Optimal colonoscopy surveillance interval period for the adenoma patients who had an adequate polypectomy at baseline colonoscopy.

The role of surveillance colonoscopy has long been established: it reduces both the incidence and the mortality of colorectal cancer. We aimed to assess the optimal colonoscopy surveillance interval period for the adenoma patients who underwent an adequate polypectomy at baseline colonoscopy to avoid overuse or underuse of colonoscopy. A retrospective study was carried out on the baseline adenoma patients who had had at least two completed colonoscopy examinations during the years 2000-2013 in the Digestive Endoscopy Center of the First Affiliated Hospital of Kunming Medical University. All the patients had a complete polypectomy of adenomas at baseline. Data on the patients' demographics and colorectal findings were extracted from a specially designed colonoscopy database. The end point was the finding of adenoma during the subsequent surveillance colonoscopy; an analysis was carried out to identify recurrence factors and the optimal colonoscopy surveillance interval period. A total of 765 (463 men, 302 women, average age 56.51±11.95) eligible patients were included in the study. Three hundred and twelve patients had adenoma and 453 had no adenoma after surveillance colonoscopies (the frequency of repeat colonoscopy is 1-10, average 1.73±1.24). The diameter of adenomas found on the follow-up colonoscopy was 0.2-3.0 cm (average 0.54±0.30 cm). The number of adenomas was 1-11 (2.21±1.53) and the surveillance adenoma interval period was 0.5-13 years (2.64±2.36 years). A total of 576 patients had baseline nonadvanced adenomas. Male sex, age older than 50 years, and more than two different intestine segment adenomas were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.85 years (95% confidence interval: 2.53-3.17) according to the recurrence rate of 5% adenomas. One hundred and eighty-nine patients had baseline advanced adenomas. Male sex, diameter of adenomas less than 1.0 cm, and adenomas in the right colon or the whole colon were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.06 years (95% confidence interval: 1.71-2.45) according to the recurrence rate of 5% adenomas. The optimal colonoscopy surveillance interval period is 3 years or so for the adenoma patients who had an adequate polypectomy at baseline colonoscopy. Male sex, age older than 50 years, less than 1.0 cm adenomas diameter and the right colon, or multisegment intestine adenomas were the risk factors for recurrence. This has significance for guiding the follow-up colonoscopy interval time of the patients with intestine adenomas.