ENDOSCOPIC SUBMUCOSAL DISSECTION FOR HIGH-RISK COLORECTAL COLITIS-ASSOCIATED NEOPLASIA IN INFLAMMATORY BOWEL DISEASE: A REAL-WORLD MULTICENTER STUDY

Background and Aim: Inflammatory bowel disease (IBD) patients have a 2-3-fold increased risk of developing colorectal cancer. High-risk colorectal colitis-associated neoplasia (HR-CAN), including non-polypoid lesions and large non-pedunculated colon polyps, are often not amenable to conventional resection techniques. Aim of this study was to evaluate effectiveness and safety of endoscopic submucosal dissection (ESD) of HR-CANs. Methods: In this real-world, multicenter, retrospective study, we included consecutive IBD patients referred to nine Tertiary Italian Endoscopy Centers (January 2014 – April 2023) to undergo an ESD or a hybrid-ESD (hESD), for HR-CANs. The primary outcome was rate of en bloc, R0 resection and adverse events (AEs). The secondary outcome was rate of local recurrence, metachronous lesions, and post-dissection surgery. Results: 96 HR-CANs (89.6% non-polypoid, 79.2% left-side colon, mean size 34.8 mm ± 16.2 mm, 15.6% invasive pit-pattern) in 91 patients with colonic IBD (58.2% male, aged 60.8 ± 12.2 yrs, 83.4% ulcerative colitis, disease duration of 183 ± 104 months, 14.3% endoscopic activity) were included. ESD and hESD were performed in 82.3% and 17.7% of cases. The final histopathological diagnoses after dissection were serrated sessile lesions in 14.6%, low-grade dysplasia in 32.3%, high-grade dysplasia in 38.5%, adenocarcinoma in 14.6%. Overall, en bloc and R0 resection were achieved in 95.9% and 85.4% of cases. AEs occurred in 12.5% of cases, all managed endoscopically and conservatively. After a mean follow-up of 23.4 months, local recurrence and metachronous lesions occurred each in 3.1% (n=3) of cases. Post-dissection surgery was required in 11.5% (n=11) of cases (7 for histopathology, 2 for recurrences, 2 for refractory IBD). At univariate analysis the left site was identified as a predictor of higher rate of en bloc resection (OR 0.07; 0.007-0.77; p=0.02), while the female sex as a predictor of lower rate of AEs (OR 0.17; 0.03-0.81; p=0.02). Further, the invasive pit pattern was associated with higher rate of post-dissection surgery (OR 6.25; 1.6-24.3; p=0.008). Conclusion: Our findings showed that ESD of HR-CANs, when performed in Tertiary Endoscopy Centers, was effective and safe in patients with colonic IBD. However, further prospective studies including a long-term follow-up are still required to highlight the impact of ESD for IBD patients’ dysplasia-free survival.