Inflammatory Bowel Disease and Cancer Risk

Inflammatory bowel disease is associated with an increased risk of several types of cancer, including colon, small bowel, and upper gastrointestinal tract cancers. A recent study suggests that there is a greater than 2-fold increased rate of cancer among patients with pediatric-onset IBD compared with general pediatric populations, due primarily to an increased rate of gastrointestinal cancers. The study findings were published in JAMA Network Open on March 01, 2022.

Although previous studies indicate that the risk of all-cause cancer is higher among those with pediatric-onset IBD compared with individuals without IBD, studies are heterogeneous and limited in size, and the estimates are variable. Furthermore, among children, the incidence of IBD and the risk of cancer have increased in recent years. Therefore, Dr. Rahma Elmahdi and his team conducted a study to evaluate the relative rate of cancer among patients with pediatric-onset IBD.

In this study, the researchers examined five population-based studies from North America and Europe, which included more than 19,812 participants with pediatric-onset IBD. They conducted a random-effects model meta-analysis of included studies using the inverse-variance method to assess the relative rate of cancer overall and by IBD subtype, sex, and thiopurine exposure among patients with pediatric-onset IBD. Among these 19,812 patients, they identified 715 cases of cancer.

Key findings of the study:

• In a meta-analysis of pooled relative rate (pRR) estimates, the researchers found a 2.4-fold increase in the rate of cancer among patients with pediatric-onset IBD (pRR, 2.46).
• They noted that the pooled relative rates were 2.03 for patients with Crohn's disease and 2.61 for patients with ulcerative colitis.
• This increased rate is primarily due to an increased rate of liver (pRR, 55.45), colorectal (pRR, 20.29), and small bowel (pRR, 16.20) cancers.
• The incidence rate of cancer among patients with pediatric-onset IBD was reported by 4 studies and ranged from 1.0 to 3.3 cases per 1000 person-years.

The authors concluded, "This meta-analysis of unselected, population-based studies showed a greater than 2-fold increased rate of cancer among patients with pediatric-onset IBD compared with the general pediatric populations, primarily owing to an increased rate of gastrointestinal cancers."

For further information:

DOI: 10.1001/jamanetworkopen.2022.0595