Clinicopathologic Factors of Lymph Node Metastasis from the Early Gastric Cancer Located in the Upper Third of Submucosa

Abstract

Introduction: Endoscopic resection (ER) of early gastric cancer (EGC) is comparable in many respects to conventional surgery, with the advantages of being less invasive and more economical. However, ER has the risk of lymph node metastasis (LNM) weighed against the risk of surgery. Proposed expanded criteria of ER was based on the accumulation of operation data about EGC. Aims and Methods: We review a large series of gastrectomies about submucosa invasive EGC to validate the expanded criteria of ER in Korea. Among the patients who had undergone the gastrectomy with lymph node dissection for EGC at Samsung medical center (SMC) in Korea, we investigated 278 EGC cases located in the upper third of submucosa, SM1. Clinicopathological factors were assessed for their possible association with LNM. Results: LNM was detected in the twenty-eight (10.7%) from 278 patients. The mean age (57.5 in positive LNM group vs. 60.0 in negative LNM group) and sex ratio (M: F; 1.80: 1 in positive LNM group vs. 2.33: 1 in negative LNM group) were not different between the two groups. The tumor size, the microscopic ulcer within tumor and the presence of lymphatic involvement showed a positive correlation with a LNM by univariate analysis. Multivariate analyses revealed that the lymphatic involvement was identified as independent risk factors for LNM (p<0.001, respectively). LNM was not found in any patient with EGC smaller than 2.0 cm confined to the upper third of the submucosal layer without lymphatic involvement. Conclusion: We have been able to clarify the risk factors of LNM associated with EGC located in SM1. Therefore, SM1 invasive EGC patients without the risk factors were considered as the candidate of ER.