Exercise Effects On Functional Performance And Physical Fitness In Patients With Metastatic Breast Cancer

Patients with metastatic breast cancer (mBC) often experience fatigue, decreased functional performance and fitness, which impair daily life activities and negatively affect patients’ quality of life (QoL). The PREFERABLE-EFFECT study (NCT04120298) was designed to assess the effects of supervised exercise on QoL and cancer-related side effects in patients with mBC. PURPOSE: Here, we report the exercise effects on functional performance and physical fitness (secondary outcomes). METHODS: EFFECT is a multinational RCT including patients with mBC from 5 European countries (DE, PL, ES, SE, NL) and Australia. Participants were randomly assigned to usual care (UC) or a 9-month supervised, combined aerobic, resistance and balance exercise program (EX). All participants received general exercise advice and an activity tracker. Measurements were performed at baseline, 3 and 6 (i.e. primary endpoint) months, and included: functional performance (Short Fullerton Advanced Balance scale (SF-FAB) and the 5 times sit-to-stand test); maximal short exercise capacity (MSEC, Steep Ramp Test); muscle strength (handgrip strength and h1-RM leg press); and aerobic capacity (endurance test). Intervention effects were determined by comparing the change from baseline to 3 and 6 months between groups using mixed models, adjusted for baseline values of the outcome, line of treatment and study center. RESULTS: We included 357 patients with mBC (EX = 178, UC = 179). Patients were, on average, 55.4 years of age (SD = 11.1), most patients received 1st/2nd line of treatment at study enrollment (74.8%) and had bone metastases (67.5%). At 6 months, participation in the exercise program resulted in statistically significant positive effects on functional performance (SF-FAB: +0.7, 95% confidence interval (CI) 0.4; 1.1, effect size (ES) = 0.31 and 5 times sit-to-stand: +1.5 sec, 0.9; 2.1, ES = 0.41), MSEC (+24.8 Watts, 17.3; 32.3, ES = 0.47), leg muscle strength (+34.2 kg, 23.0; 45.4, ES = 0.83) and aerobic capacity (+3.11 min.sec , 1.57; 4.26, ES = 0.74) compared to UC, whereas handgrip strength did not differ between groups. CONCLUSION: This study showed beneficial effects of supervised exercise on functional performance and physical fitness in patients with mBC, underscoring the importance of offering supervised exercise to these patients. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 825677 and co-funding from the National Health and Medical Research Council of the Australian Government under grant ID 1170698