Effects of supervised exercise during adjuvant endocrine therapy in overweight or obese patients with breast cancer: The I-MOVE study

BACKGROUND: Adjuvant endocrine therapy (ET) in patients with breast cancer (BC) increases the risk of becoming less physically active. Physical inactivity is associated with a higher risk of treatment-related side effects and mortality. This study investigated whether supervised exercise increased the proportion of patients adhering to the national physical activity (PA) guideline during adjuvant ET in overweight or obese BC patients. METHODS: This multicentre single-arm clinical trial included patients with BC participating in a 12-week supervised exercise intervention. An accelerometer measured moderate to vigorous PA (MVPA) at baseline (T0), after 12 (T1) and 26 weeks (T2). The primary endpoint was change in the proportion of patients with weekly ≥150 min of MVPA at T1 compared to T0. Secondary endpoints were adherence to PA guideline at T2, metabolic syndrome (MetS), body composition, health-related quality of life (HRQoL) and BC-specific functioning and symptoms, self-reported PA, self-efficacy, exercise motivation and satisfaction with life. RESULTS: 141 patients with a median age of 61 years and a mean BMI of 31.3 participated. Adherence to the PA guideline increased from 38.3% at T0, to 40.4% at T1 (p = .112) and 44.7% at T2 (p = .003). MetS, body composition, HRQoL, BC-specific functioning and symptoms (i.e. fatigue, dyspnoea), self-reported PA, self-efficacy, exercise motivation and satisfaction with life improved significantly over time. CONCLUSIONS: Supervised exercise increased the proportion of BC patients adhering to the PA guideline over time. Furthermore, MetS, body composition, HRQoL and symptoms improved. Our findings highlight the clinical relevance of supervised exercise during ET in overweight BC patients. CLINICAL TRIAL INFORMATION: (NCT02424292).