Title: FIT in high risk patients (Quantitative faecal immunochemical tests to guide colorectal cancer pathway referral for people with a change in bowel habit or abdominal pain) [DAP50] 2022
Funder: Department of Health and Social Care

Abstract: Bowel (colorectal) cancer is the fourth most common cancer in the UK. There is a better chance that bowel cancer can be treated successfully if it is found early. When a patient visits their GP with symptoms, the doctor has to decide whether they think the patient might have bowel cancer or not. _x000D_ _x000D_ Currently, if the symptoms are “low-risk” and suggest bowel cancer is unlikely, the doctor will ask the person for a faeces sample to conduct a laboratory test called a quantitative faecal immunochemical test (or FIT for short). FIT looks for very small amounts of blood in the faeces, which might be a sign of cancer in the bowel. If their symptoms are “high-risk” and suggest bowel cancer is more likely, the doctor might refer them to be seen by a specialist within two weeks. If the symptoms suggest that another bowel condition is likely, such as inflammatory bowel disease, the doctor might refer the patient for a “non-urgent” specialist appointment, which should happen within 18 weeks._x000D_ _x000D_ Specialist appointments may include a test in hospital called a colonoscopy where a special camera is inserted through the anus to look inside the bowel, or CT colonography where images of the bowel are taken from outside the body. Some patients may be offered different tests instead, based on their age and other conditions they may have._x000D_ _x000D_ Colonoscopies are good at detecting bowel cancer and other bowel diseases, but are unpleasant, carry a risk of damaging the bowel and there is limited capacity within the NHS to do them. Doctors have noticed that most of the people with high-risk symptoms who are sent for a specialist appointment do not have cancer and did not need an urgent colonoscopy. For these reasons, it is important that only the people most likely to have colorectal cancer are selected to be seen within two weeks. This could then mean that they get the treatment they need quickly, and people with other bowel conditions can also be seen more quickly._x000D_ _x000D_ This project will look to see if FIT could be used to identify which people with signs or symptoms of CRC are most likely to have cancer and need to have an urgent colonoscopy. People who have a positive test would go to hospital for an urgent colonoscopy or CT colonography to see if they have bowel cancer. People who have a negative test would not go to hospital for further tests straight away, but their doctor may refer them for non-urgent appointment. Some may be treated in primary caredepending on their symptoms and may go for tests later on if they still have symptoms, or if new symptoms start._x000D_ _x000D_ For FIT to be safe and good value for money, it will need to be very good at correctly showing who does and does not have bowel cancer. We will look for research about how many people were correctly and incorrectly identified by the test. We will use mathematical models to determine whether the test is good value for money for the NHS. We will also look at how the threshold (value) used to define a positive test impacts on how many people are sent for colonoscopies, how many people with cancer are missed and have a delay to their diagnosis, and how this impacts on the waiting times for people sent for a non-urgent appointment.

Lay abstract: Colorectal cancer (CRC) is the fourth most common form of cancer in the UK. This assessment will consider the use of FIT in people presenting to primary care with gastrointestinal symptoms indicating a risk of CRC (excluding those with rectal or anal mass, or anal ulceration who will go straight to urgent 2WW suspected CRC referral). FIT is available as quantitative tests (using immunoturbidimetric or enzyme-linked immunosorbent assay [ELISA] methods to measure haemoglobin concentration) or qualitative tests (using immunochromatographic test devices to detect haemoglobin). In line with DG30 this evaluation will focus on quantitative FIT. The population is people presenting to primary care with symptoms or signs indicating a risk of CRC, as defined by NG12 and DG30. There are unlikely to be any end-to-end studies that compare FIT to current practice in the specific population of interest.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: CANCER AND NEOPLASMS