Background Adherence to trastuzumab is essential for achieving optimal outcomes in HER2-positive breast cancer; however, real-world data on adherence to subcutaneous formulations in low- and middle-income countries remain limited. This study evaluated adherence patterns, patient-reported quality of life (QoL), and treatment barriers among patients receiving subcutaneous trastuzumab in Ghana in the neoadjuvant and/or adjuvant (curative-intent) setting. Methods An observational study incorporating a retrospective longitudinal assessment of adherence and cross-sectional evaluation of patient-reported quality of life was conducted among 90 HER2-positive breast cancer patients receiving subcutaneous trastuzumab at a tertiary oncology centre in Ghana. Adherence was assessed using Medication Possession Ratio (MPR) and Proportion of Days Covered (PDC), and categorized as high (≥80%), moderate (50–79%), or low (<50%). QoL was evaluated using the EORTC QLQ-C30 instrument. Descriptive statistics, correlation tests, and logistic regression were performed. Results The mean MPR and PDC were 84.7% and 82.9%, respectively, with 67% of patients classified as highly adherent. Missed and delayed injections were reported by 26.7% and 20.0% of patients, respectively. QoL scores indicated moderate to good functioning, with a mean global health status of 65.2. Fatigue and pain were clinically relevant symptoms, with fatigue significantly higher among patients with lower adherence (p = 0.041). Higher adherence was modestly associated with improved global health status (ρ = 0.21, p = 0.048) and lower fatigue (ρ = −0.28, p = 0.008). Financial constraint (40.0%) and transportation difficulties (26.7%) were the most commonly reported barriers. No significant predictors of adherence were identified. Conclusion Adherence to subcutaneous trastuzumab was generally high; however, structural and symptom-related barriers persist. Targeted measures, including structured adherence support is needed to optimize treatment continuity.
Mensah et al. (2026) studied this question.