Stomach Cancer Stomach cancer is a common malignant tumor in many countries around the world. The mortality rate of stomach cancer is highest in Japan and lowest in the United States. In China, the incidence and mortality rates of gastric cancer are also quite high, ranking at the forefront of malignant tumors. The etiology of gastric cancer is still not very clear. It is usually believed that its pathogenesis is multifactorial, including diet, environment, bacterial and viral infection, heredity and other factors. Primary prevention of stomach cancer: 1. Eat more fresh vegetables, fruits and melons, garlic, corn and other foods to increase the intake of vitamins A and C. 2. Increase the consumption of fresh meat, fish, eggs, milk and all kinds of soybean products, and relatively reduce the consumption of starchy foods, do not eat moldy foods, and eat fewer or no smoked, salted, deep-fried and soaked foods. 3. Develop good dietary habits, have meals on time, do not eat and drink excessively, and avoid Eat hard, coarse and too hot food; 4. Eat less salted food and reduce the amount of salt; 5. Don’t smoke, drink less strong alcohol, be cheerful and optimistic, don’t be angry, especially avoid being angry when eating. Secondary prevention of gastric cancer: the more applied measure is to screen high-risk groups for early detection of gastric cancer. Esophageal Cancer China is one of the high incidence areas of esophageal cancer in the world. Esophageal cancer may be the result of the long-term combined effect of multiple etiological factors and risk factors, i.e., nitrosamine compounds, fungi and toxins, nutritional imbalance, poor lifestyle and dietary habits as well as hereditary predisposition, mental factors and so on. Primary prevention of esophageal cancer: 1. Prevent moldy food; 2. Change dietary habits, eat less or no fermented and moldy food, no food containing fungal toxins and pay attention to nutritional balance; 3. Prevent drinking water pollution; Secondary prevention of esophageal cancer: 1. Pay close attention to precancerous lesions, such as chronic inflammation of esophagus, esophageal leukoplakia, benign esophageal stenosis, etc.; 2. If you find burning sensation at the back of the sternum, progressive difficulty in swallowing, If symptoms such as burning sensation behind the sternum, progressive difficulty in swallowing, belching, epigastric fullness, etc. are found, vigilance should be raised and timely examination should be conducted. Hepatocellular carcinoma Primary hepatocellular carcinoma (referred to as liver cancer) is one of the most important cancers that seriously threaten people’s lives. It ranks third on the cancer death spectrum in China. There are three main pathological types of liver cancer, i.e. hepatocellular carcinoma, cholangiocellular carcinoma and mixed liver cancer. Overall the etiology and pathogenesis of hepatocellular carcinoma are still unclear and may be related to a combination of factors. Currently, factors related to the development of liver cancer are found to be: viral hepatitis, aflatoxin B1, drinking water pollution, exposure to chemical carcinogens and alcoholism. Primary prevention of liver cancer: the main measures are “water control” (ensuring drinking water meets hygiene standards), “food control” (avoiding consumption of moldy food), “hepatitis prevention” (vaccination against hepatitis B), and paying attention to dietary hygiene. ), and pay attention to dietary hygiene. Secondary prevention of liver cancer: mainly early detection, early diagnosis and early treatment. Colorectal cancer The occurrence of colorectal cancer is a multi-factorial and multi-step process, and its risk factors can be categorized into three main groups – health background, genetic background and environmental background. Poor lifestyle plays an important role in the development of colorectal cancer. Primary prevention of colorectal cancer: 1. Low-fat diet with fat intake not exceeding 20% of total calories; 2. Pay attention to dietary balance; 3. At least 25 grams of fiber from different sources in the diet every day; 4. Avoid excessive calorie intake and overweight; 5. No smoking; 6. Appropriate exercise. Secondary prevention of colorectal cancer: rectal fingerprinting, sigmoidoscopy and fecal occult blood test.