Abstract C120: High-grade endometrial cancers: Persistent racial differences in survival

Abstract

Abstract Introduction: Endometrial cancer (EC) is the most common gynecologic cancer diagnosed in the United States, and high-grade cancers account for approximately 1/5 of the ECs diagnosed in non-Hispanic white (NHW) women, Hispanic women, and Asian women, but nearly 1/3 of those diagnosed in African American (AA) women. These high-grade cancers are associated with poorer outcomes, and AAs are consistently at highest risk of mortality in studies that fail to adjust adequately for potentially important treatment or comorbidity variables. Here we present survival analyses from a study of AA and NHW women with high grade EC at two academic hospitals. Methods: High-grade cancers were identified through registries at each hospital and representative slides were re-reviewed by a single gynecologic pathologist to confirm high-grade disease and subtype. The following subtypes were included: clear cell, endometrioid, mixed, and serous. We identified 258 women (n=86 NHW, n=169 AA) who were diagnosed with high-grade cancers between 1998 and 2010. Utilizing medical records and the Surveillance, Epidemiology and End Results (SEER) registry, the following data were abstracted: height, weight, comorbid conditions, type of radiation, dose and fractions, type(s) of chemotherapy, number of cycles, recurrence, and vital status. Descriptive analyses utilized chi-square and t-tests to determine differences in clinical characteristics between AA and NHW women. Kaplan Meier survival analysis was performed to test for differences by race and subtype. To compare survival while considering competing risks of death, cause-specific hazard and cumulative incidence functions were compared using Gray's test. Results: The majority of the women had ECs classified as serous carcinomas (46.1%), followed by endometrioid (39.5%), clear cell carcinomas (9.7%) and mixed cell types (4.7%). AA women with endometrial cancer had slightly higher mean body mass index (BMI) compared to NHW women (34.6 and 32.2, respectively, p-value=0.06). NHW survived significantly longer after diagnosis compared to AA women (173 months versus 87 months, respectively, log-rank p-value=0.006). This difference remained after stratification by subtype, with similar findings for endometrioid cancers (log-rank p-value=0.06) and serous cancers (log-rank p-value=0.03). When examining survival considering competing risks (death due to EC versus other causes), AA women had a greater risk of death (HR: 1.84, 95% CI: 1.10-3.03) compared to their NHW counterparts; however, no difference was seen by race for other causes of death (HR: 1.29, 95% CI: 0.71-2.32). Further analyses, showing survival differences persist despite adjustments for BMI, comorbidities, and detailed treatment, will be presented. Conclusions: AA women continue to experience greater mortality from high-grade EC despite adjustments for demographic, clinical and treatment data, warranting continued efforts to identify molecular and social factors associated with poorer survival. Citation Format: Michele L. Cote, Julie J. Ruterbusch, Tara Rangarajan, Remonda Khalil, Mohamed Elshaikh, Rouba Ali-Fehmi. High-grade endometrial cancers: Persistent racial differences in survival [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C120.