Prostate-Cancer Prevention--with Risks

By Sara Song

Say there's a drug that could significantly lower your risk of prostate cancer. Say it could also increase your chance of growing particularly aggressive tumors--those most likely to spread and kill--if you do get cancer. Should you take it? That's the question doctors and patients have been wrestling with since the results of a National Cancer Institute--sponsored trial were published last week in the New England Journal of Medicine. Compared with a placebo, Merck's finasteride--a drug currently marketed to treat baldness and benign prostate enlargement--appeared to reduce prostate cancer incidence 25%. But in the seven-year study, involving more than 9,000 men ages 55 and older, the finasteride group also had a slightly higher rate of aggressive, "high grade" tumors, which are harder to treat. Complicating matters, finasteride also caused loss of libido and impotence. Prostate cancer strikes more than 220,000 American men each year, but it's not clear that this is a drug that should be taken to prevent it. --S.S.