Risk for metachronous advanced neoplasia in patients with a modified definition of advanced adenoma: data from the New Hampshire colonoscopy registry

Published in the Clinical Gastroenterology and Hepatology. Here is a link to the article.

Regenstrief Institute authors: Thomas Imperiale, M.D.

A new analysis using data from the New Hampshire Colonoscopy Registry examined the risk of metachronous advanced neoplasia (AN) and colorectal cancer (CRC) in individuals with different subtypes of advanced adenomas (AA). The study focused on comparing patients with 10–19 mm tubular adenomas (TA) to those with modified AA characteristics—high-grade dysplasia (HGD), villous histology, or TA >20 mm.

Among 35,941 adults who underwent follow-up colonoscopy ≥12 months after index screening, five groups were analyzed. Groups 4 (TAs 10–19 mm) and 5 (modified AA) demonstrated higher adjusted risk for metachronous AN compared to low-risk Groups 1–3 (Rate Ratios: 3.67 and 4.69, respectively), with overlapping confidence intervals.

However, when the outcome was restricted to modified AA, Group 5 had a significantly higher risk than Group 4 (RR=1.52; 95% CI, 1.04–2.22). Hazard ratios for CRC were also higher in Groups 4 and 5 (HR=2.44 and 3.52, respectively) compared to the low-risk reference groups, though their confidence intervals overlapped.

These findings indicate that while both larger TAs and modified AA subtypes are associated with increased AN and CRC risk, individuals with HGD, villous features, or larger adenomas may warrant particular attention. The results suggest a need for more precise risk stratification in surveillance guidelines. Further studies are recommended to refine subgroup risks within the 10–19 mm TA population.

Authors: 

Joseph C Anderson¹, Todd A Mackenzie², Lynn F Butterly³, Thomas F Imperiale⁴

Affiliations: 

¹Geisel School of Medicine at Dartmouth, Hanover, NH; White River Junction VAMC, White River Junction VT; NH Colonoscopy Registry, Lebanon, NH. Electronic address: Joseph.Anderson@Dartmouth.edu.

²Geisel School of Medicine at Dartmouth, Hanover, NH.

³Geisel School of Medicine at Dartmouth, Hanover, NH; Department of Gastroenterology and Hepatology, DHMC, Lebanon, NH; NH Colonoscopy Registry, Lebanon, NH.

⁴Indiana University School of Medicine, Dept of Med., Div. of Gastro/Hep, Indianapolis, IN; Richard L. Roudebush VA Medical Center; Regenstrief Institute, Inc.