The most common reason for the occurrence of gastric cancer is a history of peptic ulcer, and repeated episodes can lead to chemosis or atypical hyperplasia of the mucosal epithelium of the gastric wall. It takes about 1-2 years from atypical hyperplasia to carcinogenesis. If the symptoms of irritation to the gastric wall are very obvious, prolonged overeating, eating barbecued or fried food, the process of carcinogenesis will be shortened, and some patients will change from benign ulcer to malignant tumor in about six months. In addition, benign polyps may also be transformed into cancer, which occurs within the time frame of 1-2 years. Therefore, if a polyp larger than 1 cm is found by gastroscopy, it should be ligated or gastroscopically removed in time to prevent cancer.