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IVD Technology Magazine | IVDT Article Index

Originally published May, 1997

PSA test elicits negative reaction from physicians

Prostate-specific antigen (PSA) testing has received another thumbs-down, this time from the largest group of primary-care physicians in the country.

At its annual meeting in Philadelphia this spring, the American College of Physicians--which is the nation's largest specialty physician group, with 100,000 internist members--advised against routine prostate-cancer screening. To write the new policy on PSA testing, a board of physicians drawn largely from the medical organization reviewed studies from the past 30 years.

"Screening for prostate cancer is not for everyone. It is a complex decision that patients should make after talking to their physicians, understanding the risks and benefits, and coming to an informed, individualized decision," says ACP president-elect Harold Sox, MD, in a prepared statement that accompanies the new guidelines.

A similar statement was issued late last year by the American Academy of Family Physicians, the country's second-largest organization of primary-care doctors. Both groups say there isn't solid evidence that detection lowers mortality.

Despite the two recent set-backs, however, prospects for the PSA test continue to fire competition among companies like Hybritech (San Diego) and Abbott Labs (Abbott Park, IL). Such organizations aren't likely to abandon their research efforts, despite the physicians' lack of enthusiasm. Experts predict that future R&D will focus on tumor distinction.

William Catalona, MD, a urologist at Washington University (St. Louis), is one of many research scientists who believe PSA testing is "here to stay." The reason? Continuing refinements in the PSA test will eventually disprove detractors, providing increasingly definitive evidence of benefit, he asserts.

Catalona, who has been a recipient of some research funding from Hybritech, believes that once that company's exclusive patent on the dual-monoclonal antibody assay expires, many diagnostic manufacturers will begin using the technology through licensing agreements--a move that is bound to result in greater uniformity. In the years ahead, Catalona predicts, there will be far more standardization of testing. Advances in the test will allow doctors to distinguish more effectively between aggressive and slower-growing forms of the cancer, he adds.

PSA testing, along with digital rectal examination, is advised for men over 50 by the American Cancer Society and the American Urological Association. But last year, the U.S. Preventive Services Task Force, a federal panel of scientists from research centers and universities across the country, concluded that there were significant potential drawbacks to routine, widespread screening. Noted risks include those related to unnecessary surgery to obtain samples of tissue, and the fact that there appears to be no proof that early surgical removal of cancer decreases mortality.--Anne Scheck