Researchers analyzed four prospective studies of 3,226 postpolypectomy patients to compare risk for advanced colorectal neoplasia at one-year colonoscopy. Patients were cross-classified by U.S. and U.K. surveillance guidelines.
Both U.S. and U.K. colonoscopy guidelines stratify patients into risk groups based on size and number of adenomas. However there are a few key differences between the guidelines.
The U.K. criteria do not take into consideration histologic features (the U.S. guidelines do) and they recommend a clearing colonoscopy at one year for high-risk patients, as classified by having five or more small adenomas or three or more adenomas, at least one of which is at least 1 cm.
The U.S. guidelines recommend follow-up at three years for these patients.
In their analysis, the researchers found advanced neoplasia one year after polypectomy in 11.2 percent of high-risk patients based on U.S. criteria and in 18.7 percent of patients based on U.K criteria.
The authors conclude that following the U.K. guidelines would help detect advanced adenomas two years earlier than following the U.S. guidelines for 19 percent of patients who have these lesions at one year without substantially increasing colonoscopy rates.
One-Year Risk for Advanced Colorectal Neoplasia: U.S. Versus U.K. Risk-Stratification Guidelines Ann Intern Med. 18 December 2012;157(12):856-864