Prognostic Significance of Immunohistochemical Expression of EGFR and C-erbB-2 Oncoprotein in Curatively Resected Gastric Cancer

Abstract

Purpose

The purpose of this study was to investigate the prognostic significance of the expression of EGFR and C-erbB-2 gene products by immunohistochemical analysis for curatively resected gastric adenocarcinoma.

Materials and Methods

Between January 1996 and December 2001, 739 patients with curatively resected gastric cancer patients underwent immunohistochemical staining for EGFR and C-erbB-2 proteins, and we retrospectively analyzed their correlation with the clinical outcome.

Results

The overexpressions of EGFR and C-erbB-2 were 25.4% and 26.2%, respectively. The overexpressions of EGFR was associated with the more poorly differentiated tumor (p=0.000) and with neuronal invasion (p=0.03). Overexpression of C-erbB-2 was associated with less vascular invasion (p=0.001). Tumor depth or node metastasis was not related to the overexpression of EGFR or C-erbB-2. The seven-year overall survival and relapse-free survival rates were 87.2% and 75.8%, respectively. Upon multivariate Cox regression analysis, the tumor stage, tumor size and patient age were important prognostic factors for overall survival, and tumor stage was the important factor for relapse-free survival. Overexpressions of EGFR or c-erbB-2 were not significant prognostic factors.

Conclusion

Immunohistochemical staining of EGFR and C-erbB-2 gene products were not independent prognostic factors for predicting the overall survival and the relapse-free survival in curatively resected gastric cancer.

Key words: Gastric cancer, Prognosis, Immunohistochemistry, EGFR, C-erbB-2