Abstract PO-191: Contributions of tumor characteristics, treatment, and access to care factors on racial disparities in endometrial cancer survival
Authors: Brown Jordyn A. , Sinnott Jennifer A. , Doll Kemi M. , Donneyong Macarius M. , Padamsee Tasleem J. , Llamocca Elyse , Cohn David E. , Cosgrove Casey , Felix Ashley S. 
Published: January 2022

Abstract
Background: Among women with endometrial cancer (EC), well-established mortality disparities between White and Black women have continued to widen over time. Hispanic, American Indian/Alaska Native (AI/AN) women, and women broadly categorized as Asian or Pacific Islander have not been the focus of many prior studies of racial disparities in EC survival. We examined racial disparities in survival and assessed the contributions of demographic, tumor, treatment, access to care, and health status factors on racial disparities in survival among women with EC. Methods: Participants were diagnosed between 2004 and 2015 with stages 1A through 4B, endometroid and non-endometroid EC in the National Cancer Database (NCDB). Race was categorized as non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic, Asian, Native-Hawaiian/Pacific Islander (NH/PI), and AI/AN. We used a series of Cox regression models to estimate the relative contribution of prognostic factors to excess risk of mortality. We examined the following classes of prognostic factors: age at diagnosis, tumor characteristics (stage and histology), guideline-concordant treatment, access to care (insurance status, facility type, treatment delay), and Charlson comorbidity. Each class of factors was added individually to a baseline race-only model, and we estimated the percentage contribution of each class on changes in the hazard ratio (HR) for race using the equation: (HR0 – HRn)/(HR0 – 1), in which HR0 is from the race-only model and HRn is the HR for race categories from the model with the variables of interest. Asian women comprised the reference category in all models as mortality was lowest in this group. Changes in HRs are described as percentages. Results: Our study population included 208,112 women with EC. In the race-only model, overall HRs relative to Asians were 2.49 (95% CI, 2.32-2.67), 1.41 (95% CI, 1.18-1.69), 1.29 (95% CI, 1.20-1.38), 1.18 (95% CI, 0.97-1.43), and 1.09 (95% CI, 1.01-1.18) for NHB, NH/PI, NHW, AI/AN, and Hispanic women, respectively. Age at diagnosis was the most influential variable among NHW and NH/PI women, describing 93.1% and 75.6% of the survival disparity, respectively. Tumor characteristics were the most influential contributor for NHB women (40.9%), while among Hispanic and AI/AN women, access to care (77.8%) and comorbidities (50%) were responsible for the largest attenuation in HRs, respectively. Guideline-concordant treatment was linked with a small attenuation in HRs among NHB (2.7%), NHW (3.4%), and NH/PI (7.3%). Conclusions: Contributors to racial disparities in EC survival vary by race/ethnicity. Some factors, like age, are non-modifiable and represent poor intervention targets. Conversely, other factors, like high stage, comorbidities, and low access to care, are challenging but modifiable problems that implicate the larger societal context. Our preliminary findings suggest that interventions for reducing EC survival disparities will require a tailored approach for the particular group of women for whom we are trying to intervene.
Citation Format: Jordyn A. Brown, Jennifer A. Sinnott, Kemi M. Doll, Macarius M. Donneyong, Tasleem J. Padamsee, Elyse Llamocca, David E. Cohn, Casey Cosgrove, Ashley S. Felix. Contributions of tumor characteristics, treatment, and access to care factors on racial disparities in endometrial cancer survival [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-191.