Influence of Age on the Clinical Outcome of Breast Cancer for Men and the Development of Second Primary Cancers.

BACKGROUND: Low incidence of breast cancer in men (BCM) (< 1% of all breast cancers) has led to a paucity of outcome data. This study evaluated the impact of age on BCM outcomes.

METHODS: For this study, BCM patients treated between 2000 and 2011 were stratified by age (≤ 65 or > 65 years). Kaplan-Meier methods were used to compare overall survival (OS) and breast cancer-specific survival (BCSS). Competing-risk methods analyzed time to second primary cancers (SPCs), with any-cause death treated as a competing risk.

RESULTS: The study identified 152 BCM patients with a median age of 64 years (range 19-96 years). The median body mass index (BMI) was 28 kg/m2 . Men age 65 years or younger (n = 78, 51%) were more overweight/obese than men older than 65 years (n = 74, 49%) (89% vs 74%, respectively; P = 0.008). Both groups had similar nodal metastases rates (P = 0.4), estrogen receptor positivity (P = 1), and human epidermal growth factor receptor 2 (HER2)neu overexpression (P = 0.6). Men 65 years of age or younger were more likely to receive chemotherapy (P = 0.002). The median follow-up period was 5.8 years (range 0.1-14.4 years). The 5-year OS was 86% (95% confidence interval [CI] 80-93%), whereas the 5-year BCSS was 95% (95% CI 91-99%). The BCM patients 65 years of age and younger had better OS (P = 0.003) but not BCSS (P = 0.8). The 5-year cumulative incidence of SPC was 8.4% (95% CI 3.4-13.4%). The prior SPC rate was higher for men older than 65 years (n = 20, 31%) than for those age 65 years or younger (n = 7, 11%) (P = 0.008). This did not account for differences in life years at risk. No difference was observed in SPC cumulative incidence stratified by age (P = 0.3).

CONCLUSIONS: Men 65 years of age or younger received more chemotherapy and had improved OS, but not BCSS, compared with men older than 65 years. For all BCM, SPC is a risk, and appropriate screening may be warranted.