Purpose: Adjuvant endocrine therapy (AET) significantly diminishes recurrence and mortality risks in hormone receptor-positive breast cancer (BCa) patients. Nonetheless, suboptimal adherence and premature discontinuation during the initial year of treatment undermine these positive outcomes. This study aims to understand the potential diverse factors associated with perceived barriers to AET compliance at the onset of medication. Methods: We assessed perceived barriers to AET using the ASK-20 instrument for BCa patients initiating AET within 3 months. Our survey also included demographic variables (e.g., musculoskeletal symptoms) and clinical traits (e.g., medication type). Stepwise regression analyses were employed to elucidate the links between multilevel factors and perceived barriers to AET adherence. Results: In our cohort of 272 women, the mean ASK-12 score was 38.2 +/- 9.2 (range 20-100). In the multivariable regression model, greater perceived barriers to adhering to AET were found to be associated with African American ethnicity (Β = 2.47; 0.53-4.21; p < 0.05), lower self-efficacy in medication management (Β = -0.80; -1.03--0.58; p < 0.001), higher psychological distress (Β = 2.79; 0.61-4.97; p < 0.05), increased reported distress related to musculoskeletal side effects (Β = 0.64; 0.31-0.97; p < 0.001), weight gain symptoms (Β = 0.61; 0.18-1.03; p < 0.05), less family support (Β = -0.38; -0.53--0.13; p < 0.05), and higher levels of concern pertaining to AET (Β = 0.64; 0.41-0.87; p < 0.001). Conclusions: Modifiable factors are associated with women's perceived barriers to AET at the onset of treatment. Proactively addressing patient concerns about AET, improving self-regulatory skills for medication management and family support, and enhancing symptom management strategies, along with addressing distress at the onset of treatment, hold promise for mitigating barriers to AET. Furthermore, recognizing the distinctive challenges faced by African American subgroups is crucial, necessitating culturally tailored interventions to reduce potential disparities and ensure equitable access and adherence to AET. Continued research and tailored interventions are important for optimizing outcomes and reducing the impact of modifiable barriers on AET adherence.
Keywords: adherence barriers; breast cancer; endocrine therapy.