As part of ongoing care, patients have a colonoscopy and are seen routinely under the NHS Bowel Cancer Screening Programme (BCSP).

The standard way to identify bowel polyps (small growths on the bowel lining) is by a colonoscopy, which uses a camera to check the large bowel. If polyps are seen with the camera, they are removed at the same time.

Removing bowel polyps reduces the risk of bowel cancer in the future, but it does not prevent all cases of bowel cancer. That is why researchers are looking into other possible treatments.

We are doing this research to determine if drugs or food supplements could reduce the occurrence of bowel polyps, which in turn will reduce bowel cancer risk. This type of treatment is called ‘therapeutic prevention’. In the main trial of the COLO-PREVENT research study we are looking at whether taking aspirin, or aspirin combined with metformin is better at preventing bowel polyps from re-growing. 

Patients who are invited to take part in this research have had a colonoscopy in the NHS Bowel Cancer Screening Programme (BCSP) to remove bowel polyps and require another colonoscopy in approximately 36 months’ time. 

Blood Samples

We will ask you to provide fasting blood samples to assess your health and to understand how these drugs work to prevent bowel polyps. Fasting means you will not be able to eat or drink (other than water), apart from taking your regular medication, in the 8 to 10 hours before your appointment. We will book your appointment as early in the morning as possible. You are advised to bring refreshments with you to have after the blood test. Fasting blood samples are required 6 times during the 3-year period you will be on the trial.

The amount of blood we take at each visit for the trial is 50ml (about 3 tablespoons). The blood test may cause some mild discomfort and occasionally some bruising, but this is usually short lived.

Faecal Immunochemistry Test (FIT)

This is the same test that you did as part of the Bowel Cancer Screening Programme before being invited for your screening colonoscopy. We will give you the test to take at home and post this to us. The final FIT test for the trial will need to be taken before your colonoscopy.

Polyp tissue samples

We would like your permission to look at polyp tissue taken from your bowel during your routine screening and surveillance colonoscopies.

Rectal biopsies

The taking of biopsies (small pieces of tissue) during your colonoscopy is a routine procedure and is very safe. At your surveillance colonoscopy, we would like to ask your permission to take 6 additional biopsies for research purposes from the lining of the bowel. This is to try to understand why bowel polyps come back and how treatment can affect this. Although there is a theoretical risk of perforation or serious bleeding this is very rare as the biopsies taken are very small. You usually cannot feel the actual biopsy though you may be aware of a tugging sensation as it is taken. Consent for the rectal biopsies is optional.

As these tests are solely for research and safety purposes, and not for diagnosis, we will not be able to send the results to you or your GP.

Your participation in the trial will end at your routine consultation following your surveillance colonoscopy. You will no longer receive the trial therapy, either from your GP or the research team after your surveillance colonoscopy. You will continue in the Bowel Cancer Screening Programme as normal.

Trial drugs will be given for 3 years in the aspirin and metformin main trial and 12 months in the resveratrol sub-trial, until patients have another planned BCSP colonoscopy, at which time the number and size of polyps will be measured. 

Our PPI group consists of three core members, one of whom is a named co-investigator and sits on our trial management group. They have been involved throughout the entire development and design of COLO-PREVENT; over the course of the trial, they have continued to directly influence key decisions and made significant contributions to our progress, as outlined below:

• Contributed to discussions that led to a decision to post out medication rather than have patients wait around for results of their safety bloods before they could be given their trial medication.

• Provided advice and valuable input to any requirements for patient behaviour changes, decisions around the dose of aspirin used and the strategy for management of metformin-related side effects.

• Advised on the content/presentation of the study protocol.

• Provided crucial input to the wording, content and visual appearance of the two Participant Information sheets (PIS).

• Took the lead on how we first present the study to participants – here, they suggested a simplified infographic participant information sheet, and had a major role in its design and content (see below infographic for the Main phase 3 trial).

• Played a significant role in our favourable feedback from Research ethics Committee (REC). Our PPI co-investigator, Barry Sandywell, attended the REC meeting, providing crucial lay insight and exceptional responses to questions from the REC committee around participants’ trial involvement. REC commended the simplified infographic PIS (the idea for which came from our PPI representatives), suggesting this could be utilised as an exemplar for what true patient involvement should look like.

• Contributed to the design and refinement of our trial website, which is ongoing.

• Contributed to meetings focussed on participant engagement strategies and supporting the set-up of an expanded study naïve PPI panel.