Table 1.

Risk factors [2, 4]

Cholangiocarcinoma	LE Ia	LE IIb
General risk factors	Age >65 Excessive alcohol intake	Tobacco smoking Obesity Type II diabetes
Congenital risk factors	Caroli’s disease choledochal cysts, congenital hepatic fibrosis
Viral risk factors	VHB, VHC,
Inflammatory risk factors	Primary schlerosis cholangitis, hepatolithiasis, cirrhosis, inflammatory bowel disease, biliary enteric-anastomosis
Parasitic risk factors		Clonorchis sinensis Opisthorchis viverrini
Chemical risk factors	Thorotrast	Nitrosamines, vinyl chloride, dioxin, oral contraceptives, isoniazid, asbestos
Gallbladder cancer
Inflammatory risk factors	Chronic Cholecystitis and Gallstones	Porcelain gallbladder Inflammatory bowel disease
Congenital risk factors		Anomalous junction of the pancreato-biliary duct
Bacterial risk factors	Escherichia coli, chronic carriers of Salmonella typhi or paratyphi
Others risk factors	Gallbladder polyps, obesity

LE level of evidence, VHB hepatitis B virus, VHC hepatitis C virus