Treatment outcomes of endoscopic submucosal dissection and surgery for colorectal neoplasms in patients with ulcerative colitis

OBJECTIVES: This study aimed to clarify the validity and long‐term outcomes of colorectal endoscopic submucosal dissection (ESD) of visible lesions (≥20 mm) in patients with ulcerative colitis (UC) and investigate the incidence of undetected lesions in surgical specimens. METHODS: This single‐center retrospective study included 11 lesions from nine patients with UC who underwent ESD and 19 lesions from nine patients with UC who underwent colectomy between March 2001 and January 2019. We evaluated the endoscopic findings of scarring, atrophy, and loss of haustra in the ESD group, and we determined the lesion visibility in the colectomy group. We investigated the clinicopathological features of all lesions and examined the follow‐up evaluations in the ESD group. RESULTS: The en bloc and curative resection rates of ESDs were 91% and 82%, respectively. Endoscopic findings of scarring, atrophic colitis, and loss of haustra were observed in two (18%), seven (64%), and one (9%) lesions, respectively. The two lesions with scarring showed severe submucosal fibrosis. Mortality and recurrence were not observed during the median follow‐up of 25 months. Metachronous lesions ≥20 mm were detected in two patients, which were successfully treated with ESDs. In the colectomy specimens, 21% of the lesions were undetected, 67% had multiple neoplasms, and 33% had multiple invasive cancers. CONCLUSIONS: ESD is feasible and valid for large visible lesions in patients with UC; however, for lesions with endoscopic findings of scarring, technical difficulties in endoscopic resection must be considered. In addition, intensive surveillance colonoscopy is necessary to detect undetected lesions.