Disparities in treatment and outcome for renal cell cancer among older black and white patients

Purpose: Black patients with renal cell cancer have shorter survival compared with their white counterparts, but the causes for this disparity are unclear. To elucidate reasons for this inequality, we examined differences in treatment and survival between black and white patients. Patients and Methods: A retrospective cohort study was conducted using data from the linked Surveillance, Epidemiology and End Results (SEER) cancer registry and Medicare databases. Participants included 964 black and 10,482 white patients age ≥ 65 years who were enrolled into Medicare and diagnosed with renal cell cancer between 1986 and 1999. Information on surgical treatment was ascertained from both databases, whereas data regarding coexisting illness and survival was obtained from the Medicare database. Results: The percentage of black patients receiving nephrectomy treatment was significantly lower compared with whites (61.2% v 70.4%; P < .0001). After adjustment for age, sex, median income, cancer stage, tumor size, and comorbidity index, blacks were less likely to undergo nephrectomy treatment compared with whites (risk ratio = 0.93; 95% CI, 0.90 to 0.96). Overall survival was worse for blacks than whites even after adjustment for demographic and cancer prognostic factors (hazard ratio [HR] = 1.16; 95% CI, 1.07 to 1.25); however, additional adjustment for comorbidity index and nephrectomy treatment reduced the disparity substantially (HR = 1.00; 95% CI, 0.93 to 1.09). Conclusion: This study indicates that the lower survival rate among blacks compared with whites with renal cell cancer can be explained largely by the increased number of comorbid health conditions and the lower rate of surgical treatment among black patients.