TUESDAY, Feb. 24 (HealthDay News) -- Healthy men with no signs of prostate cancer may wish to talk to their doctors about taking a drug that could further reduce their risk for the disease, new guidelines suggest.

The American Society of Clinical Oncology and the American Urological Association have issued new guidelines recommending that these men talk to their doctors about using a 5-alpha reductase inhibitors (5-ARI). These drugs -- which include finasteride (Propecia), used to treat male pattern baldness -- can reduce levels of dihydrotestosterone (DHT), a hormone that spurs prostate cancer development.

Previous studies have been shown that 5-ARIs reduce risk of contracting the illness by 25 percent.

Prostate cancer is the second-leading cause of death by cancer in men.

"Although one in every six men in the United States will be diagnosed with prostate cancer, we are not recommending that all men take 5-ARIs," co-chair of the guideline panel Dr. Barnett S. Kramer, associate director for disease prevention at the National Institutes of Health, stressed in a news release issued by the organizations. "However, we would encourage men to begin a dialogue with their doctors to determine if they could benefit from taking 5-ARIs to reduce their prostate cancer risk."

The guidelines call for doctors to discuss the pro and cons of a 5-ARI with male patients who score a 3.0 or lower on a prostate-specific antigen (PSA) test, show no signs of prostate cancer, and receive (or plan to receive) regular disease screening.

The guidelines also suggest that men already taking a 5-ARI for other conditions should discuss continuing the medication as a way to prevent prostate cancer. Today, 5-ARIs are used to treat male-pattern baldness and benign prostatic hyperplasia (enlarged prostate) among other non-cancerous conditions.

While supporting the guidelines, panel co-chair Dr. Paul F. Schellhammer noted that while 5-ARIs may decrease the risk of getting prostate cancer, it is not known whether these drugs reduce death from the disease.

"However, the demonstrated effect of 5-ARIs in reducing prostate cancer incidence makes it reasonable to recommend them for use to prevent the disease," he said in the same news release.