Contemporary systemic therapy for male breast cancer

The use, effectiveness, and tolerability of tamoxifen, aromatase inhibitors, and trastuzumab in early and advanced male breast cancer were examined at a population level.

A total of 158 consecutively referred men with invasive breast cancer diagnosed between 2000 and 2010 were identified. Stage and prognostic factors were compared with a random sample of contemporary female patients. Survival outcomes were compared with a separate female cohort matched 2:1 by prognostic and treatment factors.

Men were older (median 69.5 years) than women (median 60 years) and presented with more advanced stage disease. Estrogen receptor was positive in 96% (n = 152) of cases. Tamoxifen was more commonly used than aromatase inhibitors in the curative and metastatic settings. Adherence to adjuvant tamoxifen therapy was generally adequate with estimated actuarial rates of persistence at 1 year and 3.5 years of 89% and 70%, respectively. For the 146 men treated with curative intent, 5-year overall survival, breast cancer-specific survival and progression-free survival were 72%, 86%, and 62%, respectively. Outcomes were similar to matched female patients in univariate and multivariate analyses.

In this large population-based study, outcomes appear similar between male and risk-matched female patients with breast cancer. Side effect profiles, tolerance, adherence, and outcomes after tamoxifen, aromatase inhibitors, and trastuzumab in men appear comparable with those described in the literature for women.