Colorectal cancer is increasing among young people in Sweden, according to research from the Karolinska Institute. Researchers suggest that lifestyle factors, such as sedentary behavior and obesity, may be the cause.
In the study, which was published in Annals of Oncology, researchers examined over 135,000 Swedish patients who had colorectal cancer between 1993 and 2019.
The results show that the number of younger people under 50 who develop this form of cancer has increased over the past three decades. For rectal cancer, the number of new cases among younger people has increased by 2.04 percent per year, and for left-sided and right-sided colon cancer, the increase is 2.41 and 2.64 percent per year respectively. Overall, the disease has become two to three times more common among younger people.
Detected later in younger patients
Younger patients also more often had metastatic cancer compared to older patients, suggesting they had lived with symptoms longer before the cancer was discovered. Researchers emphasize that it’s important for both the public and healthcare professionals to know that this type of cancer can also affect younger people. This is particularly important since the chance of curing cancer increases with early detection.
The study also shows that mortality has increased among both younger and older patients up to ten years after cancer diagnosis.
— This is remarkable, since patients are often considered cured after such a long time. Our results challenge that view and underscore the need for more research into why this is happening, as well as long-term follow-up and support for both young and older patients, says Cecilia Radkiewicz, researcher at the Department of Molecular Medicine and Surgery at the Karolinska Institute in Stockholm.
Lifestyle may be the cause
It’s unclear what actually lies behind the increase in colorectal cancer among young people, but researchers believe it doesn’t appear to be driven by traditional risk factors such as inflammatory bowel disease or heredity. Instead, the results suggest that lifestyle factors may be decisive.
— Childhood obesity, sedentary lifestyle, and antibiotic use have been highlighted as contributing factors, although the underlying biological mechanisms remain unclear, says Radkiewicz.
