Clinicopathologic significance of human epidermal growth factor receptor 2 expression and gene amplification in gastric carcinoma.

Abstract

This study is aimed at determining the human epidermal growth factor receptor-2 (HER-2) gene status in gastric cancers using immunohistochemistry (IHC) and silver DNA in situ hybridization (SISH) technique and investigating the relationship between HER-2 status and clinicopathological variables. We examined 104 gastric carcinoma cases with gastrectomy specimens. The age, sex, histopathological tumor type, tumor differentiation, tumor localization, tumor size, invasion depth, lymph node metastasis status, HER-2 IHC evaluation results, and SISH evaluation results of the cases were recorded. In the present study, the SISH-confirmed HER-2 positivity rate (SISH amplification) is 14.4%. A statistically significant relationship was found between HER-2 status and tumor invasion depth (P = 0.03). It was observed that as the depth of invasion increased, HER-2 positivity decreased. No statistically significant relationship was found between HER-2 status and sex, age, tumor size, differentiation, histopathological classification, lymph node metastasis, and tumor localization (P > 0.05). The rate of HER-2 2+ cases was found to be high. HER-2 status is negatively correlated with the depth of invasion in gastric cancers, and HER-2 positivity increases as the depth of invasion decreases. HER-2 may be early molecular evidence in oncogenesis. Immunohistochemically, HER-2 2+ cases should be confirmed by the in situ hybridization (ISH) technique.