High Initiation of Adjuvant Hormonal Therapy among Uninsured Stages I-III Breast Cancer Patients Treated in a Safety-Net Healthcare System

Objective: Despite benefits of adjuvant hormonal therapy (AHT), many eligible breast cancer patients do not complete therapy as recommended. Patterns of AHT use have not been well studied among uninsured breast cancer patients who fall into coverage gaps or are ineligible for public insurance programs. Methods: We identified 291 patients newly diagnosed with stages I-III hormone receptor-positive breast cancer from January 2008 to December 2012. All patients were treated at a safety-net healthcare system and enrolled in an income-based medical assistance program that fills AHT prescriptions at low cost. We extracted and linked cancer registry, pharmacy claims, and medical record data to assess AHT initiation (defined as a new AHT prescription ≤18 months since diagnosis) and sociodemographic and healthcare utilization variables. Log-binomial regression was used to identify correlates of initiation. Results: Overall, 239 (82%) patients initiated AHT. Tamoxifen (42%) and anastrozole (55%) were most commonly prescribed. The mean copay was $4.90 for tamoxifen and $6.00 for anastrozole. Although crude analyses revealed small, statistically significant prevalence ratios for race/ethnicity (Hispanic vs. white, other vs. white), year of diagnosis (2008 vs. 2012), primary care visit before diagnosis (any vs. none), and smoking status (current vs. never), there were no significant correlates of initiation in the adjusted model. Conclusion: Safety-net healthcare systems providing access to AHT (i.e., through reduced copays) could improve the number of eligible patients initiating therapy. Continuity and integration of care in these settings may reduce disparities frequently observed in uninsured, low-income breast cancer populations.