6- to 9-mm Adenomas Again Shown to Predict Advanced Neoplasia Versus Diminutive Adenomas
Current postpolypectomy surveillance guidelines lump adenomas 1 to 9 mm in size together in a category of low-risk adenomas. Advanced adenomas are defined as those ≥10 mm in size or having high-grade dysplasia or villous elements.
Several recent studies have suggested that 6- to 9-mm adenomas have more predictive value for subsequent advanced neoplasia than do diminutive (1-5 mm) adenomas.
Another single-center study has addressed this issue. Among 2477 qualifying baseline colonoscopies with only tubular adenomas <10 mm in size, the risk of advanced neoplasia at follow-up colonoscopy was 3.6% in patients with 1- to 5-mm adenomas versus 6.9% if at least one 6- to 9-mm adenoma was present. The effect was clearer when only screening colonoscopies were considered. For screening colonoscopy, all baseline groups by number of adenomas (1-2 adenomas, 3-4 adenomas, and ≥5 adenomas) had an increased risk of metachronous advanced neoplasia if at least one of the adenomas was 6 to 9 mm in size.
Comment:
The most recent postpolypectomy surveillance recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer were that persons with one or two tubular adenomas with low-grade dysplasia and 1 to 9 mm in size could undergo follow-up colonoscopy in 5 to 10 years. Most U.S. clinicians utilize the more conservative 5-year interval. These recent studies showing that 6- to 9-mm adenomas are associated with increased risk provide a basis for risk stratifying within the 1- to 9-mm adenoma group, perhaps using the shorter end of the recommended interval in persons with a 6- to 9-mm adenoma and the longer end in persons with only one or two diminutive adenomas.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
Douglas K. Rex, MD, FASGE
Citation(s):
Hartstein JD, Vemulapalli KC, Rex DK. The predictive value of small versus diminutive adenomas for subsequent advanced neoplasia. Gastrointest Endosc 2019 Sep 13. (Epub ahead of print) (https://doi.org/10.1016/j.gie.2019.08.047)
