Risk of recurrence when cutting into intramucosal (pT1a) cancer from the cutting-plane side during gastric endoscopic submucosal dissection.

Abstract

During endoscopic submucosal dissection (ESD), procedural difficulty and poor visibility of the cutting plane sometimes cause the operator to cut into the lesion from the cutting-plane side, making the vertical margin positive (VM1) or unclear (VMX). In the present study, we evaluated the risk of recurrence of gastric cancer with VM1 /VMX after ESD. In total, 1723 consecutive gastric cancers treated by ESD at Osaka International Cancer Institute from July 2012 to December 2017 were included in this retrospective cohort study. Among them, 231 submucosal or more deeply invasive gastric cancers were excluded because nontechnical factors may contribute to VM1 /VMX in such lesions. To quantify the risk of cutting into cancer from the cutting-plane side during ESD, the proportion of lesions with VM1 /VMX among the pT1a gastric cancers treated by ESD was calculated. The proportion of recurrence among these cases was calculated after exclusion of lesions with positive lymphovascular invasion or a positive horizontal margin in order to eliminate the obvious risk factors for recurrence. Among 1492 pT1a gastric cancers treated by ESD, 28 lesions (1.9 %; 95 % confidence interval [CI] 1.3 % - 2.7 %) histologically showed VM1 /VMX. No local recurrence (0.0 %; 95 %CI 0.0 % - 12.2 %) occurred among 23 cases. The median follow-up period was 41 months (range 10 - 84 months). No local recurrence was detected in pT1a gastric cancers after VM1 /VMX resection by ESD. Surveillance endoscopy could be adopted for such cases without additional surgery.