The diagnostic accuracy of the faecal immunochemical test for the detection of early-onset colorectal cancer: an age-stratified analysis in South West England
Menée en Angleterre à partir de données portant sur 528 patients atteints d'un cancer colorectal de survenue précoce et ayant bénéficié d'un test FIT entre 2021 et 2023, cette étude évalue la performance, du point de vue de la sensibilité, de la spécificité, de la valeur prédictive positive et de la valeur prédictive négative, d'un test FIT dont le seuil de positivité est supérieur ou égal à 10 µg Hb/g
Background : The incidence of early-onset colorectal cancer (EOCRC) is rising rapidly, with diagnoses typically occurring at a more advanced stage than late-onset CRC. In the absence of screening for younger patients, diagnosis relies on symptomatic presentation. The faecal immunochemical test (FIT) is a diagnostic triage tool for patients presenting with clinical features of CRC in primary care, though its performance in individuals under 50 years is not well established.
Methods : A cohort of 38,117 symptomatic patients aged 18–49 years in upper South West England underwent FIT in primary care between 01/01/2021 and 10/07/2023. A FIT result of
≥
10 µg Hb/g faeces was considered positive. In the same region, 528 EOCRC diagnoses were recorded between 01/01/2021 and 10/10/2024.
Results : Of the 528 EOCRC patients, 105 (20%) underwent FIT in the year before diagnosis. The sensitivity of FIT was 92.4% (95% CI 85.5–96.7%), specificity was 88.5% (88.2–88.8%), positive predictive value (PPV) was 2.2% (1.8–2.6%), and negative predictive value was 100% (100–100%). PPVs decreased in younger age groups (18–29, 30–39, 40–49 years).
Conclusions : FIT performs excellently for patients aged 40–49; however, it may not be used optimally in patients <40 years. A more targeted strategy is needed to guide investigation in younger patients.
British Journal of Cancer , article en libre accès, 2025