P698 Incidence and disease course of inflammatory bowel disease diagnosed incidentally during a colorectal cancer screening programme: A retrospective multicentre study— preliminary results
I. Rodríguez-Lago*1, 2, O. Merino2, 3, J. Carrascosa2, 4, M. Fernández - Calderón2, 5, A. Maiz2, 6, A. Muñagorri2, 7, P. Arreba2, 8, R. Higuera2, 9, E. Zapata2, 10, I. Moraleja1, 2, I. Montalvo2, 11, I. Portillo12, J. L. Cabriada1, 2
1Galdakao Hospital, Gastroenterology, Galdakao, Spain, 2IBD Study Group of the Basque – Navarre Society of Gastrointestinal Diseases, Pais Vasco - Navarra, Spain, 3Cruces University Hospital, Gastroenterology, Bilbao, Spain, 4Zumárraga Hospital, Gastroenterology, Zumárraga, Spain, 5Mondragon - Alto Deba Hospital, Gastroenterology, Mondragón, Spain, 6Donostia Hospital, Microbiology, Donostia, Spain, 7Donostia Hospital, Gastroenterology, Donostia, Spain, 8Basurto University Hospital, Gastroenterology, Bilbao, Spain, 9San Eloy Hospital, Gastroenterology, Bilbao, Spain, 10Mendaro Hospital, Gastroenterology, Mendaro, Spain, 11Onkologikoa Hospital, Gastroenterology, Donostia, Spain, 12Basque Country Health Service, Colorectal cancer screening programme, Bilbao, Spain
There is scarce evidence about the prevalence of inflammatory bowel disease (IBD) in asymptomatic patients. We can only extract information from some retrospective studies in different countries. The prevalence of IBD in asymptomatic people has been reported to be up to 1.6% in the United Kingdom, 1.1% in South Korea, and 0.7% in Japan. In these cohorts a significant number of patients developed symptoms related to the disease during the follow-up. We have conducted a study to evaluate the incidence, disease characteristics, and treatment requirements in patients diagnosed of IBD during screening colonoscopies performed under the colorectal cancer screening programme in the Basque Country (Spain). The screening in our area started in 2010, and it covers people between 50 and 69 years from a population of 2.2 million people.
We have retrospectively reviewed the medical charts of all patients who underwent a colonoscopy under the colorectal cancer screening programme. All patients were assessed with faecal immunochemical test (FIT; OC-Sensor, Eiken Chemical Co., Tokyo, Japan) and, if this test was positive (cut-off 20 μg Hg/g), a colonoscopy was indicated. We included all patients with a suspicion of IBD by endoscopy and confirmed on histology. The study protocol was approved by the local ethics committee.
In total, 405.913 FIT were done in 9 hospitals (67% participation). In 25.262 of these cases a colonoscopy was performed. We have found 88 patients (0.35%) diagnosed of IBD: 67 ulcerative colitis (UC), 16 Crohn’s disease (CD), and 5 IBD unclassified. 37 of them were women (median age 57 years), and most of them were ex-smokers. UC extension was E1 in 22 patients, E2 in 21, and E3 in 24. CD extension was L1 in 7 cases, L2 in 6, and L3 in 3 patients. Only 1 patient suffered perianal disease at diagnosis. The clinical suspicion from the endoscopy report and the biopsy agreed in 95% cases. Median follow-up time since the diagnosis was 17 months [IQR 9–34]. Twenty-six patients developed symptoms during this period (mainly rectal bleeding, rectal syndrome, and diarrhoea). Treatment was prescribed in 65 patients: mesalazine in 61 cases, steroids in 11, thiopurines in 6, 1 with methotrexate, and 1 with leukapheresis. Infliximab was indicated only in one case 23 months after diagnosis. 2 patients required surgery during follow-up.
We have found a 0.35% incidence of IBD, mainly ulcerative colitis, during screening colonoscopies in our area in patients aged 50 to 69 years. A third of patients developed symptoms, and after a medium-term follow-up, the disease behaviour was relatively mild.