Risk Stratification Tool for Colorectal Polyp Surveillance

Bowel cancer screening is used to find bowel cancer and pre-cancerous lesions called polyps in patients without symptoms. The aim of screening is both to catch bowel cancers early -- making them easier to treat successfully -- and to prevent cancers by removing pre-cancerous polyps. Although timings vary across the UK, adults at a certain age are invited to submit a postal stool sample, and if traces of blood are detected, they are invited to a detailed test called colonoscopy. At colonoscopy, around 1 in 20 people are found to have cancer, while 1 in 3 have a polyp. Around a half of patients will go on to develop future polyps despite their removal at initial colonoscopy and therefore patients are asked to return for another colonoscopy in the future to look for new polyps. Guidelines exist for clinicians to help decide who needs a further colonoscopy and when they need it. However, these guidelines are not very accurate in predicting who is likely to form new polyps in the future, and a lot of people undergo colonoscopy who do not have a further polyp. Colonoscopies require patients to take powerful laxatives beforehand and sedatives during the procedure. There is a small risk of serious complication. Furthermore, patients need to attend hospital for at least one day, and are restricted with regards to driving and work the next day. Many patients find them unpleasant, they use a lot of resource within hospitals, and are costly to the NHS and society as a whole. This project, led by the University of Glasgow with NHS Greater Glasgow and Clyde, will more accurately predict which patients will develop new polyps in the future, by combining data about specific changes in the polyp when looking under the microscope, and by looking at the genetic mutations of the polyps. Using existing data and polyp tissue collected by the Scottish Bowel Cancer Screening Programme in NHSGGC we will develop a new tool to better predict further polyps. Overall this new tool could reduce the number of people needing repeated colonoscopy, reducing unpleasant experiences and complications, improving access to colonoscopy by reducing surveillance lists, and reducing costs to the NHS and the UK, while maintaining a safe follow up regime for patients who have had a large bowel polyp.