Curriculum review: colorectal cancer surveillance and management of dysplasia in IBD

Abstract

The significantly increased risk of colorectal cancer (CRC) in longstanding colonic inflammatory bowel disease (IBD) justifies the need for endoscopic surveillance. Unlike sporadic CRC, IBD-related CRC does not always follow the predictable sequence of low-grade to high-grade dysplasia and finally to invasive carcinoma, probably because the genetic events shared by both diseases occur in different sequences and frequencies. Surveillance is recommended for patients who have had colonic disease for at least 8-10 years either annually, every 3 years or every 5 years with the interval dependant on the presence of additional risk factors. Currently, the recommended endoscopic strategy is high-definition chromoendoscopy with targeted biopsies, although the associated lengthier procedure time and need for experienced endoscopists has limited its uniform uptake in daily practice. There is no clear consensus on the management of dysplasia, which continues to be a challenging area particularly when endoscopically invisible. Management options include complete resection (and/or referral to a tertiary centre), close surveillance or proctocolectomy. Technical advances in endoscopic imaging such as confocal laser endomicroscopy, show exciting potential in increasing dysplasia detection rates but are still far from being routinely used in clinical practice.

Role of endoscopy in the surveillance and management of colorectal neoplasia in inflammatory bowel disease

“…Additional potential risk factors are post inflammatory polyps, backwash ileitis and the presence of strictures. Proctitis, where inflammation is limited to the rectum and anus, is thought to not confer increased risk of cancer, hence such patients should undergo normal CRC screening[5]. All patients diagnosed with either UC or CD should be enrolled into a screening program.…”

“…Intermediate risk patients may be screened every 3 years. Low risk features, allowing for up to 5 years of surveillance intervals, include endoscopic and histological remission, no history of neoplasia and no family history of CRC[5,7]. Table 3 summarizes low, intermediate and high risk features.…”

“…Ideal conditions for surveillance include thorough bowel preparation and a non-inflamed mucosa during a quiescent disease period given the difficulty in distinguishing inflammatory from early dysplastic changes both visually endoscopically and on histology[4]. Inadequate bowel preparation may obscure non polypoid lesions and is associated with reduced dysplasia detection and increased need for repeat procedures[5]. It is important to note that surveillance should not be delayed indeterminately in waiting for disease quiescence.…”

“…Targeted biopsies should be performed on non resectable lesions and those of uncertain significance. The major limitations of chromoendoscopy are the prolonged procedure times, the additional training required on the part of the proceduralist, and the additional costs, all of which act as barriers to the widespread uptake of this technique[3,5,8].…”

“…The risk of developing CRC in ulcerative colitis (UC) is similar to that in Crohn’s disease (CD) if adjusted for the area of colonic involvement[4]. Improvements in therapy and refinements in surveillance methodology has seen an overall reduction in CRC in patients with IBD[5]. With rapid advances in technology, including high definition colonoscopy and chromoendoscopy, questions have arisen regarding the most appropriate surveillance and management strategies of colorectal neoplasia in IBD.…”