The rise in colon cancer among young people may be linked to childhood… what is the connection?
Colon and rectal cancer was once thought to mainly affect individuals in older age, but it is now increasing among the youth. A groundbreaking new study suggests that bacteria living in the intestines may be behind the recent rise in cases of early-onset colon and rectal cancer, according to the New York Post.
What is the potential cause? Colibactin, a toxic substance produced by certain strains of Escherichia coli that thrive in the colon and rectum.
Dr. Ludmila Alexandrov, the lead author of the study and a professor at the University of California, San Diego, told the New York Post: “We believe that this exposure occurs very early in life—likely during the first decade—when children are infected.”
It was previously thought that colon and rectal cancer was a disease that affected people later in life, but it is now increasing among the young in at least 27 countries.
In the United States, the number of people under 55 diagnosed with the disease has nearly doubled in the past decade, and the death toll is rising annually, according to the American Cancer Society.
Alexandrov stated: “Until now, previous studies have not been able to identify a clear cause or even distinguish between early cases and those diagnosed later in life. Our study helps change that.”
In the study, Alexandrov and his colleagues examined the genomes of cancer in early and late-stage colon and rectal cancer patients across 11 countries.
The team found that these bacteria, colibactin, leave a distinctive acidic fingerprint on colon cells when children are exposed to them. These mutations were 3.3 times more common in early-onset cases compared to those diagnosed after the age of seventy.
Researchers found that mutations linked to colibactin appear in the early stages of disease development, often during the first ten years of life.
Alexandrov noted: “Although the infection is transient, the damage it causes may last for decades.”
What is even more concerning is that the study found that about 15 percent of the mutations in the APC gene—one of the earliest genetic changes that directly trigger cancer development—are associated with colibactin.
Alexandrov reported: “If a person is exposed to one of these driver mutations before reaching the age of ten, they may be decades ahead in developing colon and rectal cancer, getting it in their forties instead of sixties.”
Is this the only reason for the rise in cases?
There is still debate over whether colibactin is the primary driver behind the increase in early-onset colon and rectal cancer, or if it is just one of several factors.
Alexandrov stated: “Colibactin is likely to play a major role in early-onset colon and rectal cancer, although other factors—such as diet, inflammation, and genetics—are also likely contributing.”
He added: “However, the impact of colibactin in our study was astonishing, as it is the first factor clearly identified and linked to the rising rates of colon and rectal cancer at an early age.”
How do children get exposed to this bacteria?
Alexandrov explained that exposure to colibactin occurs “through colonization by Escherichia coli—typically via the gut and often without any clear symptoms.”
Additionally, the study revealed varying mutation patterns in colon and rectal cancers from countries such as Argentina, Brazil, Colombia, Russia, and Thailand, indicating that local environmental exposures may influence cancer risk.
Markus Diaz-Jay, a co-author of the study and a researcher in Alexandrov’s lab, said: “It’s possible that the unknown causes of cancer differ from country to country.”
He continued: “This could open the door to targeted preventive strategies for specific regions.”
