S-2 : Risk Factors of Invasion in Early Gastric Cancer Resected by Endoscopic Submucosal Dissection

Backgroud: Knowing the exact depth of the lesion before submucosal dissection (ESD) remains a question and can only be confirmed by final pathologic report following ESD. And patients with submucosal or lymphovascular (SM/LV) invasion may need additional surgery including lymph node dissection because SM/LV invasion have relevant to higher risk for lymph node metastasis. The purpose of the study is to investigate the risk factors for SM/LV invasion in EGC. Methods: We retrospectively reviewed clinical and pathological datas in patients underwent ESD from Jan 2010 to May 2014 and presenting EGC of 2.0 cm or smaller in size, a differentiated-type adenocarcinoma, and without ulceration. Results: Among 425 lesions consecutively resected by ESD, 323 lesions in 302 patients were included in this study. Submucosal and lymphovascular invasions were detected in 42 lesions. Multivariate analysis revealed that histology of moderate-differentiated (odds ratio (OR) 4.231; 95% CI 1.925-9.013; p＝0.000), location of upper and middle third (U/M) of stomach (OR 3.200, 95% CI 1.511-7.001; p＝0.007) were significant risk factors for SM/LV invasions. Conclusions: Histology of moderate-differentiated adenocarcinoma, and location of U/M were identified as independent risk factors of SM/LV invasion in EGC meeting absolute criteria for ESD.