Does Crohn’s disease increase your cancer risk?

Crohn’s disease may increase your risk of developing certain cancers, particularly colorectal cancer.

A type of inflammatory bowel disease (IBD), Crohn’s disease is a chronic condition that inflames the digestive system. The swelling and irritation caused by Crohn’s disease can be found in any part of the digestive system, but it’s most often centered in the intestines.

Association with colorectal cancer

Research suggests that people with Crohn’s disease are more likely to develop colorectal cancer than the general population. According to some studies reviewed in the journal Digestion, colorectal cancer risk is twice as high among Crohn’s disease patients.

However, having an increased risk doesn’t mean that you will develop that cancer. People with Crohn’s disease may be more vulnerable to colorectal cancer than the average person, but most do not go on to develop the cancer.

Colorectal cancer starts in the colon or rectum, which make up the large intestine. Other types of IBD, such as ulcerative colitis, come with a similarly elevated colorectal cancer risk. IBD is often confused with irritable bowel syndrome (IBS), but the conditions are different, and IBS isn’t known to increase colorectal cancer risk.

Crohn’s disease is associated with colorectal cancer because it causes inflammation in the colon and rectum. When this inflammation persists for many years, cells within the intestinal lining may become abnormal and, eventually, cancerous. Some people with Crohn’s disease may be more at risk of colorectal cancer than others, such as those diagnosed with the condition at an early age or those who have severe and widespread inflammation in their colon. The longer that inflammation in the colon is present, the higher the risk of colorectal cancer.

People with Crohn’s disease who develop colorectal cancer tend to develop it at an earlier age than the general population. The average age of colorectal cancer onset among patients with Crohn’s disease or ulcerative colitis is 50 to 60, according to a review in the journal Cochrane Database of Systematic Reviews. Cases outside the IBD population most often occur between the ages of 65 and 75.

People with Crohn’s disease and colorectal cancer tend to have lower survival rates than colorectal cancer patients without the disease. Sometimes, Crohn’s disease is associated with primary sclerosing cholangitis, which affects the tubes that transport bile from the liver. Having both of these conditions further increases one’s colorectal cancer risk.

Screening for colorectal cancer

Getting screened for colorectal cancer may be particularly helpful for people with Crohn’s disease. Screening involves tests that check for cancer in individuals without any symptoms. A colonoscopy is one example of a screening test for colorectal cancer. Undergoing regular screening can help detect precancerous cells before they become cancerous or diagnose cancer at an early stage. Catching cancer early makes treatment more likely to succeed and improves outcomes.

• All adults between the ages of 50 and 75 are advised by the U.S. Preventive Services Task Force to undergo colorectal cancer screening. Adults between the ages of 45 and 49 may also undergo colorectal cancer screening.
• Individuals with Crohn’s disease may want to have more frequent screening tests and start screening at a younger age than the general population due to their increased risk. For example, the American Family Physician recommends that patients begin colorectal cancer screening eight to 10 years after they first experience Crohn’s disease symptoms and get additional tests every one to three years afterward.

Association with other cancers

In terms of cancer, Crohn’s disease is most strongly linked to colorectal cancer, but patients may face slightly heightened odds for other cancers, too. Some studies described in the journal Digestion have found that different types—including cancers of the bile duct, small intestine, skin and blood (myeloma and lymphoma)—seem to occur more frequently among people with IBD (both ulcerative colitis and Crohn’s disease) than among the general population.

However, the association between these cancers and IBD isn’t well established, and other studies have come to different conclusions.

The higher incidence of certain cancers among IBD patients may be attributed to the drugs used to treat IBD, some of which may increase cancer risks. For example, a type of drug called thiopurines, which helps manage IBD by suppressing the immune system, has been linked to skin cancer. However, these drugs may be necessary to help reduce inflammation, which helps prevent cancer.

What you can do

Treatments are available to help manage Crohn’s disease and keep inflammation at bay. Research suggests that treating the disease and keeping it in a state of remission (no symptoms) may bring down the risk of colorectal cancer to average levels.

If you have Crohn’s disease or another form of IBD, you and your doctor can weigh the risks and benefits of a particular treatment and early cancer screening. Your doctor may also discuss prevention or risk-reduction methods, including being physically active, eating a healthy diet and not smoking.