Title: A study to assess the feasibility and patient acceptability for an adapted diagnostic accuracy study to compare virtual vs conventional chromoendoscopy for the detection of dysplasia in colitis
Funder: Department of Health and Social Care

Abstract: Background Colitis is an inflammatory bowel disease with a 2.5-fold risk of colon cancer compared to the general population. Patients with colitis require regular, often annual, surveillance colonoscopy to try to detect areas of dysplasia: early, pre-cancerous changes on the lining of the colon. Dysplasia is easily missed at colonoscopy, so NICE guidance (CG118,2011) recommends the use of chromoendoscopy (CE) in which dye is sprayed through the colonoscope to coat and highlight the lining of the bowel, making dysplasia easier to see. However, CE is messy, time-consuming, costly and requires considerable expertise. CE has not, understandably, extended outside a few specialist centres. Newer technology provides an alternative: virtual chromoendoscopy (VCE). Available at the press of a button, during the colonoscopy, VCE digitally enhances and colours the video (mimicking CE), but also highlights surface blood vessels that harbour the earliest changes of dysplasia. VCE could therefore be better at detecting dysplasia. PPI participants told us that surveillance colonoscopy is burdensome &ndash;taking time out of their lives, relying on friends or relatives to collect them after the procedure, and -above all- undergoing a potentially uncomfortable, undignified procedure. Although they understood very clearly the need for surveillance, they expressed enthusiasm for VCE in that might result in a more comfortable examination, from which it was quicker to recover. As this is a feasibility study, our aim is to assess study design and obtain preliminary evidence to inform an application for a definitive, multicentre trial. Objectives within the feasibility study: to test the feasibility of the dual procedure design with respect to recruitment and retention rate of participants obtain information comparing patients experiences of each procedure, using validated questionnaires, and determine the feasibility of collecting this data assess contamination of one procedure by another (for patient experience) gather preliminary evidence regarding time taken and patient comfort during the procedure provide preliminary estimates of the rate of dysplastic lesions in the cohort as a whole and the missed-lesion rate for the first procedure (whether CE or VCE) inform a future application for a multicentre study with regard to the above criteria Plan of investigation In the recruitment period, 60 patients will be approached when they are invited to attend for scheduled surveillance colonoscopy. Eligible patients (18-75 yrs) who agree to participate will be randomised to undergo CE or VCE as the first procedure. Data will be captured by an Observer using a bespoke Access-based program. The site and number of any biopsy samples taken will be recorded alongside the Endoscopist s prediction, based on visual appearance, of whether they think the area biopsied is actually dysplasia. After an agreed interval (no more than 8 weeks, usually 3-6), participants will undergo a second colonoscopy with the second technique, performed by the same Endoscopist (see Research Plan for justification), and data captured as before. For each procedure, a questionnaire assessing immediate patient experience will be administered in the Endoscopy department, after the participant has recovered from the procedure. Participants will also be given a second questionnaire assessing their overall experience to take home and complete 48 hours after the procedure, which will be returned by post. Potential benefits to patients and NHS Our PPI patient meeting highlighted the importance of comfort and dignity during the procedure, but that their main concern was that dysplasia was not missed. The characteristics of VCE suggest that it may provide a quicker, more comfortable, less technically-difficult and cheaper option. VCE may therefore overcome the barriers that have prevented CE from being widely practised in the UK and facilitate the provision of a better service for more patients.

Lay abstract: Colitis, a disease of the colon (large bowel), affects 1/600 people in England. People with colitis have 2.5 times the normal risk of colon cancer, so they need regular check-ups with colonoscopy (video-telescope examination of the colon lining) to take biopsies (tiny samples). In colitis, cancer develops from flat, pre-cancerous growths called dysplasia that are particularly difficult to see. Current guidance recommends chromoendoscopy (CE), a technique using dye to highlight the colon lining during colonoscopy. The dye makes dysplasia easier to see, but CE is messy, time-consuming, costly and requires considerable expertise, so is not widely practiced. New technology means that the video image obtained during colonoscopy can be digitally enhanced and coloured at the press of a button &ndash; virtual chromoendoscopy (VCE). VCE has none of the disadvantages of CE described above and may be at least as good as CE at detecting dysplasia, benefitting patients by resulting in a shorter, more comfortable examination that s easier to recover from. We want to eventually complete a large trial comparing the ability of CE and VCE to detect dysplasia. However, we first need to determine if this will be feasible. Therefore, we are applying for funding to conduct this feasibility study where we will invite 60 colitis patients to have both CE and VCE. The procedure each participant has first will be decided at random, with the other performed within the following eight weeks. Participants will complete questionnaires about their experiences of both. We will examine: how many patients agree to participate and if any drop out whether (in our study design) one procedure has a negative effect on the other (contamination) how they vary in terms of patient experience This will demonstrate whether the larger study will be possible and can help us decide how many participants will be needed.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: CANCER AND NEOPLASMS;ORAL AND GASTROINTESTINAL