Objective The optimal approach for removing large laterally spreading lesions at the anorectal junction (ARJ-LSLs) is unknown. Endoscopic mucosal resection (EMR) is a definitive therapy for colorectal LSLs. It is unclear whether it is an effective modality for ARJ-LSLs.
Design EMR outcomes for ARJ-LSLs (distal margin of ≤20 mm from the dentate line) in comparison with rectal LSLs (distal margin of >20 mm from the dentate line) were evaluated within a multicentre observational cohort of LSLs of ≥20 mm. Technical success was defined as the removal of all polypoid tissue during index EMR. Safety was evaluated by the frequencies of intraprocedural bleeding, delayed bleeding, deep mural injury (DMI) and delayed perforation. Long-term efficacy was evaluated by the absence of recurrence (either endoscopic or histologic) at surveillance colonoscopy (SC).
Results Between July 2008 and August 2019, 100 ARJ-LSLs and 313 rectal LSLs underwent EMR. ARJ-LSL median size was 40 mm (IQR 35–60 mm). Median follow-up at SC4 was 54 months (IQR 33–83 months). Technical success was 98%. Cancer was present in three (3%). Recurrence occurred in 15.4%, 6.8%, 3.7% and 0% at SC1–SC4, respectively. Among 30 ARJ-LSLs that received margin thermal ablation, no recurrence was identified at SC1 (0.0% vs 25.0%, p=0.002). Technical success, recurrence and adverse events were not different between groups, except for DMI (ARJ-LSLs 0% vs rectal LSLs 4.5%, p=0.027).
Conclusion EMR is an effective technique for ARJ-LSLs and should be considered a first-line resection modality for the majority of these lesions.
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Contributors Conception and design: NS and MJB; analysis and interpretation of the data: NS, MS, SV, WAH, IB-Y, SS, DJT and MJB; drafting of the article: NS; critical revision of the article for important intellectual content: BH, LFH, EL, NGB and MJB; final approval of the article: MJB.
Funding The Cancer Institute of New South Wales provided funding for a research nurse and data manager to assist with the administration of the study. The Gallipoli Medical Research Foundation provided funding and support for research at Greenslopes Private Hospital. There was no influence from either institution regarding study design or conduct, data collection, management, analysis, interpretation, preparation, review or approval of the manuscript. NS is supported by the University of British Columbia Clinician Investigator Program.
Competing interests MJB: research support from Olympus Medical, Cook Medical, Boston Scientific. The remaining authors have no conflicts of interest to disclose.
Patient consent for publication Not required.
Ethics approval Centre-specific institutional review board approval is maintained at each centre. Written informed consent is obtained from each patient prior to study participation.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information.
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