In the postoperative pathology report, it is often found that the focal lesion is cancerous, that is, tumor cells can be found in very small areas of the specimen, and the depth of tumor cell infiltration is very superficial, usually in the mucosal or submucosal layer, without breaking through the muscular layer or plasma layer. The T-stage of the tumor is limited to T1 or T2 stage, so it is relatively early and no lymph node metastasis has occurred. For this kind of tumor stage, chemotherapy is not needed after surgery, unless there are high risk factors, oral chemotherapy is also needed.