Prostate test overdiagnose cancer

As many as two of every five men whose prostate cancer was caught through a PSA screening test have tumors too slow-growing to ever be a threat. The work "reinforces the message that we are overdiagnosing prostate cancer," said Dr. Len Lichtenfeld of the American Cancer Society, who was not involved in the new study. There begins the list of problems: Most men who undergo a biopsy for an abnormal PSA test often signal a benign enlarged prostate. Of those who do have cancer, there's no proof yet that early detection saves lives — as most prostate tumors grow so slowly that had they not been screened, those men would have died of something else without the anxiety.

Depending on how it's calculated, anywhere from 23 percent to 42 percent of PSA-detected cancers would otherwise never have been detected in the man's lifetime, concluded the team led by researchers at Erasmus University Medical Center in the Netherlands. The study was published online Tuesday by the Journal of the National Cancer Institute. Why is overdiagnosis such a concern? Because finding an early tumor forces men to choose among contested treatments — "watchful waiting," surgery, hormone therapy, radiation. And because some treatments can cause incontinence and impotence, men whose tumors wouldn't have been a threat can suffer serious side effects for no gain. In fact, national health guidelines issued last year said men over age 75 shouldn't undergo PSA screening, while younger men should make an individual choice after hearing the pros and cons and weighing their own cancer risk.