Racial/ethnic differences in survival rates in a population-based series of men with breast carcinoma

Abstract

Background: A rare occurrence, about 1500 men in the United States develop breast carcinoma each year. Little is known about survival patterns at the population level, particularly about racial/ethnic variation.

Methods: Using data from the Surveillance, Epidemiology, and End Results Program, we examined survival rates in 1979 men diagnosed with primary invasive breast carcinoma between 1973 and 1997. Race was defined as non-Hispanic white, non-Hispanic black, and other race/ethnicity (predominantly Asian/Pacific Islander and Hispanic). The two outcomes were all-cause and breast carcinoma- specific mortality. Survival curves were drawn using Kaplan-Meier estimates and Cox regression was used to estimate the risk of death with hazard ratios and 95% confidence intervals. For both outcomes, the racial/ethnic survival curves differed significantly when the log rank test was used. Therefore, separate models were run for each racial/ethnic group. Covariates included age, stage, histology, surgery, radiation therapy, and year of diagnosis. Estrogen and progesterone receptor status were available for 616 men.

Results: Survival rates differed significantly by race/ethnicity. Overall, 5-year survival rates were 66% for whites, 57% for blacks, and 75% for men of other race/ethnicity. Blacks presented with more advanced disease. By stage, whites and blacks had worse survival rates compared with men of other race/ethnicity. The effects of prognostic factors such as age, surgery type, and radiation were similar, but not always significant, for all groups. Diagnosis year and estrogen receptor status did not affect survival.

Conclusions: Survival following male breast carcinoma differed by race/ethnicity, whereas the prognostic factors associated with survival were similar.