Grant Number:	1R01CA310053-01A1 Interpret this number
Primary Investigator:	Butterly, Lynn
Organization:	Dartmouth-Hitchcock Clinic
Project Title:	Decreasing Colorectal Cancer: Using Longitudinal Population-Based Evidence and Modeling to Investigate Key Issues That Can Reduce Colorectal Cancer
Fiscal Year:	2026

Preventing colorectal cancer (CRC) is a pressing national mandate: CRC is the 2 nd most common cause of U.S. cancer deaths, despite being one of the few cancers that can be prevented through screening. Colonoscopy is the only test that can prevent CRC by detecting and removing potentially precancerous polyps throughout the colon, and is by far the most common U.S. screening method. To be effective, colonoscopy must be high quality, and follow-up recommendations must be informed by strong evidence. This study aims to close 3 critical evidence gaps in CRC screening through colonoscopy, focusing on the incidence of CRC itself (most research investigates advanced polyps because CRC takes many years to develop); risk and outcomes of Early-Onset CRC in adults < 50 whose CRC rates have seen recent dramatic increases, and developing more accurate colonoscopy quality metrics to optimize CRC prevention. This project combines over 20 years of comprehensive colonoscopy data from the New Hampshire Colonoscopy Registry (NHCR) with statistical and risk prediction expertise from Dartmouth College and an ongoing collaboration with the internationally recognized microsimulation modelers of the Cancer Intervention and Surveillance Modeling Network (CISNET). CISNET has been at the cutting-edge of cancer prevention research for decades, strengthening U.S. and international CRC prevention strategies, including providing key evidence to support the recent U.S. reduction of the age to begin CRC screening from 50 to 45. The participation of all 3 independent CISNET CRC models is a major strength of this study, to reduce the risk of bias from using a single model and contribute to the strongest possible evidence. One model is led by Dr. Lansdorp-Vogelaar at Erasmus Medical University in the Netherlands, a public health expert and long-standing NHCR collaborator. As a leader in the development of microsimulation models, her participation as a vendor in this study will directly inform and strengthen U.S. CRC prevention policy and research, helping further reduce the U.S. burden of CRC. Longitudinal NHCR data will be used to model the long-term risks of CRC (Aim 1.1) and in CISNET models to identify optimal follow-up intervals in patients with polyps (Aim 1.2); to investigate colonoscopy outcomes in the EO-CRC cohort (Aim 2.1) and provide CISNET with data to evaluate costs and benefits of screening this cohort (Aim 2.2); to investigate a benchmark for the newly recommended ‘all indication Adenoma Detection Rate’ and evaluate adenomas per colonoscopy as a quality metric (Aim 3.1), and to expand preliminary work on novel methods to assess incomplete polyp resection (Aim 3.2). The NHCR is a unique population-based resource with unmatched detail on all aspects of colonoscopy screening and surveillance. The combined expertise of this proposed study will significantly advance the scientific evidence-base and transform the landscape of prevention of CRC.





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