July 06, 2011
Manish Vira, MD
Another wrench is thrown into the prostate cancer prevention, screening, and treatment conundrum.
The US Food and Drug Administration (FDA) recently released a Drug Safety Communication regarding a common class of medications called 5 alpha reductase inhibitors (5-ARI) known as finasteride and dutasteride. Two large randomized, placebo-controlled trials in which a combined 27,113 men were randomized to receive either 5-ARI or placebo to reduce the incidence of prostate cancer showed a 25 percent reduction in the incidence of prostate cancer, but also revealed a higher incidence of high-grade cancers in the cohort of men on the study drug. As a result, the FDA revised the labeling of these medications to warn of the “increased risk of being diagnosed with a more serious form of prostate cancer.”
The FDA communication further advises that:
- 5-ARIs are not approved for the prevention of prostate cancer
- 5-ARIs may increase the risk of high-grade prostate cancer
- Prior to initiating therapy with 5-ARIs, healthcare professionals should perform appropriate evaluation to rule out other urological conditions, including prostate cancer, that might mimic benign prostatic hyperplasia.
It is important to understand that the FDA continues to endorse the use of 5-ARIs in the indicated treatment of men with an enlarged prostate and lower urinary tract symptoms. These medications have a proven benefit in reducing prostate volume and reducing the risk of acute urinary retention or surgery related to prostatic hypertrophy. Second, among patients being treated with 5-ARIs for prostate cancer prevention, the risk of being diagnosed with high grade cancer is very low.
Based on the results of the new analysis of data and recommendations from the FDA, patients -- especially those 75 years or younger -- should be counseled regarding the potential risks of high grade prostate cancer associated with the long term use of 5-ARIs. The medications continue to be an important tool and should be considered in the treatment of benign prostatic hypertrophy related urinary tract symptoms. Patients considering treatment should also undergo appropriate PSA testing and prostate cancer screening. Healthcare providers and patients should be cautious in any long-term off-label use of 5-ARIs.