Dr James East
For many diseases a large proportion of patients will be a low risk of developing a serious complication of their disease becoming uncontrolled over time. It is therefore important to be able to pick out those few patients who are at risk of a poor outcome. This will save the lower risk patients unnecessary investigation, treatment or surveillance, and focus our resources on those at highest risk. As an example, we will attempt using genetic analysis of precancerous polyps and stem cells to separate patients with bowel inflammation (ulcerative colitis) into those at high and low risk of severe inflammation or bowel cancer. Those at higher risk might get more intensive checking the bowel with colonoscopy or need to consider early surgery.
Colitis associated cancer risk
East is working to identify patients with colitis who are candidates for risk-reducing therapies or enhanced screening.
FIT testing and triage for post-COVID cancer risk
The COVID-19 pandemic has led to a shutdown of NHS diagnostic services, with endoscopy activity reduced to 5% of normal at the COVID peak; however cancers continue to develop, and modelling studies suggest that delays to cancer diagnoses and treatment could potentially be responsible for up to 7,000 additional deaths in England. It is therefore critical that diagnostic endoscopy services be restarted safely but at scale to try and mitigate these risks. Even when restarted the need for Personal Protective Equipment, COVID PCR testing pre-procedures and social distancing mean that endoscopy is only likely to be able to deliver 50-75% of pre-COVID capacity, and that there will be a large backlog of cases.
Restarting Endoscopy Safely
National Guidance: As part of the British Society of Gastroenterology’s (BSG) response to the COVID pandemic we along with others were asked to conduct an urgent review of how endoscopy units might be safely reopened and how procedures might be prioritised. We developed a collaborative group of 18 centres to assess pre- and post-endoscopy COVID risk (SCOTS group).
Impact 1: BSG guidance on 30th April was download more than 2000 times in the subsequent 24 hours. The document details testing procedures combining telephone triage and linear endoscopy unit flow, and using quantitative faecal immunochemical testing (FIT) testing to risk stratify cases which might have colorectal cancer, and the reviews behind this have now been published. The low level of FIT cut off chosen was on the basis of pre-publication Oxford data that was urgently analysed in order to support this risk assessment.
Impact 2: The SCOTS group rapidly collected data from 6200 patients showing 0.11% of patients had COVID following telephone triage, and zero of 6200 patients or staff caught Covid by attending for endoscopy. This helps reassure the public that it is safe to attend, and support efforts in reducing PPE levels and increasing endoscopy throughput to avoid Covid cancer collateral damage.
FIT testing for colorectal cancer test prioritisation
Despite a safe restart of endoscopy services, the volume of endoscopy possible is much lower that previously, therefore patients need to be prioritised into those at highest risk of having cancer. FIT is a test for blood in stool that was recommended by NICE in 2017.
Study: Oxford was an early adopter of FIT for symptomatic patients and had data on 14,000 FIT tests from primary care. Using a lower FIT cut off finds bowel cancer better, but at the cost of more colonoscopies. Our group determined that the optimal level was 10ng/g which detected 90% of the cancers but only 10% of the patients needed to be colonoscoped.
Impact: This level was adopted in the BSG guidance and has also been adopted in a new Thames Valley Cancer Alliance lower GI two-week wait pathway where GPs will perform FIT tests on those with symptoms, before referring only positive cases to hospital, focussing limited colonoscopy resources on those at highest risk.
Other high-risk patient groups: Patients with Lynch syndrome have a high genetic risk of developing colorectal cancer and need colonoscopy every 2 years. However they may, as a result of the pandemic, experience delays in accessing routine surveillance colonoscopy. We will be part of a group investigating whether FIT could help prioritise their colonoscopies.
Next research steps
- The collaboration developed between Oxford Gastroenterology, Primary Care and Epidemiology has led to a bid for further funds to develop “Enhancing non-invasive patient stratification for endoscopic detection of colorectal cancer in response to the COVID-19 pandemic” which was funded for £50,000.
- We are part of a group working on a BSG national consensus statement via a Delphi process to develop further guidance on the use of PPE in endoscopy.
- In conjunction with St. Mark’s Hospital London and others we are contributing to a NHSE endorsed service development project to look at the use of FIT testing to risk stratify patients with Lynch syndrome (data collection underway).
- We are investigating patient perceptions of COVID risk preventing them for attending for endoscopy ICE study.
- We are preparing a summary review of the current status of Covid-19 research in Gastroenterology for the wider Gastroenterology community to define key future questions.