The association between EGFR expression and clinical pathology characteristics in gastric cancer

Objective: The aim of this study was to investigate epidermal growth factor receptor (EGFR) expression in the gastric cancer tissues and the association of EGFR expression with clinical pathology characteristics. Methods: We firstly analyzed the copy number alteration of EGFR gene in gastric cancer by utilizing the online TCGA resources. We then gathered 71 cases of gastric cancer patients from February 2010 to February 2015 in our hospital. The cancer tissues and normal gastric tissues were tested for EGFR expression by immunohistochemical (IHC) staining and western blotting methods. The association of EGFR expression with clinical pathology characteristics and the prognosis value of EGFR expression were evaluated by the statistical software. Results: The copy number of EGFR gene was found to be increased in gastric cancer patients. Western blotting confirmed that EGFR protein was obviously upregulated in tested gastric cancer tissues. Additionally, our IHC results showed that the positive rates of EGFR expression in gastric carcinoid tumors (CTs) and distant normal gastric tissues were 45.1% (32/71) and 25.0% (9/36), respectively. The former was significantly higher than the latter (P < 0.05). The EGFR- positive expression in CTs was related to tumor size, invasion depth, and lymphatic metastasis. The median survival of the EGFR-positive patients was 15.6 months, which was less than that (23.0 months) of the EGFR- negative patients [HR = 2.12, 95% CI: 1.29-4.10 (P < 0.05)]. Also, online survival analysis showed that high expression of EGFR predicted shorter overall survival of gastric cancer patients. Conclusion: EGFR was highly expressed in gastric cancer tissues and associated with poor prognosis.