Investigating bowel cancer in people with Crohn’s or Colitis

What this research looked at

Some people with Crohn’s or Colitis have an increased risk of developing bowel cancer (colorectal cancer). Colonoscopies are a type of test used to look for bowel cancer. People with Crohn’s or Colitis who are at a higher risk of developing bowel cancer will have surveillance colonoscopies to check for the early signs of bowel cancer.

In this study, the researchers wanted to find out how effective surveillance colonoscopies are at detecting bowel cancer in people with Crohn’s or Colitis. They used these findings to see how often colonoscopies miss bowel cancer in people with Crohn’s or Colitis.

The researchers also looked at commonly prescribed medicines that have been shown to prevent bowel cancer in the general population. They wanted to see if these medicines can also prevent bowel cancer in people with Crohn’s or Colitis. 

To do this, the researchers analysed data from people with Crohn’s or Colitis who are registered in a large UK wide database called ResearchOne. ResearchOne contains the details of over 5 million people in the UK, including their prescription records. They also collaborated with Dr Eva Morris from the University of Leeds/ University of Oxford to access the COloRECTal cancer data repository (CORECT-R). This links the national bowel cancer registry to routinely collected hospital data (Hospital Episode Statistics). They used this to see how many people with Crohn’s or Colitis and bowel cancer had colonoscopies before they were diagnosed with bowel cancer.

What the researchers found

Key findings from this study included:

• 1 in every 10 missed bowel cancers in the UK were in people with Crohn’s or Colitis. Missed bowel cancers are those that were found outside of surveillance colonoscopies.
• On average 1 in 3 bowel cancers in people with Crohn’s or Colitis were missed cancers (they’d had a colonoscopy 6-36 months before cancer diagnosis)
• There was a wide variation in the rates of missed bowel cancers in people with Crohn’s and Colitis between NHS Trusts.
• Taking a high dose of statins or 5-ASA medicines reduced the risk of developing bowel cancer in people with Crohn’s or Colitis.

The researchers also used the datasets to look at rate of surgery in people with Crohn’s. They found:

• 1 in 5 people with Crohn’s will need surgery to remove part of their bowel within 5 years, and 1 in 4 will need surgery to remove part of their bowel within 10 years of diagnosis.
• Surgical rates in people with Crohn’s have decreased over time. The risk of having surgery to remove part of the bowel within 10 years reduced from 4 in 10 in people diagnosed in 1994 to 2 in 10 for people diagnosed in 2003.

What the researchers think this could mean for people with Crohn's and Colitis 

It’s important that the issue of bowel cancers being missed in people with Crohn’s and Colitis is used to improve the standards of surveillance colonoscopies in the NHS. Further work is needed to understand what the optimal surveillance strategy is for people with Crohn’s and Colitis and why the rate of missed bowel cancer in people with Crohn’s and Colitis is so high. Once the reasons are identified, then measures can be put in place to improve this for people with Crohn’s and Colitis.

Taking statins has been shown to reduce the risk of bowel cancer in the general population too. The researchers plan to confirm these findings  in people with Crohn’s and Colitis using other datasets. They will then develop a clinical trial to test whether taking statins as a chemopreventative medicine (a medicine to prevent cancer) can prevent bowel cancer developing in people with Crohn’s and Colitis.

Scientific publications

• Burr NE, Derbyshire E, Taylor J, Whalley S, Subramanian V, Finan J, Valori R, Rutter M, Morris E. Variation in post-colonoscopy colorectal cancer across colonoscopy providers in the English National Health Service: A population-based cohort study. BMJ
• Burr NE, Lord R, Hull MA, Subramanian V. Decreasing Risk of First and Subsequent Surgeries in Patients With Crohn's Disease in England From 1994 through 2013. Clin Gastroenterol Hepatol. 2019 Sep;17(10):2042-2049.
• Burr NE, Smith C, West R, Hull MA, Subramanian V. Increasing Prescription of Opiates and Mortality in Patients With Inflammatory Bowel Diseases in England. Clin Gastroenterol Hepatol. 2018 Apr;16(4):534-541

Who is leading this research? Dr Venkat Subramanian, University of Leeds
Our Funding: £116,272
Duration: 24 months
Official title of application: A study of colorectal cancer in inflammatory bowel disease. UK epidemiology, efficacy of surveillance and the potential for chemoprevention