Management Strategy of Non-curative ESD in Gastric Cancer: Curative Criteria, and the Critical Building Block for Determining Beyond It

Endoscopic submucosal dissection is performed in cases of early gastric cancer, where the risk of lymph node metastasis (LNM) is expected to be negligible, and 12%-21% of these patients are deemed to have undergone non-curative resections based on pathological criteria. In such cases, decisions regarding additional treatments must be made to maximize curability, depending on the anticipated LNM risk. Well-established risk factors for LNM include lymphatic invasion, vascular invasion, deep submucosal invasion, positive vertical margins, and larger tumor size. When pathological factors associated with a clear LNM risk, such as lymphatic or deep submucosal invasion, are present, additional gastrectomy with lymph node dissection should be considered. Conversely, in cases involving only a positive horizontal margin, additional endoscopic treatment may be an effective therapeutic option as opposed to gastrectomy because of the negligible risk of LNM despite the potential risk of residual tumors. Endoscopic resection is particularly advantageous for determining complete resection. In addition to pathological curability, patient-specific factors, such as age and comorbidities, must be considered. Several retrospective cohort studies have shown that the cause of mortality among patients placed only on observation without additional treatment after non-curative resection is generally related to underlying conditions irrelevant to gastric cancer. Thus, it is crucial to assess both GC-specific mortality and all-cause mortality to finalize treatment decisions that help minimize such mortality. Therefore, new treatment algorithms that integrate pathological curability with patient-specific factors must be developed.