Objective: To estimate whether race or ethnic and socioeconomic strata are independently associated with advanced-stage ovarian cancer-specific survival after adjusting for adherence to National Comprehensive Cancer Network treatment guidelines.
Methods: The design was a retrospective population-based cohort study of patients with stage IIIC-IV epithelial ovarian cancer identified from the Surveillance, Epidemiology, and End Results-Medicare database (1992-2009). Quartile of census tract median household income was used as the measure of socioeconomic status (quartiles 1-4). A multivariable logistic regression model was used to identify characteristics predictive of adherence to National Comprehensive Cancer Network guidelines for surgery and chemotherapy. Cox proportional hazards models and propensity score matching were used for survival analyses.
Results: A total of 10,296 patients were identified, and 30.2% received National Comprehensive Cancer Network guideline-adherent care. Among demographic variables, black race (adjusted odds ratio [OR] 1.53, 95% confidence interval [CI] 1.22-1.92) and low socioeconomic status (quartile 1, adjusted OR 1.32, 95% CI 1.14-1.52) were independently associated with nonguideline care. Stratified multivariate survival analysis using the propensity score-matched sample (n=5,124) revealed that deviation from treatment guidelines was associated with a comparable risk of disease-related death across race-ethnicity: whites (adjusted hazard ratio [HR] 1.59, 95% CI 1.48-1.71), blacks (adjusted HR 1.66, 95% CI 1.19-2.30), Asian or Pacific Islanders (adjusted HR 1.52, 95% CI 0.99-1.92), and Hispanics (adjusted HR 1.91, 95% CI 0.98-3.72). Across socioeconomic status, deviation from treatment guidelines was also associated with a comparable risk of ovarian cancer mortality for quartile 1 (adjusted HR 1.69, 95% CI 1.47-1.95), quartile 2 (adjusted HR 1.63, 95% CI 1.42-1.87), quartile 3 (adjusted HR 1.51, 95% CI 1.32-1.73), and quartile 4 (adjusted HR 1.57, 95% CI 1.38-1.79).
Conclusion: Adherence to treatment guidelines for advanced-stage ovarian cancer is associated with equivalent survival benefit across racial or ethnic and socioeconomic strata. Ensuring equal access to standard treatment is a viable strategic approach to reduce survival disparities.