PSC raises colorectal cancer risk even without IBD
Men with PSC alone were found to have a particularly elevated risk
People with primary sclerosing cholangitis (PSC) have a six times higher risk of cancer affecting the large intestine or rectum, and that risk remained elevated even for PSC patients without inflammatory bowel disease (IBD), a real-world study in the U.S. suggests.
Moreover, men with PSC alone were found to have a particularly elevated risk, being four times more likely to develop cancer of the large intestine and rectum, or colorectal cancer. IBD is an umbrella term for diseases marked by gastrointestinal tract inflammation that often occur alongside PSC.
Overall, “our findings provide real-world evidence that PSC is an independent risk factor for colorectal cancer, even in the absence of concomitant IBD,” wrote the researchers, who said the data suggest that “patients with isolated PSC may benefit from tailored [colorectal cancer] surveillance strategies.” The study, “Primary Sclerosing Cholangitis in the Absence of Inflammatory Bowel Disease Increases the Risk of Colorectal Cancer: A Multi-Centre Propensity Score Matched Analysis,” was published in Alimentary Pharmacology & Therapeutics.
PSC is an autoimmune disease marked by chronic cholangitis, or inflammation of bile ducts, the tubes that carry the digestive fluid bile from the liver to the intestines. This chronic inflammation can lead to serious conditions, such as irreversible liver scarring, or cirrhosis, liver failure, and bile duct cancer (cholangiocarcinoma).
Up to 80% of people with PSC also have IBD, particularly ulcerative colitis, which is marked by colon and rectum inflammation. The other form of IBD, Crohn’s disease, can affect any part of the gastrointestinal tract.
The link between PSC and IBD “significantly influences the clinical course and cancer risk profile of these patients,” the researchers wrote.
People with PSC and IBD may have an up to 10 times higher rate of colorectal cancer than those with IBD alone, evidence suggests, prompting major gastroenterology organizations to recommend annual colonoscopy surveillance to detect colorectal cancer and precancerous lesions early in this group.
Real-world evidence of higher cancer risk
It’s not known if there is a heightened risk of colorectal cancer in PSC patients without IBD, but because there are no clear guidelines about colorectal cancer surveillance with isolated PSC, assessing that risk, especially using real-world data, is paramount “to guide future screening recommendations and improve patient outcome,” the researchers wrote.
Here, researchers in the U.S. retrospectively analyzed de-identified electronic health records from adults with PSC registered in the TriNetX Analytics Network Platform, which contains health records from 65 healthcare organizations in the U.S. The researchers performed a real-time search on the platform in June 2024 to identify PSC patients with at least a five-year follow-up since their diagnosis.
Of the 5,575 people with identified (mean age, 47.6; 41.2% women), 2,396 had no IBD while 3,020 did have IBD. The risk of colorectal cancer was compared with that of the general population, that is, matched patients without a history of PSC or IBD.
Regardless of a history of IBD, people with PSC had a significant six times higher risk of developing colorectal cancer over the general population. Those without IBD had a nearly three times higher risk, also significant. The risk among these patients differed according to sex, with men showed a four times higher risk.
The risk of colorectal cancer was also significantly higher across age groups of all three PSC groups.
For people with both PSC and IBD, the risk of colorectal cancer was 6.5 times higher than the general population. This increased risk came mainly from those with ulcerative colitis, who showed a 6.3 times higher risk. People with PSC and IBD had a four times higher risk than PSC patients without IBD.
Subgroup analyses that considered when the IBD diagnosis was made relative to PSC showed the risk of colorectal cancer was similarly elevated in those diagnosed with IBD before PSC.
People with PSC had a nine times higher risk of various gastrointestinal cancers over the general population. Particularly high risks were seen for cancers affecting the liver, bile ducts, and the gallbladder (by nearly 28 times) and hepatocellular carcinoma, the most common type of liver cancer (by nearly 19 times). The risk of gastrointestinal cancers was even higher among those with PSC and IBD, with greater risks with ulcerative colitis than Crohn’s disease.
“Our findings provide real-world evidence that PSC is an independent risk factor for colorectal cancer, even in the absence of concomitant IBD,” the researchers wrote. “These results highlight a potentially high-risk subgroup of patients who may warrant further investigation.” The researchers said their findings should be confirmed in studies involving more diverse populations.
About the Author
