In follow up to Dr. Stark’s recent posting about the role of Selenium in prostate cancer prevention, we draw your attention to an important recent observation. In the New England Journal of Medicine an important study was published showing the continued efficacy of finasteride (Proscar) in the prevention of prostate cancer. This drug, which inhibits the conversion of testosterone to its di-hydro derivative, prevents the di-hydro compound from getting into the prostate where it stimulates the development of cancer. Native testosterone (the most potent male sex hormone) does not stimulate the prostate; only di-hydro testosterone does. There was a concern with the initial trials reported almost ten years ago that men who developed prostate cancer while on finasteride would get a more virulent and lethal form of the disease. Over the last ten years this discussion has swung back and forth. This latest paper, by the “Prostate Cancer Prevention Trial” group, lays that concern to rest. Overall there was a one-third reduction in the incidence of prostate cancer in the finasteride group, compared with those who got placebo. Among men who developed prostate cancer there was a slight tendency for the cancer to be more aggressive in the finasteride group but this did not impact on prostate-specific mortality, which was low. Dr. Stark weighs in, “This should put to rest the concern that we are putting some men at risk of dying of prostate cancer by giving them a drug to prevent it. The fifteen-year follow up is very long, a tribute to the endurance of the original investigators. Men who want to take this drug to shrink their prostate (the most common use) should be relieved that the extra benefit of the drug, the prevention of cancer, is maintained.”