Study: Prostate Cancer May Be Overtreated A popular blood test for prostate cancer is leading many men to get treated for cancer when the treatment might not make much of a difference, according to a study in the current issue of the Journal of the National Cancer Institute. The study's conclusions are in agreement with two earlier studies published last spring in the New England Journal of Medicine.

Study: Prostate Cancer May Be Overtreated

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From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.


And I'm Melissa Block. Recently, there's been uncertainty over whether all men, including healthy ones, should be screened for prostate cancer. A study released today doesn't provide a blanket answer, but it does suggest that many men get treated unnecessarily, and that's because of imprecision in the test. The study is published in the latest Journal of the National Cancer Institute. NPR's Joanne Silberner has more.

JOANNE SILBERNER: PSA blood tests were once widely promoted as a way of reducing the 27,000 deaths a year from prostate cancer. Early detection will lead to more effective treatment. But some scientists wanted proof. Last spring, an American study that compared men who were screened regularly and men who weren't screened found no benefit to screening. A European study showed a very modest benefit. So H. Gilbert Welch of the Dartmouth Institute for Clinical Health Practice and a colleague counted up the number of American men diagnosed through a PSA test from 1986 to 2005.

Dr. H. GILBERT WELCH (Professor of Medicine, The Dartmouth Institute for Health Policy and Clinical Practice): We found about 1.3 million, since the advent of PSA testing, have been diagnosed with prostate cancer who otherwise would not have been.

SILBERNER: Sounds good. But then Welch calculated that despite the 1.3 million diagnoses, only 56,000 deaths were averted. That's because there are many kinds of prostate cancer, says Welch.

Dr. WELCH: Some cancers grow very rapidly and kill, and they may grow so rapidly that screening doesn't really help. Because by the time, they're detectable by screening, they're already metastasized.

SILBERNER: There are slower growing prostate cancers. There's some benefit of early detection here. There's another group.

Dr. WELCH: Then there are cancers that are growing so slowly that they never grow enough to cause symptoms before people of die of something else.

SILBERNER: And there's yet another class, he says, cells that look like cancer but never grow at all. Right now, there's no way to tell which cancers are which. And treatment has some significant side effects. About one-third of men treated for prostate cancer end up with some level of impotence or incontinence. Welch is down on PSA screening.

Dr. WELCH: We definitely oversold its benefits and we've understated or ignored entirely its harms.

SILBERNER: So what's a guy to do? Tennis ace John McEnroe, who's working with pharmaceutical giant GlaxoSmithKline, had an answer last week on the CBS "Early Show."

Mr. JOHN MCENROE (Tennis Legend): The American Urological Association has said 40 is the new time to go out there. All it is, is get a blood test, a PSA test, that's not that difficult for us guys.

SILBERNER: That recommendation from the Urological Association, it says PSA is a good predictor but doesn't go as far as saying all men should be tested. Groups like the American Cancer Society say what Gilbert Welch and many other researchers say: Doctors should inform men of the risks and benefits and let them decide. That's the option Ian Thompson offers his patients. Thompson heads the Urology Department at the University of Texas Health Science Center in San Antonio.

Dr. IAN THOMPSON JR. (professor and chairman of the Department of Urology, The University of Texas Health Science Center): It's a matter of the man's own priorities. What concerns him? Is it the risk of cancer? In which case, that man may be more interested in screening and having a biopsy. And there may be another man for whom today's quality of life is the most important thing.

SILBERNER: And that man may say, I don't want a screening because I'm not sure treatment would be worth it. Like many health groups, the Prostate Cancer Foundation once thought screening was good. Now, it's not so simple, says foundation head Jonathan Simons.

Dr. JONATHAN SIMONS (CEO and President, Prostate Cancer Foundation): It's a very complex health message because you're saying you should be frightened to death except for this may never cause your death.

SILBERNER: So what do the experts do? Simons opts for a PSA test every year. Gilbert Welch of Dartmouth does not. And Ian Thompson?

Dr. THOMPSON: Quite frankly, I have an easy out because I know that I can participate in a clinical trial.

SILBERNER: And he does. Thompson and other men are having their blood sampled regularly so that researchers can go back and look for early markers in the men who develop cancer. And would Thompson get tested if he weren't in the study? He wouldn't say.

Joanne Silberner, NPR News.

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