When gastroscopy is done one year later, there are several cases of gastric cancer.1. When gastroscopy is done at that time, the lesion in the patient’s stomach is relatively small, which is not detected during the examination, and then after one year, the tumor gradually progresses to form gastric cancer, and the patient will have related symptoms, such as pain in abdomen, nausea, black stools and so on.2. When gastroscopy is done in the patient’s stomach, the lesion inside the stomach is relatively hidden, and the patient may not be able to find it in time if the endoscopist is not very rich in experience. If the endoscopist is not rich in experience, he may not find it in time, for example, the lesion at the bottom of the stomach may not be found.3. The lesion in the stomach is under the mucous membrane, which is not especially obvious, so it is not found during gastroscopy. If the patient has epigastric symptoms, if necessary, can do epigastric CT combined examination.