Muscle adaptation to physical exercise in post-treatment breast cancer patients: a systematic review

Abstract

Introduction: Breast cancer is the fastest growing disease in the world in a number of cases, and the second most common type in the world, is in the fifth position of the causes of cancer death in general, second only to lung cancer. One of the consequences of cancer is fatigue, studies suggest that up to 99% of breast cancer patients experience fatigue during chemotherapy, resulting in significant impairment in physical functioning, as well as in quality of life. Therefore, physical exercise is used as a non-pharmacological strategy, reducing the side effects of treatment. Objective: The aim of this systematic review will be to evaluate how physical exercise and resistance training act as factors that can help prevent breast cancer recurrence. Methods: This work is a systematic review, and the articles were selected using the PICO methodology. Results: A total of 32 articles were collected, being in BVsalud: 11, Pubmed 19 and Scielo 2, being excluded 2 for being review articles, and 8 articles for not being in accordance with the proposed methodology (aerobic or resistance exercise). After analyzing the experimental studies through this systematic review, it is observed that the articles do not provide a strong basis to support the presence of a causal relationship between aerobic exercise and relapse oncoprotection factors for breast cancer. This is probably due to the small number of studies involving aerobic exercises, as well as statistical significance and lack of evaluation protocols. Conclusion: After this systematic review it appears that we cannot affirm a relationship between aerobic and resistance exercises and the oncoprotection of recurrence for breast cancer. Further studies are needed, mainly involving aerobic exercises with an adequate sample number to avoid type I errors. However, interesting results are observed with resistance exercises, with significant improvements in patients' resistance, as well as in the risk of falls, reduction of fatigue and prevention of possible lymphedemas.