摘要
Background:A high body mass index(BMI)can indicate overweight or obesity and is a crucial risk factor for breast cancer survivors.However,the association between high BMI and prognosis in early-stage breast cancer(EBC)remains unclear.We aimed to assess the effects of high BMI on the prognosis of patients with EBC.Methods:The PubMed,Embase,and Cochrane Library databases and proceedings of major oncological conferences related to the effects of BMI on the prognosis of breast cancer were searched up to November 2021.Fixedand random-effects models were used for meta-analyses.Pooled hazard ratios(HRs)and 95%confidence intervals(CIs)for disease-free survival(DFS)and overall survival(OS)were extracted from the included literature.Results:Twenty retrospective cohort studies with 33,836 patients with EBC were included.Overweight patients had worse DFS(HR:1.16,95%CI:1.05-1.27,P=0.002)and OS(HR:1.20;95%CI:1.09-1.33,P<0.001).Obesity also had adverse effects on DFS(HR:1.17,95%CI:1.07-1.29,P=0.001)and OS(HR:1.30,95%CI:1.17-1.45,P<0.001).Likewise,patients with high BMI had worse DFS(HR:1.16,95%CI:1.08-1.26,P<0.001)and OS(HR:1.25,95%CI:1.14-1.39,P<0.001).In subgroup analyses,overweight had adverse effects on DFS(HR:1.11,95%CI:1.04-1.18,P=0.001)and OS(HR:1.18,95%CI:1.11-1.26,P<0.001)in multivariate analyses,whereas the relationship that overweight had negative effects on DFS(HR:1.21,95%CI:0.99-1.48,P=0.058)and OS(HR:1.39,95%CI:0.92-2.10,P=0.123)was not statistically significant in univariate analysis.By contrast,obesity had adverse effects on DFS(HR:1.21,95%CI:1.06-1.38,P=0.004 and HR:1.14,95%CI:1.08-1.22,P<0.001)and OS(HR:1.33,95%CI:1.15-1.54,P<0.001 and HR:1.23,95%CI:1.15-1.31,P<0.001)in univariate and multivariate analyses,respectively.Conclusions:Compared with normal weight,increased body weight(overweight,obesity,and high BMI)led to worse DFS and OS in patients with EBC.Once validated,these results should be considered in the development of prevention programs.