Can we improve the endoscopic resection of dysplastic lesions in colonic inflammatory bowel diseases?

The incidence of colonic inflammatory bowel disease (IBD) is increasing globally, with prevalence rates of approximately 1 in 200 adults in the highest-risk populations [1]. One of the consequences of longstanding colonic inflammation is the potential development of premalignant lesions and colorectal cancer (CRC). Although the risk of CRC in IBD is declining, the cumulative risk is estimated to be 1%, 2%, and 5% after 10, 20, and >20 years of disease, respectively [2].

“We should be optimistic that with improved assessment and resection techniques, high rates of en bloc, safe, and complete resection will be achieved in IBD, resulting in the very low recurrence rates seen in the non-IBD population.”

Therefore, patients with IBD are usually invited to undergo screening colonoscopies 8 years after symptom onset, followed by surveillance procedures depending on patient-specific risk factors. The aim of any screening and surveillance program is to reduce morbidity and mortality due to the disease. With improvements in colonoscopy, most IBD dysplasia can be detected and removed, meaning that the prevention of CRC is possible.

To improve prevention, complete endoscopic resection of the dysplastic lesions is important. The challenges associated with IBD dysplasia are that these lesions are often flat, without clear and discrete borders, and can be within inflamed areas of the colon. Inflammation can lead to fibrosis and tethering, limiting endoscopic resection.

In this issue of Endoscopy, Angajala et al. [3] explore the challenges associated with endoscopic resection of laterally spreading IBD-associated dysplastic lesions. The authors compared outcomes between IBD- and non-IBD-associated lesions at a tertiary referral center between 2015 and 2021.

The majority of the procedures were performed by “expert endoscopists” with dedicated training in endoscopic colonic resection. A total of 210 lesions were included (187 non-IBD and 23 IBD). The average size of the lesions was “large” at 25 mm in the IBD group and 20 mm in the non-IBD group. Most lesions were tubular adenomas with low grade dysplasia or sessile serrated lesions (91% in both cohorts). The morphology of the lesions was similar, and they were also distributed similarly throughout the colon.

Despite comparable baseline characteristics, the primary outcome of the study reported significantly higher recurrence rates in the IBD cohort (30%) than in the controls (21%). The recurrence rates in this tertiary center were high in both groups, which is a notable finding. While most recurrences can usually be dealt with endoscopically, this can be more challenging with laterally spreading lesions, and current or prior inflammation can hamper the complete removal of recurrent tissue.

With techniques such as excision of a 2–3-mm margin of normal tissue and thermal ablation of defect margins following endoscopic mucosal resection, much lower rates of recurrence are possible. In recent non-IBD cohorts, rates as low as 2% have been reported [4]. Whether these results can be achieved in IBD remains uncertain and it would be interesting to observe whether a significant difference in recurrence persists in contemporary cohorts.

The rates of en bloc resection were significantly lower in the IBD cohort (9% vs. 57%), but the difference in recurrence was maintained after adjustment, bearing in mind the small sample size. There are several reasons why en bloc endoscopic mucosal resection may be more challenging in patients with IBD. These lesions can be more difficult to inspect in areas of the colon with active or prior inflammation and scarring, and submucosal injection can be complicated by inflammation and fibrosis. Endoscopic submucosal dissection (ESD) is an obvious candidate technique for improving the rate of en bloc resection. Although ESD is technically challenging and time consuming, the efficacy of the technique is supported in the literature, with an en bloc resection rate of 100% and R0 rate of 96% achieved in a recent IBD cohort [5]. The increased risk with ESD is important to consider, with perforation and bleeding rates being 6% and 8%, respectively. Complications from ESD could be higher in a delicate IBD colon, but most can be managed endoscopically [6]. The additional benefit of achieving R0 resection is that there is a reduced need for “site-check” procedures and surveillance, which is important as the IBD cohort can be subjected to numerous endoscopies, particularly those with dysplastic lesions who undergo more intense surveillance.

There will be a rise in the overall number of IBD dysplastic lesions due to the increasing incidence of IBD, longer survival, and increased use of colonoscopy. However, it is important to remember that the overall scale of this problem is relatively small. This is reflected in the small number of patients with IBD included in this (n = 14) and other studies. This means that the experience of managing these lesions is difficult to achieve in most practices; therefore, an argument for the centralization of services in tertiary referral hospitals could be made.

To improve outcomes, the same principles for safe and complete endoscopic removal should be applied to both IBD and non-IBD lesions. These include accurate assessment of the lesion, borders, and risk of submucosal invasion, which precludes removal. A case-by-case review should be conducted to determine the appropriate resection technique that considers all options and available expertise. Before removal, there should be an open and honest discussion with the patient about the potential for recurrence, complications, risk of incomplete resection, need for surveillance, importance of controlling ongoing inflammation, and early surgical discussion where appropriate. The responsible team also needs to ensure that, as far as possible, there has been a meticulous screening procedure for synchronous lesions.

We should be optimistic that with improved assessment and resection techniques, high rates of en bloc, safe, and complete resection will be achieved, resulting in the very low recurrence rates seen in the non-IBD population. As we learn more about the risk of recurrence and the specific risk factors that predispose patients to further dysplasia and CRC, more nuanced surveillance guidelines may be able to reduce the burden of colonoscopy for the majority.

Publication History

Article published online:
05 November 2024

• References

• 1 King D, Reulen RC, Thomas T. et al. Changing patterns in the epidemiology and outcomes of inflammatory bowel disease in the United Kingdom: 2000–2018. Aliment Pharmacol Ther 2020; 51: 922-934 DOI: 10.1111/apt.15701. (PMID: 32237083)
• 2 Lutgens MWMD, van Oijen MGH, van der Heijden GJMG. et al. Declining risk of colorectal cancer in inflammatory bowel disease: an updated meta-analysis of population-based cohort studies. Inflamm Bowel Dis 2013; 19: 789-799
• 3 Angajala VT, Buxbaum JL, Phan J. et al. Comparative outcomes of endoscopic mucosal resection for laterally spreading lesions in inflammatory bowel disease. Endoscopy 2024; DOI: 10.1055/a-2369-7980.
• 4 Sidhu M, Shahidi N, Gupta S. et al. Outcomes of thermal ablation of the mucosal defect margin after endoscopic mucosal resection: a prospective, international, multicenter trial of 1000 large nonpedunculated colorectal polyps. Gastroenterology 2021; 161: 163-170.e3
• 5 Manta R, Zullo A, Telesca DA. et al. Endoscopic submucosal dissection for visible dysplasia treatment in ulcerative colitis patients: cases series and systematic review of literature. J Crohns Colitis 2021; 15: 165-168 DOI: 10.1093/ecco-jcc/jjaa158. (PMID: 32710744)
• 6 Lightner AL, Vaidya P, Allende D. et al. Endoscopic submucosal dissection is safe and feasible, allowing for ongoing surveillance and organ preservation in patients with inflammatory bowel disease. Colorectal Dis 2021; 23: 2100-2107