E-cadherin expression and prognosis of head and neck squamous cell carcinoma: evidence from 19 published investigations

OBJECTIVE: The objective of this study was to review the published literature and investigate whether E-cadherin gene is a prognostic factor in head and neck squamous cell carcinoma by conducting a meta-analysis. METHODS: Studies were identified from the databases Embase, Medline, and Cochrane Library by using the keywords “E-cadherin gene” and “head and neck cancer”. Overall survival (OS) and disease-free survival (DFS) were the primary outcome measurements. RESULTS: Our literature review identified 1,458 articles; 19 studies with a total number of 2,012 cases were eligible for inclusion in the meta-analysis. The hazard ratio (HR) for OS of patients with decreased expression of E-cadherin gene was 0.57 (95% CI =0.37, 0.89; P=0.000). However, statistical heterogeneity was unacceptably high (I(2)=74.5%, P=0.000). After sensitivity analysis, heterogeneity became acceptable, and the effect measure was still significant (I(2)=7.0%; HR =0.52; 95% CI =0.40, 0.66; P=0.000). The HR for DFS was 0.53 (95% CI =0.42, 0.67; P=0.000). CONCLUSION: This meta-analysis showed clear evidence that high E-cadherin gene expression is a positive prognostic factor of head and neck squamous cell carcinoma, resulting in better OS and DFS. However, this conclusion must be interpreted with caution due to a few limitations.