Early symptoms and prevention of primary liver cancer: Primary liver cancer is one of the common malignant tumors in China. It has a high mortality rate and ranks third after stomach and esophagus in the list of malignant tumor deaths, and it ranks second after stomach cancer in some rural areas. In China, about 110,000 people die of liver cancer every year, accounting for 45% of the deaths of liver cancer in the world. Because of relying on serum alpha-fetoprotein test combined with ultrasonography to monitor the high-risk groups, liver cancer can be diagnosed at the subclinical stage, and the long-term effect of early resection is especially remarkable. With active comprehensive treatment, the five-year survival rate of hepatocellular carcinoma has been significantly improved. Early clinical manifestations: The onset of liver cancer is relatively insidious, and there are usually no symptoms in the early stage. When patients have obvious clinical symptoms, their condition often belongs to the middle or late stage. The incidence of typical symptoms of liver cancer is basically the same both at home and abroad, and the first symptom is pain in the liver area, followed by epigastric mass. The first symptom is pain in liver area, followed by epigastric mass. Poor appetite, fatigue, emaciation, fever of unknown cause, diarrhea and abdominal pain. Right shoulder pain, etc. Some patients also show some complications of cirrhosis, such as black stools, vomiting blood. Jaundice, etc. A few patients are hospitalized because of the symptoms caused by metastases, which are not specific. Preventive measures: i. Active prevention and treatment of viral hepatitis is of great significance in reducing the incidence of liver cancer. ii. Research on the relationship between hepatitis B virus and hepatocellular carcinoma has found that: 1. Hepatitis marker in serum of patients with hepatocellular carcinoma is up to more than 90%; 2. Hepatocellular carcinoma occurs in HBsag-positive patients in high incidence areas of hepatocellular carcinoma, which is 6-50 times higher than that of the negative patients; 3. Molecular biology research has shown that the purely integrative HBV-DNA in patients with hepatocellular carcinoma in our country accounted for 51.5%. The above shows that hepatitis B virus is closely related to liver cancer and is an important risk factor for liver cancer. In recent years, the relationship between hepatitis C and hepatocellular carcinoma has attracted attention, and the combined rate of hepatocellular carcinoma and cirrhosis is 83.6%, and the concomitant rate of cirrhosis and hepatocellular carcinoma is 49.9%, of which large nodular cirrhosis accounts for 73.3%. Hepatitis B virus inactivated vaccination not only prevents and controls hepatitis, but also plays a certain role in preventing liver cancer. Preventing food mold and improving drinking water quality are also important measures to prevent liver cancer. In the high prevalence area of liver cancer, especially in the south, the investigation of corn-based food places suggests that the prevalence of liver cancer may be related to aflatoxin contamination of food. Pollution of drinking water In Qidong, Jiangsu Province, the incidence rate of liver cancer among those who drink ditch water is 60~101/100,000, and among those who drink well water is only 0~19/100,000. The relative risk of those who drink ditch water is 3.00, and the investigation found that a kind of orchid green algae in the ditch water produces algal toxin, which may be the clue of drinking water pollution and liver cancer. Hereditary factors: Liver cancer in high incidence areas sometimes appears family gathering phenomenon, especially the high rate of liver cancer among those who live together and have blood relationship. It may be related to vertical transmission of hepatitis virus. Patients with family history of liver cancer should have regular medical checkups for early detection and early treatment. Other carcinogens or cancer-causing factors suspected to cause liver cancer include: alcoholism, nitrosamines, pesticides such as organochlorine, trace elements, copper, zinc and molybdenum in water, soil, grain, hair and blood in the endemic areas of liver cancer, and the Chinese branch testicular trematode, which stimulates the bile duct epithelium to proliferate and produces cholangio-thoracic carcinoma. Trace elements, sex hormones, radioactive substances, parasites, alcoholism, smoking, genetic factors. Therefore, we should not drink alcohol, eat less pickled and smoked food, and reduce contact with pesticides, various chemicals and radioactive substances. When the prevention of liver cancer is not yet perfect, early detection, early diagnosis and early treatment of liver cancer are not called “secondary prevention” in tumor. Since the application of alpha-fetoprotein for liver cancer screening in China in 1970s, the diagnosis of primary liver cancer has entered the subclinical level, the proportion of early liver cancer has been increasing, and the five-year survival rate has also been improved significantly. the detection rate of high-risk groups (history of hepatitis, positivity, over 40 years of age) has been about 501/100,000 since the 1980s, which is 34.4 times of the detection rate of the natural population, and one-third of which is the early-stage liver cancer. The highly sensitive alpha-fetoprotein test once or twice a year together with ultrasonography is the basic method to detect early liver cancer. The combined detection rate of the two can reach 97.9%, which can not only make up for the shortage of missed detection in AFP-negative patients, but also has an important value in the timely confirmation of liver cancer with low concentration of AFP. There is a contradiction between cost and benefit in liver cancer screening, and some people think that the early detection of screening is the “lead time” in diagnosis and treatment. However, before the current prevention of liver cancer causes is effective, the “lead time” gained from screening is of great value to the increasing number of long-term survival cases of detected patients. It must be emphasized that surgical resection should be adopted as aggressively as possible for small liver cancers detected at an early stage in order to achieve the goal of radical cure. The five-year survival rate of small hepatocellular carcinoma after radical resection reaches about 70%, while non-surgical treatment mostly results in death within two years. The key to the therapeutic effect of this disease lies in early diagnosis. Changing water, preventing mold and preventing hepatitis are the main preventive measures.