If the stomach cancer is early, it is possible that the results of tumor indicators are normal. If gastric cancer is more advanced and invades the pancreas or has lymph node metastasis in the retroperitoneum, the tumor indexes may increase, such as CA199 and CEA, but in most cases, AFP is normal. If the gastric cancer progresses to a certain extent, such as systemic metastasis or intra-abdominal metastasis, all indicators will be increased, for example, AFP may be increased at the same time. In addition, routine blood tests are needed to check the hemoglobin and red blood cells, whether there is bleeding and anemia, as well as routine coagulation, biochemical and immunological tests to understand the coagulation function, liver function, kidney function and albumin.