FDA Panel to Vote on Drugs Said to Prevent Prostate Cancer

A U.S. Food and Drug Administration advisory panel is expected to decide Wednesday whether to approve two drugs for the prevention of prostate cancer, the third highest cancer killer of men. Avodart and Proscar, manufactured by GlaxoSmithKline and Merck, respectively, are already approved to treat enlarged prostates. The drug makers say their research shows the drugs also lower the risk of prostate cancer by more than 20 percent. FDA regulators have several concerns, the Associated Press reported. For one thing, black men, who are at high risk for the disease, were underrepresented in the clinical trials.

"The applicability to African-American men is not known due to marked under-representation," the FDA's online review stated. Blacks made up just 4 percent of Merck's patients and only 2 percent of Glaxo's patients, according to the AP. The panel of outside experts assembled by the FDA is also likely to discuss the overall value of preventing low-grade tumors. According to the FDA, more than three-quarters of the tumors the drugs prevent are slow-growing, meaning they are non-aggressive and probably not life-threatening for anyone with a life expectancy of less than 20 years.

If the tumors aren't aggressive, Glaxo has said they often involve unnecessary treatment and biopsies, or surgical procedures, to diagnose cancer, that pose risks of their own. Also, slightly more aggressive tumors were seen in men taking Avodart and Proscar, compared with those taking placebo pills, according to the FDA. But the pharamaceutical companies say the drugs simply make those tumors easier to detect because they shrink the prostate. The U.S. National Cancer Institute estimates that 217,730 men will be diagnosed with prostate cancer this year and 32,050 men will die of it.