3 Questions About Nonadvanced Adenomas and Metachronous Advanced Neoplasia Risk

Data from the era of standard definition colonoscopy demonstrate that patients with high-risk adenomas—large adenomas, adenomas with advanced pathology, or 3 or more adenomas—are at an increased risk for metachronous advanced neoplasia (MAN) compared with patients with low-risk adenomas.

In a new study, Carol Burke, MD, the director of the Center for Colon Polyp and Cancer Prevention at the Cleveland Clinic Foundation, Carol Rouphael, MD, second-year gastroenterology and hepatology fellow at the Cleveland Clinic Foundation, and colleagues analyzed the association between baseline adenoma features, particularly the presence of numerous nonadvanced adenomas, on the risk of MAN among patients who underwent high-definition (HD) baseline and follow-up colonoscopy.

Findings showed that compared with patients with low-risk adenomas, patients with 3 or more nonadvanced adenomas were not at an increased risk for MAN on follow-up in the era of high-quality colonoscopy.

Gastroenterology Consultant caught up with Dr Burke and Dr Rouphael about the research, which was presented at the ACG 2019 Annual Scientific Meeting and Postgraduate Course.

GASTRO CON: What prompted you to conduct the study? 

Carol Burke and Carol Rouphael: We have published previous data that showed an increase in the number of patients detected with numerous nonadvanced adenomas in the HD-scope era compared with the standard-definition scope. The adenoma detection rate (ADR) has increased substantially over time, not only because of using HD scopes in colonoscopy, but also because of using split-dose bowel preparation and the national minimum benchmarks for ADR and reimbursement changes. Historically, patients with 3 or more adenomas are considered at high risk of MAN compared with patients with 1 to 2 small tubular adenomas. This is based on data published more than a decade ago. We performed our study because we believed in the era of high-quality, HD colonoscopy; that the detection of numerous, nonadvanced adenomas was likely; and having 3 or more nonadvanced adenomas was no longer a high-risk feature for MAN.

GASTRO CON: What are the most crucial findings from your research? 

CB and CR: In our study of patients undergoing baseline and follow-up colonoscopy in the contemporary era, patients with 3 or more nonadvanced adenomas were not at increased risk of MAN compared with patients with low-risk adenoma, [that is,] those with 1 to 2 small tubular adenomas.

GASTRO CON: What is important for gastroenterologists to know? 

CB and CR: Our results are important, because the data suggest that patients with 3 or more nonadvanced adenomas can have a longer interval until their next colonoscopy, which is not significantly different than patients with low-risk adenoma. It is currently recommended that patients with low-risk adenoma undergo follow-up colonoscopy in 5 to 10 years vs in 3 years among patients with high-risk adenoma. This is based on current guidelines from the US Multi-Society Task Force on Colorectal Cancer.

Reference:

Rouphael C. Numerous non-advanced adenomas are not associated with metachronous advanced neoplasia [abstract 9]. Presented at: ACG 2019 Annual Scientific Meeting and Postgraduate Course; October 25-30, 2019; San Antonio, TX.