Abstract 1021: Predictors of receipt of guideline-concordant chemotherapy among ovarian cancer patients in the Kaiser Permanente Research on Ovarian Cancer Survival (KPROCS) Study

Abstract Background: Ovarian cancer is the fifth leading cause of cancer death among women in the US. Standard of care for ovarian cancer includes cytoreduction followed by paclitaxel-based chemotherapy. Herein, we aimed to assess patient-level factors affecting receipt of guideline concordant chemotherapy among patients diagnosed with epithelial ovarian cancer in an integrated health system. Methods: This preliminary analysis included 5, 327 patients in the ongoing Kaiser Permanente Research on Ovarian Cancer Survival (KPROCS) Cohort Study, who were diagnosed with epithelial ovarian cancer (2000-2022) and treated at Kaiser Permanente Northern California. Women were included if they were ≥18 years at diagnosis, resided in California, and received chemotherapy. Treatment and other sociodemographic and clinical information, including specific chemotherapy agents and whether neoadjuvant treatment was given were ascertained from electronic health records, and assessed for concordance against National Comprehensive Cancer Network guidelines that were in place at the time of treatment and as appropriate for clinical characteristics such as stage, grade, histotype, and comorbidities. We used logistic regression to compute odds ratios (ORs) and 95% confidence intervals (95%CI) to estimate associations of demographic and clinical characteristics with receipt of guideline concordant chemotherapy, in multivariable models including age, stage, histotype, and Charlson Comorbidity Index (CCI). Results: We included 3, 472 Non-Hispanic White (NHW) women, 297 Non-Hispanic Black (NHB) women, 771 Asian American and Pacific Islander (AAPI) women, 696 Hispanic women, and 91 women of other racial and ethnic groups. Overall, 48% of patients received guideline concordant care. In multivariable-adjusted models, NHB individuals were less likely to receive guideline care compared with NHW individuals (OR=0.76, 95%CI: 0.58-0.99), whereas AAPI individuals were more likely to receive guideline care (OR=1.13, 95%CI: 0.95-1.35) and Hispanic individuals were equally likely (OR=1.04, 95%CI: 0.87-1.24). Women were less likely to receive guideline-concordant chemotherapy if they were older (>70 vs. <50 years, OR=0.63, 95%CI: 0.52-0.78), had higher CCI (CCI 3+ vs CCI=0, OR=0.56, 95%CI: 0.46-0.68), later stage at diagnosis (Stage IV vs Stage 1; OR=0.40, 95%CI: 0.33-0.48), were diagnosed with histotype of carcinoma not otherwise specified vs. endometrioid (OR=0.28, 95%CI: 0.22-0.38), or had high body mass index (≥40 vs <25 kg/m2; OR=0.58, 95%CI:0.44-0.77). Conclusions: We found that in a managed care setting, ovarian cancer treatment disparities persisted across racial and ethnic groups, and those with higher comorbidity, later stage at diagnosis, and greater obesity were less likely to receive guideline-concordant care. Citation Format: Elisa V. Bandera, Lindsay J. Collin, Valerie S. Lee, Juraj Kavecansky, Farzin Khosrow-Khavar, Scarlett L. Gomez, Jennifer A. Doherty, Lawrence H. Kushi. Predictors of receipt of guideline-concordant chemotherapy among ovarian cancer patients in the Kaiser Permanente Research on Ovarian Cancer Survival (KPROCS) Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1021.