It’s the phenomenon that’s baffled doctors around the world: bowel cancer, usually a disease of the elderly, has soared by 50 per cent in 20, 30 and 40-somethings over the past 30 years.
Now, in a fascinating discussion between two of the world’s leading cancer experts, a new theory as to the explanation behind trend has been tabled.
While acknowledging that there is likely ‘several’ contributing factors, the top specialists have suggested that a common childhood infection could be partly to blame.
In an interview with The Health Foundation, Dr Charles Swanton, Chief Clinician of Cancer Research UK, spoke of ’emerging data’ showing that a specific type of the bacteria E. coli could ‘contribute at least to some of the cancer initiation processes.’
He added that the infection, which leads to food poisoning symptoms, has been shown to trigger mutations in blood vessels in the gut that could fuel tumour development.
Bowel cancer can cause you to have blood in your poo, a change in bowel habit, a lump inside your bowel which can cause an obstructions. Some people also suffer with weight loss a s a result of these symptoms
Top cancer doctors Kimmie Ng (left), specialist in oncology and Director of the Young-Onset Colorectal Cancer Centre at the Dana Farber Cancer Institute in Boston, and Charles Swanton (right), Chief Clinician at Cancer Research UK, discuss what’s behind this worrying rise
Dr Kimmie Ng, specialist in oncology and Director of the young-onset colorectal cancer centre at the Dana Farber Cancer Institute in the US, echoed Dr Swanton’s comments.
She responded: ‘That finding is really provocative and very interesting,’ adding that the infection is likely to be a ‘very early event’ in someone’s life.
‘This is consistent with our hypotheses that whatever exposure or inciting factor is happening is probably happening in the early life course.’
Speaking to this theory is Dr Ng’s concerning claims that many of her colorectal cancer patients are in fact children.
Dr Ng said in her own clinic she has started seeing more children with the disease than ever before.
‘Although there isn’t published data necessarily on the rate of increase and whether it’s affecting the paediatric population, at least anecdotally I have certainly been seeing some children with colorectal cancer,’ she said.
Data from JAMA Surgery showed colon cancer is expected to rise by 90 percent in people ages 20 to 34
She added that thyroid cancer has also been increasing as well as kidney cancer, which is also on the rise in young people.
The type of E. coli the experts pinpointed is a specific strain known as PKS-positive E. coli.
It is not linked to food poisoning outbreaks, but is thought to develop via interactions with the trillions of microbes in our gut.
Scientists aren’t entirely sure how PKS-positive E. coli develops, but one 2022 study found an association between the presence of the bacteria in colorectal cancers and western-style diets.
A 2020 study published in the journal Nature suggested a person’s chance of developing bowel cancer may increase after getting this specific type of E.coli infection.
Scientists believe the bacterium releases a toxin which can damage the cells that line the bowel. The study says this can potentially turn some cells cancerous over time.
Although our junk-food laden diets, smoking and obesity are often blamed for the rise in cancer, experts say these subtle gut bacteria changes are much more likely to be a major contributing factor.
Dr Ng claims that in her experience many of her patients are young and they are not obese.
In fact, many young people diagnosed with bowel cancer lead healthy and active lifestyles, suggesting it’s not just obesity behind this rise in cases.
‘Many are triathletes and marathon runners, and so it is really puzzling why this is happening,’ she said.
‘I mean, the hypothesis put out there is that the reason why the incidence is rising among all digestive system cancers is this common theme of obesity being a risk factor.
‘But I have not seen that myself in the patients whom I’ve taken care of.’
Dr Swanton added that although many scientific studies say obesity is a big risk factor in early onset colorectal cancer, he suggests this is not always the case.
He said: ‘My impression at least clinically is that that doesn’t always bear fruit, that argument, and that many of these early onset cancers are associated with individuals who aren’t obese or overweight.’
MailOnline has repeatedly documented the global rise of colon cancer among young people.
Perhaps the most recognisable victim of the trend is Deborah James — known as ‘bowel babe’ — who was diagnosed at just 35 and raised millions for charity in her final days in 2022.
Analysis suggests deaths from bowel cancer overall in the UK are set to rise by 2,500 a year between now and 2040.
Meanwhile, the number of people in the UK diagnosed with the disease will rise by around a tenth in the same period.
Bowel cancer currently kills just shy of 17,000 Brits each year with only half of those diagnosed expected to survive 10 years after learning they have the disease.
