Systematic review and meta-analysis : diagnostic accuracy of faecal immunochemical testing for haemoglobin (FIT) in detecting colorectal cancer for both symptomatic and screening population

Background : Colorectal cancer(CRC) is one of the most common cancers worldwide. A non-invasive test, with high sensitivity and specificity is essential for early detection, improved outcome and avoidance of unnecessary invasive tests. This study aims to evaluate the accuracy of the faecal immunochemical testing for haemoglobin (FIT) in the detection of CRC, both in symptomatic and screening population and to summarise the available evidence to date. Methods : Search strategy was initially developed in MEDLINE and adapted for use in other databases. Studies were included if they had fulfilled the criteria. QUADAS-2 tool was used for quality assessment and data analysis performed using STATA 15 software. Results : A total of 17 out of 92 articles were included in the final analysis. Within the symptomatic group (n= 6755), the overall pooled sensitivity and specificity of FIT to detect CRC was 0.90 (95% CI 0.87-0.92) and 0.87 (95% CI 0.83-0.90) respectively. In the screening population (n=24197), the pooled sensitivity and specificity of FIT to detect CRC was 0.69 (95% CI 0.54-0.81) and 0.94 (95% CI 0.94-0.95) respectively. Most analytics were comparable with cut off less than 20 mu g/g feces providing optimal sensitivity and specificity for symptomatic and screening populations respectively. Conclusion : For the detection of CRC within the screening population, FIT has high specificity and sensitivity. In the symptomatic group, FIT's high sensitivity (90%) supports its role as a triage test to guide the selection of patients who require urgent lower gastrointestinal tract evaluation.