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Epidemiology, risk factors, and pathogenesis of cholangiocarcinoma


Shahid A. Khan, Department of Hepatology and Gastroenterology, Division of Medicine, 10th Floor, QEQM Building, St Mary's Hospital Campus, Imperial College Healthcare NHS Trust, South Wharf Road, London W2 1NY. UK. Tel: +44 (0)207 886 6454/1208. Fax: +44 (0)207 724 9369.


Cholangiocarcinoma (CCA) is a fatal cancer of the biliary epithelium, arising either within the liver (intrahepatic, ICC) or in the extrahepatic bile ducts (extrahepatic ECC). Globally, CCA is the second most common primary hepatic malignancy. Several recent epidemiological studies have shown that the incidence and mortality rates of ICC are increasing. This review of the literature on the international epidemiological rates of CCA, both intra- and extrahepatic, explores possible explanations for the trends found. The possible role of epidemiological artifact in the findings is discussed and the known risk factors for CCA are summarized. These include primary sclerosing cholangitis, liver fluke infestation, congenital fibropolycystic liver, bile duct adenomas, and biliary papillomatosis, hepatolithiasis, chemical carcinogens such as nitrosamines, Thorotrast, chronic viral hepatitis, cirrhosis, chronic non-alcoholic liver disease and obesity. Potential pathways involved in the molecular pathogenesis of CCA are also summarized.