Expression and clinicopathologic significance of glypican 3 in hepatocellular carcinoma

Glypican 3 (GPC3) is a glycosylphosphatidylinositol-anchored membrane protein and plays an important role in regulation of cell growth, differentiation, and migration. The aims of this study were to investigate the expression of GPC3 in human liver, biliary tract, and pancreatic tumors and to evaluate its diagnostic role in differentiating hepatocellular carcinoma (HCC) from other hepatic mimickers. Immunohistochemistry was performed on a large collection of surgically resected samples from 941 primary liver tumors, 50 metastatic adenocarcinomas, and 30 normal livers as well as primary adenocarcinomas of the pancreas (n = 17), gallbladder (n = 30), and extrahepatic bile duct (n = 20). The relationship of GPC3 expression and clinicopathologic features in patients with HCC was determined. We found that 516 (52%) of the 991 liver neoplastic tissue samples demonstrated positive staining for GPC3. A high incidence of GPC3 expression (492/757; 65%) was observed in HCC, whereas intrahepatic cholangiocarcinomas, adenocarcinomas, and benign liver lesions displayed rare positive cases. There were significant correlations between GPC3 expression and clinicopathologic characteristics, including histologic grade (P < .001), intrahepatic metastasis (P = .007), and positive serum hepatitis B surface antigen (P = .042), in patients with HCC. In conclusion, our results confirm the high expression of GPC3 in HCC and suggest its potential diagnostic value as a clinical marker for this disease.