Abstract Body (Do not enter title and authors here):
Introduction: Breast cancer patients receiving anticancer therapy are at risk of developing cancer therapy-related cardiac dysfunction (CTRCD). While exercise has been shown to improve cardiorespiratory fitness in these patients, its effectiveness in preventing CTRCD remains unclear.

Research Questions: How do exercise-based interventions affect CTRCD in breast cancer patients? Which exercise modality is most effective in preventing CTRCD?

Goals: This network meta-analysis aimed to synthesize the available evidence on the effectiveness of exercise-based interventions based on cardiac function parameters and to identify the optimal exercise modality for preventing CTRCD.

Methods: A comprehensive search was conducted in PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library from inception to March 4, 2024. Studies that used exercise interventions, either exercise alone or with other interventions, were included. Outcome measures included at least one cardiac function parameter such as left ventricular ejection fraction (LVEF) or global longitudinal strain (GLS). Pairwise and network meta-analyses were performed using R software (v.4.3.3).

Results: A total of 1149 participants from 14 RCTs were included. Compared to the usual care, exercise-based interventions significantly improved LVEF (MD=1.68; 95% CI=0.59-2.77; p＜0.05) and GLS (MD=1.40; 95% CI=0.59-2.21; p＜0.05). Based on the ranking probabilities, combined aerobic and resistance exercise was the most effective way to improve LVEF (4 studies, SUCRA: 96.46%), followed by cardiac rehabilitation (2 studies, SUCRA: 45.31%) and aerobic exercise (4 studies, SUCRA: 41.57%). In terms of improving GLS, combined aerobic and resistance exercise also ranked highest (3 studies, SUCRA: 87.77%). However, cardiac rehabilitation (2 studies, SUCRA: 46.70%) and aerobic exercise (1 study, SUCRA: 44.92%) were still less effective.

Conclusion: This network meta-analysis provides low-certainty evidence for the potential efficacy of exercise-based interventions in preventing CTRCD, especially the combined aerobic and resistance training. Further rigorous studies are needed to confirm the effectiveness of exercise-based interventions in the prevention of CTRCD.