Endocrine therapy initiation among Medicaid-insured breast cancer survivors with hormone receptor-positive tumors

PURPOSE: Hormone receptor positive (HR+) cancers account for most breast cancer diagnoses and deaths. Among survivors with HR+ breast cancers, endocrine therapy (ET) reduces 5-year risk of recurrence by up to 40%. Observational studies in Medicare and privately-insured survivors suggest under-utilization of ET. We sought to characterize ET use in a low-income Medicaid-insured population in North Carolina. METHODS: Medicaid claims data were matched to state cancer registry records for survivors ages 18–64 diagnosed with stage 0-II HR+ breast cancer from 2003–2007, eligible for ET, and enrolled in Medicaid for at least 12 of 15 months post-diagnosis. We used multivariable logistic regression to model receipt of any ET medication during 15-months post-diagnosis controlling for age, race, tumor characteristics, receipt of other treatments, co-morbidity, residence, reason for Medicaid eligibility, involvement in the Breast and Cervical Cancer Control Program (BCCCP), and diagnosis year. RESULTS: Of 222 women meeting inclusion criteria, only 50% filled a prescription for ET. Involvement in BCCCP and earlier year of diagnoses were associated with significantly higher odds of initiating guideline-recommended ET (Adjusted Odds Ratio [AOR] for BCCCP: 3.76, 95%CI: 1.67–8.48; AOR for 2004 relative to 2007: 2.80, 95%CI: 1.03–7.62; AOR for 2005 relative to 2007: 2.11, 95%CI: 0.92–4.85). CONCLUSIONS: Results suggest substantial under-utilization of ET in this population. Interventions are needed to improve timely receipt of ET and to better support survivors taking ET. IMPLICATIONS OF CANCER SURVIVORS: Low-income survivors should be counseled on the importance of ET and offered support services to promote initiation and long-term adherence