Factors of Colorectal Cancer and Adenoma Affecting Immunological Fecal Occult Blood Test

Park, Doo Ho; Lee, Bo In; Choi, Kyu Yong; Bae, Sang Soo; Kim, Byung Wook; Choi, Hwang; Park, Soo Heon; Chae, Hyun Suk; Choi, Myung Gyu; Jung, In Sik; Lee, Se Young; Lee, Won Chul

Abstract

BACKGROUND/AIMS: Since immunological fecal occult blood test (iFOBT) was introduced in Korea, there has been no study on factors of colorectal cancer and adenoma which affect iFOBTs. Thus, we compared the sensitivity of the iFOBT according to differentiations and locations of colorectal cancers and sizes, histological types, degrees of dysplasia, numbers and locations of adenomas.
METHODS
Sixty patients with histologically confirmed colorectal cancer and 174 patients with colorectal adenoma who underwent colonoscopy, were included in this study. They underwent iFOBTs for their two consecutive specimens before clonoscopy examinations.
RESULTS
There was no significant difference in the sensitivity of the iFOBT according to the differentiation and the location of colorectal cancers (p=0.061 and p=0.399, respectively). The univariate analysis of colorectal adenomas showed that the positive rates of the iFOBT were increased as the size of adenoma was bigger, the degree of dysplasia was severer and the number of adenoma was larger (p=0.000, p=0.009 and p=0.015, respectively). However, in the multivariate analysis, only the size of adenoma was significant (p=0.000).
CONCLUSIONS
The iFOBT is a useful screening method which is not influenced by the location and the differentiation of colorectal cancer, but its usefulness is limited in colorectal adenoma less than 1cm.