Gallbladder cancers rarely overexpress HER-2/neu, demonstrated by Hercep test

c-erbB-2, proto-oncogene is amplified and overexpressed in a number of human adenocarcinomas. Overexpression of c-erbB-2 is indicated as a worse prognostic factor and associated with neoplastic progression in various organs. To investigate the therapeutic effect of Trastuzumab in gallbladder cancer, we studied HER-2/neu expression in 43 primary tumors, 12 metastatic lymph nodes and two liver metastasis, using the Hercep test. Among primary tumors, strong (3+) immunohistochemical intensity was found in two cases (4.7%), weak (2+) in two (4.7%) and negative (1+) (2.3%) in one case. This positivity rate was distinctly lower than those in previous reports. There was no tendency between clinicopathologic characteristics and HER-2 positivity in the primary gallbladder. Among 12 metastatic lymph nodes, only one specimen showed 2+ positivity where the primary lesion revealed 3+ intensity of HER-2. In two liver metastatic lesions, the expression of HER-2 was not found. Our study implied that Trastzumab may not contribute to improvement in treatment of gallbladder cancer. However, there may be a therapeutic possibility for cases with lymph node recurrence overexpressing c-erbB-2.