An evaluation of the feasibility of an expanded indication of endoscopic submucosal dissection for ulcer positive early gastric cancer: a case-control study from two medical centers

BACKGROUND: Endoscopic submucosal dissection (ESD) has increasingly gained broad application in the treatment of early gastric cancer (EGC). This study aimed at evaluating the clinical significance of lymph node metastasis (LNM) in patients with ulcer positive [UL (+)] EGC and assessing the feasibility of expanded indications of ESD for such cases. METHODS: Patients with UL (+) EGC undergoing radical surgical resection between January 2012 and December 2018 were retrospectively reviewed. Associations between clinicopathological factors and the incidence of LNM were investigated by univariate and multivariate linear regression analysis. RESULTS: Retrospective statistical analysis was performed on 653 EGC patients. The multivariate linear regression analysis showed that the presence of LNM was significantly associated with depth of invasion (P<0.0001) and lymphatic invasion (P<0.001). The proportion of EGC patients met absolute and expanded indication of ESD with positive LNM who were subject to the criteria of curative resection was 0.75% (4/532) and 6.67% (8/120), respectively. LNM between patients, which were subject to the absolute and expanded ESD indication, is significantly different (P=0.000274). CONCLUSIONS: Our study revealed that 6.67% (8/120) of EGC patients who did not meet all criteria of curative resection were present with LNM. EGC patients with UL (+), differentiated adenocarcinoma, tumor invasion pathologically diagnosed as T1a, and tumor diameter ≤3 cm showed for ESD are suggested for a carefully weighed treatment.