Epidermal Growth Factor Receptor and c-erbB-2 Expressions in Biliary Tract Cancers

ABSTRACT

PURPOSE: The expressions of epidermal growth factor receptor (EGFR) and c-erbB-2 have been considered to be implicated in the genesis and progression of cholangiocarcinomas. However, their clinical roles and pathological characteristics remain uninvestigated. The purpose of this study was to assess the expressions of EGFR and c-erbB-2, and to identify their clinical and pathological significances in biliary tract cancers. METHODS: One hundred and fourteen samples were obtained from surgically resected biliary tract cancers (72 extrahepatic bile duct cancers, 33 gallbladder cancers, and 9 intrahepatic bile duct cancers). Expressions of EGFR and c-erbB-2 were examined by immunohistochemical staining. Expression rates were analyzed according to the location of the tumor, histologic differentiation, depth of invasion, lymph node metastasis, lymphovascular invasion, recurrence, and survival rate. RESULTS: The expression rate of EGFR was 10.7% in biliary tract cancers. EGFR expression was more often observed in moderately- or poorly-differentiated carcinomas than in well-differentiated carcinomas (p=0.0252). No correlations were observed with age, gender, location of tumor, depth of invasion, lymph node metastasis, lymphovascular invasion, recurrence rate, or survival rate. c-erbB-2 was expressed in 4.5% of biliary tract cancers. c-erbB-2 expression had no significant relationships with clinical and pathological prognostic factors. CONCLUSION: EGFR expression can be used restrictively as a prognostic indicator of biliary tract cancers. c-erbB-2 expression in biliary tract cancers is very low, and does not show any prognostic significance.