Two US medical groups issued a joint guideline recommending that healthy men over 55 take a prostate enlargement prevention treatment to reduce the risk of prostate cancer.
The American Society of Clinical Oncology (ASCO) and the American Urological Association (AUA) recommend a daily dose of finasteride, a 5-alpha reductase inhibitor (5-ARI) also used to treat non-cancerous conditions such as male-pattern baldness and enlarged prostate, known as benign prostatic hyperplasia.
The inhibitor 5-ARI lowers the level of the male hormone dihydrotestosterone (DHT), the chief cause of hair loss in men that also contributes to the growth of prostate cancer.
The two medical groups presented the results of some 15 clinical trials showing a 25 percent reduction in prostate cancer risk among men who took finasteride regularly.
Prostate cancer is the most common non-skin cancer among men and the second-leading cause of cancer death in men, killing some 254,000 men worldwide each year.
"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," said Barnett Kramer, Associate Director for Disease Prevention at the National Institutes of Health and co-chair of the guideline panel.
"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," he added.
Finasteride and other 5-ARI inhibitors can have side effects including impotence and lower sex drive.