How can we predict the presence of missed synchronous lesions after endoscopic submucosal dissection for early gastric cancers or gastric adenomas?

Goals: To identify predictive factors associated with the presence of missed synchronous lesions after endoscopic submucosal dissection (ESD) for gastric adenoma or early gastric cancer (EGC). Background: Secondary gastric neoplasms that develop during follow-up period after ESD for gastric adenoma or EGC are divided into metachronous lesions and missed synchronous lesions. Methods: ESD was performed in 250 patients with EGC or gastric adenoma. The patients with endoscopic follow-ups of < 1 year, patients without curative resection, and patients with additional surgery were excluded from the study. Missed synchronous lesions were defined as secondary gastric neoplasms detected within one year of ESD but initially missed. We compared clinicopathologic factors between patients with missed synchronous lesions and patients without missed synchronous lesions. Results: Missed synchronous lesions were found in 11.6% of the patients (29/250). The occurrence of missed synchronous lesions had significant correlation with tumor number at the time of ESD and age in the univariate analysis. Tumor number at the time of ESD and age were significant independent predictive factors for presence of missed synchronous lesions by multivariate logistic regression analysis (odds ratio 5.302, P = 0.006; odds ratio 2.315, P = 0.040, respectively). Missed synchronous lesions tended to be smaller, often located in the same third of the stomach as the main lesions. Conclusions: Tumor number at the time of ESD and age could be predictive factors for the presence of missed synchronous lesions after ESD. Careful endoscopic surveillance should be performed after ESD for multiple lesions or for elderly patients.