Polyp Size and Advanced Histology in Patients Undergoing Colonoscopy

Polyp Size and Advanced Histology in Patients Undergoing Colonoscopy: "In summary, our analysis of asymptomatic patients undergoing colonoscopy screening in diverse clinical settings demonstrates that patients whose largest polyp is 1-5 mm have a very low risk of advanced neoplasia (1.7%), with only rare cases of cancer or high-grade dysplasia. Most of these patients can be safely observed with periodic imaging, assuming that accurate imaging is available. Our study confirms that patients whose largest polyp is ≥10 mm have a high proportion of advanced histology (30.6%). Patients whose largest polyp is 6-9 mm have an intermediate risk of advanced histology (6.6%; range, 4.6%-11.7%) including cancer or high-grade dysplasia in 0.92%. Based on these data, all patients with polyps ≥10 mm, and most patients whose largest polyp is 6-9 mm should receive colonoscopy and polypectomy. This recommendation is now embedded into new colon cancer screening guidelines.[17] Based on our data, 15%-20% of asymptomatic patients would require colonoscopy after imaging studies. These data have important implications for CTC. If large proportions of patients will require colonoscopy after CTC, patients will need to understand the likelihood of requiring colonoscopy and the possible need for 2 bowel preparations. Further study is needed to examine the cost-effectiveness of CTC if 20% of patients will require colonoscopy."