Re: "Screening" tests

From: Leonard Evens (len_at_math.northwestern.edu)
Date: 07/06/04 

Date: Tue, 06 Jul 2004 09:31:26 -0500

George Conklin wrote:

>
> Of course, we still know that every man who reaches 80 can test positive
> for prostate cancer, and probably a lot more others besides.

How do we know that? Reference please! What you say is not consistent
with what I've learned through fairly extensive reading on the subject.

You may be referring to autopsy studies which show that a large
percentage of men that age show microscopic evidence of prostate cancer.
   But different autopsy studies show different results, so I don't
think there is any authoritative final answer. In any case, I don't
remember seeing any study suggesting the percentage show such evidence
is 100 percent.

Finally, there is a big difference between being able to find evidence
of prostate cancer on autopsy and a clinical diagnosis of prostate cancer.

There is an analogy here with certain serious infectious diseases.
Often many people are infected but only some have clinically detectable
cases. Yet few people would suggest that this fact would justify not
treating those clincial cases.

> What we also
> do not yet know is if current treatments such a surgery really do add to
> life expectancy. We hope so, but no one has looked yet, after 100 years.

I presume you mean aggressive treatment for early prostate cancer as
diagnosed through PSA testing and DRE. There seems to be little doubt
that hormone therapy does increase life expectancy on the average for
men suffering from advanced prostate cancer. You should really make it
clear just what you mean.

What you mean is that there has been no strictly randomized study
showing that aggressive treatment for early prostate cancer is superior
to watchful waiting followed by hormone therapy when necessary. (Note
that the second course is also treatment.) I don't think anyone
suggests leaving all prostate cancer untreated. There is a lot of other
evidence of course, but I agree the evidence is confusing and cuts both
ways. Still the point is certainly debatable, and each of us has to
make his own choices.

Moreover, you really have to distinguish between statistical results as
applied to a population and the results in individual cases. In an
individual case, the particularities of the diagnosis and of the man
concerned will play a role in whether or not that man is likely to have
his life expectancy increased. For example, it may well turn out to be
true that for all men diagnosed with prostate cancer, life expectancy is
not signifcantly different, but for certain men, such as men under 60,
life expectancy is increased.

>
>

Relevant Pages

  • Re: "Screening" tests
    ... percentage of men that age show microscopic evidence of prostate cancer. ... I presume you mean aggressive treatment for early prostate cancer as ... that hormone therapy does increase life expectancy on the average for ...
    (sci.med)
  • Re: Delayed Treatments for Prostate Cancer
    ... It is well established that strongest evidence is prospective. ... treatment protocols for millions of men with prostate cancer based ... There are no "treatment protocols". ... Still with only self-selection to show what benefit the treatment is. ...
    (talk.politics.medicine)
  • Re: Delayed Treatments for Prostate Cancer
    ... Your assumption that using data on real-world out comes is ... It is well established that strongest evidence is prospective. ... treatment protocols for millions of men with prostate cancer based ... There are no "treatment protocols". ...
    (talk.politics.medicine)
  • Re: 30% say "nothing works"
    ... This is in men who have been referred for a biopsy because of a PSA or digital rectal examination finding. ... Moreover, in at least one study, men without indications had biopsies done and about one in six showed evidence of prostate cancer. ... Different studies show different percentages, but they do range between 50 percent and 80 percent or higher, with the higher figures for men over 80. ...
    (sci.med.prostate.cancer)
  • Re: Equality of life expectancy?
    ... >> on women's health issues. ... Note that while prostate cancer kills near ... >> well over ten times the amount of funding that prostate cancer gets. ... > to the issue of extending men's life expectancy. ...
    (soc.men)