Surgical Treatment for Patients Who Underwent Endoscopic Mucosal Resection (EMR)/Endoscopic Submucosal Dissection (ESD) of Early Gastric Cancer (EGC)

Purpose: To evaluate the necessity for additional surgical treatment after Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD), we analyzed the pathologic results of patients who underwent surgical treatment. Methods: 140 consecutive patients underwent additional surgical treatment after EMR/ESD with en bloc resection between April 2005 and November 2009 at ASAN Medical Center. Additional surgical treatments were undergone for following conditions such as incomplete dissection (involvement of margin), undifferentiated-type histology (≥2 ㎝) and submucosal cancer. Results: One patient with deep margin involvement displayed advanced gastric cancer after gastrectomy. Three of 74 patients with clear resection margin were confirmed to have residual cancer at ESD site and 2 of 3 patients displayed advanced gastric cancer after surgery. In univariate analysis for metastasis of lymph node, deep submucosal invasion (over sm2 or 500㎛) and the presence of lymphovascular invasion showed significant differences for lymph node metastasis. Especially, lymphovascular invasion was an important predictive factor for lymph node metastasis in multivariate analysis. In analysis for residual cancer, lateral margin involvement and large tumor (3 ㎝) were risk factors. And, only lateral margin involvement showed significant risk in multivariate analysis. Conclusion: Although EMR/ESD were fully accomplished for resection margin, gastrectomy and lymph node dissection were positively necessary for patients with deepsubmucosal invasion (over sm2 or 500㎛) and the presence of lymphovascular invasion to eliminate the possibility of residual cancer or more advanced gastric cancer or metastatic lymph nodes.