Risk factors associated with multiple and missed gastric neoplastic lesions after endoscopic resection: prospective study at a single institution in south Korea.

Background/Aims: Only a small part of visible gastric mucosal lesion can be removed by endoscopic resection. This study is aimed to identify incidence rate and associated risk factors of multiple and missed gastric lesions, and proper timing of follow-up endoscopy. Methodology: Endoscopic surveillance was performed on 1 week, and 1, 6, 12 months after endoscopic resection. All multiple gastric lesions were divided into main and accessory lesions. The accessory lesions were subdivided into detected and missed lesions. Results: Totally, 250 lesions of 215 patients. Were analyzed. There were 81 early gastric cancers,50 high grade dysplasias and 119 low:grade dysplasias. Thirty patients (14%) had multiple gastric neoplastic lesions, either adenoma or cancer, within 1 year follow-up after endoscopic resection. Old age, male gender and severe intestinal metaplasia were independent risk factors of multiple gastric lesions. Small size (<= 1cm) and flat morphology were major risk factors of missed lesion. Among 10 missed lesions, 9 (90%) could be detected within 6 month after resection. Conclusions: Old age, male gender, severe intestinal metaplasia were risk factors for multiple gastric lesions after endoscopic resection. Followup endoscopy is needed at least one time within six months after resection, with careful inspection of entire stomach.