Extended Indication Criteria for Endoscopic Mucosal Resection of Early Gastric Cancer with Special Reference to Lymph Node Metastasis: Examination by Multivariate Analysis

The purpose of this study was to clarify extended indication criteria of endoscopic mucosal resection (EMR) for early gastric cancer (EGC) by analyzing the independent risk factors involved in lymph node metastasis (LNM). Subjects were 422 patients who underwent gastrectomy with lymph node dissection for EGC at the Kurume University Hospital from 1994 to 2001. The EGCs were mucosal cancers (M) in 252 cases and submucosal cancers (SM) in 170 cases. Twelve clinico-pathological factors were assessed for their possible association with LNM. On univariate analysis, EGC with LNM showed the following characteristics: size; 3.1 cm or more, ulceration; present, heterogeneity; present, differentiation; poor, lymphatic vascular invasion; present, and invasion depth; SM2 (cancer penetration of submucosal layer, 0.5 mm or more from the muscularis mucosa). On multivariate analysis, the following four factors were identified as independent risk factors; invasion depth: Odds Ratio (OR) 10.9, lymphatic vascular invasion: OR 10.6, size: OR 3.2, and ulceration: OR 3.2. The incidence of LNM was 0% (01141) (95% confidence interval, 0-2.6%) when these risk factors met the following four conditions: invasion depth; M or SM1 (cancer penetration of submucosal layer, less than 0.5 mm), lymphatic vascular invasion; absent, size; 3.0 cm or less, and ulceration; absent. It is concluded that EMR is a suitable radical treatment for EGC, and that the indication criteria for EMR can be extended depending on the results of the histological evaluation of the en bloc/total resected specimen concerning the above four factors for LNM.