Well‐trained and planned: Preparation for endoscopic submucosal dissection for early gastric cancer

Doctor Hsieh et al [1] presented their experiences about the outcome of endoscopic submucosal dissection (ESD) for early gastric cancer and precancer lesion. In their report, ESD was curative for gastric tumors in 73.9% and 8.93% with local recurrence. Further analyzed, the cumulative local recurrence rates were 5.3% in the curative resection group and 56.7% in the noncurative resection group. The risk factors that affect the noncurative resection include: tumor location; deeper invasion; undifferentiated histopathology; and ulcer presence. ESD showed 95% en bloc resection rate and about a 90% complete resection rate in several Japanese studies [2,3]. In a Korean multicenter study of ESD, the rates of en bloc resection and complete resection were reported to be 95.3% and 87.7%, respectively [4]. Evidence supports that endoscopic resection for early gastric cancer without lymph node metastasis, has similar efficacy compared to open surgery [5]. ESD is better than endoscopic mucosal resection for the removal of large lesions. However, the technical difficulty requires a long learning period to achieve a similar outcome as surgery. Of the noncurative lesions, 44.44% had en bloc resection with the margin involved by cancer. ESD must be able to reduce the risk of local recurrence than endoscopic mucosal resection. However, if the lateral margin of the tumor is misdiagnosed and resected incompletely, local recurrence cases cannot be avoided. Making a precise diagnosis of the tumor is indispensable for initiating ESD. For the expanded criteria of endoscopic resection in patients with early gastric cancer, there are some issues to consider. The first is the risk of lymph node metastasis. In a Korean study, 855 patients who underwent gastrectomy with lymph node dissection for early gastric cancer were analyzed; lymph node metastasis was identified in 4.7% of