Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.
A study looking at cell changes in people with Barrett's oesophagus (TIME)
This study is using a new type of endoscopy to find and help study cell changes in people with a pre cancerous condition called Barrett’s oesophagus.
More about this trial
If you have Barrett’s oesophagus, the normal cell lining of the food pipe (oesophagus) changes and becomes more like cells of the stomach or small bowel. Sometimes people with Barrett’s oesophagus may develop ulcers, narrowing of the food pipe (strictures) and very rarely cancer of the food pipe. If you have Barrett’s oesophagus, doctors will regularly check your food pipe using a small camera on a thin flexible tube (endoscope).
Researchers want to understand more about new ways of doing endoscopy to detect cell changes that might cause Barrett's oesophagus to turn into cancer.
In this study, they will look at the food pipe using a type of endoscopy called ETMI (Endoscopic Tri-Modal Imaging). Usually endoscopes use a white light to show up areas of abnormal tissue. ETMI looks just like a standard endoscopy camera. But it also has special filters to choose green and blue light and show up changes that white light can’t. We know from research that ETMI helps doctors to see areas of the food pipe that have abnormal cells or very early cancer that standard endoscopy can’t show. They are also using a tiny microscope called pCLE (probe based Confocal Laser Endomicroscopy). pCLE is a special microscope that is passed down the ETMI endoscope, and helps doctors see changes to cells.
In this study, researchers will also study samples of tissue (biopsies) taken during the endoscopy. They will look for features (markers) that are linked to abnormal cell changes that lead to cancer.
The researchers are also testing some special dyes that glow in infra red light. They will use these dyes on some of the tissue samples and look at them under a special type of infra red camera. They think that this may be helpful for doctors in the future to find tiny areas of cancer.
They hope that information from the ETMI and from the pCLE endoscopies and study biopsies will in future help them develop a test to diagnose the disease more easily. And work out more accurately who is at higher risk of developing cancer.
Who can enter
If you are suitable for this study, a member of the study team will ask if you would like to take part. People taking part will have Barrett’s oesophagus and be in one of the following situations
- Have Barrett’s cells that form at least a 2cm band around the inside of their food pipe
- Have a patch of Barrett’s cells at least 4cm long
- Have very abnormal cell changes in their food pipe (high grade dysplasia)
- Are being monitored after endoscopy treatment for high grade dysplasia (sometimes called ‘carcinoma in situ’)
You must also be at least 18 years old to take part in this study.
You cannot enter this study if you
- Have moderate or severe redness and swelling (inflammation) of your food pipe (‘oesophagitis’)
- Have had surgery to the upper part of your digestive system or airways - if you have had surgery to stop acid reflux by wrapping the top part of your stomach around the bottom part of your food pipe (anti reflux Nissen fundoplication) you can still take part
- Have an abnormal condition of your upper digestive system – you can check this with your doctor
- Have a problem with how your blood clots, or you are taking tablets to prevent abnormal clotting, for example warfarin or clopidogrel
- Are allergic to the drug fluorescein (this is a yellow dye you may have put in your eye during a sight test)
- Have severe disease affecting your heart or lungs
- Have liver disease
- Have bleeding problems in your digestive system
- Have difficulty swallowing (dysphagia)
- May need to have treatment that uses a thin flexible tube with a camera on the end (endoscope), for a condition other than Barrett’s oesophagus
- Would not be able to communicate easily with the study staff for any reason
There are 3 parts to this study. The first phase of the study recruited 150 patients and has now ended, the researchers looked at the food pipe using just ETMI endoscopy.
The second part recruited 55 people. This part used both ETMI and the pCLE microscope. An ETMI endoscopy is similar to a regular endoscopy, but will take longer, as it will look at the tissue in different ways. pCLE is a special microscope that is passed down the ETMI endoscope, and helps doctors see changes to cells.
In the third part the team will look at tissue samples using the special dyes that glow in infra red light.
The team will also take pictures of the inside of your food pipe, as well as filming the way the procedure is carried out.
Before your endoscopy, the study team will record your height and weight, and measure your waist and around your hips. They will also ask you questions such as whether you smoke or drink, and about any medication you may be taking.
You then lie down on the couch. Instead of the throat spray you might usually have, the doctor will give you a drug to relax you and make you feel drowsy (a sedative) through a drip into a vein. You may also have a painkilling injection through this drip.
The study doctor will pass a thin, flexible tube with a tiny light and camera on the end (endoscope) down into your food pipe. They will look at the food pipe with the white light to map any abnormal areas of tissue and take pictures They will then do this with the green lights (AFI). This shows up abnormal cells as violet or purple colour. They will then see if AFI is better at showing new areas of abnormal cells compared to the white light.
The doctor will then use ‘narrow band imaging’ or ‘NBI’ to look at
After that, you will have a drug called fluorescein, as an injection into a vein. Fluorescein helps tiny structures show up clearly under the pCLE microscope. The doctor will pass the pCLE microscope down the endoscope and look again for cell changes.
As well as taking standard biopsies to monitor your condition, the study doctor will take extra study biopsies from abnormal looking areas in the food pipe, and from healthy parts of the bowel. The doctor will take samples from the bowel by passing the endoscope further down, through your stomach to the first part of your small bowel, the duodenum. Looking at the duodenum is part of any regular endoscopy and you will not feel any extra discomfort with this. You will have between 5 and 13 extra biopsies, depending on the results of your endoscopy. The study team will look at these biopsies for features (markers) that are linked to abnormal cell changes that lead to cancer. Giving these extra samples does not increase your risk of side effects from this procedure.
The doctor will tell you the test results straight away, and you will have the biopsy results in about 6 weeks. The team will not give you information about any markers they find in these biopsies. This is because researchers are unsure what this information would mean for you at this time.
The endoscopy you have in this study replaces one you would have had as routine. So you do not need to make any extra visits to hospital to take part in this study. But your appointment will take a little longer, as the ETMI endoscope looks at your food pipe in 3 different ways, and the doctor will also look at cell changes with the pCLE microscope.
Side effects for an ETMI endoscopy are the same as a regular endoscopy. These may include bleeding, and tearing (perforation) of your food pipe, but the risks are very small. After the procedure, if you are sick within about 12 hours and bring up blood, or if you pass black stools that look like tar up to 2 or 3 days after, you should contact the study team, your family doctor or local hospital.
Common side effects of fluorescein include
- Feeling and being sick
- Temporary yellowish colour of your skin and eyes - this should go within a few hours
- Allergic reaction (skin rash and itching)
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.
Dr Rebecca Fitzgerald
Experimental Cancer Medicine Centre (ECMC)
Medical Research Council (MRC)
NIHR Clinical Research Network: Cancer
The Lister Institute of Preventive Medicine