Table 1.

Risk factors for eCCA categorized according to odds ratio (OR).

Risk factor	Disease
OR > 10	Choledochal cyst [114]
	Choledocholithiasis [114]
	Primary sclerosing cholangitis [115]
	Caroli disease [115]
3 < OR < 10	Chronic pancreatitis [115]
	Cholelithiasis [114]
	Liver fluke infection (Opisthorchis viverrini, Clonorchis sinensis) [116]
	Cirrhosis [114]
OR < 3	Nonalcoholic fatty liver disease [117]
	Cholecystolithiasis [114]
	Alcohol-related disorders [114]
	Autoimmune hepatitis [114]
	Inflammatory bowel disease [114]
	HBV [114]
	HCV [114]
	Smoking [114]
	Type 2 diabetes [118]
	Hypertension [114]