Colonoscopy in symptomatic patients: Validation of AEG-SEED prioritization criteria and added value of FIT. The endoprior study.

Abstract

Background and aims: Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality. Colonoscopy is the diagnostic gold standard, although its performance in symptomatic patients is limited. During the COVID-19 pandemic, the AEG-SEED societies proposed a clinical prioritization system. The aim of this study was to validate its diagnostic performance in detecting clinically relevant lesions (CRLs), including CRC, and to compare it with the fecal immunochemical test (FIT).

Patients and methods: A national multicenter retrospective study was conducted in 12 Spanish hospitals. A total of 1078 adult patients with digestive symptoms attended between April and December 2020 were included. Colonoscopies were prospectively classified according to priority levels (P1, P2, P3).

Results: CRLs were identified in 18% of patients, including 36 cases of CRC (3%). The diagnostic yield was highest in P1 (PPV 27%, AUC 0.57 for CRLs; PPV 7%, AUC 0.64 for CRC), and decreased in P2 and P3. FIT was performed in 26% of patients based on the referring physician's clinical judgment, showing higher sensitivity and negative predictive value (NPV) for CRC (100%) and a higher AUC (0.69) compared to clinical criteria.

Conclusions: The AEG-SEED clinical criteria offer moderate value for prioritizing colonoscopies in the absence of FIT. However, FIT demonstrates superior diagnostic performance and should be systematically incorporated. The combination of symptoms improves accuracy compared to isolated symptoms.