Some cases of early gastric cancer are treated with endoscopic resection, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). However, even if the decision to perform endoscopic treatment is made, the patient may undergo remedial surgery.
Because of the limitations of imaging and endoscopy, some patients are found to have tumor invasion of deeper structures only during surgery; after pathologic examination of the endoscopically excised tissue, tumor tissue is found to remain at the cut edge, which is often referred to by physicians as not meeting the criteria for R0 resection; and physicians may also find metastases in the lymph nodes surrounding the stomach during surgery. These are all high-risk factors for recurrence and metastasis of gastric cancer after endoscopic resection. In order to reduce the risk of recurrence and metastasis after surgery, physicians will take remedial surgery to eliminate the above risk factors and strive for radical resection of localized lesions to ensure R0 resection of early gastric cancer.
Remedial surgery after endoscopic treatment does not mean that endoscopic treatment has failed, but rather is a remedy and correction for the limitations of imaging. Of course, not all remedial procedures are needed after endoscopic treatment, and this should be left to the discretion of the physician. (Pengliang Wang, Department of Gastrointestinal Oncology, The First Hospital of China Medical University, contributed to the answer)