P4-19-02: A Population-Based Study of Contemporary Systemic Therapy for Male Breast Cancer.

Abstract

Abstract Purpose: To describe the contemporary utilization, effectiveness and tolerability of tamoxifen, aromatase inhibitors, and trastuzumab in the treatment of early and advanced male breast cancer at a population level in British Columbia. Patients and Methods: Records of 158 consecutive referred cases of invasive male breast cancer diagnosed from January 2000 to March 2010 were analyzed in a population-based cancer program with respect to patient and tumour characteristics, usage of endocrine agents, toxicity and medication adherence, trastuzumab usage and outcome. This group was compared to a population-based random sample of 1000 contemporary female breast cancer patients for prognostic and demographic factors. Survival outcomes were also compared to a cohort of women, matched 2:1 on prognostic and treatment factors. Results: Pathology was most commonly infiltrating ductal carcinoma (94.3%) and estrogen-receptor positive (98.7%). Males were older (median 69.5 years) compared to women (median 60 years). Stage distribution was I (25.3%), II (43.0%), III (24.7%) and IV (7.0%), reflecting more advanced presentation compared to female cases I (43.9%), II (37.9%), III (12.5%) and IV (5.3%). Tamoxifen was prescribed as adjuvant therapy to109 patients, and as palliative therapy to 11. Fourteen (11.7%) patients discontinued tamoxifen due to toxicity. Aromatase inhibitors were prescribed as adjuvant therapy for 16 patients and as palliative therapy for 24; these were discontinued due to toxicity in 5 patients (12.5%). Five of 9 patients known to over-express Her2 were treated with adjuvant chemotherapy with trastuzumab. Overall survival, breast cancer-specific survival and progression-free survival at 5 years were 72.4%, 85.5% and 79.7%, respectively. There was no statistical difference in outcomes compared to the matched female cases. Conclusions: In this large population-based study of contemporary systemic therapy for male breast cancer, outcomes appear to be similar to those of women with the same diagnosis. Side effect profiles, tolerance, adherence and outcomes after tamoxifen, aromatase inhibitors and trastuzumab appear to be similar in men compared to that described in the literature for women. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-19-02.