DETECTION RATE OF IMMUNOCHEMICAL FECAL OCCULT BLOOD-TEST FOR COLORECTAL ADENOMATOUS POLYPS WITH SEVERE DYSPLASIA

This study was conducted to assess the accuracy of an immunochemical o ccult blood test for detecting colorectal adenomas with severe dysplas ia, and to determine the relationship between the grading of adenomato us dysplasia and the results of this test. Sixteen colorectal adenomas under 1 cm with severe dysplasia, 65 adenomas 1 cm or larger with sev ere dysplasia, 65 adenomas under 1 cm with mild-to-moderate dysplasia, 65 adenomas 1 cm or larger with mild-to-moderate dysplasia, 65 colore ctal cancers and 130 healthy controls were investigated. Each subject was tested with an immunochemical fecal occult blood test on 3 consecu tive days, and the accuracy of the test was evaluated. The detection r ate of this test was 13% for severe dysplasia under 1 cm, 45% for seve re dysplasia 1 cm or more, 17% for mild-to-moderate dysplasia under 1 cm, 40% for mild-to-moderate dysplasia 1 cm or more. and 89% for color ectal cancers, and the false positive rate was 5%. showing a significa nt difference in the detection rate between severe dysplasias 1 cm or more and those under 1 cm (P < 0.05) as well as a significant differen ce between severe dysplasias 1 cm or more and mild-to-moderate dysplas ia under 1 cm (P < 0.01), and between cancers and adenomas (P < 0.001) , whereas there was no significant difference between the detection ra tes for severe dysplasia 1 cm or more and mild-to-moderate dysplasia 1 cm or more. These results indicate that there is no association betwe en the detection rate of this immunochemical occult blood test for ade nomas and the grade of adenomatous dysplasia.