Abstract A121: Racial disparities in epithelial ovarian cancer mortality in Georgia

Abstract

Epithelial ovarian cancer (EOC) is a highly fatal disease, with an average 5-year survival of only 51%. It is well established that non-Hispanic Black (NHB) women experience worse EOC survival than non-Hispanic White women (NHW), but the drivers of this disparity are not fully understood. This study aimed to evaluate the patient, tumor, and treatment characteristics that contribute to the observed disparity in Georgia—a demographically diverse setting. We identified NHB and NHW women diagnosed with EOC and reported to the Georgia Cancer Registry. Eligible patients included those who were 18 years or older, with a first primary EOC diagnosis in Georgia between 2005–2022. We used Cox proportional hazard regression to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) comparing NHB vs NHW EOC mortality by patient (age, marital status, rurality, neighborhood poverty, and insurance), tumor (stage and histotype), and treatment (surgery, chemotherapy, and treatment sequence) characteristics. We estimated racial disparities in EOC mortality within strata of the characteristic of interest and used the common referent approach to calculate the relative excess risk due to interaction (RERI). Among 2,135 NHB and 5,770 NHW women with EOC included in the study, NHB women, compared with NHW women, were diagnosed at a younger median age (58 vs. 63 years) and were less likely to have high-grade serous histology (44% vs. 52%). Overall, NHB women experienced a 27% higher age-adjusted EOC mortality than NHW women (HR=1.27, 95% CI:1.18–1.36). Among patient characteristics, the racial disparity in mortality was most pronounced among women aged 55–69 (HR=1.55, 95% CI:1.38–1.75) and women with private health insurance (HR=1.44, 95% CI: 1.27–1.64). Across tumor characteristics, the racial disparity was most pronounced among women with stage I/II disease (HR=1.42, 95% CI:1.11–1.81) and those with clear cell (HR=2.07, 95% CI:1.33–3.22) or endometrioid (HR=1.79, 95% CI:1.02–3.14) EOC histotypes. Among treatment characteristics, the racial disparity was greatest among women who received neoadjuvant therapy (HR=1.31, 95% CI:1.17–1.46). Evidence of additive interaction was observed for stage IV disease (RERI=0.56, 95% CI: 0.36–2.50), clear cell histology (RERI=0.31, 95% CI: −0.10–0.72), lack of surgery (RERI=0.77, 95% CI: 0.24–1.31), and neoadjuvant therapy (RERI=0.65, 95% CI: 0.31–0.99). Our preliminary results highlight pronounced racial disparities in EOC mortality across patient, tumor, and treatment characteristics. Evidence of positive additive interaction was observed for tumor and treatment-related factors, suggesting these characteristics may exacerbate racial inequalities in EOC mortality beyond their independent effects. Subsequent analyses will decompose the relative contribution of each domain to the overall mortality difference, prioritizing modifiable pathways to achieve health equity. Ashleigh L. Walton, Jazmyn L. Bess, Sarah E. Dilley, Maret L. Maliniak, Lauren E. McCullough, Kevin C. Ward, Lindsay J. Collin. Racial disparities in epithelial ovarian cancer mortality in Georgia [abstract]. In: Proceedings of the 19th AACR Conference on the Science of Cancer Health Disparities; 2026 Oct 18-21; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2026;35(10 Suppl):Abstract nr A121.