O36 Prevalence of repeat FIT testing in symptomatic patients attending primary care. (19th June 2022)

• Record Type: Journal Article
• Authors: Johnstone, Mark; Digby, Jayne; Strachan, Judith; MacLeod, Campbell; Mowat, Craig; McSorley, Stephen
• Is Part Of: Gut. Volume 71(2022)Supplement 1
• Page Start: A22
• Page End: A22
• Publication Date: 2022-06-19
• Subjects: Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gutjnl-2022-BSG.36
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : Introduction: The faecal immunochemical test (FIT) is used in symptomatic referral pathways to rule out colorectal cancer (CRC) with greater accuracy than symptoms alone. NICE DG30 suggests a faecal haemoglobin (f-Hb) threshold of 10ug/g to prompt urgent referral to secondary care. However, there are limited data on the role of repeated FIT testing over time in those with persistent or recurrent symptoms. Methods: Patients with more than 1 FIT result with a gap of between 1 to 12 months between samples were identified from laboratory datasets. Data were collected across 3 Scottish Health Boards; NHS Greater Glasgow and Clyde, NHS Tayside, and NHS Highland, which utilise FIT in primary care within their symptomatic referral pathways. The unique Community Health Index (CHI) number was used to link records. Scottish cancer registry and regional cancer audit datasets were used to identify any CRC diagnoses following first FIT result to end of follow up. Caldicott approval was granted at each Health Board. Results: 5761 patients were included, of whom 42 (0.7%) were found to have CRC ( Table 1 ). Median follow up was 24 months in Tayside, 18 months in GGC, and 9 months in Highland. In all boards, females made up the majority of patients (56% - 60%), with a median age from 63 years in GGC to 69 years in Highland. The median time between samples was 5 months. Only 3 of the 3487 patients (0.1%) with both f-Hb<10ug/g were diagnosed with CRC. Of the 13 patients diagnosed with CRC who had a first f-Hb<10 ug/g, 10 were anaemic at the time of 1 st FIT, and 8 had tumours proximal to the splenic flexure. A subgroup of 734 patients submitted more than 2 FITs within a 12 month period, with 4 patients submitting 6. The likelihood of at least one f-Hb≥10ug/g rose from 40% with 2 samples to 100% with 6 samples, while the CRC rate fell from 0.8% with 2 samples to 0% with 6 samples. Conclusions: A second f-Hb of <10ug/g within 12 months of the first sample, in the context of ongoing or persistent symptoms reliably rules out CRC. These patients represent a different cohort than those who present with symptoms and referred or reassured with a single FIT test in terms of CRC incidence. Further investigation of these patients should be determined by the reason for referral and with the aim of symptom improvement rather than urgent colonoscopy.