One of the most promising types of medications to treat inflammatory bowel disease (IBD) is a trio of anti-tumor necrosis factor alpha (TNF-α) drugs. However, physicians and patients alike have wondered if these medications could be associated with an elevated risk of developing cancer.
Scientists from the Statens Serum Institute in Copenhagen followed more than 56,000 IBD patients and found no increased risk of cancer after a median follow-up of 3.7 years, according to ScienceDaily. Their findings appeared in the Journal of the American Medication Association (JAMA).
The two primary types of IBD are Crohn’s disease and ulcerative colitis. Of the 1.4 million U.S. IBD patients, roughly half have each disease, the Crohn’s & Colitis Foundation of America reports. While removal of a patient’s colon can cure ulcerative colitis, there is no cure for Crohn’s disease. Both illnesses tend to flare sporadically throughout a patient’s lifetime. Most experts believe they are caused by a combination of factors, one of which is an overactive immune system.
According to the University of Michigan Health System, the three anti-TNF-α drugs currently used to treat U.S. IBD patients are Remicade (infliximab), Humira (adalimumab), and Cimzia (certolizumab pegol). Anti-TNF-α medications work by blocking the TNF agent to suppress a patient’s immune system and reduce inflammation in IBD patients. Doctors also prescribe them for other inflammatory diseases, such as rheumatoid arthritis.
The Swedish research team studied cancer rates in IBD patients who received anti-TNF-α medication and compared them to records of those who had not received the drugs. The 56,146 subjects were at least 15 years old. Of these patients, 4,553, or 8.1 percent, were treated with anti-TNF-α medications.
Of subjects who didn’t receive the drugs, 6.7 percent, or 3,465 patients, developed cancer. Among those who took the medication, 81 subjects, or 1.8 percent, developed the disease, considering a follow-up period of 3.7 years. The researchers concluded that the use of anti-TNF-α drugs was not associated with an elevated cancer risk overall. They also saw no excessive instances of site-specific cancers.
Since these drugs suppress the immune system, their use can result in significant side effects that for some patients clearly outweigh the benefits. The most common is an increased risk of infection. Missing a dose or failing to follow the schedule recommended by a physician can result in a loss of effectiveness.
Because of the size of the sample, the small number of identified cancer cases, and the length of the follow-up period, the researchers were not able to exclude the possibility of an elevated risk of cancer over the long term.
Vonda J. Sines has published thousands of print and online health and medical articles. She specializes in diseases and other conditions that affect the quality of life.