HER2 protein expression correlates with Lauren classification and P53 in gastric cancer patients

Human epidermal growth factor receptor 2 (HER2) is a key pathological characteristic of gastric cancer (GC). However, the clinical significance of HER2 expression in gastric carcinoma remains controversial. The purpose of this study was to analyze the clinicopathological characteristics of HER2 protein expression, Lauren classification and tumor protein p53 (P53) expression and to evaluate the clinical significance of HER2 protein expression. A total of 176 consecutive patients were prospectively recruited between January 2014 and December 2016 at the Second Affiliated Hospital of Zhejiang University School of Medicine. Histological analysis of the resected tissue was performed for HER2 protein expression using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Additionally, the expression status of HER2 protein and clinicopathological features were analyzed using the chi-squared (χ(2)) test. Survival analysis was performed using the Kaplan–Meier method, and differences between the survival curves were determined using the log-rank test. All statistical analyses were conducted using SPSS 22.0 statistical software program (IBM Corp., Armonk, NY). A total of 176 patients with GC were enrolled in this study. Intratumoral heterogeneity of HER2 protein overexpression was observed in 42 of 176 cases with IHC grade 2+, accompanied by FISH positivity and IHC grade 3+. HER2 protein expression was correlated with tumor differentiation (P < .001), Lauren classification (P = .001), Borrmann type (P = .003) and P53 expression (P < .001). HER2 protein positivity was associated with significantly higher overall survival (OS) (P = .038). Overexpression of HER2 protein was observed in 23.9% of the cases and was significantly related to the Lauren intestinal subtype and P53 negative expression. HER2 protein overexpression was independently associated with higher OS.