The impact of race and comorbidity on survival in endometrial cancer.

BACKGROUND: Poorer survival from endometrial cancer in blacks than in whites is well documented. The aims of this study were to determine whether diabetes, hypertension, or other conditions influence survival and whether accounting for these conditions reduces this racial disparity.
METHODS: Using the SEER-Medicare database, we investigated the influence of diabetes, hypertension, and other comorbid conditions on survival in black and white women age ≥66 with endometrial cancer. We used Cox proportional hazards regression to evaluate the influence of comorbidities on survival for blacks and whites separately and to study survival differences between blacks and whites after adjustment for diabetes, hypertension, and other medical conditions, as well as for demographics, tumor characteristics, and treatment.
RESULTS: In both racial subgroups, women with diabetes or other conditions had poorer overall survival, whereas hypertensive black women experienced better survival [HR, 0.74; 95% confidence interval (CI), 0.60-0.92]. For disease-specific survival, diabetes was associated with poorer survival in white women (HR, 1.19; 95% CI, 1.06-1.35) but not in blacks (HR, 0.97; 95% CI, 0.73-1.30); hypertension and other conditions were not significantly related to survival. After adjustment, black women had poorer survival than white women, with HRs of 1.16 (95% CI, 1.05-1.28) for overall and 1.27 (95% CI, 1.08-1.49) for disease-specific survival.
CONCLUSIONS: Diabetes influences disease-specific survival in white women but not in blacks. The racial disparity in survival is not explained by the presence of other health conditions. IMPACT: Further research should focus on the unknown factors that lead to poorer survival in black women compared with whites.