Frequent colonoscopies needed if low-risk polyps found

Among patients in whom 1 or 2 small tubular adenomas were detected on an initial screening colonoscopy, a significant number had positive findings on a third colonoscopy; even if a second one was clear, according to a retrospective cohort study presented at the American College of Gastroenterology annual meeting.

Of those who had no adenomatous polyps found on the second exam (56/88), 25% had an adenoma detected on the third exam, in 3.6% of whom the adenomas were at an advanced stage (defined as ≥ 1 cm, or of tubulovilous histology, or with high-grade dysplasia). A finding of 1 to 2 small tubular adenomas on the second exam appeared to correlate with an even higher prevalence (39.2%) of positive finding on the third exam.

They found that irrespective of what you found on the second colonoscopy, whether a patient had a normal colonoscopy or had 1 to 2 small tubular adenomas again; the prevalence of both adenomas and advanced adenomas on the third colonoscopy was significant, said by a doctor at the Department of Medicine at the University of Pennsylvania. About 25% of patients had no polyps on a third colonoscopy.

A second colonoscopy that's normal doesn't really put you . . . in the clear.

This study looked at 88 patients (ages ≥ 49 years) from the Olympus Endoworks database who had 1 or 2 small (<10 mm) tubular adenomas (without any villous components or high-grade dysplasia) removed on an initial colonoscopy, then 2 follow-up colonoscopies almost 1 year apart. The patients had no history of polyps, cancer, colon surgery, or inflammatory bowel disease.

Some of the patients had advanced adenomas on the third exam after a normal second exam. On the second colonoscopy 36.4% of patients had ≥ 1 adenoma, and a small percentage had ≥ 3 adenomas or advanced adenomas. On the third exam 29.6% of patients had ≥ 1 adenoma, and 3.4% (3/88) had advanced adenomas on the second colonoscopy.

Although screening colonoscopy with postpolypectomy surveillance reduces colon cancer risk, the optimal timing of follow-up examinations in patients with low-risk polyps has not been determined. In this study adenomas were found on the third procedure regardless of whether it was performed ≥ 3 years after the second exam. When you adjusted for the length of time between the 2 colonoscopies it didn’t actually matter.

They advised physicians to tell their patients, even if you have a negative second colonoscopy, the fact that you’ve had polyps in the past means that you’re probably at an increased risk for finding polyps again. Current colonoscopy screening guidelines recommend surveillance every 5 to 10 years if 1 to 2 small tubular adenomas are found on an initial screening. Probably they need to look that.

The study cohort was fairly representative of the larger population, and so the results can apply to a broad range of people.