Background/aim: Early gastric cancer (EGC) with signet ring cell histology has a more favorable prognosis than other undifferentiated gastric adenocarcinomas. The presence of lymph-node metastasis is the most important factor in treating EGC by endoscopic resection. The aim of this study was to identify the factors predicting successful endoscopic treatment of EGC with signet ring cell histology.
Methods: Data from 215 patients who had undergone gastrectomy with D2 lymph-node dissection for EGC with signet ring cell histology between January 1999 and December 2007 were retrospectively reviewed. Associations between various clinicopathological factors and the presence of lymph-node metastasis were analyzed to identify factors predictive of lymph-node metastasis.
Results: The overall incidence of lymph-node metastasis was 7.9%: 1.9% with intramucosal cancer and 6% with submucosal cancer. Univariate analysis identified the depth of tumor invasion to the submucosa and positive lymphatic-vascular involvement as associated with lymph-node metastasis (both P<0.01). On multivariate analysis, positive lymphatic-vascular involvement was the most significant factor related to lymph-node metastasis (odds ratio: 43.7; 95% confidence interval: 8.7-220.9), followed by the depth of invasion (odds ratio: 4.87; 95% confidence interval: 1.02-23.21). Patients with EGC with signet ring cell histology and a diameter of less than 25 mm, invasion within the sm2 layer, and no lymphatic-vascular involvement had no lymph-node metastasis.
Conclusion: EGC with signet ring cell histology can be treated by endoscopic mucosal resection, if it is smaller than 25 mm, limited within the sm2 layer, and does not involve the lymphatic-vascular structure. More extensive prospective data are required to confirm definitive guidelines for the endoscopic treatment of patients with EGC with signet ring cell histology.