The rise in colon cancer cases among younger adults that's been seen in the United States is also occurring in wealthier nations worldwide, new research shows.
In the decade leading up to 2014, the number of cases of colon cancer among people under 50 increased by 3% a year in Denmark, New Zealand, Australia and Canada, and by 1% per year in Britain.
Need for action
The increase was most pronounced among those aged 20 to 29, noted a team led by Dr Marzieh Araghi, from International Agency for Research on Cancer in Lyon, France.
Among twenty-somethings, colon cancer cases rose by 18% a year in Denmark and 11% in Norway, according to the study published in The Lancet Gastroenterology & Hematology.
"Although the incidence of colorectal cancer in adults younger than 50 years remains much lower compared with that in older age groups, our findings are of concern and highlight the need for action to counteract the rising burden of the disease in younger people," Araghi said in a journal news release.
The increase in cases among the young runs counter to declines in colon cancer among people over 50, the researchers pointed out. For example, between 2004 and 2014 cases of colon cancer fell each year among people over 50 – by 2% in Australia and Canada, 3% in New Zealand, and 1% annually in the UK.
Colon cancer remains a huge global killer. According to the research team, in 2018 alone nearly two million cases of colon cancer were diagnosed and the disease claimed 881 000 lives worldwide.
Avoiding risk factors
But why the surge among the young? According to Araghi, the increase is likely driven in part by increases in certain risk factors, specifically obesity and poor diet.
On the other hand, he said, the decrease in colon cancer among people over 50 is most likely due to better screening stool tests or colonoscopy that catches tumours early.
Dr David Bernstein is chief of haematology and a gastrointestinal specialist at Lenox Hill Hospital in New York City. Reviewing the new report, he said similar data has already changed medical practice in the United States.
"The US, findings have led to updated [American Cancer Society] colon cancer screening guidelines, which now recommend the initiation of colon cancer screening at age 45, as opposed to previous guidelines recommending the initiating of screening at age 50," Bernstein noted.
Early screening and detection could bring colon cancer numbers down again among the young, he said.
A critical question
Dr Elena Ivanina is a gastroenterologist at Lenox Hill Hospital in New York City. She believes younger Americans need to pay more heed to avoiding colon cancer risk factors.
"This includes things like obesity, diet, smoking and other carcinogens," she said. "Patients should discuss their colon cancer risk with their physician and not ignore any symptoms like rectal bleeding, no matter what their age."
In the meantime, Bernstein said, "perhaps the more important question is 'why in high income countries is the incidence of colorectal cancer increasing among young adults, and what factors are leading to this?'" Bernstein said. "Significant work needs to be done to answer this critical question."
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