RT Journal Article SR Electronic T1 The Size of Colon Polyps Revisited: Intra- and Inter-observer Variations JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 2419 OP 2423 VO 30 IS 6 A1 CARLOS A. RUBIO A1 JON G. JÓNASSON A1 GABRIELLA NESI A1 JOANNA MAZUR A1 ELÍNBORG ÓLAFSDÓTTIR YR 2010 UL http://ar.iiarjournals.org/content/30/6/2419.abstract AB Background: It has been postulated that the occurrence of invasive carcinoma in a colon adenoma can be predicted by estimating the size of the resected polyp. Recently, significant intra- and inter-observer differences in size were found when 22 pathologists estimated the size of 12 polyp phantoms. In this work, the size of a large cohort of endoscopically-resected colon polyps was assessed with a novel method. Patients and Methods: Three pathologists measured photocopies of 148 resected polyps (adenomas at histology) in two independent trials. Results: The size recorded by the three participants was congruent in only 50% of the measurements in trial 1, and in 62% in trial 2. A significant difference in size asessment was found between the three investigators (p≤0.05). When 6 possible combinations (the 3 size limits proposed for predicting cancer risk in adenomas, and 2 different trials) were tested for the 13 adenomas showing invasive carcinoma, merely one of the three participants recorded the same size, but only in 11% of the 6 possible combinations. Conclusion: Present and previous investigations indicate that the lack of reproducibility makes the use of size limits in predicting cancer risk in polyps removed at colonoscopy unreliable.