Prognostic and Clinicopathological Value of Slug Expression in Breast Cancer: A Meta-analysis

Abstract 1.1 Background Slug as a member of the epithelial-mesenchymal transition(EMT) leads to the decrease of adhesion between cancer cells and the increase of cell migration. Many studies have been reported the relationship between prognosis and slug expression in patients with breast cancer, yet the results are controversial. Therefore, it is necessary to conclude the relationship between slug and breast cancer by a meta-analysis. 1.2 Methods We looked for studies on breast cancer and slug via PubMed, Scopus and Web of Science .A total of 1458 patients from the final eight studies were included in this meta-analysis. Overall survival (OS) and Disease-free survival (DFS) were the primary endpoints. Pooled hazard ratio (HR), pooled odds ratio (OR), and 95% confidence interval (CI) were calculated to assess the association between slug, prognosis, and clinicopathological parameters (age, tumor size, histological grade, axillary lymph nodes status(LN),TNM stage, ER(estrogen receptor) status, PR(progesterone receptor) status, HER-2(human epidermal growth factor receptor 2)status). Data analysis was carried out by using STATA version 14.0. (Stata Corporation, TX, USA)software. 1.3 Results This meta-analysis included 1458 patients from eight studies. The final results show that high slug expression leads to poor OS（pooled HR = 2.21;95%CI=1.47-3.33;p＜0.001) and DFS （pooled HR = 2.03;95%CI=1.26-3.28; P=0.004) in breast cancer. In terms of clinicopathological parameters, the results show that breast cancer patients with high slug expression have higher TNM stage(I-II/III-IV; pooled OR=0.42;95%CI=0.25-0.70;P=0.001), more prone to axillary lymph node metastasis(N+/N0;pooled OR =2.16; 95%CI =1.31-3.56; P=0.003) and more severe ER deficiency (positive /negative; pooled OR=0.67;95%CI=0.45-0.99; P=0.042).However, slug is not related to age, histological grade, tumor size, PR status and Her-2 status. 1.4 Conclusion This meta-analysis results show that high slug expression in breast cancer is associated with poor OS, DFS and axillary lymph node status, TNM stage and ER status, but not related to age, histological grade, tumor size, PR status and Her-2 status.