Should Men Take a Pill to Prevent Prostate Cancer?

The American Society of Clinical Oncology and the American Urological Association have joined to produce guidelines recommending that men consider taking a 5-alpha reductase inhibitor (5-ARI) - e.g. finasteride (Proscar®) - to help prevent prostate cancer. These guidelines, which are based on the work of an expert panel, are published in the Journal of Clinical Oncology.

Proscar was approved for the treatment of benign prostatic hypertrophy (BPH) symptoms 17 years ago, so there is a wealth of safety information. The panel reviewed published randomized studies of 5-ARIs in men aged 45 or older in which data on the possibility of prostate cancer were available. Of 15 studies that met the established strict criteria, 9 directly measured prostate cancer incidence.

In the 9 studies, the results were generally consistent in demonstrating cancer reduction with the use of a 5-ARI drug. However, it’s important to realize that all the studies were done in men who were being regularly screened for cancer. (The screening process itself increases the risk of being diagnosed with prostate cancer about 2-fold.)

The biggest study in the series was the Prostate Cancer and Prevention Trial, where a reduction in the numbers of prostate cancer was found, from 24.4% in the control group to 18.4% in the Proscar group over a 7-year period. There were concerns because high-grade tumors were more prevalent in the Proscar group, but this was considered an error, due to the fact that Proscar causes a shrinkage of the gland, making high-grade tumors easier to detect.

The actual recommendations read, in conclusion: “Asymptomatic men with a prostate-specific antigen (PSA) of 3 nanog/mL or less who are regularly screened with PSA or are anticipating undergoing annual PSA screening for early detection of prostate cancer may benefit from a discussion of both the benefits of 5-ARIs for 7 years for the prevention of prostate cancer and the potential risks (including the possibility of high-grade prostate cancer). . .” In other words, talk to your doctor. Of course, if you are already taking Proscar or Avodart® (dutasteride, the other approved 5-ARI), you should carry on.