Abstract
Variation exists in the reported incidence of synchronous and metachronous gastric cancer, likely attributable to missed synchronous gastric cancer. The purpose of this study was to determine the status of the incidence of synchronous and metachronous gastric cancer within a year post endoscopic submucosal dissection (ESD) for early gastric cancer. We also retrospectively examined whether metachronous gastric cancer could be confirmed by endoscopic images taken at the preoperative examination. A total of 40 patients were surveyed 3, 6, and 12 months postoperatively by the same surgeon using the same endoscope (Olympus 260H). We detected 2 (5.0%) synchronous and 6 (15.0%) metachronous gastric cancers ; 3 of 6 metachronous gastric cancers were confirmed by endoscopic images. Metachronous gastric cancer detected within a year of ESD is clinically considered synchronous. Based on this definition, we found the incidence of synchronous gastric cancer to be surprisingly high at 20.0%. Our findings also suggest that most metachronous gastric cancers detected within a year of ESD are missed synchronous gastric cancers.
