From treatment to survivorship: The CORE randomized study of a supervised exercise intervention in early-stage breast cancer.

638 Background: Physical exercise is recommended by international guidelines to mitigate treatment-related toxicity and improve quality of life in patients with breast cancer (BC). However, adherence to physical activity recommendations remains low, and evidence from randomized studies conducted in real-world clinical settings is limited. The CORE study evaluated the impact of a structured, supervised exercise program on fatigue and health-related quality of life (HRQOL) in patients with early-stage BC. Methods: CORE is a single-center, randomized controlled trial enrolling patients with early-stage BC undergoing or recently completing curative treatment. Seventy patients were randomized 1:1 to usual care (control, n = 45) or a 3-month supervised exercise intervention (exercise, n = 45). Primary endpoints were physical fatigue (EORTC QLQ-BR45), cardiorespiratory fitness and muscle strength, and HRQOL (EORTC QLQ-C30 summary score). Secondary analyses explored changes in additional symptom and functional scales, as well as health status assessed by the EQ-5D questionnaire. Between-group differences in change from baseline to 3 months were analyzed with adjustment for multiple comparisons. Results: At 3 months, patients assigned to the exercise intervention experienced a statistically significant reduction in physical fatigue compared with usual care (mean difference −5.3; 95% CI −10.0 to −0.6; adjusted P = 0.027). HRQOL significantly improved in the exercise group (mean difference 4.8; 95% CI 2.2–7.4; adjusted P = 0.0003). In addition, within the exercise group, significant pre–post improvements were observed across several EORTC QLQ-C30 symptom and function scales, including fatigue, pain, dyspnea, nausea/vomiting, physical functioning, and role functioning, indicating a broad positive impact of the supervised strength training program on overall health status and daily functioning. Consistently, pre–post analyses in the exercise group using the EQ-5D demonstrated significant improvements in mobility, daily activities, and pain/discomfort dimensions. Conclusions: A 3-month supervised exercise program significantly reduced physical fatigue and improved HRQOL in patients with early-stage breast cancer. These findings reinforce the role of structured, supervised exercise as a key component of survivorship and supportive care, offering a scalable and effective strategy to reduce symptom burden, enhance functional capacity, and promote overall patient well-being.