Background: Male breast cancer (MaBC) is an understudied disease, information about LRT and outcomes in patients (pts) with T1a,b,cN0M0 tumors is unknown. The aim of this study was to analyze pt characteristics, LRT and OS of T1a,b,cN0M0 MaBC. Methods: We evaluated men with T1a,b,cN0M0 microscopically confirmed invasive breast cancer reported to the Surveillance, Epidemiology, and End Results (SEER) program from 1988 to 2012. Pts with other primary either before or after breast cancer were excluded. Characteristics of pts with different tumor sizes were compared. Univariate and multivariate analyses were performed to determine the effect of each variable on OS. Results: We included 1263 pts. 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% and 66%, respectively. 83% were ductal, 95.3% ER positive, 87.2% PR positive and 21.9% grade 1. Distribution according to tumor substage was: T1a 6.5%, T1b 20.7% and T1c 72.8%. Mastectomy was performed in > 70% of pts of each tumor size group and overall 44.1% had ≥ 6 lymph nodes examined (LNE). Only 12.7% of pts received adjuvant radiotherapy. Pts with T1c tumors were older (p = 0.01), had higher grade (p < 0.0001), were more likely to have mastectomy (p = 0.003) and to die from breast cancer (p = 0.01). Univariate analysis showed that pts with T1c (p = 0.0003), no surgery (p < 0.0001) and 0 LNE (p < 0.0001) had worse prognosis. In multivariate analysis, older age (HR 11.2; p < 0.0001), grade 3/4 tumors (HR 1.8; p = 0.01), no surgery (HR 3.1; p = 0.04), 0 LNE (HR 4.8; p < 0.0001) and unmarried pts (HR 1.7; p = 0.02) had shorter OS. Race, ER, PR and radiotherapy were not associated with OS. There were no differences in OS between pts who underwent breast conservation vs mastectomy and pts who had 1-5 LNE vs ≥ 6 LNE. Conclusions: In this cohort of male pts with early breast cancer, a favorable OS rate at 10 years was observed. However, older age, higher tumor 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.
ASCO annual meeting 2015, Chicago, Illinois, EEUU. Abstract # 1072, Poster # 186