Epidermal growth factor receptor expression and gene copy number in conventional hepatocellular carcinoma

Abstract

Epidermal growth factor receptor (EGFR) is frequently overexpressed in hepatocellular carcinoma, but its relationship with EGFR gene copy number has not been studied. This study examined EGFR expression and gene copy number in hepatocellular carcinoma and evaluated their relationship to clinicopathologic features in 76 tumors. Moderate to strong expression of EGFR was observed by immunohistochemical analysis in 50 (66%) of 76 hepatocellular carcinomas. Fluorescence in situ hybridization (FISH) showed extra EGFR gene copies in 17 (45%) of 38 tumors. This was accompanied by gains of chromosome 7, indicating that this was the result of balanced polysomy rather than gene amplification. There was no correlation between EGFR expression by immunohistochemical analysis and gene copy number by FISH. EGFR expression showed borderline association with cirrhosis but not with other clinicopathologic parameters examined. EGFR overexpression is present in a majority of hepatocellular carcinomas, suggesting a role for EGFR antagonists in therapy. The increased expression does not correlate with an increase in the EGFR gene copy number.