Background and aims: Colorectal neoplastic lesions (≥ 20 mm) are commonly treated via piecemeal endoscopic mucosal resection (p-EMR) but have a high rate of local recurrence. We aimed to clarify the optimal surveillance interval after p-EMR for these neoplasias.
Methods: In this multicenter (15 participating institutions) prospective, randomized trial, 180 patients recruited over a 4-year period and were classified based on tumor location, tumor diameter, histological diagnosis, institution, and number of resected specimens. The patients underwent curative p-EMR followed by scheduled surveillance colonoscopy at 3, 6, 12, and 24 months after p-EMR (group A; n = 90) or at 6, 12, and 24 months after p-EMR (group B; n = 90). The primary endpoint was cumulative local recurrence at 6 months after p-EMR. Secondary endpoints included local recurrence and the cumulative surgical resection rate of recurrent tumors during the 24-month follow-up period.
Results: The median tumor diameter was 25 mm (IQR 20-30). Six months after p-EMR, 12 and 6 local recurrences were noted in groups A and B, which corresponded to 13 and 8 recurrences, respectively, during the 24-month surveillance period. The primary and secondary endpoints of recurrence were not significantly different between the groups on either intention-to-treat or per-protocol analysis; no surgery case was observed in group B when a strict surveillance protocol of 6-, 12-, and 24-month follow-up post-EMR was followed.
Conclusions: For patients who underwent p-EMR for neoplastic lesions, additional postprocedural 3-month surveillance did not show superior results in detecting recurrence compared with a 6-month surveillance interval.
Clinical trial registration: UMIN000015740.
Keywords: Colorectal neoplasia; Local recurrence; Piecemeal endoscopic mucosal resection (p-EMR); Surveillance colonoscopy; Surveillance interval.
© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.