CONSCOP

A trial looking at a novel way of doing a colonoscopy that involves spraying a blue dye throughout your large bowel, a method called contrast enhanced colonoscopy.

Background

Study outline - Georgina Gardner

Colorectal cancer is the second leading cause of cancer deaths in the UK. The Bowel Cancer Screening Programme (BCSP) was implemented to reduce deaths by the early prevention and detection of bowel cancer. Results from the first few years of screening and previous smaller studies show that, while in its current form it will save many lives, there continue to be polyps and cancers in the right side of the colon that may be difficult to detect. There is some evidence that these types of polyps (serrated polyps) may be at least partly responsible for cancers missed at the initial colonoscopy and have a faster rate of growth to cancer compared to conventional polyps (adenomas).

We propose to examine participants undergoing screening colonoscopy with the addition of a contrast dye (a safe food colouring agent base already used in various bowel camera procedures in standard clinical practice). This has been shown to improve detection of conventional polyps significantly and takes approximately 15 minutes of extra time. The study is a randomised controlled feasibility study comparing two groups, with and without use of dye spray throughout the right colon.

Study aim

Our primary aim is to study the feasibility of undertaking these procedures (i.e. assessment of acceptability by participants and colonoscopists, including time and costs involved in undertaking the enhanced approach). In addition to this we will also be assessing whether this technique helps to improve the detection rates of right-sided polyps in order to inform the sample size for a larger study. Removal of these polyps will enable further laboratory analysis of a collection of polyp samples in order to assess if such a sample collection might be able to answer the question of biological behaviour and growth pattern to cancer in a larger subsequent study within the BCSP. This will help to inform further studies to assess the impact of improved detection and potentially reduced incidence of interval or missed bowel cancers in longer term follow up.

Study design

CONSCOP is a feasibility study, and is a randomised open controlled trial (RCT) of contrast enhanced vs non-enhanced colonscopy in index bowel cancer screening to reduce bowel cancer mortality. The data obtained in this study will enable the assessment of the feasibility and design of a future RCT that will be powered to look for a reduction in bowel cancer mortality.

Serrated polyps are flat to the surface of the skin. The approach of using Indigo Carmine Dye was used as it may be easier to see the surface pattern and size of a polyp if it is sprayed with blue dye, therefore more polyps may be removed.

Recruitment

We aim to recruit 1,320 participants (660 per group) over a 12-month period involving all participating bowel cancer screening centres in Wales. All eligible participants (eligibility confirmed by Specialist Screening Practitioner) undertaking the BCSP will be invited to the study and participant randomisation will be performed centrally. The data collected by the BCSP nurse will include all the performance parameters already undertaken as part of the BCSP.

The challenge with recruiting potential research participants will be that the site teams in screening services that are working on the CONSCOP trial have never been involved with clinical trials before. The Chief Investigator and Trial Manger will visit each of the research sites to provide training and support.

Involving the public and patients

How have public members made a difference?

The public get involved in research for a variety reasons. Members of the public might have personal knowledge and experience of the research topic or be able to provide a more general perspective.

We involve the public by using their skills to help in the design of patient facing documents such as questionnaires, and patient/participant information leaflets. They can also ensure that the methods proposed for the study are acceptable to the potential research participant. They make certain that the research question outcome is important to the public and they can also be a voice for the seldom heard groups.

We like to have at least two research partners assigned to each trial.  We invite the research partners to our regular Trial Management Group meetings so that they can contribute and ensure that the research is being conducted in an acceptable and sensitive way to the potential research participants.