Low CRC incidence among IBD patients supports longer surveillance intervals
Patients with inflammatory bowel disease undergoing regular surveillance colonoscopy had a low incidence of interval colorectal cancer, according to recent study data, prompting researchers to suggest up to 5 years between surveillance.
To determine the effectiveness of colonoscopic surveillance in patients with IBD and to identify procedure-related factors that may contribute to the occurrence of CRC, Bas Oldenburg, MD, PhD, from University Medical Center Utrecht in the Netherlands, and colleagues, performed a retrospective analysis of data on 1,273 IBD patients (34% Crohn’s disease, 63% ulcerative colitis, 3% unclassified) who underwent a total of 4,327 surveillance colonoscopies from January 1, 2000, through January 1, 2014, as part of a surveillance program at seven hospitals in The Netherlands.
All patients were followed from their first to last surveillance colonoscopy or occurrence of colectomy or CRC (mean follow-up, 5.3 ± 3 years). The researchers classified procedure-related factors that may have contributed to CRC as inadequate procedures, inadequate surveillance, inadequate management of dysplasia, or true interval CRCs defined as those “detected within the appropriate surveillance interval, after an adequately performed surveillance colonoscopy.”
Overall, 1.3% of patients (median age, 55 years) were diagnosed with CRC, corresponding to an incidence rate of 2.5 per 1,000 years of follow-up. The median interval between last surveillance colonoscopy and diagnosis of CRC was 22 months (range, 9-42 months).
The researchers identified factors that may have contributed to CRC in 70% of the patients diagnosed with CRC, including inadequate colonoscopies in 24%, inadequate surveillance in 53% and inadequate management of dysplasia in 12%. The remaining 30% of CRC cases were categorized as true interval CRCs, corresponding to an incidence rate of 0.2 interval CRCs per 1,000 years of follow-up.
“This study shows that the incidence of CRC among IBD patients enrolled in a surveillance program is low compared with previous studies, with only 17 cancers detected during 6,823 years of follow-up evaluation,” the researchers wrote. “This might support the longer surveillance interval of up to 5 years as recommended in the current [British Society of Gastroenterology] and European Crohn’s and Colitis Organization guidelines, although the fact that one third of all CRC cases appear to be interval carcinomas underscores the need to further identify risk factors associated with the development of interval cancer.” – by Adam Leitenberger
Disclosures: Oldenburg reports he is a consultant for AbbVie BV, MSD BV and Ferring BV.