Impact of screening and follow-up colonoscopy adenoma sensitivity on colorectal cancer screening outcomes in the CRC-AIM microsimulation model

Deborah A Fisher; Leila Saoud; Kristen Hassmiller Lich; A Mark Fendrick; A Burak Ozbay; Bijan J Borah; Michael Matney; Marcus Parton; Paul J Limburg

doi:10.1002/cam4.3662

Impact of screening and follow-up colonoscopy adenoma sensitivity on colorectal cancer screening outcomes in the CRC-AIM microsimulation model

Cancer Med. 2021 Apr;10(8):2855-2864. doi: 10.1002/cam4.3662. Epub 2020 Dec 13.

Authors

Deborah A Fisher¹, Leila Saoud², Kristen Hassmiller Lich³, A Mark Fendrick⁴, A Burak Ozbay², Bijan J Borah⁵, Michael Matney², Marcus Parton², Paul J Limburg⁶

Affiliations

¹ Department of Medicine, Division of Gastroenterology, Duke University, Durham, NC, USA.
² Exact Sciences Corporation, Madison, WI, USA.
³ Department of Health Policy & Management, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
⁴ Division of Gastroenterology, University of Michigan, Ann Arbor, MI, USA.
⁵ Department of Health Services Research, Mayo Clinic, Rochester, MN, USA.
⁶ Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA.

Abstract

Background: Real-world data for patients with positive colorectal cancer (CRC) screening stool-tests demonstrate that adenoma detection rates are lower when endoscopists are blinded to the stool-test results. This suggests adenoma sensitivity may be lower for screening colonoscopy than for follow-up to a known positive stool-based test. Previous CRC microsimulation models assume identical sensitivities between screening and follow-up colonoscopies after positive stool-tests. The Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model (CRC-AIM) was used to explore the impact on screening outcomes when assuming different adenoma sensitivity between screening and combined follow-up/surveillance colonoscopies.

Methods: Modeled screening strategies included colonoscopy every 10 years, triennial multitarget stool DNA (mt-sDNA), or annual fecal immunochemical test (FIT) from 50 to 75 years. Outcomes were reported per 1000 individuals without diagnosed CRC at age 40. Base-case adenoma sensitivity values were identical for screening and follow-up/surveillance colonoscopies. Ranges of adenoma sensitivity values for colonoscopy performance were developed using different slopes of odds ratio adjustments and were designated as small, medium, or large impact scenarios.

Results: As the differences in adenoma sensitivity for screening versus follow-up/surveillance colonoscopies became greater, life-years gained (LYG) and reductions in CRC-related incidence and mortality versus no screening increased for mt-sDNA and FIT and decreased for screening colonoscopy. The LYG relative to screening colonoscopy reached >90% with FIT in the base-case scenario and with mt-sDNA in a "medium impact" scenario.

Conclusions: Assuming identical adenoma sensitivities for screening and follow-up/surveillance colonoscopies underestimate the potential benefits of stool-based screening strategies.

Keywords: adenoma; colonoscopy; colorectal neoplasms; diagnostic screening programs; sensitivity and specificity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenoma / diagnosis*
Adenoma / epidemiology*
Adenoma / mortality
Colonoscopy*
Colorectal Neoplasms / diagnosis*
Colorectal Neoplasms / epidemiology*
Colorectal Neoplasms / mortality
Follow-Up Studies
Humans
Incidence
Mass Screening / methods
Models, Theoretical
Quality-Adjusted Life Years
Sensitivity and Specificity