The liver is one of the largest digestive organs in the body. The liver is located in the right upper abdomen, protected by the right rib cage, above which is the lower lobe of the right lung, separated from the liver by the diaphragm. The liver has a wedge shape, thick on the right side and thin on the left. The liver is divided into two lobes, the left and the right, using the gallbladder as a boundary, and each lobe is divided into several segments. The liver has a dual blood supply, one with oxygen-rich arterial blood and the other with portal blood that absorbs nutrient-rich substances from the intestines. The liver has many important functions. Some nutrients and vitamins are absorbed into the liver via the intestine and stored, and these substances are exported from the liver when they are needed by other organs. There are also substances that are processed in the liver as raw materials into substances that can be used directly by other organs. The metabolism of the three major nutrients, such as carbohydrates (sugars and starches) proteins and fats, all depend on the proper functioning of the liver. The liver also has detoxification functions. The liver admits blood from the intestine, which contains many toxins from the intestine, and the liver can degrade these toxins into non-toxic substances. Primary liver cancer is one of the common malignant tumors in China, ranking third after stomach cancer and esophageal cancer among digestive system tumors. The incidence rate is greater in men than in women, and the ratio of men to women is (3~5):1. It is common in 40~49 years old and mainly distributed in southeast coastal areas of China. The disease starts insidiously, but once symptoms appear, it develops rapidly. In the past, it was thought that the natural course of the disease was 2-6 months, so it was called “King of Cancer”, but now it is thought that the natural course of the disease is about 24 months. In recent years, cases detected in early stage by methotrexate screening may not have any clinical symptoms and signs, which is called subclinical liver cancer. According to the development of hepatocellular carcinoma, it can be divided into: 1. Pre-subclinical stage, which refers to the period from the beginning of lesion to the diagnosis of subclinical hepatocellular carcinoma, when patients have no symptoms and signs and are difficult to be detected clinically. This period is about 10 months on average. 2.Subclinical stage refers to the period from the establishment of subclinical hepatocellular carcinoma diagnosis to the appearance of symptoms, when the patient still has no symptoms and signs, and the tumor is 3~5cm, which is still difficult to diagnose, and is mostly detected by AFP screening. The average time of this stage is about 8 months. 3.Once the clinical manifestation of liver cancer appears, it has reached the middle stage. At this time, the disease develops rapidly, and advanced manifestations such as jaundice, ascites, lung metastasis and even extensive metastasis and malignant mass may appear soon. These two stages will take about 6 months in total. When hepatocellular carcinoma develops to advanced stage, the tumor diameter is usually about 10cm, which is difficult to be cured. Risk factors Globally, viral hepatitis, aflatoxin and alcoholic cirrhosis are the main causes of hepatocellular carcinoma. In China, hepatitis B virus infection, aflatoxin and drinking water pollution are the three major causes. 1.Hepatitis B virus (HBV) primary liver cancer patients about 1/3 have a history of chronic hepatitis, and 60%-90% of liver cancer patients develop hepatitis B during their early childhood (0-5 years old). The positivity rate of HBsAg and other hepatitis B markers in the serum of liver cancer patients can reach 90%. In recent years, hepatitis C, like hepatitis B, has been found to be closely associated with the development of liver cancer, and vertical transmission of hepatitis is an important factor in the high incidence of liver cancer. In general, 75%-90% of liver cancer patients can be attributed to HBV infection, and those with HBV markers have 10 times greater chance of developing liver cancer than those without HBV markers, and the more markers there are, the higher the risk of liver cancer. the pathway of HBV causing liver cancer is: HBV infection → chronic hepatitis → cirrhosis → atypical proliferation of liver cells → liver cancer. 2.Cirrhosis primary liver cancer combined with cirrhosis accounts for 50%~90% of patients, and cirrhosis combined with liver cancer accounts for 49.9% of patients, and cirrhosis can develop into liver cancer in about 7 years. It is found that hepatocellular malignancy may occur in the process of hepatocyte regeneration, that is, massive damage to hepatocytes causing regeneration or atypical proliferation. In Europe and the United States liver cancer often occurs on the basis of alcoholic cirrhosis. 3.Aflatoxin and nitrosamines Aflatoxin B1, a metabolite of aflatoxin, is a strong chemical carcinogen for liver cancer. Studies have found that the high incidence of liver cancer area grain and oil food is seriously contaminated by aflatoxin B1. The content of nitrate and nitrite in soil is positively correlated with the occurrence of liver cancer. 4. Drinking water pollution is related to liver cancer. It is found that the incidence of liver cancer is 26 times higher among residents who drink pond water and gutter water, but 1/3 lower among residents who drink well water, because the ground water is often polluted by carcinogens such as hexachlorobenzene, benzopyrene, PCB and chloroform, etc. In addition, the blue and green algae growing in pond water have been proved to be strong carcinogens in recent years. 5.Hereditary tendency of liver cancer in China, especially in areas with high incidence of liver cancer, is found to have a significant family clustering phenomenon, and the risk of liver cancer for those with family history of liver cancer is higher than those without family history of liver cancer. However, many scholars believe that the cause of family clustering may be due to the vertical transmission of viral hepatitis from mother to child. 6.Microelements Some studies found that patients with liver cancer have high copper and low selenium, molybdenum and manganese in serum, and proper supplementation of selenium can reduce the incidence of primary liver cancer by 1/3~2/3. 7.Parasites Some people believe that infection of Chinese schistosomes in small bile ducts of liver can stimulate bile duct epithelial proliferation, which is one of the causes of primary bile duct cell carcinoma. 8.Other factors: long-term alcohol consumption, smoking and long-term oral contraceptive use are all related to the occurrence of liver cancer. Animal experiments prove that organochlorine pesticides can induce liver cancer in animals. Abnormal manifestations 1.Supra-abdominal fullness, loss of appetite and weight loss can be the first symptom of most patients. It may be caused by the increase of liver volume which compresses the stomach and reduces the volume of stomach, or it may be caused by liver dysfunction or ascites, so early stage of liver cancer is often considered as “stomach disease”, and the symptoms will be relieved by taking digestive drugs or reducing diet. 2.Pain in liver area is the main symptom, accounting for about 60%. The pain is often limited to the right upper abdomen, which is persistent hidden pain, distension, stabbing pain or dull pain, with the characteristic of intermittent increase. The pain is caused by the rapid growth of the mass and the pulling of the liver peritoneum. If the lesion invades the diaphragm, the pain may radiate to the right shoulder or the right back; if the tumor grows slowly, the patient may have no pain at all or only slight dull pain. 3.Fever can be present in late stage, and the patient’s body temperature is usually 37.5~38.5℃, which is mostly cancer fever. 4.Hemorrhagic tendency is manifested as epistaxis and gum bleeding, subcutaneous bruises, etc., which are caused by low liver function and hypersplenism. 5.Diarrhea may be caused by liver dysfunction and decreased fat digestion and absorption ability. This kind of diarrhea generally manifests as unshaped, thin stools, increased or not, and patients mostly have no abdominal pain and discomfort and normal diet, so it is easy to be ignored. 6, other symptoms include hypoglycemia or hyperglycemia, erythrocytosis or decreased red blood cells, white blood cells, platelets, hypercalcemia, gynecomastia, etc. 7.Large liver is the most important sign, accounting for 91% to 98.5%. The liver is progressively enlarged, often with varying degrees of pressure pain, and when the liver protrudes under the right intercostal space or under the saber, the epigastrium may appear locally elevated or full, and sometimes patients can find it on their own and seek medical attention. Jaundice is a late manifestation, mainly sclera and skin yellowing, which can be caused by hepatocellular injury or biliary obstruction caused by tumor compression and invasion of bile ducts. 9. Ascites accounts for 38%, mostly late manifestation, grass green in color, a few of them are bloody, related to portal hypertension and plasma protein reduction. The survival period of most patients is less than 2 months after the appearance of ascites. 10.Signs of chronic liver disease are splenomegaly, abdominal wall varices, spider nevus, liver palm, subcutaneous bleeding, and lower limb edema.