Accuracy of endoscopic size measurements of early gastric signet ring cell carcinoma

Background and aims Indications for endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) are expanding, but signet ring cell carcinoma (SRC) is still unclear because of its unclear boundaries. The purpose of this study was to compare pathologic size and endoscopic size in SRC-type EGC and to find risk factors associated with tumor size underestimation. Methods Medical records of 137 patients diagnosed with SRC-type EGC between January 2009 and December 2016 at our tertiary hospital were reviewed. According to pathologic and endoscopic tumor sizes, they were classified into correct estimation, underestimation, and overestimation groups, and risk factors related to underestimation were analyzed. Results Among 137 patients with SRC-type EGC, 77 patients (56.2%) had undergone correct estimation, 43 patients (31.4%) had undergone underestimation, and 17 patients (12.4%) had undergone overestimation. Mean pathologic size (SD) was 20.1 (13.8) mm and mean endoscopic size (SD) was 17.9 (10.1) mm, the correlation coefficients were 0.919 (p < 0.001) , and there was no significant difference between the two groups. Multivariate analysis showed that tumor size more than 20 mm (OR 3.419; 95% CI 1.271-9.194; p = 0.015) and atrophy (OR 6.011; 95% CI 2.311-15.633; p = 0.001) were risk factors for tumor size underestimation. Conclusion There was no significant difference in pathologic and endoscopic size in SRC-type EGC. Therefore, ESD may be considered as a therapeutic option if the size of the tumor is less than 20 mm and atrophy is not present in the surrounding mucosa.