Abstract P3-12-11: Disparities in adjuvant hormone adherence in breast cancer patients within a universal healthcare model

Background : Patient adherence to adjuvant hormonal therapy for breast cancer (BC) is correlated with improved survival. Recent publications have demonstrated ethnic disparities in adjuvant hormone adherence (AHA) for privatized healthcare models. Objective: To identify disparities in AHA for BC patients within a universal healthcare system in Alberta, Canada. Methods: Patients diagnosed from 2007-2014 with stage I-III, ER+/HER2- BC receiving adjuvant FECD or DC chemotherapy and at least one month of adjuvant hormonal therapy in Alberta, Canada were retrospectively assessed. Hormone monotherapy (tamoxifen, AI), switch strategies (tam to AI), and treatment duration were collected. Compliance was assessed with central pharmacy data. Patient ethnicity was identified using patient first/last and parental last name via Onolytics® ethnographic software. Ethnicity was further verified using a centrally collected place of birth. Age, AJCC stage, psychiatric diagnoses (mood, bipolar), and comorbidity were collected. Log rank and Chi squared were used to assess difference between adjuvant hormonal therapy for variables at 1, 2, and 5 years. Log rank p-values at 2 years are reported. Results: A total of 2,399 ER+ patients were included for analysis. AHA was non-significant for ethnicity (p=0.797), comorbidity (p=0.623), psychiatric disorders (p=0.145), or elderly cohorts (p= 0.814). AHA by stage was significant with stage III > II > I (p=0.004) having the highest compliance rates. AHA was highest for planned hormonal switch strategies (p=0.004) compared to monotherapy. Conclusion : AHA is not dependent on ethnicity, age, comorbidity, or psychiatric diagnosis in a universal healthcare model. Conversely, higher rates of AHA are seen with planned switch strategy compared to monotherapy, contradictory to the BIG I-98 trial. Patients with higher stage, and thus higher risk of BC recurrence have increased adherence compared to their low risk counterparts. Reinforcement of AHA for low/moderate risk BC patients, in addition to tamoxifen to AI switch strategies may improve overall adherence. Citation Format: Veitch ZW, Khan OF, Tilley D, Kostaras X, King K, Lupichuk S, Tang P. Disparities in adjuvant hormone adherence in breast cancer patients within a universal healthcare model [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-12-11.