Analysis of Data From Breast Diseases Treated With 5-Alpha Reductase Inhibitors for Benign Prostatic Hyperplasia

5-alpha reductase inhibitors (5ARIs) decrease the androgen levels in vivo and are currently used for the treatment of benign prostatic hyperplasia (BPH) in men. However, these inhibitors can also increase the risk of gynecomastia, breast tenderness, and breast cancer. Hence, we did a systematic review and meta-analysis to evaluate the rate of breast-related diseases in men treated with 5ARIs.

PubMed, Embase, Cochrane, and CNKI databases were searched for randomized controlled trials using 5ARIs in patients with BPH. Data were analyzed by using Cochrane Collaboration review manager program and Stata 12.0 software.

In total, 14 studies were included in the meta-analysis. Gynecomastia was significantly more common with 5ARIs treatment when compared with placebo (3.30% vs. 1.84%; P < .00001) or alpha blockers (ABs) monotherapy (2.33% vs. 1.00%; P = .0009). Both dutasteride (2.03% vs. 0.90%; P < .00001) and finasteride (4.08% vs. 2.43%; P < .00001) are associated with significantly higher risk of gynecomastia than placebo. Risk for breast tenderness was elevated in 5ARIs users (0.83% vs. 0.25%; P = .01) or in users having combination therapy with ABs (2.48% vs. 0.58%; P < .0001). Finasteride is associated with significantly higher risk of breast tenderness than placebo (0.80% vs. 0.25%; P = .02).

In male patients with BPH, 5ARIs have significantly increased the risk of gynecomastia and breast tenderness but may be not to the breast cancer. In addition, combination therapy is significantly associated with higher risk of breast tenderness compared to single ABs monotherapy.