A quarter of a million volunteers are being sought for a nationwide research project investigating the mystery of why bowel cancer diagnoses are increasing among younger adults.
Historically considered a health issue primarily affecting older generations, data reveals that cases are rising among people under the age of 50.
Medical experts note that instances of early-onset bowel cancer have increased "substantially" across the globe since 1990, with the UK suffering one of the steepest rises.
The precise triggers behind this growth are not yet known, although rising levels of obesity are thought to be a contributing factor.
Scientists from King’s College London, working in partnership with health science company Zoe, are aiming to recruit 250,000 adults from across the UK to participate.
The trial, named Prospect-UK, will follow participants over an extended period to monitor dietary habits and lifestyle patterns.
Those taking part will complete online surveys focused on their diet, daily lifestyle, environment, personal health, and related factors.
Volunteers will also be asked to link their survey responses to their electronic health records, allowing investigators to monitor any future cancer diagnoses.
A smaller subgroup of participants will be selected to provide comprehensive dietary diaries along with blood and stool samples.
"Over just a few generations our lifestyles, diets and environments have changed dramatically," said Professor Sarah Berry, chief investigator of the trial and professor of nutritional sciences at King’s College London.
"But we don’t know which of these changes are increasing people’s risk of bowel cancer or which ones could help reduce it.
"We urgently need large-scale, long-term data to uncover the true causes of early-onset bowel cancer."
Dr Rosiered-Brownson Smith, study research associate at King’s College London, said: "Although rates of early-onset bowel cancer are rising, it remains relatively uncommon, which means we need large groups of people to take part in research to help us understand why we are seeing this worrying trend.
"At the same time, our food environment has become increasingly complex, and this means we need to look at diet in much greater detail.
"In the UK, around 60% of our calorie intake comes from highly processed foods, but these foods are not all the same.
"They can differ substantially in their ingredients, processing methods and nutritional composition, even within the same food category."
Dr Smith added: "For the first time, we are collecting detailed, brand-level information about the foods people actually eat.
"This will allow us to better understand which foods and dietary patterns may be linked to the development of early-onset bowel cancer.
"Combining detailed dietary information with long-term health data, we hope Prospect-UK will help us better understand the complex relationship between what we eat and our risk of disease."
Data provided by Cancer Research UK shows that roughly 48,200 people are diagnosed with bowel cancer in the UK every year, with approximately 2,900 of those cases occurring in adults aged between 25 and 49.
The charity stated that between the early 1990s and 2019, overall cancer incidence in 25 to 49-year-olds in the UK increased by 24%.
Main symptoms of bowel cancer
According to the NHS
Symptoms of bowel cancer may include:
- changes in your poo, such as having softer poo, diarrhoea or constipation that is not usual for you
- needing to poo more or less often than usual for you
- blood in your poo, which may look red or black
- bleeding from your bottom
- often feeling like you need to poo, even if you’ve just been to the toilet
- tummy pain
- a lump in your tummy
- bloating
- losing weight without trying
- feeling very tired for no reason
Bowel cancer can cause anaemia (when you have fewer red blood cells than usual), which can make you feel very tired, short of breath and have headaches.
Dr David Scott, director of global research initiative Cancer Grand Challenges, said: "Bowel cancer is still much more common in older people, but rising rates in younger adults pose a question we are working to answer.
"Diet and lifestyle may be part of the picture, but we need to understand what else could be contributing and how these factors interact.
"Prospect-UK will help investigate that question as part of the international Prospect team’s work, through Cancer Grand Challenges.
"The global team is working to understand what is driving this rise in younger people and, ultimately, identify new ways to prevent bowel cancer."
