CRC-SPIN version 3.0 - an updated policy model for colorectal cancer screening that includes the serrated pathway

Sep 23, 2026

Uploaded by Ben

Microsimulation models use empirical evidence on cancer epidemiology and screening test performance to forecast long-term effectiveness of screening regimens and to support cancer screening guideline development. This work updates CRC-SPIN version 3.0 by incorporating information on the serrated pathway, sessile serrated lesions, and CRC risk in adults younger than 50 years, then estimates decennial colonoscopy effectiveness from ages 45–75. Bayesian calibration provides 95% credible intervals to reflect prediction uncertainty.

LanguageEnglish

CategoryHealthcare

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Pages9

Reading Time23 min

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Abstract

Background

Methods

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Introduction

JNCI: Journal of the National Cancer Institute, 2026, 118(7), 1203–1210 [https://doi.org/10.1093/jnci/djag037](https://doi.org/10.1093/jnci/djag037) Advance Access Publication Date: February 16, 2026 Article CRC-SPIN version 3.0: an updated policy model for colorectal cancer screening that includes the serrated pathway Carolyn M. Rutter , PhD􀀃 ,1 ,2 , Christopher E. Maerzluft , MS1, Laura Matrajt , PhD3,4, Pedro Nascimento de Lima , PhD5, Rachel B. Issaka , MD, MAS1,6, Tracey L. Marsh , PhD2 1Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Center, Seattle, WA, United States 2Division of Public Health Sciences, Biostatistics Program, Fred Hutchinson Cancer Center, Seattle, WA, United States 3Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, United States 4Department of Applied Mathematics, University of Washington, Seattle, WA, United States 5Department of Engineering and Applied Sciences, RAND Corporation, Arlington, VA, United States 6Division of Public Health Sciences, Cancer Prevention Program, Fred Hutchinson Cancer Center, Seattle, WA, United States 􀀃 Corresponding author: Carolyn M. Rutter, PhD, Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Seattle, WA 98109, United States ([crutter@fredhutch.org](crutter@fredhutch.org)) . Abstract Background: Microsimulation models use empirical evidence about cancer epidemiology and screening test performance to predict the long-term effectiveness of screening regimens and are essential for developing cancer screening guidelines. Colorectal cancer (CRC) provides a clear example. CRC arises through 2 pathways, the adenoma-carcinoma pathway and the serrated pathway. Sessile serrated lesions (SSLs) are the primary serrated precursor lesion. SSLs are more difficult to detect and remove than adenomas. Methods: We describe version 3.0 of the Colorectal Cancer Simulated Population model for Incidence and Natural history, which adds new information about the serrated pathway and CRC risk in adults younger than 50 years, then estimate the effectiveness of decennial colonoscopy from 45 to 75 years old. The model was calibrated using a Bayesian approach to estimate 95% credible intervals (CIs) that reflect uncertainty in predictions. Results: The model validated well to studies of the effect of 1-time screening and outcomes from surveillance colonoscopy. In the absence of screening, SSLs accounted for 10.6%(95% CI ¼ 3.3-21.6) of CRC, increasing to 23.5%(95% CI ¼ 7.7% -46.0%) with screening because of selective removal of adenomas. Screening was predicted to prevent 93.9%(95% CI ¼ 92.0% -94.3%) of CRC and 95.3%(95% CI ¼ 93.8% -96.5%) of CRC mortality. Conclusions: Although SSLs are less common than adenomas, they likely make up a large fraction of CRC that arises in people who participate in screening. This points to the importance of improving the ability to detect SSLs, especially large SSLs, at colonoscopy. Introduction Microsimulation models use evidence about cancer epidemiology, test performance, and screening behaviors to predict the longterm effectiveness of screening regimens. Long-term outcomes, such as cancer mortality, are key to comparing screening strategies that typically have early costs and later benefits. Even a shift to earlier stage at detection does not necessarily translate to improved survival, because it can result from increased detection of indolent disease or longer lead time.1 Fielding a randomized trial to estimate the effect of screening on mortality is expensive, requires recruiting a large number of healthy participants who are followed over a long time period, and can only compare a limited number of interventions. Worse, with changing technology, trial results may arrive too late to have an impact on clinical practice. Microsimulation models bridge short-term evidence and longterm outcomes to inform policy decisions.

FAQs

What problem does the CRC-SPIN model address in colorectal cancer screening policy?

It uses microsimulation to connect screening test performance and cancer epidemiology with long-term outcomes, helping compare screening strategies for policy decisions.

What new elements does CRC-SPIN version 3.0 add?

It adds new information about the serrated pathway, including sessile serrated lesions, and estimates CRC risk for adults younger than 50 years.

How does the model estimate the impact of decennial colonoscopy on colorectal cancer outcomes?

It predicts prevention of 93.9% of CRC and 95.3% of CRC mortality, using Bayesian calibration to quantify uncertainty with 95% credible intervals.

Sep 23, 2026

Uploaded by Ben