Some thoughts on screening

[Guest guest]

Thanks to Jack jennings on another group for this.

Basically this sums up to the opinion that screening benefits are a matter

of point of view. Screening does prolong some people's life - but this may

be at a cost of loss of quality. I know from talking to PCa sufferers who

have ahd radical treatment that the effects may vary from almost

imperceptable to a major inconvenience. The question I ask those who are

having treatment is are you glad you found out that you had treatment??? I

think I will geta mixed set of replies and the ones who are most positive

about how they have been treated are the opnes who were given most

information before the decision was made. I still am astounded by the lack

of information supplied by some consultant's clinics!

Please fell free to comment.

For background, here are some excerpts from the

NewsHour show of December 3rd that triggered his inquiry (for full

interview go to

http://www.pbs.org/newshour/bb/health/july-dec02/prostate_12-03.html):

" GWEN IFILL: Millions of men will undergo one of two tests to

determine whether they have prostate cancer this year. These tests,

including the PSA, or Prostate-Specific Antigen test, are now

routinely given to men over the age of 50. But how effective are

they? A government task force has been studying that question, and

has come up with a mixed answer. Joining me now is the chairman of

that task force, Dr. Alfred Berg. He also heads the Department of

Family Medicine at the University of Washington. So, Dr. Berg, what

are we to make of these test results? Is a PSA test taken after the

age of 50 an effective predictor of cancer death?

DR. ALFRED BERG: Well, our group found the evidence was insufficient

to recommend for or against routine prostate cancer screening, and

the reason is that we have inconclusive evidence that screening and

early treatment improves health outcomes. So we were unable to

determine whether the balance of benefits and harms favored benefits

or the harms.

GWEN IFILL: In 1996, your group, as I understand it, also just flat

out said that these screenings aren't really worth it. So this has

been a move back toward the middle kind of, hasn't it?

DR. ALFRED BERG: Well, I wouldn't overstate the change. There are two

things that have happened. First of all, of course, in the last six

years there's been more scientific evidence; but secondly, the

methods that we've used to do these reviews and the criteria that we

use to reach our conclusions have changed. So that we now consider,

for example, not only the quality of evidence but the balance of

benefits and harms. So we have new evidence, new methods and new

criteria and now a new recommendation. "

" GWEN IFILL: Is there any discussion also going on about how you

convince someone if they have cancer that it shouldn't be treated.

How do you tell someone they have cancer which they are led to

believe is a deadly disease that they should just watch and wait?

DR. ALFRED BERG: Well, I think that the first choice should be

whether or not you have the screening test done. You really shouldn't

have the screening test done unless you're willing to the evaluation

and the potential treatment. So the choice really should be made

before you get to that difficult decision.

GWEN IFILL: So the choice, just to be clear, should be made before

you get the test or after you get the result of the test and before

you opt for treatment?

DR. ALFRED BERG: Our recommendation is that you ought to consider the

potential benefits and harms before you have the test and make the

decision on that basis and not wait until you have a positive test in

order to decide whether you want further evaluation and treatment. "

The report in question by the U.S. Preventive Services Task Force

(chaired by Dr. Berg) appears in the December issue of the ls of

Internal Medicine. Here is the ful text of the article:

CLINICAL GUIDELINES

Screening for Prostate Cancer: Recommendation and Rationale

U.S. Preventive Services Task Force*

Pages 915-916

* For a list of the members of the U.S. Preventive Services Task

Force, see the Appendix.

Ann Intern Med. 2002;137:915-916.

Summary of the Recommendation

The U.S. Preventive Services Task Force (USPSTF) concludes that the

evidence is insufficient to recommend for or against routine

screening for prostate cancer using prostate-specific antigen (PSA)

testing or digital rectal examination (DRE). This is a grade I

recommendation. (See Appendix Table 1 for a description of the USPSTF

classification of recommendations.)

The USPSTF found good evidence that PSA screening can detect

early-stage prostate cancer but mixed and inconclusive evidence that

early detection improves health outcomes. (See Appendix Table 2 for a

description of the USPSTF classification of levels of evidence.)

Screening is associated with important harms, including frequent

false-positive results and unnecessary anxiety, biopsies, and

potential complications of treatment of some cases of cancer that may

never have affected a patient's health. The USPSTF concludes that

evidence is insufficient to determine whether the benefits outweigh

the harms for a screened population.

Clinical Considerations

Prostate-specific antigen testing and DRE can effectively detect

prostate cancer in its early pathologic stages. Recent evidence

suggests that radical prostatectomy can reduce prostate cancer

mortality in men whose cancer is detected clinically. The balance of

potential benefits (the reduction of morbidity and mortality from

prostate cancer) and harms (false-positive results, unnecessary

biopsies, and possible complications) of early treatment of the types

of cancer found by screening, however, remains uncertain. Therefore,

the benefits of screening for early prostate cancer remain unknown.

Ongoing screening trials, and trials of treatment versus " watchful

waiting " for cancer detected by screening, may help clarify the

benefits of early detection of prostate cancer.

Despite the absence of firm evidence of effectiveness, some

clinicians may opt to perform prostate cancer screening for other

reasons. Given the uncertainties and controversy surrounding prostate

cancer screening, clinicians should not order the PSA test without

first discussing with the patient the potential but uncertain

benefits and the possible harms of prostate cancer screening. Men

should be informed of the gaps in the evidence, and they should be

assisted in considering their personal preferences and risk profile

before deciding whether to be tested.

If early detection improves health outcomes, the population most

likely to benefit from screening will be men 50 to 70 years of age

who are at average risk and men older than 45 years of age who are at

increased risk (African-American men and those with a first-degree

relative with prostate cancer) (1). Benefits may be smaller in

Asian-American persons, Hispanic persons, and persons in other racial

and ethnic groups that have a lower risk for prostate cancer. Older

men and men with other significant medical problems who have a life

expectancy of fewer than 10 years are unlikely to benefit from

screening (1).

Prostate-specific antigen testing is more sensitive than DRE for the

detection of prostate cancer. Prostate-specific antigen screening

with the conventional cut-point of 4.0 ng/dL detects a large majority

of prostate cancer; however, a significant percentage of early

prostate cancer (10% to 20%) will be missed by PSA testing alone (2).

Using a lower threshold to define an abnormal PSA level detects more

cases of cancer at the cost of more false-positive results and more

biopsies.

The yield of screening in terms of cancer detected declines rapidly

with repeated annual testing (1). If screening were to reduce

mortality, biennial PSA screening could yield as much benefit as

annual screening.

The brief review of the evidence that is normally included in USPSTF

recommendations is available in the complete recommendation and

rationale statement on the USPSTF Web site

(http://www.preventiveservices.ahrq.gov).

Recommendations of Others

Most major U.S. medical organizations recommend that clinicians

discuss with patients the potential benefits and possible harms of

PSA screening, consider patient preferences, and individualize the

decision to screen. They generally agree that the most appropriate

candidates for screening include men older than 50 years of age and

younger men at increased risk for prostate cancer but that screening

is unlikely to benefit men who have a life expectancy of fewer than

10 years. These organizations include the American Academy of Family

Physicians, the American Cancer Society, the American College of

Physicians-American Society of Internal Medicine, the American

Medical Association, and the American Urological Association (3-7).

None of these organizations endorses universal or mass screening for

any group of men. In 1994, the Canadian Task Force on Preventive

Health Care recommended against the routine use of PSA or transrectal

ultrasonography as part of the periodic health examination (8); while

recognizing the limitations of DRE, it concluded that the evidence

was insufficient to recommend that physicians discontinue use of DRE

in men 50 to 70 years of age. The Canadian Task Force is in the

process of updating its recommendations.

Appendix

Members of the U.S. Preventive Services Task Force are Alfred O.

Berg, MD, MPH, Chair (University of Washington, Seattle, Washington);

Janet D. Allan, PhD, RN, Vice-Chair (Dean, School of Nursing,

University of land, Baltimore, Baltimore, land); Frame,

MD (Tri-County Family Medicine, Cohocton, and University of

Rochester, Rochester, New York); J. Homer, MD, MPH (National

Initiative for Children's Healthcare Quality, Boston, Massachusetts);

Mark S. , MD, MPH (University of Medicine and Dentistry of New

Jersey-New Jersey Medical School, Newark, New Jersey); D.

Klein, MD, MPH (University of Rochester School of Medicine,

Rochester, New York); A. Lieu, MD, MPH (Harvard Pilgrim Health

Care and Harvard Medical School, Boston, Massachusetts); D.

Mulrow, MD, MSc (University of Texas Health Science Center, San

, Texas [member and affiliation at time recommendation was

finalized]); C. Orleans, PhD (The Wood

Foundation, Princeton, New Jersey); F. Peipert, MD, MPH

(Women and Infants' Hospital, Providence, Rhode Island); Nola J.

Pender, PhD, RN (University of Michigan, Ann Arbor, Michigan); Albert

L. Siu, MD, MSPH (Mount Sinai School of Medicine, New York, New

York); M. Teutsch, MD, MPH (Merck & Co., Inc., West Point,

Pennsylvania); Carolyn Westhoff, MD, MSc (Columbia University, New

York, New York); and H. Woolf, MD, MPH (Virginia Commonwealth

University, Fairfax, Virginia).

Author and Article Information

From the U.S. Preventive Services Task Force, Agency for Healthcare

Research and Quality, Rockville, land.

Requests for Single Reprints: Reprints are available from the USPSTF

Web site (http://www.preventiveservices.ahrq.gov) and in print

through the Agency for Healthcare Research and Quality Publications

Clearinghouse ().

References

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the evidence for the U.S. Preventive Services Task Force. Ann Intern

Med. 2002;137:917-29. | ls Abstract | PubMed |

2. RP, Lohr KN, Beck R, Fink K, Godley P, Bunton A. Screening

for Prostate Cancer. Systematic Evidence Review No. 16 (Prepared by

the Research Triangle Institute-University of North Carolina

Evidence-based Practice Center under Contract no. 290-97-0011).

Rockville, MD: Agency for Healthcare Research and Quality, December

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http://www.ahrq.gov/clinic/serfiles.htm.

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Academy of Family Physicians. Accessed at

http://www.aafp.org/exam.xml on 15 October 2002.

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11577479] Accessed at http://www.cancer.org on 25 October 2002.

| PubMed |

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and Early Detection of Prostate Cancer. American Medical Association.

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http://www.ama-assn.org/ama/pub/article/2036-2928.html on 1 March

2001.

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[PMID: 10736812] Accessed at http://www.auanet.org. on 25 October

2002. | PubMed |

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http://www.ctfphc.org/index.html on 1 March 2002.