AbstractBACKGROUND:Racial differences in the treatment of men with localized prostate cancer remain poorly understood. This study examines whether hospital racial composition is associated with the type of treatment black and white men receive.METHODS:The authors performed a retrospective cohort study of men in Surveillance, Epidemiology, and End Results‐Medicare diagnosed with localized prostate cancer from 1995 to 2005 linked to hospital and census data. A total of 134,291 men were assigned to the hospital where they received care. Generalized estimating equations were used to determine whether hospital racial composition was associated with the receipt of definitive therapy and type of treatment.RESULTS:Black men were less likely to receive radiation and/or prostatectomy compared with white men (55.5% vs 63.7%, P < .001) and, among those who received definitive therapy, were less likely to undergo prostatectomy (27.5% vs 31.9%, P < .001). The percentage of black men who received their care at hospitals with a high proportion of black patients was 48.0%, compared with only 5.2% of white patients who received care in this subset of hospitals. Men were significantly less likely to receive definitive treatment (odds ratio, 0.81; 95% confidence interval, 0.74‐0.90) in hospitals with a high proportion of black patients compared with men seen at hospitals with fewer black patients. The association between hospital racial composition and treatment did not significantly differ by patient race.CONCLUSIONS:Hospital racial composition is consistently associated with the care that men receive for localized prostate cancer. Better understanding of the factors that determine where men receive care is an important component in reducing variation in treatment. Cancer 2011;. © 2011 American Cancer Society.