Number of advanced adenomas on index colonoscopy: Important risk factor for metachronous advanced colorectal neoplasia

Background/Aims: Although the patients with multiple advanced adenomas (AA) in index colonoscopy may have an increased risk for subsequent advanced colorectal neoplasia (CRN), the current guidelines do not consider this factor. We aimed to compare the risk of metachronous advanced CRN according to the number of AAs. Methods: A total of 2250 patients with >= 1 adenoma at index colonoscopy were included. The patients were divided according to the number of AAs (1, 2 and >= 3 AAs). The relative and 3-year absolute risk of metachronous advanced CRN was compared between the AA groups. Results: The relative risk of metachronous advanced CRN was higher in the patients with >= 3 AAs than in the patients with one AA (16.7% vs. 6.8%, p = 0.004). The 3-year absolute risk of metachronous advanced CRN was higher in the patients with >= 3 AAs than in the patients with 1-2 AA (19.4% vs. 6.9%, p = 0.04). Having >= 3 AAs (odds ratio, 5.42; 95% confidence interval 1.75-16.83) was a significant risk factor for developing advanced CRN. Conclusions: The risk of metachronous advanced CRN in the patients with >= 3 AAs was higher than that in the patients with one or two AAs. More intensive surveillances might be needed for these patient groups. (c) 2018 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.