I. China is a region with high incidence of gastric cancer, with the second highest incidence and mortality rate of malignant tumors Gastric cancer is one of the common gastrointestinal malignant tumors in the world, with relatively poor prognosis, which seriously affects human health. According to the statistics of the International Agency for Research on Cancer, in 2012, there were about 951,000 new cases of gastric cancer and 723,000 deaths due to gastric cancer worldwide, which ranked 5th in incidence and 3rd in mortality of malignant tumors, respectively. More than 70% of the new cases of gastric cancer occurred in developing countries, especially in eastern Asia, and are mainly concentrated in China. According to the 2015 China Cancer Data Report, the incidence and mortality rate of gastric cancer in China ranked the second in the incidence of malignant tumors. There are obvious geographical differences in the incidence of gastric cancer in China, and the incidence rate of gastric cancer in northwest and eastern coastal areas of China is significantly higher than that in southern areas; the age of prevalence is above 50 years old, and the ratio of male to female incidence rate is 2:1. What factors are related to the incidence of gastric cancer? 1. Bad diet is closely related to the development of gastric cancer. Avoid consuming moldy food, which contains carcinogenic substances such as aflatoxin and leucococcus, which may lead to the occurrence of gastric cancer after long-term consumption. The cooking process of barbecue contains a lot of harmful substances, which is also closely related to stomach cancer. In addition, pickled food contains a large amount of nitrate and nitrite, which are also the culprits of cancer. A balanced diet, fresh fruits and vegetables and protein intake process can not only ensure the balanced nutrition of human body, but also reduce the probability of cancer. Suggestions: eat more green vegetables and fruits; eat less pickled and barbecued foods; do not smoke and drink less alcohol (the carcinogenic substances in tobacco are related to various cancers) 2. Stomach underlying diseases can be transformed into stomach cancer. HP infection can cause damage to mucosal epithelial cells of the stomach, which can lead to gastric ulcer, chronic atrophic gastritis and other diseases, and such diseases can be converted into gastric cancer through a series of processes. Therefore, regular anti-HP treatment is of great significance for the prevention and treatment of gastric cancer. In addition, diseases such as adenomatous polyp, remnant stomach, atrophic gastritis and gastric ulcer are precancerous lesions and closely related to the occurrence of gastric cancer. It is recommended that patients with H. pylori infection should actively seek regular treatment in gastroenterology; patients with the above-mentioned gastric diseases should have regular hospital checkups. 3.Hereditary gene. The power of hereditary gene is powerful, and the development of gastric cancer has the phenomenon of family gathering. It is found that parents and siblings of stomach cancer patients have an average risk of stomach cancer three times higher than the general population. In Napoleon’s family, his grandfather, father and three sisters all died of stomach cancer, and the whole family, including himself, had 7 people suffering from stomach cancer. What are the symptoms of stomach cancer? The symptoms of early gastric cancer are not typical, so it is easy to be ignored and mistaken for gastritis or gastric ulcer. If the tumor develops to a certain extent, it can be manifested as: indigestion, abdominal distension, loss of appetite, nausea and vomiting and other non-specific manifestations; pain in the upper abdomen, and patients with previous gastric ulcers need to pay attention to the cancerous changes of ulcers when there are changes in the nature, location and rhythm of pain; black stool. In particular, middle-aged and old people (mostly men) with long-term upper abdominal discomfort and recent loss of appetite, lethargy and weight loss should be alerted to the occurrence of gastric cancer. What is the most important thing in the prevention and treatment of gastric cancer? Regular physical examination! Chinese gastric cancer patients usually have obvious symptoms when the tumor is found, and most of them have developed into progressive gastric cancer. Compared with Japan and Korea, which also have high incidence of gastric cancer, the prognosis of Chinese gastric cancer patients is obviously worse, and the main reason is the late detection of gastric cancer in China. According to the author’s comparison of 10 years of data on gastric cancer between Peking University People’s Hospital and Seoul St. Mary’s Hospital in Korea, the progression of stage I gastric cancer in our hospital is 16%, while that in Korean hospitals is 65%. 5-year survival rate, according to the SEER database in the United States: for tumors confined to the stomach wall, it is 67&, for those with local lymph node metastasis, it is reduced to 30.7%, and for those with distant metastasis, it is only 5.2%. Therefore, early detection of gastric cancer is very important. Since there are no specific symptoms in the early stage of gastric cancer, it is recommended that high-risk groups: those older than 40 years old, areas with high prevalence of gastric cancer, those with H. pylori infection, those with chronic atrophic gastritis, gastric ulcer, post-surgical residual stomach, and those with family history of gastric cancer need to review gastroscopy at least once a year under the premise that we have not yet achieved national gastric cancer screening.