Why are young adults getting colorectal cancer? E. coli may be a clue
Exposure to a bacterial toxin in childhood may be playing a key role in the global rise of early onset of colorectal cancer, according to a new study.
The study, published April 23 in Nature, found that a toxin called colibactin, produced by certain strains of E. coli that live in the colon and rectum, is capable of altering DNA.
The researchers from the University of California reported that early exposure to colibactin leaves a unique mark on colon cell DNA — one that could bump up your chances of getting colorectal cancer before 50.
However, it's important to note that the study did not prove colibactin caused cancer, it only identified a link between mutations linked to the toxin and early-onset disease.
'These mutation patterns are a kind of historical record in the genome, and they point to early-life exposure to colibactin as a driving force behind early-onset disease,' said study senior author Ludmil Alexandrov, professor in the department of cellular and molecular medicine at the University of California San Diego.
Story continues below advertisement
'If someone acquires one of these driver mutations by the time they're 10 years old, they could be decades ahead of schedule for developing colorectal cancer, getting it at age 40 instead of 60,' he said in a media release.
2:08
'Could've been avoided': Colon cancer survivor advocates for colonoscopies
Colorectal cancer includes two types of cancers: cancer of the colon and cancer of the rectum.
Generally, it spreads more slowly than many other cancers, often lingering in the colon or rectum for months or even years before spreading elsewhere. That means if it's detected early, treatment is usually very effective.
While colorectal cancer rates have been falling among older adults, they've been climbing in people under 50 — both in Canada and around the world — over the past few decades, for reasons that still aren't clear.
Story continues below advertisement
If current trends continue, it's projected to become the leading cause of cancer-related death among young adults by 2030.
Get weekly health news
Receive the latest medical news and health information delivered to you every Sunday. Sign up for weekly health newsletter Sign Up
By providing your email address, you have read and agree to Global News' Terms and Conditions and Privacy Policy
'The fastest-growing subset of the population who get colorectal cancer, and primarily rectal cancer, are between the ages of 28 and 39 years old,' said Barry Stein, president and CEO of Colorectal Cancer Canada.
'And we don't have a reason to understand why these people are being diagnosed or why they're getting colorectal cancer in the first place.'
The question of why this is happening is what led the University of California researchers to dig deeper. Stein explained that there's already some evidence linking gut bacteria to colorectal cancer — whether it's a cause or just a correlation — and said this study adds another piece to the puzzle.
3:55
Health Matters: Colon cancer risks
What the study found
To help explain the medical mystery, the study's researchers looked at 981 colorectal cancer genomes from patients with both early- and late-onset disease across 11 countries (including Canada) with varying colorectal cancer risk levels.
Story continues below advertisement
The researchers found that colibactin leaves behind DNA mutation patterns in colorectal cancer that are 3.3 times more common in adults diagnosed before 40 than in those diagnosed after 70, and these patterns are especially frequent in countries with high rates of early-onset colorectal cancer.
Previous studies, including earlier work from Alexandrov's lab, have found colibactin-related mutations in about 10 to 15 per cent of all colorectal cancer cases.
Bu, these studies either focused on late-onset cases or didn't differentiate between early- and late-onset disease. This latest study is the first to specifically highlight a significant increase in colibactin-related mutations in early-onset cases, the researchers said.
2:20
Should the screening age for colon cancer be lowered?
The researchers found that the damage caused by colibactin seems to kick in surprisingly early. By analyzing the molecular 'timing' of different DNA mutation patterns, they were able to show that the mutations linked to colibactin tend to show up early in the process of tumour development, often during the first decade of life.
Story continues below advertisement
This means the colibactin-producing bacteria might be taking hold in children's digestive systems early on, quietly altering their DNA in ways that could increase the risk of developing colorectal cancer later in life, long before any warning signs emerge, the study said.
Dr. Shuji Ogino, chief of the molecular pathological epidemiology program at the Brigham and Women's Hospital in Boston, called the study findings 'fascinating.'
'Cancer develops in a long-term process. So people have cancer at age 40, age 45 or age 60, right? They have a symptom, go to the doctor,' he said. 'But in reality, it's likely that the process starts earlier. We don't know yet when it starts, but it could start quite early, even as a baby.'
And that's what the study points to, he added.
What's next?
Although it's too early to tell, Stein said if there is a link between the bacteria and colorectal cancer, it may have 'very profound effects.'
Story continues below advertisement
'For example, maybe these are things that we could look for when we're doing screening for the disease in terms of preventing the disease in the first place,' he said. 'Or maybe it's something that, through treatment, through developing a vaccine or developing a drug, we can attack those types of bacterium, which could stop the cause of colon cancer.'
In the meantime, the researchers say there's still a lot we don't know — and this discovery opens the door to a whole new set of questions.
How exactly are kids being exposed to colibactin-producing bacteria, and is there a way to reduce or prevent that exposure? Are certain diets, environments or lifestyle factors making the body more hospitable to these microbes? And how can someone even find out if they already carry these kinds of mutations?
The team is actively digging into these questions. They're exploring various theories, including whether probiotics could help safely wipe out harmful strains.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Toronto Star
5 hours ago
- Toronto Star
These Durham public beaches are open for swimming
According to public health guidelines from the Ontario Ministry of Health and Long-Term Care, water is considered unsafe for swimming when one sample contains 400 or more E. coli bacteria per 100 millilitres, or the geometric mean of five samples is 200 or more. Collecting, transporting and testing beach water for E. coli can take a day or more, so the latest available data may not reflect current conditions at the beach. Swimming is not recommended when it's raining, the water is wavy or cloudy, there are lots of birds, or for two days after a big storm. Consuming E. coli can cause serious illness, including stomach cramps, diarrhea and vomiting. When high levels of the bacteria are detected it's more likely that other harmful organisms are present as well, including those that cause skin rashes and eye, ear, nose and throat infections. A beach may also be considered unsafe for swimming due to weather conditions, runoff, pollution, spills, smells, garbage, sharp debris and dead fish. In addition, public beaches are monitored for blue-green algae, which can be highly toxic to humans, dogs and other animals.
National Post
5 hours ago
- National Post
'Swallowing razor blades': What to know about the painful symptom linked to latest COVID strain
Article content The World Health Organization recently designated NB.1.8.1 as a variant under monitoring. The strain, nicknamed 'Nimbus,' has reportedly been causing extremely painful sort throats in those who have been infected with it. Article content Cases of the Nimbus variant have been rising. It has been detected in 22 countries as of May 18 and made up 10.7 per cent of the global COVID samples taken in late April, WHO said. That was considered a 'significant rise in prevalence' since it only made up 2.5 per cent of global COVID samples four weeks prior. However, WHO deemed the overall risk of Nimbus to be low. Article content Article content 'Despite a concurrent increase in cases and hospitalizations in some countries where NB.1.8.1 is widespread, current data do not indicate that this variant leads to more severe illness than other variants in circulation,' according to WHO. Article content Article content It has been described by some as 'akin to swallowing shattered glass or razor blades,' news network NTD reported. Article content However, infectious disease specialist at University of California San Francisco Dr. Peter Chin-Hong, told the San Francisco Chronicle that a sore throat from COVID is 'not novel at all.' Article content Other symptoms of COVID include runny nose, new or worsening cough, shortness of breath or difficulty breathing, fever, chills, fatigue or weakness, muscle or body aches, new loss of smell or taste, headache, abdominal pain, diarrhea and vomiting. Article content Article content This particular strain 'isn't too different from the Omicron variant, but it does have some tweaks to its spike protein,' according to general practitioner from private healthcare centre Pall Mall Medical in the United Kingdom Dr. Chun Tang, The Independent reported. That means it could 'spread a bit more easily or slip past some of our existing immunity.' Article content 'That said, early signs suggest it doesn't seem to cause more serious illness, but of course, we're still learning more about it,' said Tang.
Toronto Star
6 hours ago
- Toronto Star
Stay out of the water at six Niagara public beaches
According to public health guidelines from the Ontario Ministry of Health and Long-Term Care, water is considered unsafe for swimming when one sample contains 400 or more E. coli bacteria per 100 millilitres, or the geometric mean of five samples is 200 or more. Collecting, transporting and testing beach water for E. coli can take a day or more, so the latest available data may not reflect current conditions at the beach. Swimming is not recommended when it's raining, the water is wavy or cloudy, there are lots of birds, or for two days after a big storm. Consuming E. coli can cause serious illness, including stomach cramps, diarrhea and vomiting. When high levels of the bacteria are detected it's more likely that other harmful organisms are present as well, including those that cause skin rashes and eye, ear, nose and throat infections. A beach may also be considered unsafe for swimming due to weather conditions, runoff, pollution, spills, smells, garbage, sharp debris and dead fish. In addition, public beaches are monitored for blue-green algae, which can be highly toxic to humans, dogs and other animals.
