Background
Low incidence of breast cancer in men (BCM) (
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.