Crohn's Disease and Colon Cancer

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Each year, approximately 145,000 Americans are diagnosed with colon or rectal cancer. Some of those people also have Crohn’s disease. In 1973, researchers published a paper documenting an increased incidence of colorectal cancer in patients with Crohn’s disease. Since then, scientists have been working to untangle the link between Crohn’s and colorectal cancer risk. Here’s what we know so far about Crohn’s disease and cancer.

Crohn’s Disease and Increased Risk of Colorectal Cancer

People who have Crohn’s disease are approximately 4.5 times more likely to develop colorectal cancer than people who do not have Crohn’s, according to scientific studies. However, having Crohn’s disease does not mean you will develop cancer. Most people who have Crohn’s disease remain cancer-free throughout their lives.

People who have severe, long-standing Crohn’s disease seem to have a higher risk of developing colon cancer than newly diagnosed Crohn’s patients or those with mild disease. The risk of colon cancer begins to increase after 8 to 10 years of Crohn’s symptoms, according to the Crohn’s & Colitis Foundation. People who are diagnosed with Crohn’s disease before age 25 also are more likely to develop colorectal cancer than people who receive a Crohn’s diagnosis later in life.

Cancer Screening Recommendations for Crohn’s Disease

If caught early, colorectal cancer is highly treatable. Because people who have Crohn’s disease have an increased risk of developing cancer, they may need to begin colorectal cancer screening earlier in life than their peers and may need to undergo more frequent screening.

Most people at average risk begin colorectal cancer screening (via a stool test or colonoscopy) at age 45 or 50. Experts recommend that most people with Crohn’s disease undergo a colonoscopy every 1 to 2 years, especially if they’ve had symptoms for at least 8 years.

People with Crohn’s disease should not rely on less invasive colon cancer screening tests, such as fecal occult blood testing, because their disease could interfere with the results of the test. Colonoscopy allows doctors to view the inside of the bowel; if there are unusual areas, the doctor can immediately remove a small amount of tissue for analysis. The results of the analysis will help the doctor and patient decide on appropriate medical follow-up or treatment.

Risk Reduction Strategies

People who have Crohn’s disease may be able to reduce their risk of colorectal cancer by:

  • Controlling Crohn’s disease inflammation. Taking medications as prescribed may decrease inflammation in the colon, which may decrease the risk of developing colon cancer.
  • Eating a healthy diet. Avoiding foods that trigger symptom flare-ups can also decrease inflammation.
  • Undergoing regular colorectal cancer screening. Regular colonoscopies may allow physicians to detect precancerous changes in the colon—and intervene before colorectal cancer develops.
  • Asking about chemoprevention. Some evidence suggests a specific type of anti-inflammatory medicine (5-aminosalicylates) may decrease the risk of developing colorectal cancer in people with inflammatory bowel disease (Crohn’s or ulcerative colitis). However, very few of these studies looked specifically at people with Crohn’s disease; most focused on people with ulcerative colitis, and more research is needed on chemoprevention for Crohn’s disease.

Most people with Crohn’s disease do not develop colorectal cancer. Your healthcare provider can help you figure out the best way to manage your risk of colon cancer based on your health and family history.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Apr 30
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