Table 2

Established risk factors for cholangiocarcinoma (CC)

Risk factorReferences and details
Age65% of patients aged >65 years17 19
Chronic intraductal gallstonesParticularly in Asia where up to 10% of patients with hepatolithiasis (oriental cholangiohepatitis) develop intrahepatic CC17 19 15 17 19
Bile duct adenoma and biliary papillomatosis
Choledochal (bile duct) cysts and Caroli's disease (intrahepatic biliary cysts)Lifetime risk of CC of 6–30%; risk of CC increases with age, and the average age of CC detection is in the fourth decade, younger than sporadic CC15 19
ThorotrastRadiological agent is no longer licensed for use, although risk of CC induced by Thorotrast lasts several decades15 16
Liver flukes (Opisthorcis viverrini and Clonorchis sinensis)South-east Asia such as north-east Thailand where CC is relatively common13 19
Chronic typhoid carriageSouth-east Asia; sixfold increased risk of all hepatobiliary malignancy13 19