Data regarding the risk of gastrointestinal and extraintestinal cancers in Crohn’s disease and ulcerative colitis are needed to understand the clinical course of inflammatory bowel diseases (IBDs) and their treatments.
Dr Michael Kappelman and colleagues from North Carolina, USA performed a nationwide historical cohort study using Danish health care databases.
The research team identified patients with a diagnosis of Crohn’s disease or ulcerative colitis, recorded from 1978 through 2010, and followed them up until the first occurrence of cancer, death, or emigration.
|The relative risk of extraintestinal cancers among patients with IBD was relatively stable over time|
|Clinical Gastroenterology & Hepatology|
The team used standardized incidence ratios (SIRs) to compare cancer incidence in Crohn’s disease and ulcerative colitis patients with that expected in the general population.
Excluding cancers diagnosed within 1 year of IBD diagnosis, 772 cases of invasive cancer occurred among 13,756 patients with Crohn’s disease, and 2331 occurred among 35,152 patients with ulcerative colitis.
The researchers found that Crohn’s disease was associated weakly with gastrointestinal cancers, and extraintestinal cancers, with the strongest associations for hematologic malignancies, smoking-related cancers, and melanoma.
The team observed that associations between ulcerative colitis and gastrointestinal and extraintestinal cancers were weaker.
The research team noted that the relative risk of extraintestinal cancers among patients with IBD was relatively stable over time, although the risk of gastrointestinal cancers decreased.
Dr Kappelman's team comments, "Patients with IBD, particularly Crohn’s disease, are at increased risk for gastrointestinal and extraintestinal malignancies."
"The relative risk of gastrointestinal malignancy has decreased since 1978, without a concomitant increase in the risk of nongastrointestinal malignancy."