Résumé
Introduction: Health-related quality of life (HRQoL) in older patients with breast cancer (BC) (>= 70 years) is not well studied. This study assesses aging-related differences in patient-reported outcomes among estrogen receptorpositive (ER+) patients with BC treated with breast conservation surgery (BCS), radiation therapy (RT), and endocrine therapy (ET). Materials and Methods: Among the 2,057 patients with ER+ early-stage BC enrolled in the prospective multicenter REQUITE study, 1,003 patients receiving adjuvant RT + ET as the only systemic therapy constitute our study population. Patients were stratified by age into younger (<70 years, n = 810 patients) and older (>= 70 years, n = 193 patients) groups. Prospectively collected HRQoL was measured using the validated European Organization for Research and Treatment of Cancer (EORTC) quality of life of cancer patients (QLQ-30) and breast cancer-specific quality of life (QLQ-BR23), and Multidimensional Fatigue Inventory (MFI-20) measures at baseline following BCS and pre-adjuvant treatment, post-RT, and at one-year, two-year, and three-year intervals. Statistical analysis involved a mixed model analysis of variance, weighted by propensity scoring. Results: Older patients had a higher burden of comorbidities, larger tumor size, and higher rates of N1 disease compared to the younger group. RT boost to the lumpectomy site was more often delivered in younger participants (72 %) compared to older (50 %). Younger patients predominately received tamoxifen (63.5 %), while older patients more commonly received aromatase inhibitors (67.4 %). Throughout the follow-up, we observed that the younger patients showed greater recovery in QoL domains including sexual enjoyment, systemic side effects, breast symptoms, global health status, and emotional, physical, and social functioning compared to the older group. Cognitive function, which declined from baseline in both groups, improved over time in younger participants but persisted at lower levels in older patients at the three-year follow-up period. Discussion: Adjuvant treatments differentially impacted HRQoL, with older patients experiencing greater and more persistent adverse effects compared to younger counterparts. These findings underscore the need for tailored interventions that address the unique challenges in HRQoL recovery among older BC survivors.