A Comparison of Immunochemical Fecal Occult Blood Test and Total Colonoscopy in an Asymptomatic Population

Background: There is evidence that the mortality rate of colorectal cancer can be reduced by using the the fecal occult blood test. However, there has not been sufficient investigation of the association between the FOBT and colorectal adenomatous polyps. AIM: The aim of this study was to determine the usefulness of the immunochemical FOBT (iFOBT) for colorectal adenomatous polyps in an asymptomatic population. METHODS: 1281 asymptomatic individuals underwent a 2-day iFOBT, and total colonoscopy (CS) simultaneously. This study was approved by the ethics committee of our hospital. RESULTS: Of the 1281 examinees, 108 (8.4%) had a positive iFOBT result. The average tumor size (including adenoma< 10mm) in the iFOBT (+) group was significantly larger than that in the iFOBT (-) group (4.8 mm vs. 3.9 mm; P=0.02). The prevalence rate of advanced neoplasia (tubular adenoma >10 mm, adenoma with villous histology, or high-grade dysplasia) was low and was not significantly different in the iFOBT (+) and iFOBT (-) groups (2.8% and 0.9%, respectively; P=0.107). The prevalence rate of <10mm polyps was high in both groups without a significant difference (28.7% and 27.4%; P=0.735). CONCLUSION: The results suggest that iFOBT is inadequate as a screening test for detecting colorectal adenomatous polyps, especially subcentimetric polyps. We recommend adding screening CS as an official optional method for preventing CRCs.