Effects of physical exercise on cognitive function of breast cancer survivors receiving chemotherapy: A systematic review of randomized controlled trials

BACKGROUND: Cognitive impairment has a great negative impact on quality of life for breast cancer survivors. Emerging evidence suggested that physical exercise can improve cognitive function in order adults with Alzheimer's disease. However, less is known about the effects of physical exercise on cognitive function for breast cancer survivors. The purpose of this meta-analysis was to evaluate the effect of physical exercise on cognitive function in breast cancer survivors. METHODS: EMBASE, the Cochrane Library, Web of Science and PubMed were searched from the establishment of the databases to June 2021. Randomized controlled trials were included. All analysis were conducted using the Revman 5.3. RESULTS: 12 studies (936 participants) indicated that exercise improved self-reported cognitive function (MD 10.12, 95% CI [5.49,14.76], p < 0.0001), cognitive fatigue (MD -5.41, 95% CI [-10.31,-0.51], p = 0.03) and executive function (MD -13.63, 95% CI [-21.86,-5.39], p = 0.0001). CONCLUSION: Physical exercise can improve cognitive function for breast cancer survivors, particularly in self-reported cognitive function, and executive function. Future studies need to explore the effect of exercise on cognitive function from the frequency and duration of exercise.