The age of onset of bile duct cancer is mostly between 50 and 70 years old, and it is more common in men than in women. It is believed that bile duct cancer is related to bile duct stones, liver fluke infection, viral infection (hepatitis B virus, hepatitis C virus, especially hepatitis C virus), autoimmune diseases (primary sclerosing cholangitis, chronic ulcerative colitis), alcoholism and other factors. Special location and difficult surgery For this disease, the key is early detection. Once diagnosed, the biliary obstruction caused by the tumor should be addressed first, followed by removal of the tumor, because liver failure and biliary infection caused by biliary obstruction are the main causes of death of patients. About 2/3 of bile duct cancers grow in the porta hepatis. This is a special location where blood vessels are intertwined like wires, and coupled with the fact that the cancer cells tend to invade the vascular nerve tissues when discovered mostly in the middle and late stages, the treatment is difficult and the prognosis is poor. According to statistics, after most bile duct cancer patients are diagnosed, the one-year survival rate of those who take internal and external bile duct drainage is less than 50%; the 5-year survival rate after radical resection is only 13.4%-25.7%. In the Department of Hepatobiliary and Pancreatic Diseases, bile duct cancer is considered as the “King of Cancer” which is more dangerous than pancreatic cancer. Nine factors of bile duct cancer 1. Chronic inflammation and infection of bile duct: long-term chronic inflammatory stimulation is the basis of bile duct cancer, because clinically, diseases associated with bile duct cancer can lead to chronic inflammation of bile duct. Long-term stimulation of bile duct mucosa by certain substances in bile (such as metabolites of bile acids) leads to epithelial atypical hyperplasia. 2.Bile duct and gallbladder stones: 20%~57% of bile duct cancer patients are accompanied by gallstones, thus it is believed that chronic stimulation of stones may be a carcinogenic factor. 3.Ulcerative colitis: It has been reported that the incidence of bile duct cancer in patients with ulcerative colitis is 10 times higher than that of the general population. Patients with cholangiocarcinoma with ulcerative colitis have an earlier age of onset of 20-30 years than the general population, with an average age of 40-45 years, and often have a long-term history of colitis, and chronic bacteremia of the patient’s portal venous system may be the cause of cholangiocarcinoma and PSC. 4.Cystic malformation of bile duct (congenital bile duct dilatation): it has become a consensus that congenital bile duct cyst is prone to cancer, and the incidence of bile duct cancer in patients with congenital bile duct cyst is as high as 2.5%~28%. Although 75% of bile duct cystic malformations show symptoms in infancy and childhood, 3/4 of patients with bile duct cancer develop symptoms of bile duct cystic malformations in adulthood. Regarding the mechanism of bile duct cancer caused by cystic malformation of bile duct, it is believed that when the opening of the pancreatic duct into the bile duct is abnormally high, it will cause the reflux of pancreatic juice into the bile duct causing bile duct epithelial malignancy. Other factors that may lead to malignancy include bile stagnation, stone formation and chronic inflammation in the cystic lumen. 5.Hepatic schistosome infection: Schistosoma haematobium infection is also considered to be related to the occurrence of bile duct cancer. Although Schistosoma haematobium is mostly parasitized in intrahepatic bile ducts, it can also be parasitized in extrahepatic bile ducts. 6.History of bile duct surgery: bile duct cancer can occur 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. 7.Radioactive thorium dioxide: In patients with history of exposure to thorium, the age of onset of bile duct cancer is 10 years earlier than those without history of thorium exposure, and its average latency is 35 years (after exposure to thorium), and it occurs more often at the end of intrahepatic biliary tree. 8.Malignant transformation of sclerosing cholangitis: Patients with primary sclerosing cholangitis (PSC) also have a higher chance of developing cholangiocarcinoma than the general population, and PSC is also associated with ulcerative colitis. 9.Hepatitis B virus infection: Some domestic patients with cholangiocarcinoma are accompanied by hepatitis B virus infection, whether there is a link between the two remains to be further elucidated.