Male breast cancer (MaBC) is an understudied disease; information about locoregional treatment and outcomes in patients with early stage is unknown. We aimed to analyse patient characteristics, locoregional treatment and overall survival (OS) of T1a,b,cN0M0 male breast cancer.

We evaluated men with T1a,b,cN0M0 breast cancer reported to Surveillance, Epidemiology, and End Results program from 1988 to 2012. Univariate and multivariate analyses were performed to determine the effect of each variable on OS.

We included 1263 patients. Median age was 66 years (range 27-103). Median follow-up was 62 months (range 1-294). OS at 5 and 10 years were 85.1% and 66.5%, respectively. Distribution according to tumour sub-stage was: T1a 6.5%, T1b 20.7% and T1c 72.8%. Mastectomy was performed in >74% of patients of each tumour size group and overall 44.1% had >5 lymph nodes examined (LNE). Univariate analysis showed that patients with T1c, no surgery and 0 LNE had worse prognosis. In multivariate analysis, older age (hazard ratio [HR] 11.09), grade 3/4 tumours (HR 1.7), no surgery (HR 3.3), 0 LNE (HR 5.1) and unmarried patients (HR 1.7) had significantly shorter OS. There were no differences in OS between breast conservation versus mastectomy and 1-5 LNE versus > 5 LNE.

Men with early breast cancer have a favourable OS. However, older age, higher grade, no breast surgery, no LNE and unmarried status emerged as poor prognostic characteristics. Efforts to decrease the high rates of mastectomy and extensive LNE should be taken given similar OS observed with breast conservation and 1-5 LNE, respectively.