Benefits of weight loss programs for breast cancer survivors: a systematic reviews and meta-analysis of randomized controlled trials.

BACKGROUND: Obesity and weight gain have been associated with poor disease-specific and health-related outcomes in breast cancer survivors (BCS). But the benefits of weight loss in managing BCS have not been elucidated. OBJECTIVE: To evaluate the beneficial effects of weight loss programs in randomized controlled trials on BCS. METHODS: We searched English databases PubMed, the Cochrane Library, EMBASE, Scopus, Web of Science, CINAHL, and Chinese databases China National Knowledge Infrastructure (CNKI), Weipu Information Chinese Periodical Service Platform (VIP), China Biomedical Literature Service System (SinoMed), and Wanfang from the inception to January 2021 and collected randomized controlled trials (RCTs) of weight loss programs for BCS. Two reviewers independently screened the literature, extracted the data, and assessed the risk of bias in the included studies. The data synthesis was performed on RevMan (version 5.3), and the publication bias was calculated with STATA (version 15.1). RESULTS: Ten RCTs were included in the meta-analysis. The current study showed that diet and exercise interventions resulted in significant improvements in body weight (MD = - 4.43 kg, 95%CI: - 6.23 to - 2.63, P < 0.00001), waist circumference (MD = - 2.81 cm, 95%CI: - 4.37 to - 1.26, P = 0.004), hip circumference (MD = - 3.01 cm, 95%CI: - 4.24 to - 1.77, P < 0.0001), body mass index (MD = - 1.69 kg/m2, 95%CI: - 2.16 to - 1.21, P < 0.00001), systolic blood pressure (MD = - 12.12 mmHg, 95%CI: - 18.97 to - 5.27), p = 0.0005), C-reactive protein (MD = - 1.83 mg/L, 95% CI: - 2.74 to - 0.91, p < 0.0001), body fat (MD = - 1.19 kg, 95%CI: - 1.75 to - 0.63, P < 0.001), fat mass (MD = - 2.29 kg, 95%CI: - 3.12 to - 1.46, P < 0.0001), and lean body mass (MD = - 2.15 kg, 95%CI: - 3.66 to - 0.65, P = 0.005). Alternatively, compared with the effects of control interventions, weight loss programs did not affect fat-free mass, total cholesterol, low-density leptin cholesterol, glucose, insulin, and leptin (P > 0.05). CONCLUSIONS: This review summarizes the benefits of weight loss programs for BCS. The results indicated that weight loss programs could significantly improve specific anthropometric outcomes but not affect biochemical indicators. Researchers should tailor weight loss interventions to the body fat status of BCS. Evidence to support the translation of effective weight loss intervention programs into wider-scale implementation is needed to be part of routine survivorship care.