Adenoma size and number are predictive of adenoma recurrence: implicationsfor surveillance colonoscopy

Background: Three-year colonoscopic surveillance after initial polypectomy may not be required for all patients. Those with multiple baseline polyps a nd large adenomas, implicated as predictors of colon cancer, merit close ob servation. Conversely, patients with single small adenomas may be subjected to early endoscopic surveillance unnecessarily. Methods: From our Adenoma Registry we evaluated patient and adenoma charact eristics in 697 patients. All had an adenoma recurrence within 3 years of a positive baseline colonoscopy. Potential risk factors studied were age, ge nder, number of adenomas, size of largest adenoma and histology. We defined a significant outcome as size of 1 cm or greater, tubulovillous or villous histology, high-grade dysplasia, carcinoma in situ, invasive cancer, or 4 or more adenomas. Results: Having 3 or more adenomas on initial colonoscopy with at least 1 m easuring 1 cm or larger greatly increased the chance of a significant findi ng on the first surveillance colonoscopy. Conversely, patients with 1 or 2 adenomas all measuring less than 1 cm were at extremely low risk of an impo rtant outcome within 3 years. Conclusions: Patients with 1 or 2 adenomas all measuring less than 1 cm are an identified low risk group and their first surveillance examination may be delayed beyond the standard 3 years.