Abstract A127: Comparing outcomes in breast cancer treatment between fee-for-service and Medicare Advantage patients
Authors: Shearn-Nance Galen , Sachdev Rishi , Vu Long , Dong Weichuan , Rose Johnie , Koroukian Siran 
Published: December 2023

Abstract
Introduction: Relative to Medicare beneficiaries receiving care through the traditional fee-for-service system (FFS), the percentage of Americans covered by Medicare Advantage (MA) plans has increased over the last decade. As more patients enroll in MA plans, the comparison of outcomes between FFS and MA groups has gained renewed importance. Ohio has a high penetration of MA plans, but differences in outcomes between FFS and MA plans in Ohio is under-studied. Breast cancer is the second most common type of cancer among women, therefore understanding nuances in breast cancer treatment outcomes has broad applicability. In this study, we compare receipt of standard care, time to treatment initiation (TTI), and overall survival (OS) between FFS and MA women diagnosed with incident breast cancer. Methods: We used the Ohio Cancer Incidence Surveillance System (OCISS) cancer registry data linked with Medicare enrollment files and identified patients diagnosed with local and regionally staged breast cancer between 2011-2016. All variables except for FFS and MA enrollment were derived from the OCISS. We developed logistic regression (for analysis of receipt of standard treatment) and Cox regression models (for analysis of TTI and OS) to evaluate the independent association between FFS/MA status and our outcomes of interest, adjusting for age, race, marital status, type of county of residence, neighborhood poverty level, stage at diagnosis, hormone receptor status, and Medicaid dual enrollment. Standard care was defined as receipt of breast-conserving surgery (BCS) or mastectomy, radiotherapy if BCS was received; chemotherapy if regionally staged; and hormone therapy if hormone receptor positive. Results: 12,349 patients were identified that met our inclusion criteria, with 6,801 and 5,548 patients in the FFS and MA groups at the time of diagnosis, respectively. A slightly higher percentage of MA patients were identified as Black (10.3 vs 8.0% on FFS plans). FFS Medicare patients were found to have similar odds of receiving standard care as patients on MA plans (adjusted odds ratio 0.95 [95% CI: 0.88, 1.03]). We detected no difference in TTI between FFS and MA patients, (adjusted hazard ratio (aHR) 0.98 [95% confidence interval (CI): 0.94, 1.01]), or in OS (aHR 1.06 [95% CI: 0.95, 1.18]). No difference was found in receipt of standard care between Black and White patients (aOR 0.88 [95% CI: 0.76, 1.03]). An interaction term with race found that FFS Black patients had significantly lower odds of receiving standard care than their MA counterparts (aOR 0.70 [95% CI: 0.54, 0.92]). We did not find any significant interaction between MA status and race for OS or TTI. Conclusions: MA plans were not associated with any difference in TTI, OS, nor odds of receiving standard treatment for breast cancer compared to FFS Medicare plans. These findings are reassuring given the growing market share of privately administered MA plans, but raise questions with the notable disparity in receipt of standard care between Black FFS enrollees versus Black MA enrollees.
Citation Format: Galen Shearn-Nance, Rishi Sachdev, Long Vu, Weichuan Dong, Johnie Rose, Siran Koroukian. Comparing outcomes in breast cancer treatment between fee-for-service and Medicare Advantage patients [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr A127.