New epidemiologic trends in cholangiocarcinoma

Cholangiocarcinoma (CCA) is the most common biliary tract malignancy and the second most frequent primary hepatic malignancy after hepatocellular carcinoma. During the past three decades, the incidence of intrahepatic cholangiocarcinoma (iCCA) has risen in Western Europe, while the incidence of extrahepatic cholangiocarcinoma (eCCA) has remained stable or fallen. The mortality rates of iCCA, which are greater than those of eCCA, showed also an increasing trend, while those of eCCA remained stable. Well-known risk factors like hepatobiliary flukes, hepatolithiasis and choledochal cysts are important in the development of iCCA particularly in Asian countries. In Western countries, the primary sclerosing cholangitis is the most common risk factor for CCA. Hepatitis B virus (HBV) or hepatitis C virus (HCV) infection and cirrhosis are considered to be risk factors for iCCA. Emergent risk factors such as obesity, diabetes and MAFLD are increasingly associated mostly with iCCA.