Title: COLOFIT - Optimal use of Faecal Immunochemical Testing for patients with symptoms of possible colorectal cancer.
Funder: Department of Health and Social Care

Abstract: Bowel cancer (also called Colorectal Cancer or abbreviated here to CRC) is the third commonest cancer in the UK. There are around 42,300 new cases diagnosed each year, leading to 16,300 deaths. Around 700 000 English patients are referred by GPs (primary care) to hospitals (secondary care) per year for investigation of possible CRC symptoms, though less than 5% of those people end up diagnosed with CRC. Symptoms include bleeding from the back passage, change in bowel habit, weight loss, iron deficiency with anaemia or having a swelling in the abdomen (tummy) or back passage. These symptoms are common in the general population so are only a weak signal for CRC. Once referred to hospital, most patients have a colonoscopy (where a tube is inserted into the bowel to look for cancer) or Tomographic Colonography (CAT scan). Both tests have some risks, they need hospital attendance and are also expensive. The NHS is struggling to meet demand: indeed, only 55% of English units meet urgent cancer wait targets. This has got worse in the Covid -19 pandemic. We need better ways to find out which patients are most at risk (and those at low risk) of CRC so that tests can be used for those who need them, and so that low risk patients are not put through unnecessary tests. Faecal immunochemical testing (FIT) is a method of measuring blood within faeces (stool / poo tests) and early research suggests it may help in finding CRC._x000D_ _x000D_ This research (named COLOFIT) has four Work Packages (WP 1-4). WP1 will undertake a full review of all published evidence on FIT and include other potential risk factors for CRC such as age, sex, family history, patient’s weight, or other blood test results. WP2 will then develop a mathematical model of risk and will test that model to see if it works in available datasets (sets of information on patients including FIT levels and other risk factors). WP3 will study patients, doctors and nurses and other stakeholders (e.g., health services, cancer charities) views on FIT based assessment of patient risk. This will cover a wide range of issues including acceptability of stool-based testing, not being referred to hospital with symptoms because the FIT test was negative, and safety netting (picking up CRC patients with a negative test). WP4 will study the health economics (costs to health service and individuals) using the results of the other WPs. This health-economic model will look at cost of investigations, the savings that doing fewer investigations might bring and how those resources might be better used._x000D_ _x000D_ Overall, COLOFIT will work out the best way of using FIT for patients with possible CRC. It will develop a risk assessment tool based on the best available evidence, will test it, will explore patient and clinician acceptability, and will assess value for money. The benefits of this research will be better use of resources. It will allow those at highest risk to be investigated quickly and correctly and reduce unpleasant investigations for those who do not need them.

Lay abstract: Colorectal Cancer (CRC) is the third commonest cancer in the UK and second commonest cause of cancer death. Around 42,300 new cases are diagnosed in the UK each year, with 16,300 deaths. Around 700,000 English patients are referred from primary to secondary care annually for investigation of possible CRC symptoms, though less than 5% have CRC. Symptoms associated with CRC include rectal bleeding, altered bowel habit, weight loss, iron deficiency anaemia, abdominal or rectal mass. Lower GI symptoms are common in the general population so are poorly discriminatory for CRC. Once referred to hospital, most patients undergo colonoscopy or Computerised Tomographic Colonography (CTC). Both investigations are invasive, with associated risks: requiring attendance at secondary care and pre-procedural bowel preparation._x000D_ The NHS is struggling with colonoscopy and CTC capacity, with only 55% of English units meeting urgent cancer wait targets. This has worsened during the Covid-19 pandemic with a significant backlog of patients awaiting cancer investigations. Improved strategies to define patients by CRC risk are needed so that invasive investigations can be targeted at those most at risk. Enhanced triage will also reduce potential overtreatment and overdiagnosis. Faecal immunochemical testing (FIT) measures the level of haemoglobin within the stool. It is now the basis of population-based screening programmes and has an evolving role in symptomatic patients._x000D_ _x000D_ COLOFIT will evaluate the evidence and develop a risk-based algorithm for implementation of a FIT-based strategy for patients with possible CRC symptoms presenting to primary care. This will be achieved through four Work Packages (WP 1-4). WP1 will undertake systematic reviews of published evidence on FIT and include other potential CRC risk factors such as age, sex, family history, Body Mass Index or blood markers. WP2 will develop a mathematical model of risk and test the model to see if it works in available datasets. WP3 will study patient, clinician and stakeholder views on FIT-based assessment of risk covering a wide range of issues including acceptability of stool-based testing, not being referred with symptoms when FIT was negative, safety netting and non-CRC diagnoses. WP4 will study health economics using results of WPs1-3, examining cost of investigations, savings from fewer investigations and how resources might be better used._x000D_ _x000D_ Overall, COLOFIT will establish the optimal use of FIT for patients with possible CRC. It will develop an algorithm based on best available evidence, will test it, will explore patient and clinician acceptability, and will assess value for money. The benefits of this research will be a patient pathway that allows those at highest risk to be investigated quickly and correctly and reduce unpleasant investigations for those who do not need them. It will additionally study the health economics of such a pathway.

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