Feasibility of Aerobic Exercise Training to Mitigate Cardiotoxicity of Breast Cancer Therapy: A Systematic Review and Meta-Analysis

Current anticancer treatments for breast cancer (BC) may cause cardiotoxicity. This study aimed to investigate the effectiveness of aerobic exercise in mitigating cardiotoxicity caused by BC therapy. PubMed, Embase, Cochrane Library, Web of Science, and the Physiotherapy Evidence Database were searched until February 7, 2023. Clinical trials investigating the effectiveness of exercise training, including aerobic exercise, in BC patients receiving treatments that could cause cardiotoxicity were eligible. Outcome measures included cardiorespiratory fitness (CRF) (peak oxygen consumption, VO2peak), left ventricular ejection fraction, and peak oxygen pulse. Intergroup differences were determined by standard mean differences (SMD) and 95% confidence intervals (CIs). Trial sequential analysis (TSA) was utilized to ensure whether the current evidence was conclusive. Sixteen trials involving 876 participants were included. Aerobic exercise significantly improved CRF measured by VO2peak in mL/kg/min (SMD 1.79, 95% CI 0.99-2.59) when compared to usual care. This result was confirmed through TSA. Subgroup analyses revealed that aerobic exercise given during BC therapy significantly improved VO2peak (SMD 1.84, 95% CI 0.74-2.94). Exercise prescriptions at a frequency of up to 3 times per week, an intensity of moderate to vigorous, and a >30-minute session length also improved VO2peak. Aerobic exercise is effective in improving CRF when compared to usual care. Exercise performed up to 3 times per week, at a moderate-to-vigorous intensity, and having a session length >30 minutes is considered effective. Future high-quality research is needed to determine the effectiveness of exercise intervention in preventing cardiotoxicity caused by BC therapy. The purpose of this meta-analysis was to evaluate the effectiveness of adjunctive aerobic exercise in mitigating cardiotoxicity caused by breast cancer therapy. The current evidence shows that cardiorespiratory fitness significantly improves after the intervention, while left ventricular ejection fraction and peak oxygen pulse did not receive any significant effects.