대장 폴립형 선종과 비교한 편평 선종의 임상 및 병리학적 특성과 악성화 빈도

Abstract

Background/Aims: Colorectal flat adenomas have been a topic of debate in the view of malignant potential. The aims of this study are to investigate the clinicopathological features of flat adenomas compared to that of polypoid adenomas and to identify the determinants for malignant transformation in colorectal flat and polypoid adenomas. Methods: This was a prospective, cross sectional study of 3,360 patients who diagnosed as adenomas via total colonoscopy and polypectomy at 13 tertiary medical centers between July 2003 and July 2004. Potential risk factors for malignant transformation were analyzed. Results: Out of 3,360 adenomas, 207 (6.2%) were flat adenomas and 3,153 (93.8%) were polypoid adenomas. The patients with flat adenoma were older (59.6 vs. 57.1, p＜0.01) and more frequently located in the right colon than polypoid adenomas (49.3% vs. 32.0%, p<0.01). The incidence of high grade dysplasia or cancer in flat adenomas was similar to that of polypoid adenomas (5.4% vs. 4.6%, p=0.36). Multivariate analysis revealed that the size ≥11 mm (OR 6.8; 95% CI 4.8-9.7) and location of adenoma in the left colon (OR 1.6; 95% CI 1.07-2.38) were significant determinants for malignant potential of colonic adenoma. Conclusions: Clinicopathological determinants for malignant potential in colorectal adenomas were not gross morphology but size and location of adenoma.