Eluri S, et al. - Researchers carried out this study to determine the prevalence and characteristics of inflammatory bowel disease (IBD) associated high-grade dysplasia (HGD) or colorectal cancer (CRC) that was undetected on prior colonoscopy. In IBD, the prevalence of previously undetected HGD/CRC found at colectomy was 29%. The high proportion of undetected rectal and right-sided HGD/CRC recommended that during surveillance, these areas could need greater attention.

Methods

• The researchers performed this single-center, retrospective study from 1994 to 2013.
• A confirmed IBD diagnosis was found in all participants and they underwent a colectomy with either HGD or CRC found in the colectomy specimen.
• Participants in the undetected group had no HGD or CRC on prior colonoscopies.
• Participants in the detected group displayed HGD or CRC identified on previous biopsies.

Results

• Patients with ulcerative colitis (UC) (n = 47), Crohn’s disease (CD) (n = 21), and indeterminate colitis (n = 2), 29% (n = 20) had undetected HGD/CRC at colectomy (15 HGD and 5 CRC), among 70 participants.
• Seventy-five percent had prior LGD, 15% had indefinite dysplasia, and 10% had no dysplasia (HGD was found in colonic strictures) in the undetected group.
• In the undetected group, patients were more likely to have pancolitis (55 vs 20%) and multifocal dysplasia (35 vs 8%).
• Findings revealed that the undetected group was less likely to have CRC at colectomy (25 vs 62%).
• A trend toward right-sided HGD/CRC at colectomy (40 vs 20%; p=0.08) was found.
• Moreover, at colectomy, 84% of the lesions found in the rectum were not seen on prior colonoscopy in the undetected group.