Prevalence of repeat faecal immunochemical testing in symptomatic patients attending primary care

Johnstone, M. S., MacLeod, C., Digby, J., Al-Azzawi, Y., Pang, G., Watson, A. J.M., Strachan, J., Mowat, C. and McSorley, S. T. (2022) Prevalence of repeat faecal immunochemical testing in symptomatic patients attending primary care. Colorectal Disease, 24(12), pp. 1498-1504. (doi: 10.1111/codi.16240) (PMID:35776684)

Abstract

Aim: The faecal immunochemical test (FIT) for faecal haemoglobin (f-Hb) helps determine colorectal cancer (CRC) risk and has been integrated into symptomatic referral pathways. ‘Safety netting’ advice includes considering referral for persistent symptoms, but no published data exists on repeated FIT. We aimed to examine the prevalence of serial FIT in primary care and CRC risk in these patients. Method: A multicentre, retrospective, observational study was conducted of patients with ≥2 consecutive f-Hb results within a year, from three Scottish health boards which utilise FIT in primary care. Cancer registry data ensured identification of CRC cases. Results: 135396 FIT results were reviewed of which 12359 were serial results reported within 12 months (9.1%), derived from 5761 patients. 42 (0.7%) were diagnosed with CRC. 3487 (60.5%) patients had two f-Hb <10μg/g, 944 (16.4%) had f-Hb ≥10μg/g followed by <10μg/g, 704 (12.2%) f-Hb <10μg/g followed by ≥10μg/g and 626 (10.9%) had two f-Hb ≥10μg/g. CRC rate in each group was 0.1%, 0.4%, 1.4% and 4.0%. 734 patients submitted >2 FITs within a year. The likelihood of ≥1 f-Hb ≥10 μg/g rose from 40.4% with two samples to 100% with six, while CRC rate fell from 0.8% to 0%. Conclusion: Serial FITs within a year account for 9.1% of all results in our Boards. CRC prevalence amongst symptomatic patients with serial FIT is lower than single FIT cohorts. Performing two FITs within a year for patients with persistent symptoms effectively safety nets, while performing >2 within this timeframe is unlikely to be beneficial.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Johnstone, Mr Mark and McSorley, Dr Stephen
• Authors: Johnstone, M. S., MacLeod, C., Digby, J., Al-Azzawi, Y., Pang, G., Watson, A. J.M., Strachan, J., Mowat, C., and McSorley, S. T.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Colorectal Disease
• Publisher: Wiley
• ISSN: 1462-8910
• ISSN (Online): 1463-1318
• Published Online: 01 July 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Colorectal Disease 24(12): 1498-1504
• Publisher Policy: Reproduced under a Creative Commons License