[Biological and clinical implications of aromatase inhibitors in early male breast cancer patients].

OBJECTIVE: To evaluate the efficacy, biological behaviors and safety of aromatase inhibitors in early male breast cancer. METHODS: A total of 12 male breast cancer patients of stages I and II took aromatase inhibitors. Their levels of estradiol were measured before and after medication. Another 12 patients received tamoxifen as controls. The recurrence, mortality and side effects were monitored and analyzed. RESULTS: Their 5-year disease-free survival rates were 69.4%, 77.0% and 5-year overall survival rates 75.0%, 83.4% respectively. No drug withdrawal occurred because of side effects. No inter-group statistical significance existed in estrogen receptor (9 vs 10 cases), progesterone receptor (10 vs 9 cases ), human epidermal growth factor receptor 2 (2 vs 3 cases ), stage T, N, M and disease-free survival rate, disease related 5-year overall survival rate (both P > 0.05) . There was statistical difference in the level of estradiol before and after medication. The level of estradiol was initially <5 ng/L in one patient, but rose during disease progression. CONCLUSIONS: The efficacy of aromatase inhibitors and tamoxifen in early male breast cancer patients is comparable. And the activity of aromatase inhibitors is correlated with a significantly reduced level of E(2) level. Some patients may develop secondary resistance.