Analysis of factors related to lymph node metastasis in undifferentiated early gastric cancer

Background/aims: This study was conducted to analyze the factors related to lymph node metastasis in undifferentiated early gastric cancer and to investigate whether endoscopic resection can be performed. Methods: Three hundred sixty-two early gastric cancer patients who were diagnosed with undifferentiated early gastric cancer and underwent surgery were divided into groups depending on their age, sex, location of tumor, macroscopic findings, presence of an ulcer, histological type, tumor size, depth of invasion, and lymphatic involvement, and the correlations between clinicopathological characteristics and lymph node metastasis were analyzed. Results: Lymph node metastasis was detected in 31 (8.5%) of the 362 patients. Univariate analysis revealed correlations between lymph node metastasis and various factors ranging from patient age, location of tumor, presence of an ulcer, and depth of invasion to lymphatic involvement. However, in multivariate analysis, presence of an ulcer and lymphatic involvement were found to be independent risk factors. After selecting and analyzing only patients with intramucosal early gastric cancer, we found that lymphatic involvement was the only independent risk factor. Conclusions: Though presence of an ulcer is an independent predictive factor for lymph node metastasis before operation in patients with undifferentiated early gastric cancer, caution is required in the interpretation. In addition, clinicopathologic:al characteristics such as histological type and tumor size did not have a significant effect on lymph node metastasis. Therefore, we found that the evidence was insufficient to select endoscopic resection even when there is a small lesion, and we believe that the decision on the use of endoscopic resection for patients with undifferentiated early gastric cancer should be made more carefully when there is an ulcer.