To Screen for Prostate Cancer or Not? Men who undergo the prostate-specific antigen, or P.S.A., test do so in the common belief that it is always good to catch and eliminate a cancer early before it has a chance to spread. They seldom focus on potential harms from follow-up procedures. In this case, the United States Preventive Services Task Force concluded that the benefit of the test in preventing cancer deaths was minimal and was more than offset by the adverse effects of surgery or radiation to remove slow-growing tumors that would never have killed the patient. As the leader of the task force summarized the evidence, for every 1,000 men screened, at most one will avoid a cancer death over the course of a decade. In that same group, two to three will have a serious complication of treatment such as a blood clot, heart attack, stroke, or even death, and up to 40 will have erectile dysfunction, urinary incontinence or both. The professional society for urologists and some cancer experts have challenged the conclusions, saying they are based on studies that have methodological flaws and that only followed participants for a decade, not enough time, they claim, for a final judgment. But, as Otis Brawley, chief medical officer of the American Cancer Society, noted recently in the Annals of Internal Medicine, the task force is "ideally suited to provide an objective, unbiased assessment" because its members, unlike many of their critics, "have no emotional, ideological or financial conflicts of interest." The best advice for perplexed patients is to have a frank discussion with their doctors of the potential risks and benefits before proceeding with screening or with any treatments to remove tumors found in the screening.