- 1 Health system implications
- 2 Unresolved issues
- 3 Studies currently underway
- 4 Future research priorities
- 5 References
Health system implications
Dedicated inflammatory bowel disease (IBDInflammatory bowel disease) services able to provide high-quality colonoscopy and advanced endoscopic imaging technologies are recommended. Expert referral centres that can perform endoscopic mucosal resection, endoscopic submucosal dissection and full-thickness resections are required to reduce the need for colectomy. Dedicated training of advanced imaging techniques used in IBDInflammatory bowel disease surveillance is recommended. Confirmation of dysplasia with a second experienced gastrointestinal pathologist is required to confirm diagnosis and establish the grade of dysplasia.
Endoscopic resection of dysplasia, followed by close surveillance, can reduce the need for colectomy. Treatment should be individualised according to a patient's wishes. Recommendations should be provided following a multidisciplinary discussion incorporating colorectal surgeon, gastroenterologist and pathologist.
Surveillance for IBDInflammatory bowel disease-associated dysplasia should be performed in dedicated tertiary centres by endoscopists with expertise in IBDInflammatory bowel disease surveillance. These centres should have access to high quality, high-definition white-light endoscopy and chromoendoscopy. Inflammatory bowel disease patients with a high risk of dysplasia, including those with concurrent primary sclerosing cholangitis or prior flat dysplasia might benefit from panoramic imaging such as full-spectrum endoscopy combined with chromoendoscopy. This would ensure a standardised, high level of care and constitute a platform for education and training, as well as permit data-collection and creation of a centralised database of IBDInflammatory bowel disease-associated dysplasia.
Since the initial 2011 version of these guidelines, there has been an overall move away from routine colectomy in patients with high-grade dysplasia (HGDHigh grade dysplasia). Although the overall incidence of HGDHigh grade dysplasia is low, the expertise available for high-quality IBDInflammatory bowel disease surveillance utilising chromoendoscopy and high-definition colonoscopy may only be available at a restricted number of centres. Since these patients may require intensive surveillance, this might generate a greater IBDInflammatory bowel disease surveillance workload at such expert centres and a greater need for IBDInflammatory bowel disease patients, particularly those from rural and remote areas, to travel to expert centres. Notwithstanding this, these guidelines are not anticipated to alter current resourcing levels as the overall incidence of HGDHigh grade dysplasia is low (approximately 3.2% of all IBDInflammatory bowel disease patients).
Resources will need to be allocated towards:
- recruitment and training of additional medical, nursing and support personnel to operate dedicated surveillance endoscopy lists, supported by expert gastrointestinal pathologists experienced in dysplasia diagnosis, and colorectal surgical units experienced in IBDInflammatory bowel disease surgery.
- purchase and installation of high-resolution endoscopes, dye-spray catheters and pump sets for chromoendoscopy, and endoscopy systems that can provide panoramic imaging to reduce miss rates of dysplasia. Inflammatory bowel disease centres should be resourced to conduct advanced endoscopic resection.
Barriers to implementation
Barriers to implementation of the recommendations for colonoscopic surveillance and management of dysplasia in patients with IBDInflammatory bowel disease include:
- poor awareness of surveillance guidelines
- low-quality surveillance colonoscopy
- too frequent surveillance colonoscopies or inappropriate performance of surveillance procedures in patients with a low yield of dysplasia (e.g. proctitis or ileitis), in whom surveillance is not indicated
- shortage of resources
- lack of awareness of dysplasia surveillance guidelines
- lack of established IBDInflammatory bowel disease centres to provide dysplasia surveillance.
Attitudes of gastroenterologists will determine willingness to refer patients to a specialized IBDInflammatory bowel disease endoscopy unit for a service they themselves could provide.
Elevated dysplasia in IBDInflammatory bowel disease
Nomenclature for IBDInflammatory bowel disease-related dysplasia needs to be standardised to allow physicians to communicate colonoscopic and histopathologic findings effectively. The ongoing use of descriptions such as dysplasia associated lesion or mass (DALMDysplasia associated lesion mass) and ALM is impractical and does not guide management of dysplasia in IBDInflammatory bowel disease. Use of these terms should be discouraged.
Long term data are needed to assess the impact of endoscopic resection followed by close surveillance on the natural history of IBDInflammatory bowel disease patients, in whom dysplasia develops.
High-grade dysplasia in IBDInflammatory bowel disease
The natural history of HGDHigh grade dysplasia remains unclear. Studies that have evaluated HGDHigh grade dysplasia are limited by low patient numbers or the small size of the cohort with HGDHigh grade dysplasia within a much larger group including patients with LGDLow grade dysplasia. More longitudinal studies are needed to develop a better understanding of HGDHigh grade dysplasia.
More studies are needed to understand patient preferences and decision-making in the setting of dysplasia, given that the natural history of HGDHigh grade dysplasia is likely to remain elusive for the foreseeable future. While it is generally perceived that patients prefer colonoscopic surveillance over colectomy, it is also well known that clinicians are poor patient surrogates. In the absence of robust data about the likelihood of developing colorectal cancer (CRCColorectal cancer), patient preference data are needed to assist with shared decision making.
The appropriate frequency of surveillance after complete resection of HGDHigh grade dysplasia is unclear. More frequent surveillance colonoscopies following resection of HGDHigh grade dysplasia would seem to be a sensible extrapolation of existing post-polypectomy surveillance recommendations in non-IBDInflammatory bowel disease patients. While this would seem reasonable, more studies are needed define appropriate surveillance intervals.Surgical resection for HGDHigh grade dysplasia or CRCColorectal cancer in Crohn's disease is typically a total proctocolectomy, as segmental resections might be followed by the development of Crohn's disease at the anastomosis. However, these recommendations are based upon small series and, in patients with limited and well-controlled Crohn's colitis, the risk of metachronous or synchronous CRCColorectal cancer might be low.
Low-grade dysplasia in IBDInflammatory bowel disease
The recommendations for surveillance colonoscopy in preference to colectomy in the setting of LGDLow grade dysplasia are largely individualised. To date there are no studies which compare surveillance colonoscopy with colectomy for managing LGDLow grade dysplasia, or which clarify the natural history of visible dysplastic lesions managed by endoscopic resection.
Indefinite dysplasia in IBDInflammatory bowel disease
Histologic indefinite dysplasia (IDIndefinite dysplasia) may be due to ongoing low-grade inflammation, and it is important to take ongoing disease activity into account when evaluating a diagnosis of IDIndefinite dysplasia. Repeat examination after treating inflammation can be helpful in this case. The natural history of IDIndefinite dysplasia is unknown, and the risk for progression to cancer appears to be low. Studies on IDIndefinite dysplasia do not routinely report the presence of associated inflammation and, in the past, have not used current methods of classifying flat/polypoid dysplasia.
Studies currently underway
No large prospective trials on IDIndefinite dysplasia are underway. Some larger units periodically report on ulcerative colitis surveillance outcomes collected prospectively, and these data may add insight regarding long-term outcomes of IDIndefinite dysplasia.
Future research priorities
Longitudinal cohort studies reporting long-term outcomes of patients opting for endoscopic resection or colonoscopic surveillance are required.
Longitudinal cohort studies of outcomes from surveillance versus colectomy are necessary. The formation of a centralised database could assist in this endeavour.
Clarification of the long-term outcomes for indefinite dysplasia is required. Prospective evidence as to whether repeat examination with enhanced imaging techniques improves lesion detection or outcomes (or otherwise) is needed.
- Leong RW, Ooi M, Corte C, Yau Y, Kermeen M, Katelaris PH, et al. Full-Spectrum Endoscopy Improves Surveillance for Dysplasia in Patients With Inflammatory Bowel Diseases. Gastroenterology 2017 May;152(6):1337-1344.e3 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/28126349.
- Strong S, Steele SR, Boutrous M, Bordineau L, Chun J, Stewart DB, et al. Clinical Practice Guideline for the Surgical Management of Crohn's Disease. Dis ColonThe main part of the large bowel, which absorbs water and electrolytes from undigested food (solid waste). Its four parts are the ascending colon, transverse colon, descending colon and sigmoid colon. RectumThe final section of the large bowel, ending at the anus. 2015 Nov;58(11):1021-36 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/26445174.
- Kiran RP, Nisar PJ, Goldblum JR, Fazio VW, Remzi FH, Shen B, et al. Dysplasia associated with Crohn's colitis: segmental colectomy or more extended resection? Ann Surg 2012 Aug;256(2):221-6 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/22791098.
- Maser EA, Sachar DB, Kruse D, Harpaz N, Ullman T, Bauer JJ. High rates of metachronous colon cancer or dysplasia after segmental resection or subtotal colectomy in Crohn's colitis. Inflamm Bowel Dis 2013 Aug;19(9):1827-32 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/23669402.
- Toh JWT. Surgery for Colorectal Cancer in Crohn's Disease: Should We Perform a Total Proctocolectomy for All Patients With High-Grade Dysplasia and Cancer in Crohn's Disease? Dis ColonThe main part of the large bowel, which absorbs water and electrolytes from undigested food (solid waste). Its four parts are the ascending colon, transverse colon, descending colon and sigmoid colon. RectumThe final section of the large bowel, ending at the anus. 2017 Aug;60(8):e605 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/28682975.