Re: Question on Falk Foundation's research on PSC and UDCA

[Guest guest]

One thing we do know (via

studies) is that people with PSC are at a higher risk of developing several

types of cancer. Those with long

standing UC & cirrhosis are at the greatest risk. We also know (again, via many studies)

that those on high dose URSO have the best fighting chance against colon

cancer. So maybe when they speak

about “improved survival” they are talking about surviving one or several

different causes of death that could befall someone with PSC.

Just my Barb in Texas guess.

-----Original Message-----

From: slhussey

Second

paragraph states there IS " a tendency to improved survival in UDCA treated

patients. " Third paragraph says there's " NO significant effect on

survival in patients

with

PSC. " What am I missing?

[Guest guest]

> I'm quoting from page 71, and would love someone to explain the

> second and third paragraph's apparent contradiction to me

> (beginning " However, there was a... " ). Second paragraph states there

> IS " a tendency to improved survival in UDCA treated patients. " Third

> paragraph says there's " NO significant effect on survival in patients

> with PSC. " What am I missing?

My guess is that the authors are making a distinction between an observed

pattern (the " tendency " for improved survival in UDCA treated patients)

and statistical significance ( " significant effect. " ) I think that they are

saying that the observed tendency could be entirely explained by chance.

I imagine that a possible reason that they can't get statistical

significance is because their sample sizes are too small.

Shauna

[Guest guest]

I agree with Shauna. The authors of the study were using statistical

terms to describe their result, which showed a trend or tendency but

not a statistically significant effect. To achieve statistical

significance there needs to be a large number of occurrences to show

a small effect. For instance if a coin is flipped 10 times and comes

up heads 6 and tails 4, that result is expected to occur frequently

just by chance. But if the flipping continues for 1000 times and

there are 600 heads and 400 tails it can be stated with some degree

of confidence that the coin is not a fair coin as it is biased to

come up heads. A whole branch of mathematics exists to determine if a

series of events is statically significant and if so to what level of

confidence.

Tim R

> My guess is that the authors are making a distinction between an

observed

> pattern (the " tendency " for improved survival in UDCA treated

patients)

> and statistical significance ( " significant effect. " ) I think that

they are

> saying that the observed tendency could be entirely explained by

chance.

> I imagine that a possible reason that they can't get statistical

> significance is because their sample sizes are too small.

>

> Shauna

[Guest guest]

Hi ;

I agree with Shauna and Tim, that the study probably saw a

difference in survival but it was not statistically significant

because of small sample size.

I am a bit surprised that Broome published this without reporting

the actual numbers of those who survived in the two groups.

As Barb pointed out there is growing evidence that URSO/UDCA

protects against colon cancer and cholangiocarcinoma.

If fact, U. Broome is one of the authors of the recent paper:

Brandsaeter B, Friman S, Broome U, Isoniemi H, Olausson M, Backman

L, Hansen B, Schrumpf E, Oksanen A, zon BG, Hockerstedt K,

Makisalo H, Kirkegaard P, Bjoro K 2003 Outcome following liver

transplantation for primary sclerosing cholangitis in the Nordic

countries. Scand. J. Gastroenterol. 38: 1176-1183.

which shows that no ursodeoxycholic acid (UDCA) treatment was one of

the main predictors of malignancy! [see also pages 76 - 78 of the

abstract booklet]. If this is true, surely this must have an impact

on survival?

Best regards,

Dave

[Guest guest]

>

> If fact, U. Broome is one of the authors of the recent paper:

>

> Brandsaeter B, Friman S, Broome U, Isoniemi H, Olausson M, Backman

> L, Hansen B, Schrumpf E, Oksanen A, zon BG, Hockerstedt K,

> Makisalo H, Kirkegaard P, Bjoro K 2003 Outcome following liver

> transplantation for primary sclerosing cholangitis in the Nordic

> countries. Scand. J. Gastroenterol. 38: 1176-1183.

>

> which shows that no ursodeoxycholic acid (UDCA) treatment was one

> of the main predictors of malignancy!

Sorry folks! I meant to refer to the following paper:

Brandsaeter B, Isoniemi H, Broome U, Olausson M, Backman L, Hansen

B, Schrumpf E, Oksanen A, zon BG, Hockerstedt K, Makisalo H,

Kirkegaard P, Friman S, Bjoro K 2004 Liver transplantation for

primary sclerosing cholangitis; predictors and consequences of

hepatobiliary malignancy. J. Hepatol. 40: 815-822.

Dave