HONOLULU — A 5-year wait before surveillance colonoscopy following removal of a high-risk adenomatous polyp appears to be sufficient, instead of the currently recommended 3 years, Mihir Bakhru, M.D., said at the annual meeting of the American College of Gastroenterology.
Lengthening the surveillance interval in patients with such lesions from 3 to 5 years—as now looks to be safe—should free up more time for busy gastroenterologists to perform primary screening colonoscopies, added Dr. Bakhru of the Cleveland Clinic Foundation.
Current national guidelines recommend postpolypectomy surveillance colonoscopy 5 years after removal of polyps categorized as moderate risk and 3 years after clearance of high-risk polyps. But direct evidence to support the safety of the 5-year interval has been lacking.
That uncertainty was the impetus for Dr. Bakhru's study in which he compared the surveillance colonoscopy findings in 163 patients who underwent the procedure 5 years post polypectomy with an equal number of age- and gender-matched patients who underwent the procedure at 3 years.
Because these prospective but nonrandomized data were generated prior to current national guidelines, 57% of patients in the 3-year-interval group were at moderate risk, as were 49% in the 5-year-interval group, he said.
The primary study end point was the percentage of patients found to have recurrent neoplasia at surveillance colonoscopy: 49% with 3-year follow-up, a rate not significantly different from the 51% rate with 5-year follow-up. The rate of advanced neoplasia was 11% with 3-year and 10% with 5-year follow-up. Of the recurrent neoplasms detected in the 3-year follow-up group, 79% were tubular adenomas, as were 80% of those found with 5-year surveillance. No cancers were detected in either group.
Results from a multivariate analysis indicated that patients with more than two adenomas at screening colonoscopy, a polyp greater than 1 cm in size, and high-risk pathology were at more than a threefold increased risk of recurrent or advanced neoplasia at follow-up, although none of these three factors alone was predictive. Older age and nonwhite race were also predictive of recurrent or advanced neoplasia.
Dr. Bakhru received a 2005 ACG Auxiliary Award for his study.