Huge breakthrough as scientists pinpoint cause of colon cancer in young people… with 100,000 exposed yearly
A common food bug may fueling a colon cancer epidemic in young people, according to a bombshell study.
Colorectal (bowel) cancer, a disease most often associated with old age, is increasingly striking people in their 20s, 30s and 40s in the US, UK and across the globe in a phenomenon that has baffled doctors.
Now, researchers at the University of California San Diego have honed in on E. coli, a foodborne bacteria that infects around 75,000-90,000 Americans each year and thousands of Britons.
The experts analyzed DNA samples from young colon cancer patients, finding they had unique genetic changes compared to people who developed the disease later in life.
The team also found colibactin, a toxin produced by bacteria like E coli, lurking in colon tumors of young colon cancer patients, defined as people under age 50.
And the damage starts early. The researchers found mutations caused by colibactin can occur within the first 10 years of a person’s life, increasing the risk of colon cancer developing earlier in life.
This means bacteria that produce colibactin, such as E coli, could be silently colonizing in children’s colons, altering their DNA and setting the stage for colon cancer.
The above graph shows the increase in US colorectal cancers in men and women from 2000 through 2021
Bailey Hutchins of Tennessee, pictured at left, died of colon cancer earlier this year at age 26. Evan White, pictured at right with his fiancee and dog, died of colon cancer at age 29
Ludmil Alexandrov, senior study author and professor of cellular and molecular medicine at the University of California San Diego, said: ‘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.
‘This reshapes how we think about cancer. “It might not be just about what happens in adulthood—cancer could potentially be influenced by events in early life, perhaps even the first few years.
‘Sustained investment in this type of research will be critical in the global effort to prevent and treat cancer before it’s too late.’
According to the latest data, early-onset colon cancer diagnoses in the US are expected to rise by 90 percent in people 20 to 34 years old from 2010 to 2030.
In teens, rates have surged 500 percent since the early 2000s.
The American Cancer Society estimates 154,270 Americans will be diagnosed with colon cancer this year, and 52,900 will die.
In the UK, 44,063 cases are diagnosed per year, and the nation experiences 16,808 deaths every year.
The study, published Wednesday in the journal Nature, looked at the DNA of 981 colon cancer tumors in patients who were either under 40 or over 70.
Patients were spread across 11 countries, including the US and UK.
They found colibactin caused genetic mutations that were 3.3 times more common in early-onset colon cancer cases than late-onset, meaning younger patients were more likely to have them.
These mutations were also most common in countries with high rates of early-onset colon cancer, such as the US and UK.
The researchers also estimated colibactin-related mutations are present in 10 to 15 percent of all colon cancers.
Dr Marcos Diaz-Gay, first study author and former postdoctoral researcher in Alexandrov’s lab, said: ‘When we started this project, we weren’t planning to focus on early-onset colorectal cancer.
‘Our original goal was to examine global patterns of colorectal cancer to understand why some countries have much higher rates than others. But as we dug into the data, one of the most interesting and striking findings was how frequently colibactin-related mutations appeared in the early-onset cases.’
E coli bacteria sickens 265,000 Americans, with young children being the most at risk. Children may catch it at petting zoos or by eating contaminated foods
The team also found colibactin-related mutations start early in colon tumor development, with is consistent with previous research suggesting these mutations occur in the first 10 years of life.
They found colibactin-related mutations account for 15 percent of APC driver mutations, which are some of the earliest genetic alterations directly linked to cancer, in colon cancer.
Alexandrov said: ‘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.’
And despite the notable rises in the US and UK, the researchers found colon cancers in Argentina, Brazil, Colombia, Russia and Thailand were had the largest increases in colibactin-related mutations.
Diaz-Gay said: ‘It’s possible that different countries have different unknown causes. That could open up the potential for targeted, region-specific prevention strategies.’
The researchers plan to investigate how children are being exposed to colibactin-producing bacteria and if medications like probiotics can eliminate harmful strains of bacteria.
The team also plans to look into how environmental exposures later in life can increase the risk of colon cancer.
Alexandrov said: ‘Not every environmental factor or behavior we study leaves a mark on our genome.
‘But we’ve found that colibactin is one of those that can. In this case, its genetic imprint appears to be strongly associated with colorectal cancers in young adults.’
