New Study Fuels Debate Over PSA Screening Test

A new study involving the most widely used screening test for prostate cancer seems certain to further fuel the debate over how aggressively doctors should look for and treat the disease.

The study of nearly 3,000 men, reported in the New England Journal of Medicine, found that some 15 percent of older men whose scores on the prostate specific antigen (PSA) test were within what is generally regarded as the "normal" range (under 4.0) actually had prostate cancer.

Most of the cancers appeared to be so slow-growing that they were unlikely to ever require treatment, but researchers said biopsies found that about 15 percent of the cancers were of an "aggressive" nature and potentially life threatening.

Dr. Ian M. Thompson, chief of urology at the University of Texas Health Science Center at San Antonio, who led the study, said the findings seemed certain to provide ammunition to both sides in the debate over the value of the PSA test.

Some leaders argue that men with a PSA level over 2.5 should be biopsied, even though treatment -- and even the biopsy -- are not without risk. Others contend too many men already are being treated for prostate cancers that would have never killed them, suffering side effects such as impotence and urinary incontinence as a consequence.

"I think that this study reinforces something that's very important: prostate cancer is very, very common. And men who have PSAs less than 4.0 very commonly have prostate cancers," said Dr. Ballentine Carter, a professor of urology at Johns Hopkins School of Medicine.

"We know by definition that we have the ability to detect a lot of cancers that are never going to harm people," Carter said. "And we should be very, very cautious about recommending biopsies in these men."

Other Sources: New England Journal of Medicine