【論文摘要】Effect of Exercise Intervention on Cardiac Function and Exercise Capacity in Breast Cancer Patients Receiving Chemotherapy

Abstract

Background and Purpose: Reviewed studies have shown, breast cancer patients were observed decreased in left ventricle function and increased the risks of heart failure and cardiovascular disease after receiving chemotherapy. Exercise capacity associated with peak VO_2 reduction were also found in breast cancer survivors and patients receiving chemotherapy that was significant related to prognosis and over-all mortality. Previous studies have shown exercise intervention was effective in improving cardiac function in heart failure patients and exercise capacity among breast cancer survivors to reduce risk of cardiovascular disease. However, most of the current study results of exercise intervention limited to breast cancer survivors. Studies of exercise training in breast cancer patient during chemotherapy were insufficient and inconsistent. In order to prevent subsequent cardiac side effects of chemotherapy, this study aimed to evaluate the effect of early exercise intervention on cardiac function, cardiac fitness, and exercise capacity in breast cancer patients during chemotherapy. Methods: This randomized control trial enrolled breast cancer patients to investigate the effect of exercise training during chemotherapy in subclinical cardiotoxicity and exercise capacity compared to usual cancer care. Participants were randomly assigned to either exercise training group (EX) with 24 sessions of program lasting for 3 months combined with aerobic, resistance and flexibility training, or control group (CTL) that was under usual cancer care. The primary outcome was left ventricular cardiac function examined by 2D and M-mode echocardiography before and 3 months after starting chemotherapy and the variables of cardiopulmonary exercise test that was test at baseline, 1.5 months and 3.0 months. The secondary outcomes were hemodynamic responses of 3-min-step test evaluated at baseline, 1.5 months and 3.0 months after starting chemotherapy. Results: A total of 16 breast cancer patient was involved in this study (EX: n = 10; CTL: n = 6). Left ventricle ejection fraction (LVEF) was significantly higher in EX (72.67%) in contrast with reduction in CTL (from baseline to 3.0 months: 70.22% to 63.95%). Peak VO_2 was significantly different between groups at 3.0 months after starting chemotherapy (EX vs. CTL: 14.0 vs. 11.8 mL/kg/min). The results of 3-min-step test were found no intragroup or intergroup difference. Conclusion: Exercise during chemotherapy prevents deterioration of LVEF and improve cardiac capacity in peak VO_2 in breast cancer patients. Clinical Relevance: The results suggested exercise intervention during chemotherapy prevents deterioration of cardiac function and improve cardiac capacity in breast cancer patients.