Prostate Cancer Prevented by Pill? Not So Fast, Experts Say

(CBS/AP)Can popping a pill prevent prostate cancer?

It's a question some men are asking, in light of new research showing that two prescription drugs used to treat benign prostate enlargment cut the risk of prostate tumors in men.

But we're not there yet, doctors say.

GlaxoSmithKline has asked the FDA to approve its drug Avodart for reducing prostate cancer, after research showed a 23 percent reduction in low-grade prostate tumors.

Merck achieved similar results with its drug Proscar and is asking the FDA to approve labeling about its drug's benefits in reducing prostate cancer risks.

But the drugs don't seem to affect the incidence of the aggressive tumors that are more likely to result in serious illness and death, Dr. Abraham Morgentaler, assistant clinical professor of urology at Harvard Medical School, tells CBS News.

"Prostate cancer comes in at least two 'flavors,'" he says. "The drugs clearly reduce the number of low-grade tumors," he says, but not the more aggressive tumors doctors worry about. What's more, he says, the drugs can cause sexual side effects, including reduced sex drive and erectile dysfunction.

"What this mean for experts in the field and for men in general is unclear," he says. "My own feeling is that the evidence is not in."