Optimal surveillance interval after piecemeal endoscopic mucosal resection for large colorectal neoplasia: a multicenter randomized controlled trial

Takeshi Nakajima, Taku Sakamoto, Shinichiro Hori, Shinya Yamada, Hiroaki Ikematsu, Keita Harada, Han Mo Chiu, Shinsuke Kiriyama, Tomoki Michida, Kinichi Hotta, Naoto Sakamoto, Takashi Abe, Akiko Chino, Masakatsu Fukuzawa, Nozomu Kobayashi, Kazutoshi Fukase, Takahisa Matsuda, Yoshitaka Murakami, Hideki Ishikawa, Yutaka Saito

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3 Citations (Scopus)


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.

Original languageEnglish
JournalSurgical Endoscopy
Publication statusAccepted/In press - 2021


  • Colorectal neoplasia
  • Local recurrence
  • Piecemeal endoscopic mucosal resection (p-EMR)
  • Surveillance colonoscopy
  • Surveillance interval

ASJC Scopus subject areas

  • Surgery


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