TBA (24W156)

The DETECTION Study: DETection by Endoscopy of Colitis in Screening ImplementaTION.

Author(s)

Lloyd, A; Hanly, M; Nolan, B; Doran, R; McCarville, L; Rea, J; Macmathuna, P; Coffey, H; Semenov, S; Adetona, O; Ooi, S; Rajan, M; Dokic, D; Manj, J; Morahan, F; Lucey, M; Walsh N; Musial, O; Sugrue, K; Twomey, R; O’Sullivan, C; O’Brien, L; Gleeson, S; Sheehan, D; McDonald, C; Moran, C; Iacucci, Buckley, M; M; McDermott, E; Cullen, G; Horgan, G; Mulcahy, H; Buckley, M; Sheridan, J; Egan, L; Kevans, D; Leyden, J; O’Toole, A; McNamara, D; Allen, P; Burns, R; Slattery, E; O’Connor, A; Boland, K; Lahiff, C; O’Donnell, S; Kelly, O; Sengupta, S; Hartery, K; McCarthy, J; Doherty, G.

Department(s)/Institutions

INITIATIVE IBD Research Group. Gastroenterology Department, St. Vincent’s University Hospital, Dublin. Gastroenterology Department, Beaumont University Hospital, Dublin. Gastroenterology Department, Our Lady of Lourdes Hospital, Drogheda, Dublin. Gastroenterology Department, St. James’s University Hospital, Dublin. Gastroenterology Department, Mater Misericordiae University Hospital, Dublin. Gastroenterology Department, Tallaght University Hospital, Dublin. Gastroenterology Department, Galway University Hospital, Galway. Gastroenterology Department, Mercy University Hospital, Cork.

Introduction

The National Bowel Screening Program (Bowelscreen), a nationwide initiative program, aims to provide direct access to those aged 55-74 (currently 59-69) for colonoscopy assessment deemed high risk for colorectal cancer via positive faecal immunochemical test (FIT). Inflammatory Bowel Disease (IBD) follows a bimodal distribution of onset with European studies reporting 10-15% diagnosis after age 60. No published research exists on IBD incidence via FIT-based population screening and associated outcomes.

Aims/Background

Determine incidence rates/severity of incident IBD cases found via FIT-based colorectal screening programme. How often screening colonoscopy is performed for patients with known IBD and positive FIT.

Method

Retrospective review was conducted of all index colonoscopes conducted in FIT positive screening participants (aged 59-69) in multiple Irish centres between 2015-2024. Inclusion criteria: histological diagnosis of colitis. Parameters measured: distribution of colitis, histology, clinical sequalae/IBD history, faecal calprotectin (FCP) and treatment escalation based on screening colonoscopy.

Results

154/4849 (3.2%) of index screening colonoscopies analysed reported endoscopic diagnosis of colitis. 64/4849 (1.3%) satisfied diagnostic criteria for classic IBD (72% UC; 28% Crohn’s; 2% IBD-U), of which the majority were new diagnoses (65%). 23% cases of segmental colitis associated with diverticulosis (SCAD) were identified. 15% cases of NSAID induced colitis were identified. Colitis distribution: 23(15%) pancolitis, 32(20.7%) proctitis, 56(36.3%) left-sided, 16(10.4%) right-sided, 8(0.5%) mixed and 19(12.3%) enteric. 48% reported symptoms at endoscopy. Median FCP following diagnostic colonoscopy was 216.5μg/g. 7.8% of newly diagnosed IBD patients required biologic escalation.

Conclusions

Incidental diagnosis of colitis occurs in 3% of FIT-positive screening participants in a population based screening programme with new diagnoses of IBD including UC, Crohn’s and SCAD requiring treatment. This is a novel, unintended benefit to FIT-based population screening.