A trial looking at aspirin, metformin and resveratrol to prevent bowel polyps (COLO-PREVENT)

Cancer type:

Bowel (colorectal) cancer
Colon cancer
Rectal cancer

Status:

Open

Phase:

Phase 2/3

This trial is looking at aspirin by itself and in combination with metformin to prevent bowel polyps. The researchers are also looking at a food supplement called resveratrol to see if this can prevent bowel polyps.

It is open to people who have had a colonoscopy to remove polyps Open a glossary item from their bowel as part of the NHS Bowel Cancer Screening Programme (BCSP). 

More about this trial

You might have a colonoscopy as part of the NHS Bowel Cancer Screening Programme (BCSP) if you are at a higher risk of developing bowel cancer. During the procedure the doctor might see polyps. Polyps are non cancerous outgrowths of tissue from the bowel. If left in place, these polyps might develop into cancer over time. So the doctor will remove them. This can reduce the risk of getting bowel cancer in the future, but does not prevent it completely. 

Researchers are looking for ways to improve the prevention of bowel polyps to reduce the risk of cancer. In this trial they are looking at:

  • aspirin
  • metformin
  • resveratrol 

Aspirin is a common painkiller. Doctors also use aspirin to prevent heart disease and stroke. Research has shown that taking aspirin might reduce the risk of developing bowel cancer. 

Doctors use metformin to treat diabetes. Research has shown that taking metformin might reduce the risk of developing cancer.

Resveratrol is a natural substance found in many foods such as grapes, peanuts and mulberries. Research shows that resveratrol could have many possible health benefits such as reducing inflammation and the risk of cancer. 

This trial has 2 parts:

  • aspirin and metformin
  • resveratrol

In the aspirin and metformin part, you take either:

  • aspirin only or
  • aspirin and metformin

In the resveratrol part, you take one of the following:

  • a low dose of resveratrol
  • a higher dose of resveratrol
  • a dummy drug (placebo Open a glossary item)

Your doctor will tell you which part you can go into. 

The aims of this trial are to find out:

  • how well these treatments work in stopping bowel polyps 
  • more about the side effects of these treatments

Who can enter

The following bullet points are a summary of the entry conditions for this trial. Talk to your doctor or the trial team if you are unsure about any of these. They will be able to advise you. 

Who can take part

You may be able to join this trial if all of the following apply.

  • You have had a colonoscopy as part of the NHS Bowel Cancer Screening Programme. You had polyps Open a glossary item removed and have been told that you will be invited back for a surveillance colonoscopy in three years time as part of the BCSP. 
  • You are able to continue having colonoscopies as part of your screening. 
  • Your kidneys and liver work well enough. Your doctor will test for this. 
  • You have satisfactory blood test results.
  • You are between 50 and 71 years old for the aspirin and metformin part of the trial. You are between 50 and 73 years old for the resveratrol part of the trial. 

Who can’t take part

You cannot join either part of this trial if any of these apply. You:

  • have a cancerous (malignant) change in a polyp
  • had, or plan to have, part of your bowel removed by surgery
  • have an inherited condition such as FAP Open a glossary item or hereditary nonpolyposis colorectal cancer (Lynch syndrome) Open a glossary item. Or you have the gene changes (mutation Open a glossary item) that causes these conditions. 
  • have inflammatory bowel disease
  • have a condition which means that you bleed or bruise easily
  • are taking medication such as warfarin to thin your blood, this is apart from aspirin. Or you are taking medication such as clopidogrel, prasugrel and ticagrelor that stops your platelets Open a glossary item from sticking together.
  • have had an experimental drug as part of another clinical trial in the past 30 days
  • have a serious medical condition that could affect you taking part in this trial 
  • are pregnant or breastfeeding 

Aspirin and metformin 

As well as the conditions above, you cannot join this part of the trial if any of these apply. You:

  • are taking aspirin on a regular basis more than 3 times a week 
  • are taking other non steroidal anti inflammatory drugs (NSAIDs) Open a glossary item. If your doctor has not prescribed the NSAIDs, you can take part if you are willing to stop taking them. 
  • are taking medication for diabetes. This includes if you have previously taken metformin.
  • have, or had, a medical condition that affects the lining of your digestive system Open a glossary item (peptic ulcer disease)
  • have had a build up of lactic acid (lactic acidosis) in the bloodstream or you have a condition which means you are more likely to have lactic acidosis
  • are taking long term steroids Open a glossary item that reach the whole body
  • are allergic to, or unable to take ibuprofen, naproxen, metformin, aspirin or salicylate

Resveratrol 

As well as the conditions listed above for either part of the trial, you cannot join this part of the trial if any of these apply. You:

  • are not willing to stop taking supplements that contain resveratrol during the trial
  • have a yeast allergy
  • are allergic or sensitive to the resveratrol capsules or anything they contain

Trial design

After you have had your routine colonoscopy as part of the NHS Bowel Cancer Screening Programme (BCSP), a member of the trial team will give you an information sheet about the trial. They will then phone you later to find out if you are interested in taking part. 

There are 2 parts in this trial. They are:

  • aspirin and metformin
  • resveratrol

Your doctor will tell you which part you are able to go into.

Aspirin and metformin
This is a phase 3 trial. The team need 862 people to take part. 

This is a randomised trial. A computer puts you into 1 of 2 groups. Neither you nor your doctor can choose which group you go into. The 2 groups are:

  • aspirin
  • aspirin and metformin

Aspirin is a tablet. You take 1 tablet once a day. 

Metformin is a tablet. You take 1 tablet once a day for 4 weeks. You then take 1 tablet in the morning and 1 tablet in the evening. 

You continue treatment for 3 years. 

You fill in a questionnaire about your food intake before starting treatment, then at:

  • 1 year 
  • 2 years
  • 3 years

The team ask for a poo (stool) sample before starting treatment, then at:

  • 1 year 
  • 3 years 

They will give you a Faecal Immunochemistry Test (FIT) kit to take home and collect the poo sample. This is the same type of kit that you used as part of screening in the BCSP. The kit contains instructions on how to collect the sample.

The team will ask for a piece of the polyp taken from your bowel when you have your colonoscopies. 

Resveratrol 
This is a phase 2 trial. The trial team need 477 people to take part. 

This is a randomised trial. A computer puts you into 1 of 3 groups. Neither you nor your doctor can choose which group you are in. Neither you nor your doctor will know which group you are in. This is a double blind trial.

Your doctor will be able to find out which group you are in if it is necessary to know.

The 3 groups are:

  • a low dose of resveratrol
  • a higher dose of resveratrol
  • a dummy drug (placebo)

Resveratrol and the dummy drug are capsules. You take 4 capsules once a day. You continue treatment for 1 year. 

You fill in a questionnaire about your food intake before starting treatment and 1 year later.

The team ask for a poo sample, before starting treatment and 1 year later. 

They will give you a Faecal Immunochemistry Test (FIT) kit to take home and collect the poo sample. This is the same type of kit that you used as part of screening in the BCSP. The kit contains instructions on how to collect the sample.

The team will ask for a piece of the polyp taken from your bowel when you have your colonoscopies.

Hospital visits

Everyone sees the doctor before taking part. This is for:

  • blood tests
  • recording information about your medical history and any medications that you are taking
  • checking your blood pressure (aspirin and metformin trial only)
  • a wee (urine) sample (resveratrol trial at selected hospitals only)

A member of the trial team will phone everyone at:

  • 4 weeks 
  • 12 weeks 

This is to see how you are. 

Aspirin and metformin
You see the doctor every 6 months for 3 years. You have another colonoscopy at 3 years, this is your routine NHS BCSP colonoscopy. A member of the team will call you 2 weeks later to see how you are. 

After 3 years in the trial, your doctor will tell you how often they want to see you.

Resveratrol
You see the doctor at:

  • 6 months
  • 1 year

You have another colonoscopy at 1 year. A member of the team will call you 2 weeks later to see how you are. This colonoscopy is an extra procedure required for the trial.

After 1 year in the trial, your doctor will tell you how often they want to see you and when you will have your routine surveillance colonoscopy under the NHS BCSP. 

Side effects

The trial team monitor you during treatment and afterwards. Contact your advice line or tell your doctor or nurse if any side effects are bad or not getting better. 

Aspirin and metformin have been in use for many years and are safe to take. But like all medication, they do have side effects.

The most common side effects of aspirin are:

  • stomach problems such as indigestion
  • an increased risk of bleeding

The most common side effects of metformin are:

  • when first taken, feeling or being sick, diarrhoea, tummy (abdominal) pain and loss of appetite. To try and avoid these, you will start on a very low dose and build this up to a dose that we know that most people manage without problems.
  • taste changes
  • low level of vitamin B12 

While taking metformin you should avoid drinking a lot of alcohol. 

Research shows that most people are able to take resveratrol without many side effects. The most common side effects of resveratrol are:

  • diarrhoea or constipation
  • feeling or being sick
  • tummy (abdominal) cramp
  • more fat in your poo (stool)
  • a burning feeling in the chest (heartburn) caused by stomach acid going up towards the throat (reflux)
  • flatulence and bloating

Your doctor will talk to you about the side effects of the treatments used in the trial and answer any questions you have before you agree to take part. 

Location

Aylesbury
Bristol
Coventry
Dorchester
Hartlepool
High Wycombe
Kettering
Leeds
Leicester
London
Milton Keynes
Northumberland
Norwich
South Tyneside
Sutton in Ashfield
Swindon
Truro

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Ajay M Verma

Supported by

Cancer Research UK
University of Leicester
Leicester Experimental Cancer Medicine Centre

Other information

This is Cancer Research UK trial number CRUK/19/011.

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

17182

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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