Can high-risk adenoma surveillance wait 5 years?

Clinical takeaway: For patients with high-risk adenomas removed at high-quality colonoscopy, a first surveillance colonoscopy at 5 years appeared as safe as the current 3-year approach for colorectal cancer detection, raising questions about whether many patients undergo follow-up too frequently.

Current guidelines generally recommend surveillance colonoscopy 3 years after removal of high-risk adenomas because these patients are considered at elevated risk for colorectal cancer. However, surveillance colonoscopy is resource-intensive, costly, and burdensome for patients, and robust randomized evidence supporting the 3-year interval has been limited.

In the European Polyp Surveillance (EPoS II) trial, investigators randomized 10,799 patients from eight European countries who had undergone removal of high-risk adenomas to receive their first surveillance colonoscopy either 3 years or 5 years later. After a median follow-up of approximately 5.5 years, colorectal cancer incidence was nearly identical between groups: 0.82% with the 3-year strategy and 0.77% with the 5-year strategy. The longer interval met the study's prespecified criteria for noninferiority.

Importantly, investigators found no meaningful differences in cancer stage at diagnosis, and colorectal cancer deaths were rare in both groups, occurring in just 2 patients in the 3-year group and 3 patients in the 5-year group. More than 99% of participants remained free of colorectal cancer within 5 years of adenoma removal regardless of surveillance strategy.

The 5-year approach also substantially reduced healthcare utilization, resulting in roughly 4,200 fewer colonoscopies during the study period. The findings represent an interim analysis, with final 10-year outcomes still pending.

“More than 99% of the patients in this trial did not receive a diagnosis of colorectal cancer within 5 years after polyp removal,” the authors wrote, adding that the results may prompt reconsideration of whether these patients should continue to be categorized as being at high risk for colorectal cancer.

In an accompanying editorial, Drs. Aasma Shaukat and Theodore Levin noted that “for decades, surveillance after adenoma removal has been guided by a reasonable instinct: more vigilance must be better,” but said the trial “offers an important corrective.”

Source: Jover R, et al. (2026 Sep 17) N Engl J Med. Colonoscopy Intervals and Colorectal Cancer Incidence after Adenoma Removal