Gastric cancer refers to the malignant tumor occurring in the gastric mucosa epithelium, with a high incidence, ranking second in male malignant tumors and fourth in female malignant tumors. The mortality rate is also high, with men ranking third and women ranking fifth. Generally speaking, gastric cancer is a malignant tumor growing in the stomach, most of which are adenocarcinoma of the stomach. This is the most common type of gastric cancer. Next, there is a malignant tumor of the stomach called gastric lymphoma. When the doctor suspects that there is a tumor in the stomach, an indispensable examination is gastroscopy, which is used to obtain tumor tissue for pathological diagnosis. If the examination result shows gastric cancer, the first choice is surgery, and then consider chemotherapy and radiotherapy. If the result is gastric lymphoma, surgery is not necessary. And it can be completely treated by chemical drugs, which can achieve very good curative effect and even cure. Therefore, if there are tumors in the stomach, they must be differentiated by pathological diagnosis through gastroscopy, so gastroscopy is very important!