The incidence and clinicopathologic features of metachronous gastric tumors after endoscopic submucosal dissection.

Abstract

37 Background: Endoscopic submucosal dissection (ESD) has become a standard method of treatment for gastric tumors. The synchronous and metachronous development of two or more primary adenocarcinomas occurs in 10 to 20% of all cases of stomach cancer. Therefore, metachronous recurrence should be a consideration after ESD has been performed. The aim of this study was to review our experiences in the management of patients with synchronous and metachronous lesions, and to evaluate their incidence and clinicopathologic features. Methods: We reviewed 194 patients who underwent ESD for gastric tumors between January 2007 and December 2011. Synchronous lesions were defined as secondary gastric tumors detected within 6 months after the initial ESD. Metachronous tumors were defined as those detected more than 6 months after the initial ESD. We investigated the incidence and clinicopathologic features of synchronous and metachronous tumors after ESD. Results: In total, 20 patients (10.3%) had synchronous lesions and 19 patients (9.8%) had metachronous lesions. The annual incidence of metachronous tumors after ESD was 2.93%. The median period until discovery after initial ESD was 40.1 months. Female patients developed synchronous and metachronous tumors more frequently than male patients (p = 0.037). Patients with H. pyloriinfections developed tumors more frequently than those without (p = 0.04). There were no significant differences with respect to the type and differentiation of tumors. Conclusions: Synchronous and metachronous lesions of gastric tumors were considerably prevalent after ESD. Considering the results of this study, careful endoscopic investigation should be performed after ESD for female patients and those with H. pylori infections. However, further large-scale and longer prospective studies are needed.