The influence of black race on treatment and mortality for early-stage breast cancer

Background: Black Americans have higher mortality from breast cancer than white Americans. This study explores the influence of socioeconomic factors and black race on treatment and mortality for early-stage breast cancer.

Methods: A cohort of 21,848 female black and white, non-Hispanic subjects from the Massachusetts Cancer Registry diagnosed with stage I or II breast cancer between 1999-2004 was studied. Subjects with tumors larger than 5 cm were excluded. We used mixed modeling methods to assess the impact of race on guideline concordant care (GCC), defined as receipt of mastectomy or breast conserving surgery plus radiation. Cox proportional hazard regression was used to assess disease-specific mortality.

Results: Blacks were less likely to receive GCC after adjusting for age and clinical variables (OR: 0.75; 95% CI: 0.61, 0.92). Marital status and insurance were predictors of receipt of GCC. After adjustment for all covariates, there were no longer significant differences between black and white women regarding the receipt of GCC. Nevertheless, black women were more likely to die of early-stage breast cancer than white women after adjusting for clinical, treatment, socioeconomic variables, and reporting hospital (HR: 1.6; 95% CI: 1.1-2.1).

Conclusions: Socioeconomic factors are mediators of racial differences in treatment outcomes. Significant racial differences exist in disease-specific mortality for women with early-stage breast cancer. Attention to reducing socioeconomic barriers to care may influence racial differences in breast cancer treatment and mortality.