Study of Colorectal Mass Survey with Total Colonoscopy as 2nd Close Examination

Abstract

A colorectal mass survey was conducted in the 2 model districts with total colonoscopy as the 2nd close examination between 1993 and 1995 (CS survey), and the characteristics of detected tumorous lesions were studied and compared with barium enema studies conducted between 1990 and 1992 (BE survey). The postivity rate of the fecal occult blood test was 5.5% in the CS survey, and 3.4% in the BE survey, and the acceptability rates of close examinations were 71.5% in the CS survey and 83.0% in the BE survey. More tumorous lesions were statistically detected in the CS survey than in the BE survey (0.725 vs.0.253 as the rate of detected tumor numbers). The number of detected cancers was 19 lesions in the CS survey and 7 lesions in the BE survey. Especially more submucosal invasive cancers were detected in the CS survey than in the BE survey. There was no signficant difference of size between findings in the CS and BE surveys (19.5±8.2mm vs.24.1+12.2mm). In all detected lesions, 58 lesions of superficial type (II a, II a+II c and creeping type) were included in the CS survey, but only 6 lesions in the BE survey. It was considered that the CS survey is an effective means to detect early colorectal cancer in a screening mass survey.