PTH-088 Incidental Diagnosis of Inflammatory Bowel Disease in a British Bowel Cancer Screening Cohort: A Multi-Centre Study

Abstract

Introduction The UK Bowel Cancer Screening Programme (BCSP) was launched in 2006 and rolled out in successive waves covering the entire population of England and Wales. It screens individuals aged 60-69 years with a Faecal Occult Blood test (FOBt) followed by a screening colonoscopy if FOBt positive. Our study aimed to quantify the incidental diagnosis of Inflammatory Bowel Disease (IBD) through BCSP and patient outcome in this cohort. Methods We conducted a retrospective review of BCSP outcomes at our centres from launch in February 2007 until August 2012. Screening data included the number of patients invited, number screened (FOBt outcome "normal" or "abnormal") and number of colonoscopies performed. In those with newly diagnosed IBD at colonoscopy confirmed on histology, clinical data including demographics, disease characteristics, treatment and outcome were obtained from case note and electronic patient record review. Results Of 477,553 patients invited, 219,705 were screened, representing an uptake of 46.01% and FOBt positivity of 2.35%. Colonoscopy was performed in 5350 patients (female 2287). Polyps were detected in 2344 (39.86%), cancer in 339 (5.77%) and 1383 (23.52%) had a normal examination. One hundred and twelve patients had endoscopic appearance suggestive of IBD, confirmed at histology in 66. Eleven patients were excluded as the diagnosis of colitis preceded the screening examination on case note review. Twenty-one of 55 incidental cases were female. Median age at diagnosis was 64. Sixteen patients had Crohn's disease (CD), 33 ulcerative colitis (UC) and 6 had IBD-type unclassified (IBDU). Forty-two patients had follow-up data available with a mean follow-up period of 23.9 months. Twenty patients (47.6%) were asymptomatic at diagnosis. Seven (35.0%) of the asymptomatic patients reviewed became symptomatic during the follow-up period. Treatment included steroids (11), 5-ASA (34), immunomodulators (azathioprine 6; methotrexate 1) and anti-TNF (infliximab 2; adalimumab 1). None required surgery. In those requiring escalation of therapy (14.3%) the median time to immunomodulation was 21 months (range 5-30 months). Those requiring immunomodulators and/or anti-TNF therapy (male 4; female 2) had asymptomatic extensive UC, symptomatic left-sided UC, symptomatic left-sided IBDU, symptomatic Crohn's colitis and symptomatic stricturing terminal ileal CD (2) at diagnosis. Conclusion An incidental diagnosis of IBD is not uncommon and with the advent of bowel cancer screening this number is set to increase. A proportion of these patients appear to demonstrate rapid disease progression with requirement for immunomodulator and/or anti-TNF therapy. These patients may present an important model for study of early disease with novel insights and evolving treatment paradigms.