Methodological quality of systematic reviews on physical exercise for breast cancer patients. Meta-epidemiological study

Objective: several clinical trials have been published in recent years to investigate the potential benefits of physical exercise for women with breast cancer. This meta-epidemiological study aimed to map and critically assess the methodological quality of systematic reviews on physical activity for breast cancer patients. Methods: a meta-epidemiological study including systematic reviews of randomized clinical trials that evaluated the effects of physical exercise on breast cancer patients. The search was performed in MEDLINE. The methodological quality was assessed using the AMSTAR-2 tool. We collected additional information regarding included systematic review search details. Results: we included 57 systematic reviews published between 2006 and 2021, including only randomized clinical trials on the effects of any physical activity on breast cancer patients. The results showed that 58% of the included reviews were classified as low or critically low quality. Only 10% presented high methodological quality, and 32% were classified as moderate. Furthermore, complete search strategies were presented in 54,4% of the reviews, and 59,6% fully described the search date; 61,4% presented data and/or language restrictions, and 52,6% conducted additional hand searches. Conclusion: The findings of this study showed the methodological frailty of most systematic reviews on the effects of physical exercises on breast cancer patients. Caution is needed on the part of health professionals, managers and policymakers in health, patients and the general population when interpreting the applicability of this evidence, and it is suggested to perform systematic reviews of high methodological quality to assist decisionmaking.