Role of human epidermal growth factor receptor 2 as a prognostic factor for survival in esophageal carcinoma: evidence from 2872 subjects.

INTRODUCTION: The prognostic value of human epidermal growth factor receptor 2 (HER2) in esophageal carcinoma (EC) remains controversial. Our study aims to clarify the correlation between HER2 overexpression and survival in patients with EC. EVIDENCE ACQUISITION: A comprehensive search of EMBASE, PubMed, and Web of Science was performed from inception to April 17, 2016 to search published literature regarding the potential association between HER2 overexpression and prognosis in EC patients. A pooled hazard ratio (HR) with 95% confidence intervals (CIs) was applied to evaluate the effect of HER2 overexpression for overall survival (OS) and disease-free survival (DFS). EVIDENCE SYNTHESIS: Eighteen studies were identified (2872 patients). HER2 overexpression was significantly associated with poor OS (HR=1.43, 95% CI: 1.11-1.85, P=0.006). This effect was observed both ESCC (HR=1.48, 95% CI: 1.04-2.11, P=0.031) and in EAC (HR=1.62, 95% CI: 1.07-2.46, P=0.023). Besides, similar striking correlations were demonstrated for DFS (HR=2.02, 95% CI: 1.55-2.65, P<0.0001), and also discovered in ESCC (HR=2.45, 95% CI: 1.26-4.76, P=0.008) as well as EAC (HR=1.95, 95% CI: 1.45-2.62, P<0.0001). Additionally, the pooled HR of sensitivity analysis ranged from 1.37 (95% CI: 1.06-1.76) to 1.52 (95% CI: 1.17-1.97) for OS, and 1.94 (95% CI: 1.46-2.58) to 2.15 (95% CI: 1.55-2.99) for DFS, respectively. No single article significantly influenced the pooled HR, and there were no obvious publication biases. CONCLUSIONSː These results provide further evidence that HER2 overexpression is significantly associated with reduced survival in EC. HER2 may be used as a prognostic biomarker for EC patients.