Carcinomas of the biliary tract have a poor prognosis. It is important to understand the molecular genetic characteristics of these tumours in order to employ newer effective treatments and to improve patient prognosis. There is increasing evidence that overexpression of tyrosine kinase growth factor receptors such as ErbB-2, epidermal growth factor receptor (EGFR), and Met may play important roles in the development of biliary tract carcinomas. The aim of this study was to assess the potential for novel chemotherapies targeting these receptors. Overexpression of the tyrosine kinase receptor proteins was examined by immunohistochemistry in 221 biliary tract carcinomas, of which 28 were from the intrahepatic bile duct, 78 from the extrahepatic bile duct, 89 from the gall bladder, and 26 from the ampulla of Vater. Positively stained tumours were further examined for gene amplification by fluorescence in situ hybridization. Overexpression of ErbB-2 was found in 15.7%, 11.5%, and 5.1% of carcinomas of the gall bladder, ampulla of Vater, and extrahepatic bile duct, respectively, and gene amplification was present in 79% of these. Overexpression of EGFR was found in 8.1% of tumours with no predominant location and was also associated with gene amplification with high frequency (77%). Met overexpression, most frequent in intrahepatic bile duct carcinomas (21.4%), was not associated with gene amplification. It is proposed that the new adjuvant chemotherapies could be directed to carcinomas of the biliary tract in which ErbB-2 and EGFR are overexpressed.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in tumor cells without toxicity to normal cells, but some recombinant versions of TRAIL caused hepatocyte death. We generated fully human monoclonal antibodies (mAbs) that bind specifically to TRAIL receptor 1 (TRAIL-R1) and TRAIL receptor 2 (TRAIL-R2), which mediate apoptosis signal when they ligate with TRAIL, to investigate the contribution of each receptor to induce tumor cell apoptosis and hepatocyte toxicity. All of mAbs to TRAIL-R1 and TRAIL-R2 induced cell death in several cancer cell lines susceptible to TRAIL but not in human umbilical vein endothelial cells in vitro. Both anti-TRAIL-R1 mAbs and anti-TRAIL-R2 mAbs also caused cell death in hepatocytes. However, a subset of mAbs to TRAIL-R2, which was characterized by the TRAIL blocking activity, did not show strong hepatocyte toxicity. These results indicate that human normal hepatocytes are susceptible to both TRAIL-R1-and TRAIL-R2-mediated apoptosis signal.

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Low-grade cribriform cystadenocarcinoma (LGCCC) is a rare tumor, defined in the 2005 WHO classification as a primary salivary duct tumor. Previously, the neoplasm had been recognized as a variant of salivary duct carcinomas. A 56-year-old Japanese woman noticed a mass in the left subaural region. On radiological examinations, a multicystic tumor was seen in the left parotid gland. Fine-needle aspiration biopsy was performed. The smears revealed several characteristic cytologic features. The tumor cells were arranged in irregular overlapping and showed inconspicuous nuclear atypia with variable-sized and irregularly shaped cytoplasmic vacuoles. Based on these findings, a cystic tumor with uncertain malignancy was diagnosed. A parotidectomy was performed, because the tumor was slowly growing and contained solid components on the radiological images. Based on the histologic findings, along with immunohistochemistry, LGCCC was diagnosed based on resemblance to breast low-grade ductal carcinoma in situ and intraductal proliferation of tumor cells. This is the first report of the cytomorphological findings of LGCCC.

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