Abstract B101: Race is associated with receipt of guideline-concordant treatment among women with endometrioid endometrial cancer: A National Cancer Database study

Background: Among women with endometrial cancer (EC), African American women have a 93% higher likelihood of dying compared to white women. This disparity is driven, in part, by the more frequent diagnosis of late stage and non-endometrioid tumors among African American women. However, even among women diagnosed with indolent forms of EC, including early stage or endometrioid histology, African American women are more likely to die. Differential receipt of guideline-based treatment might underlie worse survival among African American women. EC treatment guidelines are based on several randomized clinical trials, which provide consistently strong evidence on treatment regimens for women with early stage, endometrioid EC. Using the National Cancer Database (NCDB), we assessed the hypothesis that among women with less aggressive forms of EC, minority women would have lower odds of receiving guideline-concordant treatment than white women. In addition, we examined whether a survival benefit exists for EC patients who receive guideline-concordant treatment. Methods: We defined receipt of guideline-concordant EC treatment using the National Comprehensive Cancer Network (NCCN) guidelines, which stratify treatment decisions based on tumor characteristics. We used multivariable logistic regression models to compute odds ratios (OR) and 95% confidence intervals (CIs) for the association between race, categorized as non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic, and Asian/Pacific Islander (API), and receipt of guideline-concordant treatment. We used multivariable Cox proportional hazards regression models to estimate hazards ratios (HRs) and 95% CIs for relationships between receipt of guideline-concordant treatment and overall survival. Results: A total of 89,976 women diagnosed with stages 1A through 3C, endometrioid EC between the years 2004 and 2014 were included, among whom, 71.5% (n=64,316) received treatment in line with NCCN guidelines. In multivariable adjusted models, NHB (OR=0.91, 95% CI=0.86 – 0.97) and Hispanic women (OR=0.93, 95% CI=0.86 – 0.99) had lower odds of receiving concordant treatment compared to NHW women. Receipt of guideline-concordant treatment did not differ between API and NHW women. During the study period, NHB women had the highest proportion of deaths (28.7%) followed by NHW (22.0%), Hispanic (16.0%), and API women (14.2%). In models adjusted for patient, clinical, and facility characteristics, women not receiving guideline-concordant care were 8% more likely to die (HR=1.08, 95% CI=1.05 – 1.12). Conclusions: Receipt of guideline-concordant treatment differed according to race, with minorities less likely than NHW women to receive guideline-directed therapy. Further, in the overall study population, overall survival was better among those receiving guideline-concordant care. Future studies should evaluate reasons underlying disparate EC treatment. Citation Format: Mara K. Kaspers, Elyse Reamer, Jhalak Dholakia, Ritu Salani, Ashley S. Felix. Race is associated with receipt of guideline-concordant treatment among women with endometrioid endometrial cancer: A National Cancer Database study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B101.