Therefore, we should pay more attention to the prevention of such diseases in our life, so what are the common main causes of bile duct cancer? 1.History of bile duct surgery Bile duct cancer can occur many years after surgery and can occur in bile ducts without stones, mainly due to chronic bile duct infection leading to epithelial interstitial changes, often after bile duct internal drainage surgery. 2.Radioactive thorium dioxide In patients with a history of exposure to thorium, the age of onset of bile duct cancer is 10 years earlier than in those without a history of thorium exposure, and its average latency is 35 years (after exposure to thorium), and it occurs more often at the end of the intrahepatic biliary tree. 3, sclerosing cholangitis malignant transformation primary sclerosing cholangitis (PSC) patients also have a higher chance of developing bile duct cancer than the general population, PSC is also associated with ulcerative colitis. 4.Hepatitis B virus infection Some domestic patients with cholangiocarcinoma have hepatitis B virus infection, whether there is a link between the two remains to be further elucidated.