I. What are malignant tumors of the biliary system? As the name suggests, it refers to malignant tumors occurring in the biliary system, including cancer of epithelial origin and sarcoma of mesothelial origin. The vast majority of malignant tumors of the biliary system originate from epithelial tissue, so cancer is the most common, such as: gallbladder cancer, bile duct cancer. The malignant tumors of biliary system usually refer to the tumors originated from biliary system, and the broad concept also includes the malignant diseases originated from other organs and metastasized to the biliary system, such as: hepatoduodenal ligament lymph node metastasis of gastric carcinoma causing obstructive jaundice, and cholangiocarcinoma embolus of primary hepatocellular carcinoma. So where does the biliary system fit in? The biliary system consists of the gallbladder and the bile ducts, the latter of which includes the capillary bile ducts, intrahepatic bile ducts and extrahepatic bile ducts. The intrahepatic and extrahepatic bile ducts are usually differentiated above and below the confluence of the right and left hepatic ducts. Malignant tumors occurring in these areas are often heard of as gallbladder cancer, intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, and choledochal jugular carcinoma. Among intrahepatic cholangiocarcinomas, those that originate from the epithelium of the smaller intrahepatic bile ducts are also called cholangiocellular carcinomas, and they belong to a type of primary liver cancer. According to the 7th edition of AJCC (2009), extrahepatic bile duct cancers can be divided into perihilar cholangiocarcinoma (also known as hilar cholangiocarcinoma, proximal cholangiocarcinoma, upper segment cholangiocarcinoma) and distal cholangiocarcinoma (also known as lower segment cholangiocarcinoma), which are roughly defined by the confluence of the cystic ducts. Perihilar cholangiocarcinoma actually refers to cholangiocarcinomas involving the upper third of the extrahepatic bile ducts, and often involving the confluence of the hepatic ducts, the right and left hepatic ducts. Why are malignant tumors of the biliary system scary? Malignant tumors of biliary system not only show abnormal proliferation of cells out of control, continuous growth of tumors, formation of substantial occupancy in the biliary system, and characteristic obstructive jaundice when involving bile ducts below the hepatic ductal confluence, which seriously impairs the liver function, but also secondary biliary tract infections, which aggravate the damage of other organs. Moreover, it also shows the invasion of adjacent normal tissues (liver, portal vein, hepatic artery, etc.), as well as the formation of hepatic hilar and retroperitoneal regional lymph node metastasis via lymphatic pathway, the formation of abdominal extensive implantation metastasis in the late stage, and hepatic and distant hematogenous metastasis. These are often the causes of death from biliary tract malignancies. Despite the fact that malignant tumors have been ranked second among the various causes of death in our country, thankfully, malignant tumors of the biliary system are still outside the top 15 in the rankings of malignant tumors in terms of incidence and adjusted mortality. According to the statistical data of 90-92 years in China, the adjusted mortality rate of biliary tract malignant tumors is much lower than that of its “close relative”-liver cancer, as well as gastric, liver, lung, esophageal, colorectal and anal cancers which are in the first five places, which is mainly due to the low incidence rate, but its incidence rate has a gradual increasing trend. However, there is a trend of gradual increase in the incidence of these cancers. The relative incidence rates of gallbladder cancer and bile duct cancer are higher than that of bile duct cancer in western countries, while there are large regional differences in China. The prognosis of malignant tumors of biliary system is not ideal, the prognosis of lower bile duct cancer is relatively good, the prognosis of hepatoportal cholangiocarcinoma has been improved this year, the prognosis of intrahepatic cholangiocarcinoma and gallbladder cancer is not better than that of hepatocellular carcinoma, especially the notorious gallbladder cancer, the survival rate of 5-years after surgical resection is still maintained at a low level of 2~4%. How to prevent malignant tumors of biliary system? Some people want to ask since the biliary system malignant tumor is so terrible, can we not have this disease? That is to say, can it be prevented? The occurrence of human malignant tumors, more than 80% is due to environmental factors, according to epidemiology, etiology of a large number of studies have confirmed: most of the malignant tumors can be avoided and prevented, biliary tract system malignant tumors are no exception. Now we take common gallbladder cancer and bile duct cancer as examples. The incidence rate of gallbladder cancer increases with age, and gallbladder cancer is more common in women, with the peak age of incidence at 60-69 years old. Although its etiology is not completely clear, it is generally recognized that gallbladder stones are an important causative factor of gallbladder cancer. 50-80% of gallbladder cancers are accompanied by stones, and some scholars reported that the chances of gallbladder cancer in gallbladder stones are 7 times higher than that of gallbladder without stones, and the bigger the stones are, the higher is the risk of developing gallbladder cancer. Chronic cholecystitis combined with calcification of gallbladder wall (also known as “porcelain gallbladder”) is one of the high-risk factors, and its cancer rate can reach 1.5-61%. Adenoma of gallbladder and adenomyosis of gallbladder are considered precancerous lesions of gallbladder cancer. Abnormalities of pancreaticobiliary ductal conjunction are associated with a high rate of gallbladder cancer. The incidence of gallbladder cancer is higher in rubber workers and automobile workers who are frequently exposed to chemicals. The incidence of cholangiocarcinoma is slightly higher in males than females, with the peak age of incidence at 50-59 years. The cause of bile duct cancer is not clear, but there is a close relationship between bile duct cancer, especially intrahepatic cholangiocarcinoma, primary bile duct stones and hepatic bile duct stones, and the incidence rate of hepatic cholangiocarcinoma is high in areas with high incidence of hepatic bile duct stones. Cystic diseases of the bile ducts are often cancerous, and the cancer rate of congenital choledochal cysts can reach 3-16.7%. Primary sclerosing cholangitis has a higher chance of developing cholangiocarcinoma than the general population. In the south of China, the infection of Schistosoma oryzae parasitized in the hepatic duct system is thought to be related to the development of cholangiocarcinoma. The incidence of biliary tract malignant tumors in patients with ulcerative colitis is 10 times higher than that of the general population. So what should be done to prevent tumors of the biliary system? This is the question of preventive countermeasures, and of course we are talking here mainly about etiological prevention, that is, level I prevention, that is, elimination or reduction of factors that may lead to biliary malignant tumors to reduce the incidence rate. We have already introduced the risk factors of biliary system malignant tumors, and generally speaking, these factors come from the environment, living habits, diet, infections, congenital diseases, etc. At present, there is no conclusion about the obvious correlation between dietary habits, food types, and food components and biliary system malignant tumors, and by improving the environment, changing the bad living habits, scientific diet, active prevention, and treatment of benign biliary system tumors that have a relationship with biliary malignant tumors By improving the environment, changing the bad living habits, scientific diet, actively preventing and treating the benign diseases of the biliary system that are related to biliary malignant tumors (e.g. cholecystitis, cholangitis, cholelithiasis, congenital choledochal cysts, biliary parasites, etc.), the incidence of biliary malignant tumors can be reduced or even avoided. How to diagnose malignant tumor of biliary system? First of all, the purpose of diagnosis is to clarify whether there is a malignant tumor or not, and to know its location, scope and degree, so as to draw up a treatment plan and estimate its prognosis. As we all know, whether early diagnosis can directly affect the treatment effect and prognosis of patients, so both for patients and doctors, early diagnosis is crucial. In general, it seems that the diagnosis of malignant tumors of the biliary system with obvious symptoms (such as abdominal pain, epigastric mass, jaundice, etc.) is not difficult, and what is difficult is the early diagnosis and the diagnosis of patients with no obvious symptoms because of the lack of an ideal specific early diagnostic method. Among the malignant tumors of the biliary system, gallbladder cancer is the most difficult to diagnose preoperatively due to the lack of specificity of its clinical manifestations and the fact that its early signs are often masked by gallbladder stones and their complications. The diagnosis of intrahepatic cholangiocarcinoma is similar to that of gallbladder cancer, especially intrahepatic cholangiocarcinoma secondary to intrahepatic bile duct stones belongs to delayed pathological changes, and its early signs are often masked by the manifestations of intrahepatic bile duct stones. Early diagnosis of both is difficult. With the development of modern imaging technology, it is easier to diagnose hepatoportal cholangiocarcinoma and lower bile duct cancer. Hepatoportal cholangiocarcinoma can be combined with cholelithiasis, or involve one side of hepatic bile duct in early stage without jaundice, which makes early diagnosis difficult. However, jaundice can be seen in early stage of lower bile duct cancer, which is conducive to early diagnosis. Comprehensive diagnosis of junction and history, physical signs, tumor markers and imaging examination is the effective method for early diagnosis of malignant tumor of biliary system. There is no highly specific tumor marker for malignant tumors of the biliary system, and the abnormalities of CA19-9 (glycocalyx antigen), CEA (carcinoembryonic antigen), and AFP (alpha-fetoprotein) indexes can be used as references, especially the former. There is a wide variety of imaging methods for biliary tract diseases, and early diagnosis can only be achieved through effective selection and application of imaging methods and correct judgment of the results. ultrasound has become the first line of diagnosis of malignant tumors of the biliary tract system due to its simplicity, non-invasiveness and reproducibility. CT (computed tomography) scanning and MRI (magnetic resonance imaging) are able to show the occupying pathology of the biliary tract system more clearly. CT (computed tomography) scanning and MRI (magnetic resonance imaging) can more clearly show the occupying lesions of the biliary system, the dilatation of the bile ducts, and can be used for angiographic enhancement to further understand the extent of tumor infiltration and dissemination. ptc (percutaneous transhepatic puncture cholangiography) and ercp (retrograde endoscopic cholangiopancreatography) can clearly show the images of the bile ducts inside and outside of the liver, which is beneficial to the diagnosis of extrahepatic cholangiocarcinoma, but as an invasive test, it has a risk of bile duct infections, hemorrhage, leaks, and other complications. MRCP (magnetic resonance cholangiopancreatic imaging), although its imaging quality is not as clear as that of PTC and ERCP, is gradually gaining popularity in the diagnosis of cholangiocarcinoma due to its advantages of being non-invasive and being able to show the whole picture of the biliary system and the surrounding tissue structure. With the application of spiral CT, CT biliary tract three-dimensional imaging, CT biliary tract multiplanar reorganization, and CT biliary tract simulation endoscopic imaging provide richer basis for early diagnosis. The application of high-resolution CT and ultra-high-speed multi-row spiral CT has made it possible to diagnose the imaging of tiny lesions and tiny blood vessels in the early stage of tumors of 3~5mm. Ultrasound endoscopy has certain advantages for diagnosing lower bile duct cancer.PET (positron emission tomography) and MRSI (magnetic resonance spectroscopy imaging) can reflect the presence of early tumors from the level of functional and metabolic changes that precede the organic changes of tumors. The progress of molecular pathology research, the application of molecular diagnostic technology from the molecular level so that the genetic changes of the tumor is first reflected. How to treat biliary system malignant tumors? With the change of medical model from biomedical model to biosocial-psychological medical model and the rapid development of clinical oncology, the concept of multidisciplinary comprehensive treatment for malignant tumors has become a consensus. The treatment of malignant tumors of the biliary system needs to be based on the physical and mental condition of the patient, specific location of the tumor, pathological type, invasion range and development tendency, combined with cellular molecular biology. The treatment of malignant tumors of the biliary tract system needs to be based on the patient’s physical and mental condition, tumor location, pathological type, invasive range and developmental trend, combined with the changes in cellular molecular biology, and the planned and rational application of existing multidisciplinary and various effective therapeutic means in order to achieve the best therapeutic effect at an appropriate cost, and at the same time maximize the improvement of patients’ quality of life. For malignant tumors of the biliary system, surgical treatment is still the mainstay, and combined with radiotherapy, chemotherapy, interventional therapy, biotherapy and traditional Chinese medicine, etc. The development of multidisciplinary comprehensive treatment plan should focus on grasping the principles of local and systemic concurrently, staged treatment, individualized treatment, concurrently of survival rate and quality of life, concurrently of cost and effect, and concurrently of traditional Chinese and western medicine. The principles of surgical treatment for malignant tumors of the biliary system are: 1. Define the diagnosis as much as possible before surgery. 2.Develop a reasonable treatment plan based on the location of the tumor, biological characteristics, clinical staging and physical and mental conditions of the patient, choose a reasonable surgical method, ensure sufficient resection range, and strive for surgical cure. 3, Adequate preoperative preparation, including necessary biliary drainage and portal vein embolization techniques. 4.Strict application of tumor-free techniques during surgery, and avoiding the spread of medical tumor as much as possible. When choosing surgical methods, curative surgery, including radical surgery and extended radical surgery, should be performed for those whose tumors are confined to the site of origin and adjacent regional lymph nodes or those whose tumors can be resected in one piece from the site of origin even though they have invaded the adjacent organs. For example, radical surgery for gallbladder cancer, extended radical surgery for gallbladder cancer, radical surgery for hilar cholangiocarcinoma, pancreaticoduodenectomy and so on. It should be noted that in view of the high complication rate and surgical mortality rate of extended radical surgery, it is only applicable to patients with good general condition and sufficient preoperative preparation. For patients in whom curative resection is no longer possible, conservative means of treatment may be used. The treatment focuses on two aspects: one is biliary drainage, if there is obstructive jaundice, it is necessary to perform drainage of bile ducts above the obstruction (internal and/or external drainage), PTCD (percutaneous hepatic puncture biliary drainage) and ERCP (retrograde cholangio-pancreatic cholangiopancreatography via endoscopy) to place plastic drainage tubes or metal stents. Another aspect is anti-tumor combination therapy, including radiotherapy, TCM and immunotherapy.