Changing Advanced/High-Risk Adenoma Definition Would Reduce Colonoscopies With Limited Delay in CRC Diagnoses

Patients with advanced or high-risk adenomas are recommended to undergo surveillance earlier than patients with low-risk adenomas. In the U.S., the traditional high-risk group classification for patients includes those with adenomas ≥1 cm, high-grade dysplasia or villous elements, or ≥3 adenomas. In 2020, the European Society of Gastrointestinal Endoscopy (ESGE) redefined the high-risk group as those with adenomas ≥1 cm, high-grade dysplasia, or ≥5 adenomas. A Polish study was used to create a novel definition of adenomas ≥20 mm or high-grade dysplasia.

Using national registries in Norway, investigators identified and studied a group of patients with cancer and a subcohort of patients with adenomas. The patients were diagnosed between 1993 and 2007 and followed for a median of 12.7 years.

The fraction of the adenoma cohort having high-risk findings was 52.7%, 45.2%, and 27% with the traditional, ESGE, and novel risk classification schemes, respectively. A diagnosis of colorectal cancer (CRC) would have been delayed in 3.4% of cases using the ESGE classification and 24.1% using the novel classification.

The low-risk adenoma cohorts had CRC risk below the general population risk using all 3 definitions of high risk.