Abstract
BACKGROUND: Breast cancer is the most common malignant tumor among women, and its etiology and progression are closely associated with hormone levels. Hormone levels undergo significant changes in pre- and postmenopausal women. Exercise intervention, as a safe and effective lifestyle intervention, may modulate hormone levels and affect the incidence and prognosis of breast cancer. METHODS: Three databases were searched to identify relevant literature for this study, which included 11 studies in the meta-analysis. The impact of an exercise intervention on breast cancer-related hormones was evaluated, including estrone, estradiol, free estradiol, testosterone, SHBG, 2-OH E1, 16a-OH E1, androstenedione, testosterone, and free testosterone, in both pre- and postmenopausal women. RESULTS: The study findings suggest that the impact of exercise intervention on breast cancer-related hormones in pre- and postmenopausal women may not be significant. This lack of significance could be linked to differences in exercise intervention protocols, study quality, changes in body fat percentage post-exercise, and the specific characteristics of the populations (pre- and postmenopausal) analyzed in the studies. However, subgroup analyses suggested that exercise intervention might have a significant effect on certain estrogens in postmenopausal women and women who engaged in exercise for more than 6 months. CONCLUSION: The impact of exercise intervention on hormone levels may be influenced by body fat and menopausal status, as well as the duration of follow-up. Further high-quality and standardized studies are needed to confirm and enhance the findings of this research. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024430643, Identifier CRD42024430643.