Racial differences in definitive breast cancer therapy in older women: are they explained by the hospitals where patients undergo surgery?

BACKGROUND: Prior research has documented racial disparities in patterns of care and outcomes for women with breast cancer. OBJECTIVES: To assess whether black women receive care from lower-quality or lower-volume hospitals and if such differences explain disparities in receipt of definitive primary breast cancer therapy. RESEARCH DESIGN: Observational study of a population-based sample of breast cancer patients included in the SEER-Medicare database. SUBJECTS: Fifty five thousand four hundred seventy white or black women aged >65 diagnosed with stage I/II breast cancer during 1992-2002. MEASURES: Surgery at a high-quality hospital (top quartile rates of radiation after breast-conserving surgery) or high volume (top quartile) hospital and receipt of definitive primary therapy (mastectomy or breast-conserving surgery with radiation). RESULTS: Black women were significantly less likely than white women to be treated at high-quality hospitals (adjusted odds ratio [OR] 0.60; 95% confidence interval [CI]: 0.40-0.87) but not high-volume hospitals (adjusted OR 0.85; 95% CI: 0.54-1.34). Black women were less likely than white women to receive definitive primary therapy, a finding partially explained by having surgery at a high-quality hospital but not by having surgery at a high-volume hospital. CONCLUSIONS: Older black women were more likely than white women to undergo breast cancer surgery at hospitals with lower rates of radiation following breast-conserving surgery, and this explains some of the reported racial disparities previously observed in receipt of definitive therapy for early-stage breast cancer. Interventions to help hospitals treating large numbers of black women improve rates of radiation after breast-conserving surgery may help to decrease racial disparities in care. (July 2009)