July 15, 2017
David H. Bruining, M.D., is a gastroenterologist at Mayo Clinic's campus in Rochester, Minnesota, with research interests that include advanced imaging modalities in inflammatory bowel disease (IBD), colorectal cancer (CRC) screening and gastrointestinal bleeding.
What are the current CRC screening guidelines for patients with IBD, and why is screening important in this population?
Patients with ulcerative colitis or Crohn's disease are at an increased risk of developing CRC. Current guidelines recommend annual screening and biopsies at the time of diagnosis for patients with IBD colitis and primary sclerosing cholangitis; annual colonoscopy eight years after diagnosis in patients with ulcerative colitis and pancolitis or left-sided colitis; and annual colonoscopy eight years after diagnosis in Crohn's colitis involving more than one-third of the colon.
What is the optimal endoscopic surveillance strategy for patients with ulcerative colitis and Crohn's colitis, and what are the associated challenges?
This topic remains controversial. The traditional approach uses white light endoscopy (WLE) to perform random and targeted biopsies. Gathering specimens taken at regular intervals throughout the colon can involve significant procedural time and costs, and prior studies have shown that many gastroenterologists do not obtain the recommended number of specimens. It's also important to note that random biopsies typically have a lower yield than targeted biopsies, and colon dysplasia can be more difficult to detect using WLE in patients with IBD because it is often flat and multifocal. The current standard of care at Mayo Clinic is the use of high definition WLE with or without chromoendoscopy.
How does chromoendoscopy (CE) function as a CRC screening tool in patients with IBD, and what advantages does it offer?
CE involves topical application of stains, dyes or pigments to delineate surface abnormalities and improve dysplasia detection. Although use of CE in patients with IBD has been limited, a growing body of data supports the use of CE as a diagnostic tool in patients who are at increased risk of CRC. CE identifies dysplastic lesions, including flat lesions, with a higher sensitivity than WLE. Recent consensus guidelines also support consideration of CE rather than WLE for initial dysplasia surveillance in patients with IBD.
You and several colleagues recently published an article in Gastrointestinal Endoscopy about the diagnostic yield of CE and outcomes in patients with IBD who had a history of colorectal cancer. Can you describe the aims and methods of this research?
We hypothesized that using CE in patients with IBD and a history of colorectal dysplasia would detect additional dysplastic lesions that were not seen on the index colonoscopy with standard or HD WLE. We also sought to explore whether such findings influenced the management of these patients. To address these questions we identified a retrospective cohort of patients with IBD with colorectal dysplasia on WLE who subsequently underwent CE, and we compared endoscopic and histologic findings among the index WLE, first CE and subsequent CE. We also assessed outcomes, including endoscopic lesion removal, surgery or repeat CE, and diagnosis of colorectal cancer.
What were your key findings and conclusions in that study?
Initial and subsequent CE performed in patients with IBD who have a history of colorectal dysplasia on WLE frequently identified new lesions, including flat lesions, most of which were amenable to endoscopic treatment. Multifocal dysplasia was also identified, resulting in surgical resection and identification of CRC. Subsequent CE identified new lesions compared with the initial CE. These data support the use of CE as a surveillance procedure in this high-risk population.
Are Mayo researchers planning or conducting any additional related research?
We continue to seek methods and procedures to increase the diagnostic yield for patients while simplifying the procedure for providers. Ongoing studies at Mayo will further clarify the benefit of endoscopic mucosal resection and endoscopic submucosal dissection in patients with dysplastic lesions.
For more information
Deepak P, et al. Incremental diagnostic yield of chromoendoscopy and outcomes in inflammatory bowel disease patients with a history of colorectal dysplasia on white-light endoscopy. Gastrointestinal Endoscopy. 2016;83:1013.