The role of exercise in the prevention of cancer therapy-related cardiac dysfunction in breast cancer patients undergoing chemotherapy: systematic review

Aims: Breast cancer (BC) patients undergoing chemotherapy are at risk of developing cancer therapy-related cardiac dysfunction (CTRCD). Exercise has been proposed to prevent CTRCD; however, its effectiveness remains unclear. The aim of this systematic review was to establish the effect of exercise on global longitudinal strain (GLS) and left ventricular ejection fraction (LVEF) in BC patients undergoing chemotherapy, to determine if exercise can prevent the development of CTRCD.

Methods and results: Four databases (Medline, Scopus, eMbase, SPORTDiscus) were searched. Studies were eligible for inclusion if they measured GLS or LVEF prior to and following an exercise intervention of any length in BC patients undergoing chemotherapy and were published in English from 2000 onwards. Risk of bias was evaluated using the QUADAS-2 tool. Of the 398 studies screened, eight were eligible. Changes were similar in exercising (EX) and non-exercising (CON) groups for GLS (EX: pre: -19.6 ± 0.4, post: -20.1 ± 1.0, CON: pre: -20.0 ± 0.4, post: -20.1 ± 1) and LVEF (EX: pre: 58.5 ± 4.1%, post: 58.6 ± 2%, CON: pre: 56.6 ± 4.2%, post: 55.6 ± 4.6%). Exercise maintained or improved peak oxygen uptake (VO2peak) during chemotherapy, while declines were observed in non-exercising groups. The included studies were limited by methodological deficiencies.

Conclusion: The ability of exercise to prevent CTRCD is unclear. However, exercise positively impacts cardiorespiratory fitness in BC patients undergoing chemotherapy. Future research must address the methodological limitations of current research to understand the true effect of exercise in the prevention of CTRCD.