propecia reduces your chances of prostate cancer

[CCS]

yeah, DHT causes the prostate to enlarge and sometimes lead to cancer in older men. 50% of men over age 50 have enlarged prostates. You know what proscar is, don't you. It is a well known fact that reducing DHT in people with mild or no symptoms greatly reduces the risks of getting the most common cancer in men. prostate surgery anyone?

 

[Resultsnottypical]

Is there any evidence, such as a clinical trial (or repeated ones) that showed propecia reduced the chance of prostate cancer?

It was my understanding, that that was never confirmed for any dose lower than 5mg.

In my view, other than costs, I think most people could take the 5mg version, daily, with little or no side effects.

 

[bubka]

what was your question?

there has been a longterm study on this, all show it reduces the risk of prostate cancer: pro

http://content.nejm.org/cgi/content/abs ... oa030660v1

 

[Bryan]

Far from "greatly reducing" the risk of prostate cancer, all it did was reduce it somewhat. Furthermore, there's even a "Catch-22" in THAT, which is the part about increasing the risk of higher-grade cancers. All in all, I consider the PCPT trial of finasteride for prostate cancer to be a failure, because it shows that overall mortality remains about the same.

Having said all that, however, I still think it's true that finasteride can be extremely useful as a prostate cancer preventative, but only if you start it early enough in life.

Bryan

 

[bubka]

but the increased risk of more aggressive high-grade cancers was 1.3%, 6.4 vs 5.1... easily within the margin of error, so really one cannot make that claim

 

[Bryan]

but the increased risk of more aggressive high-grade cancers was 1.3%, 6.4 vs 5.1... easily within the margin of error, so really one cannot make that claim

???

Did you not bother to read that abstract for the PCPT at that link above? The difference was highly statistically significant (p<0.001). Your attempt to subtract 5.1 from 6.4 and come up with "1.3%" as a final result is an absurd attempt to downplay the significance of those numbers. READ THE ABSTRACT CAREFULLY.

Bryan

 

[HARM1]

DON'T BE TO SURE
Gynecomastia and Breast Cancer during Finasteride Therapy
http://content.nejm.org/cgi/content/extract/335/11/823

Finasteride (Propecia) and the Promotion of High-grade Prostate Cancer
http://archderm.ama-assn.org/cgi/conten ... 40/7/885-a

Unilateral Gynecomastia Induced by Treatment With 1 mg of Oral Finasteride
http://archderm.ama-assn.org/cgi/conten ... /138/4/543

The Influence of Finasteride on the Development of Prostate Cancer
http://content.nejm.org/cgi/content/abstract/349/3/215

 

[powersam]

Harm1 if you post something, post it once. do not start tagging it onto threads all over the place because its just not necessary.

 

[HARM1]

Harm1 if you post something, post it once. do not start tagging it onto threads all over the place because its just not necessary.

This is relvent to the issue. would it make such a differnce if I were to give a link to my older topic ?

 

[bubka]

but the increased risk of more aggressive high-grade cancers was 1.3%, 6.4 vs 5.1... easily within the margin of error, so really one cannot make that claim

???

Did you not bother to read that abstract for the PCPT at that link above? The difference was highly statistically significant (p<0.001). Your attempt to subtract 5.1 from 6.4 and come up with "1.3%" as a final result is an absurd attempt to downplay the significance of those numbers. READ THE ABSTRACT CAREFULLY.

Bryan

maybe I am reading the data wrong, but if the P value is less than that of what the null hypothesis is, than it should be rejected... P=0.005 while it was P<0.001 for both groups. I may be totally wrong here...

DON'T BE TO SURE
Gynecomastia and Breast Cancer during Finasteride Therapy
http://content.nejm.org/cgi/content/extract/335/11/823

Finasteride (Propecia) and the Promotion of High-grade Prostate Cancer
http://archderm.ama-assn.org/cgi/conten ... 40/7/885-a

Unilateral Gynecomastia Induced by Treatment With 1 mg of Oral Finasteride
http://archderm.ama-assn.org/cgi/conten ... /138/4/543

The Influence of Finasteride on the Development of Prostate Cancer
http://content.nejm.org/cgi/content/abstract/349/3/215

the cancer studies are based off the study in discussion, and the gyno are case studies

 

[Bryan]

maybe I am reading the data wrong, but if the P value is less than that of what the null hypothesis is, than it should be rejected... P=0.005 while it was P<0.001 for both groups.

I don't understand what you mean. Can you clarify? Whichever number you use (0.005 or 0.001), it's still clearly below the level generally accepted as statistically significant (0.05).

Bryan

 

[bubka]

yeah, that is true, but in medical experiments, one would never use .05 / 95% but rather something "higher", more significant, as used here

if i understand this correctly, they used a P of .001 and it is .005

 

[Bryan]

yeah, that is true, but in medical experiments, one would never use .05 / 95% but rather something "higher", more significant, as used here

I can see you haven't read very many medical studies! :wink: The 5% level is BY FAR the most common one required for statistical significance. I can show you REAMS and REAMS of such medical experiments!

if i understand this correctly, they used a P of .001 and it is .005

That's not correct. BOTH of those numbers referred to the probability that the difference they observed in high-grade tumors was due only to chance, but they were apparently for differing groups of patients. They didn't explain that detail terribly well in the abstract.

In any event, we do know that the effect was very statistically significantly. There's no way to get around that.

Bryan

 

[bubka]

yeah, that is true, but in medical experiments, one would never use .05 / 95% but rather something "higher", more significant, as used here

I can see you haven't read very many medical studies! :wink: The 5% level is BY FAR the most common one required for statistical significance. I can show you REAMS and REAMS of such medical experiments!

if i understand this correctly, they used a P of .001 and it is .005

That's not correct. BOTH of those numbers referred to the probability that the difference they observed in high-grade tumors was due only to chance, but they were apparently for differing groups of patients. They didn't explain that detail terribly well in the abstract.

In any event, we do know that the effect was very statistically significantly. There's no way to get around that.

Bryan

well having a degree in biology, i have done a few experiments with .05 p values, and remember that if this were doing something with actual human trials (pharma drugs per say) you would use something a lot more significant. Even so, that alone does not prove that the treatment differences between the two groups significant

I am not one of these arguing people here, but I believe that it does not mean anything... as you said, it was not explained that terribly well, and they gave three possible reasons in the discussion... so a lot more testing should be done to actually determine what the difference actually means... and the fact that it has been many years and it didn't seem to alarm anyone shows that the difference was nothing close to earth shattering in terms of causing high grade prostate cancers

 

[Bryan]

well having a degree in biology, i have done a few experiments with .05 p values, and remember that if this were doing something with actual human trials (pharma drugs per say) you would use something a lot more significant.

Would you like me to post a ream or two of such studies where they DID use the 5% value?

Even so, that alone does not prove that the treatment differences between the two groups significant

Are you referring to STATISTICAL significance, or CLINICAL significance?

Those numbers are statistically significant. You personally may not accept p=0.005 (or even p<0.001) as being significant, but if you don't, you're the only on God's Green Earth that doesn't.

I am not one of these arguing people here, but I believe that it does not mean anything... as you said, it was not explained that terribly well, and they gave three possible reasons in the discussion...

What "three possible reasons" are you talking about?

so a lot more testing should be done to actually determine what the difference actually means... and the fact that it has been many years and it didn't seem to alarm anyone shows that the difference was nothing close to earth shattering in terms of causing high grade prostate cancers

True, but the point of all this is that if you're considering the use of finasteride SPECIFICALLY TO PREVENT PROSTATE CANCER, it _does_ become an important consideration. The increase in high-grade tumors probably cancels the benefit from the modest overall decrease in the occurrence of prostate cancer.

Bryan

 

[bubka]

well having a degree in biology, i have done a few experiments with .05 p values, and remember that if this were doing something with actual human trials (pharma drugs per say) you would use something a lot more significant.

Would you like me to post a ream or two of such studies where they DID use the 5% value?

Even so, that alone does not prove that the treatment differences between the two groups significant

Are you referring to STATISTICAL significance, or CLINICAL significance?

Those numbers are statistically significant. You personally may not accept p=0.005 (or even p<0.001) as being significant, but if you don't, you're the only on God's Green Earth that doesn't.

yeah, clinically significant... like i said, i could be wrong, and clinically significant will use a lower P value... 95% is not good enough for heart valves and other life saving drugs

What "three possible reasons" are you talking about?

from the full text:

High-grade disease was noted in 6.4 percent of the men in the finasteride group, as compared with 5.1 percent of those in the placebo group. A difference in the rate of high-grade disease was seen within the first year of the study. One possible explanation for this difference is a grading bias: histologic changes that mimic those of high-grade disease are caused by androgen-deprivation therapy.14,15,16,17,18 There are, however, differences of opinion as to whether this effect occurs with finasteride. It is possible that finasteride induces high-grade tumors by reducing the level of intracellular dihydrotestosterone within the prostate. There is evidence that the prostate tumors that develop in men with low testosterone levels have higher Gleason grades and worse outcomes than the prostate cancers that develop in men with normal testosterone levels.19,20,21 It is also possible that finasteride selects for high-grade tumors by selectively inhibiting low-grade tumors. Long-term follow-up in these men and further laboratory research will be required to determine the reason for the association between finasteride and high-grade prostate cancer.

http://content.nejm.org/cgi/content/full/349/3/215

 

[Bryan]

yeah, clinically significant... like i said, i could be wrong, and clinically significant will use a lower P value... 95% is not good enough for heart valves and other life saving drugs

Uhhh.....they don't actually use P values for clinical significance. That's something associated purely with statistics; specifically, helping to decide whether or not an observed effect is due to chance alone.

BTW, I'm still confused about those "three possible reasons". Reasons for WHAT, is what I'm asking! Out of that text you quoted, there's only ONE attempt to propose a theory that the increase in high-grade tumors from finasteride usage is not a real one, and that's the one about the alleged "grading bias".

Bryan

 

[tpeter]

Bryan is pwning..