FIT Triage Accurately Flags High-Risk Symptomatic Patients for Colonoscopy: Study
UK: Faecal immunochemical testing (FIT)–based triage can effectively identify which symptomatic patients are most likely to benefit from colonoscopy, a large real-world analysis from the United Kingdom has revealed.
Using data from the UK National Endoscopy Database, researchers found that patients with FIT values of at least 10 μg Hb/g were at substantially higher risk of colorectal cancer, inflammatory bowel disease, and large polyps, while those with FIT values below this threshold had a very low likelihood of serious pathology.
The nationwide study, published in Alimentary Pharmacology & Therapeutics, was led by David Beaton of Northumbria NHS Foundation Trust, North Shields, UK, and colleagues. The investigators evaluated how FIT performs in routine clinical practice as a triage tool for symptomatic colonoscopy referrals, and whether age, sex, and presenting symptoms influence diagnostic yield.
The analysis included 447,109 symptomatic colonoscopies performed between June 2023 and August 2025 across 412 sites in the UK. Symptomatic procedures included referrals for gastrointestinal symptoms, anaemia, and iron-deficiency anaemia. FIT results were available for 202,219 procedures, reflecting the growing integration of FIT into routine referral pathways. For analysis, results were grouped as FIT values below 10 μg Hb/g, including negative or low numeric values, and FIT values of 10 μg Hb/g or higher, including all positive results.
The following findings were reported:
- Colorectal cancer was identified in 1.9% of all symptomatic colonoscopies included in the analysis.
- Cancer detection varied substantially according to FIT results.
- Colonoscopies following a FIT value of ≥ 10 μg Hb/g had a colorectal cancer detection rate of 3.8%.
- In contrast, procedures performed after FIT values < 10 μg Hb/g showed a markedly lower cancer yield of 0.3%.
- Increasing FIT concentrations demonstrated a strong and graded association with colorectal cancer risk.
- Higher FIT values were linked to large polyp detection, although this association was weaker than that observed for colorectal cancer.
- FIT levels showed minimal association with the detection of small polyps.
- Detection rates for colorectal cancer and large polyps rose progressively with increasing age.
- Across all age categories studied, including individuals aged 40–49 years, cancer detection rates were consistently higher in patients with FIT values ≥ 10 μg Hb/g compared with FIT-negative patients.
- Even among younger adults aged 16–39 years, colorectal cancer yield was higher when FIT values met or exceeded the 10 μg Hb/g threshold.
Symptom type further refined risk stratification, with iron-deficiency anaemia emerging as a strong independent predictor of colorectal cancer, conferring more than twice the risk compared with rectal bleeding. Anaemia without iron deficiency was also linked to increased cancer risk, though to a lesser degree.
Models integrating FIT results with age and iron-deficiency anaemia showed that limiting colonoscopy to patients with an estimated cancer risk of at least 1% could detect over 94% of colorectal cancers while reducing colonoscopy demand by more than 40%.
The authors concluded that FIT-based triage is superior to symptom-based referral alone and should be universally adopted in symptomatic pathways to improve cancer detection, avoid unnecessary procedures in low-risk patients, and optimise access to colonoscopy.
Reference:
Beaton, D., Mohamed, M., Sharp, L., Pohl, K., & Rutter, M. Real-World Performance of FIT Triage for Symptomatic Colonoscopy: Analysis of the UK National Endoscopy Database (NED). Alimentary Pharmacology & Therapeutics. https://doi.org/10.1111/apt.70537
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