Long-term programmatic participation patterns, positivity rates, and yields for neoplasia in Catalonia’s organized fecal immunochemical (FIT)-based colorectal cancer screening program

Aims Programmatic participation is a critical determinant of the effectiveness of colorectal cancer (CRC) screening tests. The emergence of blood-based biomarkers intensifies the demand for data on the real-world long-term uptake and yield of FIT – the established non-invasive CRC screening standard. Such data published in detail are scarce. The aim of this study is to characterize long-term participation patterns, FIT positivity rates and yields for neoplasia in the Catalan FIT-based CRC screening program since 2010.

Methods Participation, FIT positivity and yield (CRC; high-risk precursors=advanced adenoma/sessile serrated lesion or 5+non-advanced ones) were determined with two perspectives: 1) Program (all persons regardless of age at entry); 2) Adherent cohort (entry at 50-51 years-old with longitudinal consistent/frequent participation).

Results Participation patterns: Among 2.81M persons with 1-9 rounds offered/person, participation patterns were: 29.2% consistent [100% of offered rounds], 8.6% frequent [99-66%], 16.0% occasional/intermittent [1-65%], and 46.2% never. Colonoscopy completion in FIT+was 87.3% in the Program, and 88.9% in the Adherent Cohort.

FIT participation ' positivity: Per-round FIT completed/offered ranged 39-60% for the Program, and 91-98% for the Adherent Cohort. FIT-positivity was highest in round 1 and settled at a steady state (approximately 1% lower) in rounds 2+in both scenarios.

Neoplasia yield: CRC detection was substantially higher in round 1 vs. rounds 2+in both scenarios. Similarly, high-risk precursor and CRC detection at colonoscopy were highest in round 1, with CRC detection settling at a steady state and high-risk precursor detection remaining substantial in rounds 2+.

Adherent Cohort vs. Program: FIT-positivity and neoplasia yield were higher at a given round in the Program vs. Adherent Cohort. This may be explained partly but not fully by age, since positivity and yield were still higher in the Program vs. Adherent Cohort even across rounds with similar median age.

Conclusions With current program design (invitation letter, FIT dispensed by pharmacy), 46% of eligible persons do not participate, and among participants, 70% are consistent/frequent. Yield is highest at round 1, as expected due to detection of prevalent neoplasia, but yield at rounds 2+remains substantial. The Adherent Cohort vs. Program results across rounds with similar ages suggest that consistent/frequent participation may decrease CRC incidence, presumably by removal of CRC precursors. We detect no specific round at which it seems reasonable to discontinue screening overall.

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Artikel online veröffentlicht:
27. März 2025