Lymph node metastasis in differentiated-type early gastric cancer: a single-center retrospective analysis of surgically resected cases

Background. Lymph node metastasis (LNM) from early gastric cancer (EGC) is rare, especially for differentiated-type EGC. However, LNM has been reported in a few cases after endoscopic curative resection of differentiated-type EGC. This study aimed to evaluate LNM risk factors to identify those that should be considered during the preoperative evaluation of differentiated-type EGC. Patients and methods. A total of 976 EGC patients who underwent radical gastrectomy were reviewed in this study. Univariate and multivariate analyses were used to analyze the predictive factors for LNM based on the histology of the differentiated-type EGC cases. Results. Differentiated-type EGC was observed in 59% of the cases. The rate of LNM was 6.6% (38/576 patients) in the differentiated-type EGC cases. Macroscopic shape, ulcers, tumor size, deeper invasion and lymphovascular invasion were shown to be related to LNM in differentiated-type EGC. Multivariate analysis revealed that size, depth, ulceration and lymphovascular invasion were independent predictors of LNM in differentiated-type EGC. When lymphovascular invasion was absent, the presence of one or more of the risk factors of ulcer lesions, tumor size >30 mm and submucosal invasion increased the rate of LNM. Thirteen patients who underwent radical gastrectomy were shown to have differentiated-type EGC with LNM that met the standard and expanded criteria of endoscopic submucosal dissection. Conclusions. As endoscopic resection is widely used, it is important to clarify the clinical significance of LNM in differentiated-type EGC and to screen for LNM with this incidence in mind and to follow the clinical courses of such cases, especially in China.