Detection of Her-2/neu expression in gastric cancer: Quantitative PCR versus immunohistochemistry

Abstract

The aim of this study was to compare quantitative polymerase chain reaction (qPCR) with immunohistochemistry (IHC) for the detection of Her‑2 in gastric cancer, and to investigate the correlation between the expression levels of human epidermal growth factor receptor 2 (Her‑2) and clinical features. Clinical data from 426 cases of gastric cancer were collected. Her‑2 expression levels in cancerous tissue were detected using IHC, and the Her‑2/neu gene expression levels were determined by qPCR. The correlation between the expression level of Her‑2 and clinical features was investigated. The positive expression rate of Her‑2 in cancerous tissue detected using qPCR and IHC was 11.17% (46/412) and 13.38% (57/426), respectively. The positive expression of the Her‑2 protein/gene was significantly correlated with the depth of invasion and lymphatic metastasis, as well as the TNM stage (P<0.05). No significant correlation was identified between positive expression of the Her‑2 protein/gene and tumor location, age, gender, differentiation degree and Lauren classification (P>0.05). The diagnostic consistency was good between the two methods (κ=0.828). The results indicate that the expression of Her‑2/neu is closely associated with the development of gastric cancer. qPCR is a convenient, objective and efficient method, which may be used as an alternative to IHC or fluorescence in situ hybridization for the detection of Her‑2/neu gene.