Role of EGFR as a prognostic factor for survival in head and neck cancer: a meta-analysis

The prognostic role of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) remains controversial. The goal of this study was to summarize existing evidence regarding whether EGFR overexpression is a prognostic factor in HNSCC. Relevant studies were identified using Pubmed, Ovid, and Web of Science databases. A meta-analysis was conducted on the prognostic value of EGFR expression for overall survival (OS) and disease-free survival (DFS). Thirty-seven studies were included. Primary analysis indicated that EGFR overexpression was associated with reduced OS (hazard ratio [HR]: 1.694, 95 % confidence interval [CI]: 1.432-2.004). DFS, on the other hand, was not associated with EGFR expression after adjusting for publication bias (HR: 1.084, 95 % CI: 0.910-1.290). Subgroup analysis gave a statistically significant pooled HR for OS in laryngeal carcinoma (HR: 2.519, 95 % CI: 1.615-3.928) and in oropharyngeal carcinoma (HR: 2.078, 95 % CI: 1.605-2.690). The pooled HR was statistically significant for DFS with respect to oropharyngeal carcinoma (HR: 1.055, 95 % CI: 1.020-1.092), but not laryngeal carcinoma (HR: 1.750, 95 % CI: 0.911-3.360). When dividing studies based on the immunohistochemistry (IHC) scoring system, only the group that evaluated EGFR expression according to the intensity and extent of staining showed no between-study heterogeneity for both OS and DFS. Overall, EGFR overexpression was associated with shortened OS, but not DFS. Future studies are needed that stratify patients by specific tumor sites. Furthermore, when estimating protein level by the IHC method, it is advisable to consider both intensity and extent of staining.