6 Focus on FIT What the Experts Say In November 2017 Alpha Laboratories held an educational Digestive Diseases Day in Birmingham. Experts in the field discussed recent advances in clinical diagnostics for gastroenterology and FIT was a key focus area. Here are summaries of the presentations from three key opinion leaders. You can watch videos of the complete talks at www.faecal-immunochemical-test.co.uk/events Sally Benton is co-chair of the World Endoscopy Organization Expert Working Group on Faecal Immunochemical Tests for Colorectal Cancer Screening. She is also Chair of an International Federation of Clinical Chemistry working group to standardise and harmonise FIT testing. As such she is a leading authority on FIT and puts into context the significance of NICE DG30 in relation to the pathology of colorectal cancer (CRC) and the struggles faced by the NHS in terms of endoscopy resource. "The NICE Guidance makes recommendations regarding; the science of the test, the specific analysers, cut-off values, and the actions to be taken by those involved in the wider patient pathway. The recommendations from NICE are better understood when seen as a comparison with the current patient pathways. Data on the negative predicative values of FIT emphasises the rationale behind why the test should be utilised as a ‘rule-out’ test for CRC rather than ‘rule-in’. During evidence based studies, it was noted that despite some cancers being missed when the cut-off was 10 µg Hb / g of faeces, they would have been detected had the cut-off been 7 µg Hb / g. This poses an interesting differentiation between symptomatic and screening requirements. More work is required prior to widespread roll-out and it is important to address areas for continuing development, for both the test and patient pathway. From a clinician’s standpoint, the issues may include reporting data (using the limit of quantitation in place of ‘undetectable’), the point in the pathway that the test should be requested, and the safety-netting of negative test results. Laboratories also have reservations regarding FIT such as pre-analytical variation, operationalisation of the test, EQA schemes challenges, and test standardisation." Sally also discusses, the subject of ‘essentialism versus consequentialism’. "Essentialism is, “the theory that the value of a medical test should be judged by the ‘trueness’ of its results”, whereas consequentialism focuses on, “the theory that the value of a medical test should be judged on the value of its consequences”. In the laboratory, it is important to value the trueness and the accuracy of a method, however, the clinician is more concerned whether the result is fundamentally correct. FIT is well positioned for essentialism; the science is robust, deficiencies are understood, and there remains a continuous drive for improvement. FIT also has a place with regards to consequentialism, with evidence to show patients are being correctly categorised after their FIT tests." Overall, this presentation addresses some key advantages, and areas for continuous improvement in the NICE DG30 guidance, and is valuable to all those wishing to change, or add to, their service offerings in line with NICE recommendations. FIT in the Symptomatic Patient NICE DG30 Guidance Sally C Benton FRCPath, Consultant Biochemist, Surrey Pathology Services, Royal Surrey County Hospital, Director, Bowel Cancer Screening Hub – South of England
RkJQdWJsaXNoZXIy MTUyODc1Mw==