Racial disparities in survival for patients with clinically localized prostate cancer adjusted for treatment effects

Objective: To examine whether racial disparities in survival exist among black, Hispanic, and Asian patients compared with white patients with clinically localized prostate cancer (CLPC) after adjustment for the effects of treatment. Patients and Methods: We performed a retrospective cohort study of patients with CLPC diagnosed from January 1, 1995, through December 31, 2003, as documented in the Surveillance, Epidemiology, and End Results registry. Treatment-stratified, risk-adjusted Cox proportional hazards models were constructed. Results: During the study period, CLPC was diagnosed in 294,160 patients. Of these patients, 123,850 (42.1%) underwent surgery and 101,627 (34.5%) underwent radiotherapy, whereas 68,683 (23.3%) received no treatment. Overall 5-year and 10-year survival rates for Asians (85.6% and 67.6%, respectively), Hispanics (85.9% and 69.0%, respectively), and whites (83.9% and 65.7%, respectively) were higher than for blacks (81.5% and 61.7%, respectively) (P<.001). Prostate cancerespecific survival also varied significantly by race (P<.001). A risk-adjusted model stratified by primary treatment modality revealed that blacks had worse overall survival than whites (hazard ratio, 1.37; 95% CI, 1.33-1.41; P<.001), whereas Asians had better survival compared with whites (hazard ratio, 0.79; 95% CI, 0.76- 0.83; P<.001). After the effects of treatment were accounted for, Hispanics had similar overall survival compared with whites (hazard ratio, 0.97; 95% CI, 0.94-1.01; P=.10). Conclusion: Blacks with CLPC have poorer survival than whites, whereas Asians have better survival, even after risk adjustment and stratification by treatment. These data may be relevant to US regions with large underserved populations that have limited access to health care.