The Risk of Cancer from Certain IBD Medications

John Kisiel, M.D., discusses a recently published article in The Journal of the American Medical Association about the risk of cancer from certain medications used to treat inflammatory bowel disease (IBD).

The medications specifically looked at for this study are infliximab (Remicade), adalimumab (Humira), and certolizumab (Cimzia), which have been extremely effective for treating IBD. Studies on the cancer risk of these drugs have been an interest for clinicians and patients because the drugs all treat the immune system and could theoretically alter the ability to fight certain cancers. These drugs are also used to treat rheumatoid arthritis and other connective tissue disease. Studies of patients with those conditions have been conflicting in regard to the risk of cancer while exposed to these drugs. In IBD literature, knowledge has been hampered by small sample sizes and short duration of follow-up. To try and address this question, Dr. Anderson and colleagues examined patients participating in the Danish nationwide cohort, which is a collect of patients in Denmark from 1992-2010 exposed to one of the anti-TNF drugs. The researchers found more than 56,000 patients had been exposed to an anti-TNF drug during the study period and followed them forward for more than nine years. After adjusting for other risk factors, they found the risk of cancer was not specifically increased with anti-TNF drugs. This mirrors other findings commented on in an earlier blog post. The study didn't find any evidence of a dose response to anti-TNF drugs, meaning the cancer risk didn't go up with number of anti-TNF doses. Also, the researchers didn't find an increase in the specific types of cancer such as lymphoma, skin cancer, or colorectal cancer. This study does have some limitations. The sample size was small enough that unless the cancer risk increased by a third, it might not have been detected. In a large observation study with long-term follow-up, the cancer risk isn't significantly increased with use of infliximab (Remicade), adalimumab (Humira), and certolizamab (Cimzia). Patients should be aware that azathioprine could modestly increase the risk of cancer and they should discuss the use of this medication in combination with anti-TNF drugs with their physician. It's becoming standard practice to use this combination of drugs as the body of evidence suggests the benefit to patients with Crohn's disease and ulcerative colitis is significant and greater than the risk of cancer.

Read the full article online here.

For more information about IBD, visit mayoclinic.org/ibd.

Dr. Kisiel is a gastroenterologist specializing in the care of inflammatory bowel disease at Mayo Clinic.