Abstract A061: Receipt of standard treatment by breast cancer patients on Medicaid, pre- and post-expansion

Abstract Background: Medicaid expansion in Ohio went into effect in 2014. While prior studies have shown earlier breast cancer stages at diagnosis post-expansion, its impact relative to receipt of standard treatment remains understudied. Here, we examined changes in stage-appropriate standard treatment by women with invasive incident breast cancer pre- and post-expansion, and by their timing of enrollment in Medicaid relative to cancer diagnosis – a key marker of inadequate access to care. Methods: We used 2011-2017 Ohio Cancer Incidence Surveillance System (OCISS) data linked with Medicaid enrollment and claims files. Our study population included women 18-65 years of age diagnosed with local- or regional-stage cancer (n=1,053 and n=2,264 women in the pre- and post-expansion periods, respectively). We identified women as Previously Enrolled if they enrolled in Medicaid at least 3 months prior to cancer diagnosis and remained continuously enrolled for 4 months post-diagnosis, and as Newly Enrolled if they enrolled in Medicaid in the 3 months before or after cancer diagnosis. We used the OCISS for sociodemographic and treatment data. We defined standard treatment as the receipt of mastectomy, or lumpectomy and radiation in all women. In those with regional-stage cancer, we required standard treatment to also include chemotherapy; and for those with positive hormonal status, we required hormonal therapy. From claims data, we identified comorbid conditions, grouped as none, physical conditions only, mental conditions only, and physical and mental conditions, with or without substance abuse. In addition to descriptive analysis, we conducted multivariable logistic regression analysis to evaluate the independent association between Medicaid expansion and receipt of standard treatment, after adjusting for patient demographics, tumor characteristics, and comorbid conditions. Results: The median age was 50.6 years and 51.8 years in the pre- and post-expansion periods. The percent of Newly Enrolled women relative to the total decreased from 24.8% to 18.9%. Women in this group were healthier than those in the Previously Enrolled group, as evidenced by the higher percent of women with no comorbid conditions (43.3% and 42.4% vs. 21.7% and 22.5%, Pre- and Post-expansion, respectively). From Pre- to Post-Expansion, receipt of standard treatment increased from 52.3% to 58.8% and from 58.6% to 61.6% among the Previously and Newly Enrolled, respectively. Results from the multivariable logistic regression analysis showed that compared to women diagnosed in the pre-expansion period, those diagnosed in the post-expansion period had 10% higher odds to receive standard treatment, after adjusting for patient covariates. Conversely, the timing of enrollment in Medicaid relative to cancer diagnosis was not associated with our outcome of interest. Conclusion: Medicaid expansion in Ohio was associated with improvements in receipt of stage-appropriate standard treatment for breast cancer. Future studies should elucidate the mechanisms at play. Citation Format: Siran M. Koroukian, Weichuan Dong, Kirsten Eom, Uriel M. Kim, Johnie Rose, Jeffrey Albert, Cynthia Owusu, Kristine Zanotti, Gregory S. Cooper, Jennifer Tsui. Receipt of standard treatment by breast cancer patients on Medicaid, pre- and post-expansion [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A061.