In recent years, with the continuous improvement of living standard of our people, sanitary conditions, and the popularization of hepatitis B vaccine, the incidence rate of liver cancer is on a decreasing trend, while the incidence rate of cholangiocarcinoma is on a relatively high trend. Compared with hepatocellular carcinoma, cholangiocarcinoma has a high degree of malignancy, greater difficulty in surgery and poor prognosis, so it should be more important to attract our attention. Unlike hepatocellular carcinoma which has clear causative factors (hepatitis B, fatty liver), cholangiocarcinoma has no clear causative factors so far, but there are several factors related to its development, including: hepatitis virus infection, non-alcoholic steatohepatitis, congenital malformation of bile ducts (choledochal cysts), choledocholithiasis, bile duct parasites. Many cholangiocarcinomas have no clear cause, which makes prevention difficult. 2.What kinds of bile duct cancer can be categorized? First of all, let’s have a general understanding of bile duct cancer. Cholangiocarcinoma includes malignant tumors originated from the mucosal epithelium of the entire biliary tree, including intrahepatic cholangiocarcinoma, hepatoportal cholangiocarcinoma, and lower bile duct cancer according to anatomical sites. Originally, there was also a cancer of the middle bile duct, which was classified as hepatoportal cholangiocarcinoma or lower bile duct cancer, but was not classified as a separate cancer, and was then categorized as hepatoportal cholangiocarcinoma or lower bile duct cancer. Intrahepatic cholangiocarcinoma has been categorized as primary liver cancer because its biological characteristics, treatment and prognosis are completely different from hepatocellular carcinoma, but similar to extrahepatic cholangiocarcinoma, and its incidence rate has shown a significant upward trend in recent years, so it has been categorized as a biliary tract tumor since the seventh edition of NCCN guidelines was formulated in 2010, and this categorization reflects people’s continuous upgrading of the understanding of intrahepatic cholangiocarcinoma. This classification actually reflects that people’s understanding of intrahepatic cholangiocarcinoma has been upgraded, emphasized and deepened, and also reflects that this disease has become a greater and greater threat to human health. Extrahepatic cholangiocarcinoma includes hepatoportal cholangiocarcinoma and lower bile duct cancer. The overall incidence rate of these types of bile duct cancers is highest in hepatoportal bile duct cancer, accounting for about 60%-70%, while intrahepatic bile duct cancer accounts for the smallest proportion, about 10%-15%. However, in terms of malignancy, intrahepatic cholangiocarcinoma has the highest malignancy and the worst prognosis. 3.How to treat bile duct cancer? First of all, for intrahepatic cholangiocarcinoma, at present, for patients, the only treatment that can get cure is radical resection of tumor. Except for mass type, radical resection of intrahepatic bile duct cancer requires regional lymph node dissection. At present, the treatment of intrahepatic cholangiocarcinoma in China is not standardized, and the treatment is mostly equivalent to hepatocellular hepatocellular carcinoma without regional lymph node dissection, which leads to recurrence of lymph node metastasis in the early stage of postoperative period, therefore, it is necessary to go to the specialized hepatobiliary surgical centers with corresponding technical conditions for diagnosis and treatment. Surgery is only the first step of treatment. For tumors with poor prognosis, adjuvant treatment must be followed, otherwise, it is useless even if the surgery is clean. If radical resection is achieved, chemotherapy with Tegio (combined with oxaliplatin) can be used to eliminate any remaining cancer cells in the body and prevent early recurrence. If it is a palliative resection, it can be treated with a combination of radiotherapy and chemotherapy. In recent years, rapid advances in biotechnology and medicine have provided several new treatment opportunities for patients, mainly including targeted therapy and immunotherapy (PD-1). The resected specimen can be taken for genetic testing to look for gene mutations, the initial pathogenetic factor of the tumor. The ideal result is to find a clear mutation site and to have a targeted drug for that site. In addition to targeted therapy, immunotherapy can be performed based on the microsatellite stability status of the tumor and the tumor’s mutational load. Due to the high malignancy of intrahepatic cholangiocarcinoma, many patients are already in advanced stages when they are found, and there is no chance of resection, does this not mean that patients have no chance at all? Yes. This part of the cases can also be palliative resection or biopsy of the tumor to obtain tumor specimens, take them for genetic testing, looking for targeted therapy or immunotherapy drugs. We have been able to significantly shrink unresectable giant intrahepatic cholangiocarcinoma through targeted therapy combined with PD-1 therapy, and there have been several such cases, so there is hope as long as you don’t give up. Extrahepatic cholangiocarcinoma includes hepatoportal cholangiocarcinoma and lower bile duct cancer, and these patients tend to present with jaundice, so they are mostly found in earlier stages than intrahepatic cholangiocarcinoma, and the chances of surgical resection are also higher. Our experience is that, for the sake of surgical safety, the first step is to reduce jaundice and alleviate the damage caused by jaundice, utilizing PTCD (percutaneous transhepatic cholangiocarcinoma catheter drainage), and we do not recommend ERCP (endoscopic retrograde cholangio-pancreatic catheterization). Lower bile duct cancer is one kind of peripelvic cancer (including pancreatic head cancer, lower bile duct cancer, juxtapapapillary cancer and duodenal papillary cancer), and the treatment of these tumors is similar, and the treatment mostly requires pancreaticoduodenectomy, and the choledocholithiasis and pancreatic head cancer also need to carry out regional lymph node contouring, pancreaticoduodenectomy is very traumatic, and it needs to resect a lot of organs (stomach, gallbladder, bile ducts, duodenum, upper jejunum, head of pancreas, and leptospirosis), and the anastomosis (pancreatic head and hooks) after resection is very difficult, and it is not recommended. The anastomosis after resection (pancreatico-enteric anastomosis, biliary-enteric anastomosis, gastro-enteric anastomosis), especially pancreatico-enteric anastomosis, is very easy to pancreatic leakage in the postoperative period, and pancreatic leakage is a fatal complication. Now we have adopted a new type of pancreatico-enteric anastomosis, which has significantly reduced the complication rate, shortened the operation time (from 8 hours to 3.5 hours), shortened the hospitalization day, and correspondingly reduced the hospitalization cost. After resection of extrahepatic cholangiocarcinoma, adjuvant treatment is also needed, probably the same as intrahepatic cholangiocarcinoma, you can refer to the above content. I believe that with the deepening understanding of the biological characteristics of cholangiocarcinoma, especially the pathogenic mechanism, one day people will be able to cure cholangiocarcinoma completely.