Abstract
BACKGROUND: Breast cancer survivors (BCSs) are at increased risk of late effects. While research has reported positive effects of exercise therapy on fatigue and health-related quality of life (HRQoL) among short-term BCSs, evidence in long-term survivors remains scarce. METHODS: The CAUSE (CArdiovascUlar Survivors Exercise) trial was a 2-armed randomized controlled trial. Long-term BCSs were assigned to 5 months of thrice-weekly supervised aerobic exercise or usual care. Late effects and HRQoL were assessed by Chalder Fatigue Questionnaire, European Organization for Research and Treatment of Cancer QLQ-BR23 and QLQ-C30 questionnaires, and Scale for Chemotherapy-Induced Long-term Neurotoxicity at baseline (T0), post-intervention (T1), and 1-year follow-up (T2). RESULTS: In total, 140 BCSs (mean age 59.0 ± 6.4 years, 11 ± 1 years post-treatment) were included. Loss to follow-up at T1 was 6% and 19% in the exercise- and usual care group, respectively. From T0 to T1, the exercise group significantly improved total fatigue (between groups mean difference [MD] = -3.0, P < .001), body image (MD = 6.7, P = .043), physical- (MD = 3.2, P ≤ .001), role- (MD = 9.6, P = .019), and cognitive function (MD = 3.4, P = .038), insomnia (MD = -9.0, P = .017), and global health/QoL (MD = 5.3, P ≤ .001) compared to usual care. The exercise benefits were more pronounced in BCSs experiencing versus not experiencing late effects at baseline. At 1-year follow-up, most improvements regressed toward baseline values. CONCLUSION: Aerobic exercise significantly improves fatigue, body image, physical-, role-, and cognitive function, insomnia, and HRQoL in long-term BCSs. These findings suggest that exercise therapy should be a core component of managing late effects and enhancing HRQoL in long-term BCSs. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov/. Registration number: NCT04307407.