Male breast cancer: Are there racial disparities in incidence and tumor characteristics?

Background: While female Breast Cancer (BC) outcome disparities have been studied intensively and well documented, little is known about male BC especially in minorities. Methods: Data (1973 to 2011) from the Surveillance, Epidemiology, and End Results Program database were used to compare BC among Non-Hispanic Black (NHB) and Non-Hispanic White (NHW) males and their female counterparts. Differences in incidence, and tumor characteristics including ER/PR receptor status, stage and grade were examined. Results: Prior research shows higher incidence of BC for NHW compared to NHB women. In contrast, over the entire period of this study and in all age groups, NHB males had the highest incidence of BC (0.93 per 100,000) compared to NHW males (0.62 per 100,000) with a rate ratio of 1.50 (95% CI [1.41 – 1.60]). The proportion of BCs that are ER negative is much lower in men compared to women generally, but similar to NHB women, NHB men have a higher proportion of ER negative tumors (8.9%) compared to NHW men (5.2%) with an OR of 1.66 (95% CI [1.22 – 2.25]) to develop ER negative BC and an OR of 1.78 (95% CI [1.26 – 2.52]) to develop ERPR negative BC.  Although not statistically significant, NHB males have a higher proportion of grade 3 BC (36.54 vs 33.89 for NHW men). Conclusion: As observed among NHB females, NHB males are more likely to have prognostic factors consistent with more aggressive tumors (higher grade and proportion of ERPR negative tumors) but additionally, NHB males have a higher incidence of BC compared to NHW men.