Wright State University, Boonshoft School of Medicine Dayton, OH
Sara Yacyshyn, MD1, Patrick Chen, DO1, Joy Wang, MD1, Samuel Theis, DO1, Ronald J. Markert, PhD2, Padmini Krishnamurthy, MD1; 1Wright State University, Boonshoft School of Medicine, Dayton, OH; 2Boonshoft School of Medicine, Dayton, OH
Introduction: Evidence suggests detection and removal of adenomatous colon polyps may prevent colorectal cancers (CRC) and reduce mortality. Guidelines for surveillance colonoscopy define high-risk adenomas (HRA) as having one or more of these features - ≥3 adenomas, adenoma(s) ≥10mm, villous histology, or high-grade dysplasia (HGD). Methods: We performed a single-center retrospective study at the Dayton Veterans Affairs Medical Center. The baseline demographic characteristics of age, sex, and race were collected. (Table 1) The number of adenomas, size of the largest adenoma, and histology were recorded both at index and surveillance colonoscopy. We created two time periods for surveillance colonoscopy – within five years and more than five years. Results: From 2008 and 2011, 1960 patients had adenomatous polyps during CRC screening colonoscopies, with 406 patients having HRAs. The mean age for the 406 study patients was 65.7±7.0 years, 99% were male, while 88.4% were Caucasian and 11.6% African American.
Patients with ≥3 sub-centimeter adenomas at index colonoscopy (IC) had a higher rate of ≥3 sub-cm adenomas (52.3% vs. 39.4%, p=0.043) and >10 mm adenoma(s) (22.7% vs. 13.0%, p=0.038) if their surveillance colonoscopy (SC) was >5 years compared to SC ≤5 years. (Table 2). No other differences were found when comparing SC >5 years to SC ≤5 years. Discussion: As a single comprehensive health care system, Veterans Affairs is committed to CRC screening and surveillance. To our knowledge, this investigation is the first study of HRA subtypes in the US veteran population.
Our study found that patients with ≥3 sub-centimeter adenomas at IC had a higher rate of ≥3 sub-cm adenomas and >10 mm adenoma(s) if their SC was >5 years compared to SC ≤5 years. This indicates that surveillance colonoscopy can be considered at 5 years. This result supports the U.S Multi-Society Task Force (USMSTF) 2020 guidelines that favor a 3-5-year interval for 3-4 sub-cm adenomas.
The relatively small number of patients with HGD and CRC identified on SC limited our study’s ability to compare incidence of HGD and CRC at SC ≤5 years and > 5 years. This suggests that a larger initial sample size may be necessary to reveal potential differences in HGD and/or CRC between different time periods for surveillance. This also highlights the need for future research to clarify risk stratification and the management of post-polypectomy patients. Similar studies are needed in the future to support best practices.
Table 1. Baseline demographic characteristics and index HRAs of 406 patients
Table 2. High-risk adenomas for surveillance colonoscopy at ≤5 years vs. > 5 years
Disclosures: Sara Yacyshyn indicated no relevant financial relationships. Patrick Chen indicated no relevant financial relationships. Joy Wang indicated no relevant financial relationships. Samuel Theis indicated no relevant financial relationships. Ronald Markert indicated no relevant financial relationships. Padmini Krishnamurthy indicated no relevant financial relationships.