The development of advanced adenoma after colorectal endoscopic submucosal dissection and appropriate follow-up colonoscopic examinations

Purpose: The aim of this study was to examine advanced adenomas after colorectal endoscopic submucosal dissection (ESD). Methods: We studied 465 colorectal tumors which were followed after ESD (Mean follow-up period: 20.6 months). The clinical features of advanced adenomas developing during follow-up periods were analyzed. Advanced adenomas were defined neoplastic lesion more than 10 mm in size according to previous report. Results: The number of advanced adenoma was 58 lesions in 47 cases (10.8%, 47/465). Of the 58 tumors, 41 were located in the right-sided colon (70.7%) and 27 in the left sided colon (27.6%) and 1 in the rectum (1.7%). The median period by detection of these lesions was 22.2 Mo (range: 3-45 Mo). The histopathological diagnosis was as follows: 52 tumors were adenoma (89.7%), 2 tumors were intramucosal carcinoma (3.4%), 1 tumors were carcinoma with submucosal invasion (1.7%), and 3 tumors were advanced colonic cancer (5.2%). Concerning of factors about ESD, lesions of ESD in the right sided colon had higher rate of developing lesions than those in the rectum (13.4% vs 4.8%, P=0.01). Conclusions: The development of advanced adenoma was detected in about 10% after colorectal ESD. Follow-up total colonoscopic examinations 3 to 45 Mo after ESD is expected appropriately.