What are the risk factors for residual tumor cells after endoscopic complete resection in gastric epithelial neoplasia?

Abstract

Background: In early gastric cancer (EGC) and gastric adenoma, residual tumors may develop despite complete endoscopic resection (ER). To improve the chance of curative resection, we investigated the risk factors of residual tumor development in completely resected gastric epithelial neoplasia after ER. Methods: In total, 3,879 gastric epithelial neoplasms showing complete resection after ER were examined; 46 (1.2 %) residual tumors were found upon follow-up endoscopy. Clinicopathological characteristics were evaluated between those with and without residual tumors. Results: For gastric adenoma, high-grade dysplasia and severe intestinal metaplasia (IM) in the background mucosa were significantly associated with residual tumors. For EGC, poorly differentiated adenocarcinoma (PD), signet ring cell carcinoma (SRC), having a minimum lateral safety margin of <3 mm, and localization in the upper third of the stomach were significantly associated with residual tumors. Multivariate analysis revealed that a lateral safety margin of <3 mm (OR 13.8; p < 0.001), PD (OR 16.3; p = 0.014), and SRC (OR 9.8; p = 0.009) among EGC patients, and severe IM in the background mucosa (OR 9.0; p = 0.024) among gastric adenoma patients, were significantly associated with residual tumors. Conclusions: For neoplasms with undifferentiated histology (PD or SRC), short-term endoscopic follow-up may help to detect residual tumors that form after complete resection via ER. For EGC, the lateral margin may be considered safe if greater than 3 mm. However, the possibility of satellite lesions should be investigated when the gastric adenoma to be resected is surrounded by severe IM.