Differential Effects of Race, Socioeconomic Status, and Insurance on Disease-Specific Survival in Rectal Cancer

BACKGROUND: National Comprehensive Cancer Network guideline adherence improves cancer outcomes. In rectal cancer, guideline adherence is distributed differently by race/ethnicity, socioeconomic status, and insurance. OBJECTIVE: This study aimed to determine the independent effects of race/ethnicity, socioeconomic status, and insurance status on rectal cancer survival after accounting for differences in guideline adherence. DESIGN: This was a retrospective study. SETTINGS: The study was conducted using the California Cancer Registry. PATIENTS: This study included patients aged 18 to 79 years diagnosed with rectal adenocarcinoma between January 1, 2004, and December 31, 2017, with follow-up through November 30, 2018. Investigators determined whether patients received guideline-adherent care. MAIN OUTCOME MEASURES: ORs and 95% CIs were used for logistic regression to analyze patients receiving guideline-adherent care. Disease-specific survival analysis was calculated using Cox regression models. RESULTS: A total of 30,118 patients were examined. Factors associated with higher odds of guideline adherence included Asian and Hispanic race/ethnicity, managed care insurance, and high socioeconomic status. Asians (HR, 0.80; 95% CI, 0.72-0.88; p < 0.001) and Hispanics (HR, 0.91; 95% CI, 0.83-0.99; p = 0.0279) had better disease-specific survival in the nonadherent group. Race/ethnicity were not factors associated with disease-specific survival in the guideline adherent group. Medicaid disease-specific survival was worse in both the nonadherent group (HR, 1.56; 95% CI, 1.40-1.73; p < 0.0001) and the guideline-adherent group (HR, 1.18; 95% CI, 1.08-1.30; p = 0.0005). Disease-specific survival of the lowest socioeconomic status was worse in both the nonadherent group (HR, 1.42; 95% CI, 1.27-1.59) and the guideline-adherent group (HR, 1.20; 95% CI, 1.08-1.34). LIMITATIONS: Limitations included unmeasured confounders and the retrospective nature of the review. CONCLUSIONS: Race, socioeconomic status, and insurance are associated with guideline adherence in rectal cancer. Race/ethnicity was not associated with differences in disease-specific survival in the guideline-adherent group. Medicaid and lowest socioeconomic status had worse disease-specific survival in both the guideline nonadherent group and the guideline-adherent group. See Video Abstract at http://links.lww.com/DCR/ B954.