Gene amplification and protein overexpression of HER-2/neu in human extrahepatic cholangiocarcinoma as detected by chromogenic in situ hybridization and immunohistochemistry: its prognostic implication in node-positive patients.
The proportions of positive cases for EGFR, VEGF, and HER2 overexpression were 27.4, 53.8, and 0.9% in intrahepatic cholangiocarcinoma (IHCC), and 19.2, 59.2, and 8.5% in extrahepatic cholangiocarcinoma (EHCC), respectively.
Specificities are observed for some alterations and anatomical subtypes: frequent fibroblast growth factor receptor 2 (FGFR2) and isocitrate dehydrogenase 1/2 (IDH1/2) alterations are specific to intrahepatic cholangiocarcinomas (ICCs), whereas frequent ERBB2 oncogene alterations are specific to extrahepatic cholangiocarcinomas (ECCs) and gallbladder carcinomas (GBCs).
IDH1/2 mutations appeared more frequently in ICC (23.6%, P = 0.0002) than in GBC (4.0%) or ECC (2.3%), while ERBB2/3 mutations were found only in GBC (20.0%) and ECC (11.4%).