This meta-analysis showed that reduced E-cadherin expression in BC patients predicted poor OS (a random-effect model, hazard ratio [HR] = 2.73, 95% confidence interval [CI]: 1.74–4.27, p < 0.001; I2 = 65.3%, p = 0.001; Figure 2A), PFS (a random-effect model, HR = 6.39, 95% CI: 3.48–11.73, p < 0.001; I2 = 49.1%, p = 0.047; Figure 2B), and RFS (a fixed-effect model, HR = 2.48, 95% CI: 1.68–3.64, p < 0.001; I2 = 43.3%, p = 0.116; Figure 2C). This evidence concerns the gene CDH1 and breast cancer.