25]

Fecal porphyrin quantification by HemoQuant can be false positive due to exogenous blood and various porphyrins. HemoQuant is the most sensitive test for upper gastrointestinal bleeding and therefore may be most appropriate fecal occult blood test to use in the evaluation of iron deficiency [26] Advised to stop red meat and aspirin for 3 days prior to specimen collection [27] False positives can occur with myoglobin, catalase, or protohemes[13] and in certain types of porphyria[citation

needed]

The DNA based PreGen-Plus was four times more sensitive than fecal blood testing, including detection of early stage disease, when treatment is most effective.[28] Sensitivity increased to 51.6% compared to 12.9%.[29] Additional clinical trials of the PreGen-Plus method are underway to more fully characterize its clinical performance.[30] Expanding the range of DNA testing by looking at additional known genetic markers, such as CTNNB1, or by analyzing epigenetically methylated genes[31] such as MLH1 which is very common in hyperplastic polyps (HP) with microsatellite instability (MSI)[32][33] and in proximal colon tumours that have poorer differentiation, does not appear to appreciably increase the sensitivity of the method because CTNNB1 mutations are infrequent in sporadic colorectal cancer, and because BAT26 alterations and lack of MLH1 expression show a high degree of overlap.[34]

==================================

http://www.ncbi.nlm.nih.gov/pubmed/19174764

Nat Clin Pract Gastroenterol Hepatol. 2009 Mar;6(3):140-1. Epub 2009 Jan 27.

Which fecal occult blood test is best to screen for colorectal cancer?

Young GP, Cole SR.

Flinders Centre for Cancer Prevention and Control, Flinders University, Room 3D230, Bedford Park, Adelaide, SA 5042, Australia. graeme.young@...

Comment on:

Gastroenterology. 2008 Jul;135(1):82-90.

Abstract

Fecal immunochemical tests (FITs) for hemoglobin represent a major advance over guaiac-based fecal occult blood tests (GFOBTs) for colorectal cancer screening. FITs specifically detect human hemoglobin in stool samples, whereas GFOBTs only detect heme. Studies show that FITs increase the detection rates of cancer and advanced adenoma compared with early-generation GFOBTs, and do so without the unacceptably high number of colonoscopies that high-sensitivity GFOBTs generate. Also, FITs are simpler to use than GFOBTs, they improve rates of patient participation, and their cut-off points for positive versus negative tests can be modified. A large, Dutch, population-based, randomized controlled trial has compared the performance of a GFOBT and a FIT on an intention-to-screen basis. This study found that the FIT detected two-and-a-half times as many cancers and advanced adenomas as did the GFOBT, despite similar colonoscopy rates. The latest generation of

FITs should replace traditional GFOBTs in two-step (test then colonoscopy) screening for colorectal cancer.

=============================

This article is getting outdated, but still had some interesting info...

http://www.aacc.org/SiteCollectionDocuments/Publications/cln/2007January/fecalImmunoTest_updated.pdf

==============================

-- Â Â Â MDÂ Â Â Â Â Â ph Â Â fax impcenter.org

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Fecal Occult Blood Testing - which flavor of card?

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