| George Conklin 2004-10-04, 2:21 am |
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"Leonard Evens" <len@math.northwestern.edu> wrote in message
news:3JadnTdjDaAYSMfcRVn-uQ@comcast.com...
> MB wrote:
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>
> Let's hope that doesn't happen. If your PSA weere to go up at that
> rate, the most recent research (Catalona, et. al.) suggests that a
> biopsy is very likely to show prostate cancer, and the cancer is also
> likely to be aggressive.
>
> But let me the Devil's advocate here. It is possible that in
> circumstances like that it wouldn't make much difference if you were
> treated. That is, it might be true that if the PSA were increasing
> that fast, the probability of metastasis would be very high even with
> treatment, and the treatment made no difference. In fact what the above
> study showed was that the probability of recurrence after treatment
> depended on the rate of increase in the year before. The study doesn't
> quantify what decrease in metastasis rate might follow treatment.
>
> To test this in a completely scientific manner, you would have to
> collect a large number of men, do PSA testing on them, select those with
> a high PSA rate of increase, and in that group randomly choose some to
> be treated and some to receive no treatment. You would then have to
> follow them for a long time. It would be at least 10 years or perhaps
> longer. (Aggressive cancers tend to develop faster, so periods like 15
> or 20 years might not be necessary.) If the metastasis rate in both
> groups was essentially the same---meaning it couldn't be attributed
> purely to chance---you would have to conclude that the treatment had no
> effect. It can get even more complicated. There are other things you
> can look at: the overall number of deaths within some period of time,
> the deaths due to prostate cancer within that period of time, quality of
> life considerations in both groups, etc. It is very hard to quantify
> some of these factors and to compare them. Sometimes people interested
> in proving a preconceived notion will select one or the other criteria
> which is strongest in making their case, but to be objective one should
> look at all the factors and try to come to a balanced judgement.
>
> Now the problem is that this study will never be done. For relatively
> nonaggressive cancers, it may be possible to do such a study, but few
> doctors or patients are willing to stand still in the face of evidence
> of an aggressive cancer. So they use other evidence, obtained by other
> kinds of studies, which are not as definitive, to help them understand
> the situation. Doctors who treat prostate cancer don't do so without any
> scientific basis for what they do.
>
> Some people, like George, argue that until it is proven by unassailable
> methods that treatment, even in aggressive cases, is more effective than
> non-treatment, the default ought to be to suspend judgement and not
> treat. Their argument is that some of the men who are treated will
> suffer significant side effects, and that is unnecessary misery for
> them. I suspect George in his heart believes that in fact treatment is
> ineffective, so it makes him angry that all that unnecessary
> incontinence and impotence takes place. (He also doesn't know much
> about the actual incidence of those things today with treatment using
> the best techniques.) Others think that the treatment at least may be
> partially effective, and perhaps they believe in their hearts that it is
> highly effective. If so, doing nothing would a mistake.
>
> So if you go by the science, in its current state, I think there is some
> evidence that such cases should be treated, but it is very far from a
> watertight case. The critics may prove to be right. That makes it very
> difficult for a layman to make a decision.
>
> Personally, here is how I would look at it. Fortunately, while my PSA
> was increasing too fast, it wasn't in the high increase category. But
> let's assume it was. The evidence shows that I have a cancer which is
> likely to metastasize. If it does, I will have a variety of problems
> which make the side of effects of treatment seem trivial. I've looked
> at the likelihood of side effects of treatment and they don't scare me.
> With a good surgeon, serious incontinence is highly unlikely.
> Impotence is more likely, but it can be treated and doesn't mean an end
> of my sex life. (I was impotent in fact for 18 months after RP, and my
> sex life continued without significant interruption.) I don't know
> that treatment will actually prevent metastasis, but I think from all
> I've read that there is some chance it may prevent it or at least delay
> it. So I would opt for treatment since it seems to me with all the
> uncertainties that it is the better bargain. The fact that I am pretty
> healthy and would otherwise expect a long comfortable old age also plays
> a role.
>
> I should add that there is not one single answer for all cases where
> prostate cancer is diagnosed. It could be true that the effectiveness
> of treatment in case with a very high rate of increase for PSA is
> different than the effectiveness in cases with a modera rate of
> increase. So beware of people who always say the same thing about
> prostate cancer as if it were a simple disease which always must be
> treated or never should be treated.
>
Except such studies ARE being done and the results are negative so far.
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