Local Recurrence and Its Risk Factor after Incomplete Resection of Colorectal Advanced Adenomas: A Single Center, Retrospective Study.

Background/Aims: Colonoscopy can detect precancerous lesions, which can subsequently be removed and reduce incidences of and mortality from colorectal cancer (CRC). However, recently published data have highlighted a significant rate of CRC in patients who previously underwent colonoscopy. Among many reasons, incomplete resection has been considered as a significant contributor. However, to date, there have only been a few studies regarding incompletely resected polyps, especially advanced colorectal adenoma (ACA). Hence, we aimed to evaluate the prognosis of incompletely resected ACA.

Methods: We retrospectively reviewed the medical records of patients with ACA who had underwent endoscopic treatment with incomplete resection. The primary outcomes were (1) the incomplete resection rate of ACA, as determined by a histopathologic examination and (2) the recurrence rate of incompletely resected ACA. We also investigated the probable contributing factors that may have led to a relapse of incompletely resected ACA.

Results: A total of 7,105 patients had their colorectal polyps resected by endoscopic treatment, and 2,233 of these were considered as ACA. Of these, 354 polyps (15.8%) were resected incompletely, and only 163 patients were followed-up. Of those followed-up, 31 patients (19.0%) experienced local recurrence. The risk factors for recurrence after incomplete resection were evaluated; age, morphology of adenoma, and use of rescue therapy, such as argon plasma coagulation, were found to be associated with adenoma recurrence.

Conclusions: Incompletely resected ACA in older patients or in patients with sessile-type adenomas should be monitored strictly, and if incomplete resection is suspected, rescue therapy must be considered.