Letrozole combined with gonadotropin-releasing hormone analog for metastatic male breast cancer

The role of aromatase inhibitors combined with gonadotropin-releasing hormone analog in metastatic male breast cancer patients remains unknown. In this retrospective study we evaluated the activity of letrozole combined with a gonadotropin-releasing hormone analog as a first- or second-line therapy for metastatic male breast cancer patients. 19 men entered the study. We did not observe any grade 3 or 4 adverse events. 2 patients (10.5 %) had complete response, 7 patients (36.8 %) experienced a partial response, 7 patients (36.8 %) had stable disease lasting ≥6 months, and 3 patients (15.8 %) had progressive disease. Overall, the disease control rate was 84.2 %. Median progression-free survival was 12.5 months (95 % CI 8.2–16.9), median overall survival was 35.8 months (95 % CI 24.4–49.2), 1- and 2-year survival rates were 89.5 and 67 %, respectively. Interestingly, 3 out of 4 patients treated with the combination following disease progression while on aromatase inhibitor monotherapy confirmed or improved the best overall response observed in the first-line setting. The combination of letrozole and gonadotropin-releasing hormone analog is effective and safe in hormone-receptor positive, metastatic male breast cancer patients.