Colorectal cancer (CRC) is the second most common cause of cancer deaths, despite being preventable by removing precancerous colon polyps. Therefore, polyp detection rates are a critical measure of endoscopist performance quality. After polyp removal, endoscopists depend on national guidelines to provide evidence- based recommendations for appropriate intervals between colonoscopies. Serrated polyps include hyperplastic polyps (HPs) and sessile serrated polyps (SSPs). Recent evidence indicates that a subset of serrated polyps are important precursors to CRC, highlighting the need for evidence to clarify optimal detection and follow up of serrated lesions. Long-term outcome data to support specific surveillance guidelines in patients with serrated polyps is lacking. Current screening guidelines consider patients with only small HPs in the recto-sigmoid to be at average-risk, and recommend a 10 year return interval. Patients with SSPs are thought to be at higher risk, and shorter return intervals are suggested, based on limited evidence. However, even expert pathologists differ as to whether some polyps are HPs or SSPs, and it remains unclear whether proximally located polyps designated as HPs should be considered SSPs, with accordingly higher risk and shorter surveillance intervals. The New Hampshire Colonoscopy Registry (NHCR), a statewide population-based registry, is uniquely able to provide the long-term outcome data needed to move this developing field forward. Comprehensive data on endoscopist polyp detection rates will identify sources of variation in serrated polyp detection. By 2017, 13,000 NHCR patients will surpass the critical 10 year follow-up interval recommended for patients with normal exams or only small HPs. Increasing numbers of patients will return for repeat exams, and the NHCR database will contain data on risk factors, colonoscopy characteristics and pathology for 145,000 patients, nearly 13,500 with serrated polyps, allowing research into outcomes following all types of serrated polyps.
Specific Aims : 1) To investigate variability in serrated polyp detection rates among the approximately 100 endoscopists participating in the NHCR, exploring factors associated with variable detection rates, including patient, endoscopist, procedure, and endoscopy facility characteristics, and 2) To identify factors associated with an increased risk for advanced outcomes - defined as histologically advanced polyps or CRC - at follow- up colonoscopy in patients with baseline serrated polyps. We will investigate the outcomes for serrated polyp subtypes, according to their baseline size, location in the colon, and number of serrated polyps detected, and also analyze the impact of patient risk factors, baseline colonoscopy characteristics, and other findings (such as concurrent conventional adenomas), on future risk of advanced outcomes. This study aims to provide new high-quality population-based evidence needed to refine and strengthen current surveillance guidelines and quality indicators and thereby improve the effectiveness of screening in preventing CRC.

Public Health Relevance

Colonoscopy detects and removes polyps in the colon before they become cancer. Serrated polyps, recently recognized potential precursors to cancer, are an important focus of colonoscopy, yet there is no established benchmark for their detection, and there is very little data describing later findings in patients with these polyps. This study aims to provide the new high?quality evidence needed to refine and strengthen current guidelines for patients with serrated polyps, to help guide endoscopists as they determine the appropriate time interval to recommend between one colonoscopy and the next.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21CA191651-02
Application #
9187870
Study Section
Special Emphasis Panel (ZCA1)
Program Officer
Doria-Rose, Paul P
Project Start
2015-12-01
Project End
2017-11-30
Budget Start
2016-12-01
Budget End
2017-11-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Dartmouth College
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
Anderson, Joseph C; Butterly, Lynn F; Robinson, Christina M et al. (2018) Risk of Metachronous High-Risk Adenomas and Large Serrated Polyps in Individuals With Serrated Polyps on Index Colonoscopy: Data From the New Hampshire Colonoscopy Registry. Gastroenterology 154:117-127.e2
Anderson, Joseph C; Lisovsky, Mikhail; Greene, Mary A et al. (2017) Factors Associated With Classification of Hyperplastic Polyps as Sessile Serrated Adenomas/Polyps on Morphologic Review. J Clin Gastroenterol :
Andrew, Angeline S; Baron, John A; Butterly, Lynn F et al. (2017) Hyper-Methylated Loci Persisting from Sessile Serrated Polyps to Serrated Cancers. Int J Mol Sci 18:
Anderson, Joseph C; Butterly, Lynn F; Weiss, Julia E et al. (2017) Providing data for serrated polyp detection rate benchmarks: an analysis of the New Hampshire Colonoscopy Registry. Gastrointest Endosc 85:1188-1194
Patel, Chirag J; Kerr, Jacqueline; Thomas, Duncan C et al. (2017) Opportunities and Challenges for Environmental Exposure Assessment in Population-Based Studies. Cancer Epidemiol Biomarkers Prev 26:1370-1380
Anderson, Joseph C; Weiss, Julia E; Robinson, Christina M et al. (2017) Adenoma Detection Rates for Screening Colonoscopies in Smokers and Obese Adults: Data From the New Hampshire Colonoscopy Registry. J Clin Gastroenterol 51:e95-e100