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Updated: Aug 9, 2025
Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
Published on: June 8, 2020
Adenoma Detection Rate and Colorectal Cancer Risk in Fecal Immunochemical Test Screening Programs : An Observational
Manuel Zorzi1, Giulio Antonelli2, Claudio Barbiellini Amidei1
1Veneto Tumor Registry, Azienda Zero, Padova, Italy (M.Z., C.B.A., J.B.).
Background:
Colorectal cancer (CRC) screening programs based on fecal immunochemical tests (FITs) represent the standard of care for population-based interventions. Their benefit depends on the identification of neoplasia at colonoscopy after FIT positivity. Colonoscopy quality measured by adenoma detection rate (ADR) may affect screening program effectiveness.
Objective:
To examine the association between ADR and postcolonoscopy CRC (PCCRC) risk in a FIT-based screening program.
Design:
Retrospective population-based cohort study.
Setting:
Fecal immunochemical test-based CRC screening program between 2003 and 2021 in northeastern Italy.
Patients:
All patients with a positive FIT result who had a colonoscopy were included.
Measurements:
The regional cancer registry supplied information on any PCCRC diagnosed between 6 months and 10 years after colonoscopy. Endoscopists' ADR was categorized into 5 groups (20% to 39.9%, 40% to 44.9%, 45% to 49.9%, 50% to 54.9%, and 55% to 70%). To examine the association of ADR with PCCRC incidence risk, Cox regression models were fitted to estimate hazard ratios (HRs) and 95% CIs.
Results:
Of the 110 109 initial colonoscopies, 49 626 colonoscopies done by 113 endoscopists between 2012 and 2017 were included. After 328 778 person-years follow-up, 277 cases of PCCRC were diagnosed. Mean ADR was 48.3% (range, 23% and 70%). Incidence rates of PCCRC from lowest to highest ADR group were 13.13, 10.61, 7.60, 6.01, and 5.78 per 10 000 person-years. There was a significant inverse association between ADR and PCCRC incidence risk, with a 2.35-fold risk increase (95% CI, 1.63 to 3.38) in the lowest group compared with the highest. The adjusted HR for PCCRC associated with 1% increase in ADR was 0.96 (CI, 0.95 to 0.98).
Limitation:
Adenoma detection rate is partly determined by FIT positivity cutoff; exact values may vary in different settings.
Conclusion:
In a FIT-based screening program, ADR is inversely associated with PCCRC incidence risk, mandating appropriate colonoscopy quality monitoring in this setting. Increasing endoscopists' ADR may significantly reduce PCCRC risk.
Primary Funding Source:
None.
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