The 2023 Impact of Inflammatory Bowel Disease in Canada: Cancer and IBD

Cancer is a major cause of morbidity and mortality among people with inflammatory bowel disease (IBD). Intestinal cancers may arise as a complication of IBD itself, while extra-intestinal cancers may arise due to some of the immunosuppressive therapies used to treat IBD. Colorectal cancer (CRC) and small bowel cancer risks remain elevated among persons with IBD as compared to age-and sex-matched members of the general population, and the lifetime risk of these cancers is strongly correlated to cumulative intestinal inflammatory burden. However, the cumulative risk of cancer, even among those with IBD is still low. Some studies suggest that IBD-CRC incidence has declined over the years, possibly owing to improved treatment standards and improved detection and management of early neoplastic lesions. Across studies of extra-intestinal cancers, there are generally higher incidences of melanoma, hepatobiliary cancer, and lung cancer and no higher incidences of breast cancer or prostate cancer, with equivocal risk of cervical cancer, among persons with IBD. While the relative risks of some extra-intestinal cancers are increased with treatment, the absolute risks of these cancers remain low and the decision to forego treatment in light of these risks should be carefully weighed against the increased risks of intestinal cancers and other disease-related complications with undertreated inflammatory disease. Quality improvement efforts should focus on optimized surveillance of cancers for which surveillance strategies exist (colorectal cancer, hepatobiliary cancer, cervical cancers, and skin cancers) and the development of cost-effective surveillance strategies for less common cancers associated with IBD.This article reviews studies about the risk of cancer in people with inflammatory bowel disease (IBD). IBD is a disease that causes the intestines to become inflamed. Long-term inflammation that is not treated can lead to certain cancers. Thus, there is a higher risk of cancer in people with IBD than in people without IBD. It must be said that the overall risk of cancer in people with IBD is still low. There are some drugs used to treat IBD that may also make cancer risk higher for people with IBD. Even with an increased risk of cancer due to some drugs, properly treated IBD decreases cancer risk. People with IBD should have regular screening for cancer during follow-ups with their physicians. Regular high-quality screening can reduce the risk of cancer. People concerned about cancer risk due to drugs used to treat IBD should talk with their physicians. During this talk, they can be part of shared decision-making about treatment and risks.