Gastric cancer remains one of the most common malignancies in the global population, with statistics showing that approximately 900,000 new cases are diagnosed globally each year, while 700,000 people die from gastric cancer. Although there is a slight decrease in the incidence of gastric cancer worldwide, the overall treatment effect is still unsatisfactory and the mortality rate still remains high. Stomach cancer is prevalent in Asian countries such as Japan, Korea and China, among which, China has the highest number of new cases in the world every year. Stomach cancer is the third most common tumor in China, with more than 400,000 new cases and 300,000 deaths per year, with incidence rates of 37.1/100,000 and 17.4/100,000 for men and women respectively, and incidence rates of about 13.73/100,000 for men (ranked second) and 8.71/100,000 for women (ranked third) in the developed city of Shanghai. Stomach cancer is mostly seen in men, and the age of incidence is most common between 40-60 years old, with a male to female ratio of 2.67:1, and rare under 30 years old. Causes of gastric cancer Stomach cancer is caused by multiple factors, but the following are the most common ones: 1. Long-term irregular diet, overeating, consumption of moldy grain, moldy food, salted food, smoked and pickled fish, excessive intake of salt, etc. can increase the risk of gastric cancer. 2.The presence of Helicobacter pylori infection and its secreted toxin can cause gastric mucosa lesions. 3.Genetic factors. According to epidemiological survey, stomach cancer has the tendency of family gathering, such as hereditary diffuse gastric cancer. 4. Precancerous lesions, i.e. systemic or local diseases and states prone to malignant changes, such as chronic atrophic gastritis, adenomatous gastric polyps, residual gastritis, etc. Clinical diagnosis of gastric cancer What are the clinical symptoms of gastric cancer? Most of the gastric cancers have no specific symptoms in the early stage, but there are symptoms similar to gastritis, such as fullness and vague pain in the middle and upper abdomen, increased acid reflux and belching, decreased appetite, and the feeling of obstructed swallowing when eating, etc. These symptoms are often ignored by patients; with the development of the disease, there will be bleeding and nausea, vomiting, weakness, wasting and other wasting symptoms, and when the tumor is bleeding, there will also be vomiting blood and black stool. When the tumor invades the retroperitoneal nerve tissue, back pain may also appear; and in the middle and late stage, systemic symptoms such as ascites, tumor intestinal obstruction and malignant fluid will appear. The main diagnostic methods are: gastroscopy, upper gastrointestinal tract imaging, CT examination, endoscopic ultrasound, etc., and finally, pathological diagnosis is required. Prevention of gastric cancer 1.Improve diet structure, eat more fresh vegetables and fruits; drink more milk and soy milk; reduce the intake of tobacco and alcohol, avoid long-term intake of unhealthy foods such as pickled, high salt, spicy, fermented and moldy foods, and eat less smoked, fried and baked foods. 2, improve eating habits and ways: to eat on time and in the right amount, avoid overeating; food should not be too hot, eating should not be too fast; eating with a happy mood, cheerful mood. 3, after the age of more than 40 years, once there is no obvious acute irritation factors resulting in upper abdominal discomfort or gastrointestinal symptoms, you should actively seek medical advice and perform gastroscopy. 4. Patients with long-term atrophic gastritis, gastric mucosal erosion, atypical hyperplasia of gastric mucosal glands or intestinalization, especially those with family history of suspected gastric cancer, should undergo regular gastroscopy annually. 5. Patients with H. pylori, who are heavily infected or have symptoms, should be actively treated with sterilization.