Feasibility of expanded indication for endoscopic submucosal dissection in undifferentiated early gastric cancer

Objective To evaluate the feasibility of expanded indication for endoscopic submucosal dissection (ESD) in undifferentiated early gastric cancer, to investigate the risk factors of lymph node metastasis (LNM), so as to provide the theoretical evidence for the choice of treatment. Methods From June 2007 to December 2018, at the Affiliated Hospital of Qingdao University, the clinical and pathological data of 807 patients with undifferentiated early gastric cancer and undergoing gastrectomy plus lymphadenectomy were retrospectively analyzed. Chi-square test was performed to analyze the correlation between clinicopathologic characteristics of early gastric cancer and LNM. Multivariate logistic regression model was used to analyze the independent risk factor of LNM. Results LNM was found in 17.2% (139/807) patients with undifferentiated early gastric cancer. And no LNM was detected in 110 patients who met the expanded indication of ESD. The results of univariate analysis indicated that LNM was significantly associated with increased carcinoembryonic antigen (CEA), tumour size, gross type, ulcer, invasion depth, lymphovascular invasion and perineural invasion (χ2=4.500, 13.332, 16.611, 6.083, 51.064, 0.564 and 17.006, all P 500 μm ; OR=3.014, 95%CI 1.753 to 5.181, P<0.01) were independent risk factors of LNM in early gastric cancer. Conclusions The expanded ESD indication of undifferentiated early gastric cancer is applicable for endoscopic treatment considering the low risk of LNM. In early undifferentiated gastric cancer, maximum diameter of tumor over 20 mm, lymphovascular invasion, submucosal superficial and deep invasion are the independent risk factors of LNM. Key words: Endoscopic submucosal dissection; Risk factor; Undifferentiated early gastric cancer; Expanded indication; Lymph node metastasis