Five-Alpha Reductase Inhibitor and Breast Cancer Risk in Men: A Systematic Review

The systematic review analyzed 6 studies with a total of 137,421 subjects taking 5-alpha reductase inhibitors (5ARIs) and 568,469 control subjects to determine if there was an association between 5ARI use and breast cancer risk in men. The studies reviewed, which included randomized controlled trials, case-control studies, and cohort studies, found no evidence that 5ARIs, such as finasteride and dutasteride, increase the risk of breast cancer in men. Although the results showed variable risks, none were statistically significant. The authors suggested the need for further research to confirm these findings and to explore the effects of 5ARIs on the endocrine system.