Han JK, et al. - Researchers assessed the impacts of physical exercise on the changes of physiologic markers to identify the role of physical exercise in modulating the insulin-like growth factor (IGF) system in women with breast cancer. Until October 2020, PubMed, Embase, CENTRAL, and SPORTDiscus were systematically searched. Randomized controlled trials assessing the effects of physical exercise on the insulin-like growth factor system in women with breast cancer were included as eligibility criteria. Twelve randomized controlled studies including 736 candidates were analyzed. In women with breast cancer, physical exercise had a favorable effect on the IGF system.