Physical activity interventions for women with metastatic breast cancer: A systematic review of published and ongoing randomised controlled trials

Purpose We systematically reviewed published and ongoing physical activity (PA) trials in women with metastatic breast cancer (MBC). We examined: i) the effectiveness of PA interventions on key outcomes, and identified: ii) the type of interventions being evaluated, iii) how they were delivered; iv) their theoretical basis. Methods Seven databases and two trial registries were searched in August 2024 for; randomised controlled trials, testing any PA intervention in people with MBC, reporting a PA outcome. The Joanna Briggs Institute (JBI) handbook was followed, including quality assessment using the JBI Critical Appraisal Checklist for RCTs. Data were summarised narratively. Intervention details were extracted using the TIDieR framework. Results 1687 records were screened and 96 assessed for eligibility. 28 reports were included (13 full reports, 4 protocols, 11 trial registries). Sample sizes ranged from 21-357 participants. 21/28 reports were phase II, pilot, or feasibility trials. Most interventions did not cover all types of recommended PA. Methodological quality of studies was moderate. Intervention adherence was moderate to high (≥50% in 10 studies). Among studies reporting on safety (9), only one recorded any serious events (two events) related to the intervention. Evidence indicates that PA can improve fatigue, health-related QoL, physical fitness and functioning over the short and medium-term (≤6 months). Conclusions Physical activity is safe, well adhered to, and improves physical function and QoL in MBC. Future trials could clarify the optimal PA type, duration, delivery mode, frequency, and long-term effectiveness. Women with MBC should be supported by healthcare professionals to be active.