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Study Shows Margin Treatment Was Good but Not Perfect for Colorectal Laterally Spreading Lesions 40 mm or Larger

Douglas K. Rex, MD, MASGE reviewing Nader SM, et al. Gastrointest Endosc 2022 Oct 25.

Thermal treatment of the margin after piecemeal endoscopic mucosal resection (EMR) of laterally spreading lesions (LSLs) ≥20 mm is now considered standard of care because it lowers the recurrence rate, which has been a longstanding concern about the use of piecemeal EMR. Meta-analyses have shown that thermal margin treatment reduces recurrence rates by 75% to 80%. 

In a retrospective analysis of a prospectively collected database of LSLs, the impact of margin treatment on lesions ≥40 mm was evaluated. The study excluded lesions smaller than 40 mm, not followed up at the study center, or in which argon plasma coagulation was used for either margin treatment or ablation of residual polyp. Propensity score analysis was used to account for differences between patients in treated versus nontreated groups. 

There were 68 lesions ≥40 mm removed without snare tip soft coagulation (STSC) treatment and 133 removed with STSC. The recurrence rates were 9% with STSC and 35% without STSC (P<.00001 by direct comparison and P=.008 using propensity score analysis).


The 75% reduction in recurrence with STSC is consistent with previous studies. As thermal margin treatment is increasingly used, a subset of lesions removed by piecemeal EMR may be appropriate for a single follow-up for recurrence, perhaps at 1 year. The absolute recurrence rate seen here for lesions ≥40 mm suggests that an initial follow-up at 6 months is still warranted. The absolute recurrence rate of 9% could reflect residual polyp left in the EMR defect base or ineffective thermal ablation of the margin.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Douglas K. Rex, MD, MASGE

Bio and Disclosures


Nader SM, Lahr RE, Rex DK. Impact of margin thermal treatment after endoscopic mucosal resection of giant (≥ 40 mm) colorectal lateral spreading lesions. Gastrointest Endosc 2022 Oct 25. (Epub ahead of print) (