EPRIMM
Research type
Research Study
Full title
Investigating the effect of pelvic radiotherapy on the intestinal microbiome and metabolome to improve the detection and management of gastrointestinal (GI) toxicity.
IRAS ID
297042
Contact name
Caroline Henson
Contact email
Duration of Study in the UK
2 years, 0 months, 0 days
Research summary
Research Summary
8 in 10 patients will develop bowel problems during radiotherapy, eg diarrhoea, pain and incontinence, half will develop difficult long-term bowel problems. We do not know why some people get bowel problems and others do not, and we do not have a test to predict who will develop bowel problems following their treatment.
There is a link between the changes in the number and type of gut bacteria (the microbiome) in some bowel conditions and we can test for these different bacteria in a simple stool sample using genetic testing. Also gut bacteria produce different gases in the stool called “volatile organic compounds” (VOCs), which we can measure in stool samples. Specific VOC patterns have been seen in other bowel conditions and small studies suggest that there are specific VOC and gut bacteria patterns in the stool of those undergoing pelvic radiotherapy to identify people who will get difficult bowel problems. Diet can change the microbiome/VOCs so diet change could improve bowel symptoms after radiotherapy.We would like to test stool samples of patients with womb/cervix/bladder cancer having pelvic radiotherapy to see if there are differences in the number/type of gut bacteria and VOCs between those who get severe bowel symptoms compared to those with mild bowel symptoms. We also want to see whether differences in VOCs or gut bacteria can tell who will develop severe bowel symptoms during or after radiotherapy and determine the effect of diet.
The first step is to run the study on a small scale to confirm that a larger full study would work. This will make sure we can recruit and consent people safely and will test the best ways of measuring bowels symptoms using several questionnaire options. We will collect the data needed for us to work out how many people we would need in a large trial to fully test our theory. Ultimately, we would like to use differences in the number/type of gut bacteria and VOCs to find ways to better prevent and treat bowel problems after pelvic radiotherapy.
People referred to The Christie Hospital for pelvic radiotherapy will be invited to be in the study, given information and a chance to talk to researchers. Those who agree to be involved will bring stool samples on the first day of their radiotherapy, their 20th radiotherapy treatment and to their clinic appointment 6 months after radiotherapy. They will also fill in 3 short questionnaires about their bowels and quality-of-life and complete food diaries for 3 days before each appointment.
Stool samples will be tested for VOCs and bacteria to look for differences in people who have the worst bowel symptoms and those who have the least bowel symptoms according to the questionnaires.This simple stool test will allow doctors to predict who will get radiotherapy-related bowel problems and then tailor their treatment accordingly. It will help us understand what changes in the gut cause the symptoms and what treatments may help.
Summary of Results
Background:
8 in 10 patients will develop bowel problems during radiotherapy, half will develop more difficult long-term bowel problems. We do not know why some people get bowel problems and others do not, and there is no test to know who will get bowel problems following their treatment. There is a link between the changes in the number and type of bowel bacteria (microbiome) in some bowel conditions. We can test for these different bacteria in a simple stool sample using genetic testing. These bacteria produce gases in the stool called “volatile organic compounds”(VOCs),which we can measure in stool samples. Specific VOC patterns have been seen in other bowel conditions and small studies suggest that there are distinctive VOC and bacteria patterns in the stool of those undergoing pelvic radiotherapy. These patterns may help to identify people who will get difficult bowel problems.
Aims and objectives:
We ran a study on a small scale to test stool samples of patients with womb/cervix/bladder cancer whilst having radiotherapy to look for differences in the bowel bacteria and VOCs between those who get severe bowel symptoms compared to those with mild symptoms. The study is aimed to make sure that we can recruit and consent people safely and test our procedures. We will use the results of this study to work out how many people we would need in a larger trial. Ultimately, we would like to use differences in bowel bacteria and VOCs to predict, prevent and treat bowel problems after pelvic radiotherapy.
How the study was carried out:
People referred to The Christie Hospital were invited to be in the study. Those who agreed to be involved brought stool samples on the first day of their radiotherapy, their 20th radiotherapy treatment and to their clinic appointment 6 months after radiotherapy. They also filled in 3 short questionnaires about their bowels and quality-of-life and food diaries for 3 days before each appointment. Stool samples were tested for VOCs and bacteria.
Key findings and conclusions:
Seventeen people took part in the study. Bowel symptoms were at their worst during radiotherapy with improvement after 6 months. Two VOCs (heptanal and octanal) were found in lower amounts before radiotherapy in people who had more severe bowel symptoms during radiotherapy. People with the worse bowel symptoms during radiotherapy had fewer different types of bacteria in their stool before radiotherapy.
Fewer people than expected wanted to be part of the study. This was partly because of the impact of the COVID pandemic, but also we found people with cervix cancer did not want to be involved. We think this is because the time from diagnosis to radiotherapy is very short and it is overwhelming. Once people started the study they tended to finish it.
The next step is to develop a larger study to confirm whether heptanal and/or octanal levels before radiotherapy can tell us who will get bowel symptoms during radiotherapy and whether the number of different bacteria in the stool before radiotherapy can tell us who will get bowel symptoms during radiotherapy.REC name
West Midlands - Edgbaston Research Ethics Committee
REC reference
21/WM/0084
Date of REC Opinion
16 Apr 2021
REC opinion
Further Information Favourable Opinion