Patient Preferences and Quality-of-Life Changes after Switching from Intravenous to Subcutaneous Trastuzumab in HER2-Positive Breast Cancer: A Prospective Observational Study

Background: Patient preferences and health-related quality of life are complementary measures of treatment experience. We assessed these outcomes among women with HER2-positive breast cancer transitioning from intravenous to subcutaneous trastuzumab in routine clinical practice in Morocco. Methods: This prospective observational study enrolled 150 women in Casablanca, Morocco, between June 2023 and April 2024. Quality of life was assessed before the first subcutaneous injection and after eight injections using validated Moroccan Arabic EORTC QLQ-C30 and QLQ-BR23 questionnaires. Administration preferences were assessed using a separate questionnaire. Score changes were analyzed using paired t-tests with Holm adjustment across 23 domains. Results: Subcutaneous administration was preferred by 133 patients (88.7%), intravenous administration by 8 (5.3%), while 9 (6%) reported no preference. Time saving and treatment simplicity were the main reasons for preferring subcutaneous administration. Mean global health status increased from 37.1 to 68.9 (mean change, 31.8 points; 95% CI, 28.3–35.4). Emotional functioning improved and pain and fatigue scores decreased, whereas physical functioning declined and diarrhea and systemic therapy side effect scores increased (all Holm-adjusted P < 0.001). Injection-site pain was reported by 48% of patients; among those affected, 70% described it as mild and 87% as brief. Conclusion: Most patients preferred subcutaneous trastuzumab. Quality-of-life changes were heterogeneous and cannot be attributed to the administration route alone. Patient preferences and domain-specific quality-of-life assessments provide complementary information when discussing administration options.