There are nearly 200,000 new cases of gastric cancer in China every year, accounting for 17.2% of all malignant tumors and ranking first in the incidence of all malignant tumors. The mortality rate of gastric cancer accounts for 23.02% of all malignant tumor deaths, which also ranks first among all types of cancer deaths, and about 160,000 people die from gastric cancer every year. The 5-year survival rate of patients with early gastric cancer, regardless of whether there are lymph node metastases or not, exceeds 90% after surgery, and the 10-year survival rate of small gastric cancer and micro gastric cancer in the initial stage can reach 100%. Therefore, early, timely and accurate detection of gastric cancer is of great importance to reduce the mortality rate of gastric cancer. The occurrence of gastric cancer is the result of the long-term combined effect of infection, environmental factors and host genetic factors and lifestyle. The development of gastric cancer is related to many risk factors, all of which can be used as early warning indicators of gastric cancer. Domestic and international studies have reported different risk factors for gastric cancer, which mainly include the following aspects. Helicobacter pylori infection (Hp): Hp is an important pathogenic factor for many chronic gastric diseases. Prospective studies have shown that the risk of gastric cancer can be increased 2-3 times in Hp-infected individuals. Epidemiological studies have also shown that the decreasing trend of Hp infection in developed countries is consistent with the decreasing trend of gastric cancer incidence in recent years. EBV infection (EBV): EBV can be detected in the tissues of most rare lymphoepithelioma-like gastric cancers and a few common gastric adenocarcinomas, and EBV infection plays an important role in the development of EBV-associated gastric cancer. N-nitroso compounds: Exogenous N-nitroso compounds and their precursors nitrate and nitrite intake are associated with gastric cancer, and endogenous nitrosamine synthesis capacity is also associated with gastric mucosal lesions. Dietary nitrates and nitrites can form these compounds. Polycyclic aromatic hydrocarbons and heterocyclic amine contamination: Heterocyclic amines with mutagenic and carcinogenic effects are produced in fish and meat foods during frying and deep-frying. In addition, when the food is smoked and fried on the fire, the organic matter can form polycyclic aromatic hydrocarbons by high temperature decomposition and incomplete combustion, followed by metabolic activation into highly toxic metabolites, which can irreversibly damage biological macromolecules and produce many toxic effects in the body. Occupational factors: certain substances in the working environment may play a role in the development of stomach cancer. Some studies have shown that leather manufacturing, construction, metal manufacturing may be related to the development of stomach cancer. Some domestic and foreign studies on occupational exposure to asbestos have shown that it is associated with the risk of gastric cancer development, but there may be methodological bias in these studies. Drinking water contamination: Drinking water chlorination disinfection by-products may be a causative factor for digestive system cancer and urinary tract cancer, but the results of studies in different regions are not yet consistent . Stomach disease: Since Hp infection is a risk factor for gastric and duodenal ulcers and gastric cancer, early peptic ulcers are naturally considered to be associated with gastric cancer risk. History of gastric surgery: Many studies have shown that gastric surgery can increase the risk of gastric cancer, and this risk mainly occurs 15 years after gastric surgery. History of smoking: The exact mechanism by which smoking increases the risk of gastric cancer is not known. In gastric cancer cases in which smoking is associated with significantly more DNA adducts than in non-smokers. Studies have shown a weak to moderate correlation between smoking and gastric cancer. History of alcohol consumption: Beer and whiskey may contribute to the development of gastric cancer due to the presence of nitrosamines in beer and whiskey, and alcohol itself may be a risk factor for gastric cancer. A French study showed that the risk of stomach cancer in alcoholics who consume more than 567g of alcohol per week is 6 times higher than that of non-drinkers. Dietary factors: Diet plays an important role in the occurrence of gastric cancer. Carbohydrate-rich foods, smoked and salted products, and dried fish are risk factors for gastric cancer, as is the long-term consumption of hot and spicy foods. Long-term high-salt diet may increase the risk of gastric cancer due to atrophic gastritis. High-risk groups of stomach cancer 1. Those who have been infected with H. pylori 2. Men who have exceeded 20-25 kg of normal weight or men who smoke 3. Those who often eat pickled food and smoked fish 4. Those who have a history of stomach polyps or stomach surgery 5. Those with family history of tumor 10.Patients with blood type A 11.Patients with chronic atrophic gastritis 12.Patients with gastric ulcer