The increasing incidence of colorectal cancer deaths among those under the age of 50 is worrying doctors and prompting more research to understand the reasons for this disturbing trend.

A study published in the Journal of the National Cancer Institute last year, based on data from Australia, Canada, the United States, and the United Kingdom, revealed that those born in the 1990s are four times more likely to develop colorectal cancer than those born in the 1960s.

A major cause of death

Colorectal cancer is now the leading cause of cancer death among people under 50 in the United States, according to a study published in JAMA last month.

“It’s really scary, but the rates that were initially recorded were very low,” says Helen Coleman, professor of oncology at Queen’s University Belfast.

However, the majority of cases are among older people, with colorectal cancer among under-50s accounting for only 6% of all diagnosed cases, according to research conducted in Northern Ireland.

Coleman noted that infection rates are stabilizing or declining among the elderly in some areas as a result of improved early detection programs.

However, because young people do not think about the possibility of developing this cancer, they are often diagnosed at a late stage, as happened with American actor James Van Der Beek, who died last week at the age of 48 due to complications from the disease.

The same disease also claimed the lives of American actor Chadwick Boseman, known for his role in the movie “Black Panther,” at the age of 43.

What is the reason for the increase?

As with other cancers that affect young people, colorectal cancer is associated with overweight and an unhealthy lifestyle, including poor diet, lack of exercise, alcohol consumption, and smoking.

But these factors alone do not explain “the significant increase observed over a relatively short period of time,” according to Coleman.

Ironically, a large number of young patients with colorectal cancer were following a healthy lifestyle, such as James Van Der Beek, who was diagnosed with the disease in 2023.

“I was going to the sauna, taking cold showers, etc., and I had stage 3 cancer without knowing it,” the father of six said in December.

What could explain this relatively sudden increase? “We don’t know,” Jenny Seligman, a colorectal cancer researcher at the University of Leeds in the United Kingdom, told AFP.

This mystery prompted researchers to explore other paths, especially the microbes that live in the human intestine, which are still shrouded in mystery.

Screening before the age of 50

Coleman noted that a study published last year in the journal Nature highlighted “very important preliminary evidence” in this field.

This study revealed that mutations in the DNA of a gene toxin called colibactin, a weapon used by bacteria to protect themselves from other microbes and produced by Escherichia coli, were more common in young people with colorectal cancer than in older patients. But this result needs to be confirmed by additional research.

Other research suggests that frequent antibiotic use may be linked to earlier onset of colorectal cancer.

Seligman also noted that she observes several subtypes of colorectal cancer, indicating the diversity of its causes. She believes that “it would be very difficult to pinpoint just one cause.”

Before his death, actor James Van Der Beek, who was thin, urged anyone with any symptoms, no matter how minor, to get tested. “I want to announce it to everyone: If you are 45 or older, see your doctor!” he said.

Diarrhea and constipation, in addition to blood in the stool, unexplained weight loss, and fatigue, are symptoms that cause concern.

In the face of this rise in cases among young people, the United States in 2021 lowered the recommended age to start screening from 50 to 45 years.

Calls are growing for other countries to follow suit, with the UK and France introducing screening from the age of 50.