The effects of a prescribed exercise programme in people with metastatic breast cancer: a systematic review

To synthesise available evidence on the effects of a prescribed exercise programme in People with Metastatic Breast Cancer (PwMBC).

Medline, Embase, CINAHL, Web of Science and Scopus were searched up to January 2024.

Randomised controlled trials (RCTs) recruiting PwMBC to an exercise intervention were included. The primary outcome was Quality of Life (QOL). Secondary outcomes included physical performance, muscle health, cancer-related fatigue (CRF) and physical activity (PA).

Meta-analysis was not possible due to the low number of included studies. We calculated the effect size (ES), with 95% confidence intervals (95% CIs) of individual studies, adjusting for small sample size. Cohen's criteria for small (0.2 to 0.5), moderate (0.5 to 0.8) and large (>0.8) describe the size of the effect. Risk of bias (ROB) was assessed using the Cochrane (ROB) version 1 tool.

Three RCTs (n = 149 PwMBC) were included. Results showed no significant between-group effects in the primary outcome, QOL. Whilst effects in favour of prescribed exercise were observed in CRF (ES 1.3, 95% CI 0.06 to 2.35) and PA (ES 0.83, 95% CI 0.14 to 1.42) in two separate studies, as the lower bound of the 95% CI did not reach Cohen's threshold, there is considerable uncertainty regarding the treatment effect.

There is currently insufficient evidence to support the use of prescribed exercise to improve QOL, physical performance, muscle health, CRF and PA in PwMBC. Further high-quality trials are required to investigate the effectiveness of exercise interventions in PwMBC.

PROSPERO CRD42022304528. CONTRIBUTION OF THE PAPER.