Male Breast Cancer: A Comparative Analysis from the National Cancer Database

Purpose: Breast cancer (BC) in males accounts for <0.5% of all male cancer diagnoses and -1% of all BCs in the United States. We sought to describe clinicopathologic characteristics among male and female BC patients and differences in overall survival (OS) through the National Cancer Database over 13 years (2004-2016). Materials and Methods: Secondary to the 1:99 ratio of male to female BC cases, we randomly selected female cases for equal comparison to males cases by diagnosis year. Chi-square and t-tests compared demographic and tumor characteristics. OS was examined using Kaplan Meier survival analysis. Results: Among the -2.7 million BC patients, 9 per 1,000 BCs were in males, the rate remained similar over time. The mean (SD) age was 64.9 +/- 13.0 years for males and 60.7 +/- 13.6 years for females. Most of the male BC cases were white (non-Hispanic) (n=19,015 [0.2%]), clinical stage I (n-7,353 132.1%1) or stage II disease (n-7,923 134.6%]), and tumors were moderate or poorly differentiated (84.5%). Males exhibited more comorbidities, presented with a larger proportion of disease, and decreased OS (p<0.005) than females. Male OS was >10% lower at 5-years and nearly 20% lower at 10-years for males. More males had primary BC tumors under the nipple; the 10-year OS rate for this site was 48.8%. Conclusions: This study reports clinicopathologic characteristics of a large cohort of male BC. Males present at older age, with a greater comorbidity index, at later stages of disease. Increased education regarding the continued risks of male breast cancer may be warranted.