Comparing modalities for detecting dysplasia in patients with IBD

Aug. 15, 2020

People with inflammatory bowel disease (IBD), such as Crohn's disease and ulcerative colitis, are at increased risk of developing colorectal cancer compared with the general population, and colorectal cancer is a significant cause of mortality in the IBD population. Therefore, it is standard of care to do routine surveillance colonoscopies in patients with IBD to allow for early detection at the precancerous stage and early treatment, reducing morbidity and mortality of this significant IBD complication. However, the optimal modality for endoscopic surveillance remains unknown.

Standard endoscopy visualizes the colonic mucosa using standard-definition white light in order to detect polyps and therefore dysplasia. Chromoendoscopy, which uses contrast dyes to improve visualization of polyps and nonpolyp dysplasia, represented an advance in endoscopic surveillance with superior detection rates, but it is time-consuming, costly, not widely available and requires expertise to perform well. Newer endoscopic visualization technology uses high-definition white light without contrast dyes to improve polyp detection. However, it is unclear based on previous studies if chromoendoscopy is superior to high-definition white light endoscopy as with standard definition white light endoscopy.

Mayo Clinic's division of Gastroenterology is a leader in IBD care and endoscopic surveillance, conducting more of these procedures on an annual basis than any other center in the world. Mayo Clinic researchers used this vast clinical experience to conduct a retrospective cohort study to determine whether chromoendoscopy detected polyps and nonpolypoid dysplasia in patients with IBD more often than did high-definition white light endoscopy.

In a period of one year, over 800 surveillance colonoscopies, either chromoendoscopy or high-definition white light, were performed; the choice of modality was at the discretion of the ordering physician. Multiple risk factors for detection of dysplasia were found, including advanced age, a history of prior nonpolypoid dysplasia, having comorbid primary sclerosing cholangitis and having an IBD specialist performing the endoscopy procedure. After adjusting for these underlying factors, chromoendoscopy was not superior to high-definition white light endoscopy in detecting dysplasia in patients with IBD. The results of this study, led by Nayantara Coelho-Prabhu, M.B.B.S., and Edward Loftus, Jr., M.D., were recently published in the journal Inflammatory Bowel Diseases.

"Advances in endoscopic imaging have made detection of dysplasia more accurate, and at Mayo Clinic in Rochester, Minnesota, we have one of the largest cohorts in the world for study," said Dr. Coehlo-Prahbu.

This study suggests chromoendoscopy and high-definition white light endoscopy have similar diagnostic yields for dysplasia detection in patients with IBD after taking into account known risk factors. Therefore, with the advancement of imaging modalities and the use of high definition white light endoscopes, the need to perform the more costly and complicated chromoendoscopy procedure may not be warranted. This knowledge could lead to significant improvements in cost reduction and efficiency in surveillance colonoscopy in patients with IBD.

For more information

Coelho-Prabhu N, et al. A 1-year cross-sectional inflammatory bowel disease surveillance colonoscopy cohort comparing high-definition white light endoscopy and chromoendoscopy. Inflammatory Bowel Diseases. June 2020.