Anti-TNF therapy could lower colorectal cancer risk for IBD patients

Receiving a colorectal cancer diagnosis on top of one for IBD may be the last thing a patient wants to hear. A patient’s risk of developing colorectal cancer depends on certain factors, including if they have ulcerative colitis or Crohn’s disease affecting the colon, they have had IBD for eight years or longer, severe or extensive colon inflammation, Primary Sclerosing Cholangitis (a rare condition that causes bile duct inflammation and scarring), dysplasia, or changes in cells that are precursors of cancer, of the colon or rectum, or family history of colorectal cancer. Additionally, increased age is another risk factor, in addition to sex, obesity, alcohol and smoking history, and others. 

Though the exact pathway is unknown, chronic inflammation of the gastrointestinal tract is the likely link between IBD and colorectal cancer. Inflammation raises the likelihood of a healthy cell mutating to give rise to a tumor cell. One of the drivers of inflammation is a protein made by a gene called tumor necrosis factor alpha (TNF-α). Anti-TNF drugs, like infliximab and adalimumab, suppress the production of this protein, thereby reducing inflammation. 

It sounds counterintuitive, but researchers behind a new study published in Inflammatory Bowel Diseases investigated whether anti-TNF drugs and other IBD treatments, including steroids, immune system modulators, and non-steroidal anti-inflammatory drugs, lowered patients’ risks for colorectal cancer. They found a significant risk reduction associated with anti-TNF drug treatments for both UC and Crohn’s disease, suggesting a path for future research and an effective therapy for managing both one’s IBD and risk for colorectal cancer.

Specifically, the researchers found the following:

• Both patients with Crohn’s disease and UC were less likely to be diagnosed with colorectal cancer if they were treated with any regimen of anti-TNF drug — whether an anti-TNF drug alone or in combination with immunomodulators
• Anti-TNF drugs lowered the odds of being diagnosed with colorectal cancer more for Crohn’s disease patients than UC patients 
• Other agents, including vedolizumab, ustekinumab, natalizumab, and tofacitinib, had smaller sample sizes (numbers of patients) compared to anti-TNFs and we need to wait for more data to see if the same positive benefit is seen for these medications
• Steroids and immunomodulators alone did not significantly change the odds of Crohn’s patients receiving a colorectal cancer diagnosis. However, each of these therapies raised the odds for UC patients.
• 5-ASAs, which are nonsteroidal anti-inflammatory drugs, also lowered the odds of a colorectal cancer diagnosis for both Crohn’s and UC patients.

What this means for patients

These results suggest that therapies to treat the underlying inflammation at the root of IBD may also reduce patients’ risk for colorectal cancer development. The researchers note in the study that “these results are reassuring that anti-TNFs seem to be associated with a decreased risk of [colorectal cancer] in IBD.”

Still, this research identifies an association using retrospective data — future research will want to confirm this link by looking at cohorts prospectively, or into the future. Additionally, anti-TNF drugs are one in a range of treatment options for IBD: they may or may not be prescribed based on a particular patient’s disease severity, among other factors. 

How to lessen your risk of colorectal cancer

Though most patients with Crohn’s disease and ulcerative colitis will never develop colorectal cancer, it is important to discuss the risk with your doctor. Colorectal cancer is a highly treatable disease when it’s found early. Here are some ways you can help minimize your risk of developing colorectal cancer:

• See your gastroenterologist at least once a year
• Keep a list of any new or concerning symptoms you are experiencing to bring up with your doctor
• Take your medication as prescribed to keep your symptoms under control
• Continue taking your medications, even when you are feeling well

Click here to learn more about colorectal cancer and IBD.