Published: 18:30 BST, 14 August 2026 | Updated: 18:34 BST, 14 August 2026
A chronic digestive condition suffered by about one in 400 Americans has been linked to an increased risk of a range of deadly cancers.
Crohn's disease, which causes debilitating abdominal pain, chronic diarrhea and exhaustion, is an incurable type of inflammatory bowel disease (IBD) that causes inflammation in the digestive tract and affects about a million Americans.
The chronic digestive condition has now been linked to a heightened risk of several cancers, according to a large Swedish study tracking nearly 40,000 patients over seven years.
The findings confirm that people with Crohn's face a higher cancer rate than the general population, regardless of whether they have treated their condition with immune-suppressing drugs.
That includes an elevated risk of blood cancers, as well as cancers of the lung, small bowel and the liver and bile ducts. The study also found a particularly strong link to skin cancers, especially squamous and basal cell carcinomas.
The increased risk is real but modest, at roughly one extra cancer per 1,000 patients annually, after excluding non-melanoma skin cancers.
That excess risk appears to be driven largely by the disease itself; specifically, the chronic inflammation it causes, rather than by the medications used to treat it.
Over time, that persistent inflammation can damage cell DNA, promote abnormal cell growth, and create an environment where tumors are more likely to develop.
An estimated 1 million people in the US are living with Crohn's disease, an incurable inflammatory bowel disease (stock image)
To get a clearer picture of cancer risk, the study, published in the American Journal of Gastroenterology, tracked nearly 39,000 Swedish Crohn’s patients diagnosed between 2007 and 2022 using national health databases that capture every diagnosis, prescription and outcome.
They then matched each Crohn’s patient with up to ten healthy people of the same age, sex and geographic location, creating a comparison group of more than 360,000 people without any type of IBD.
Matching ensures that any differences in cancer rates could be more confidently attributed to Crohn’s itself, rather than age, sex or where people live.
The researchers divided Crohn’s patients into groups based on their treatment history, including one consisting of people who had never taken immunosuppressive drugs – the standard treatment for Crohn’s.
The other group consisted of people who had taken immunosuppressive drugs such as thiopurines, Humira, vedolizumab or ustekinumab – or combinations of them.
