Abstract
Objective: We evaluated the utility of immunochemical fecal occult blood (IFOB) levels in screening for colorectal cancer in health check-ups.
Subjects: From January 2007 to September 2014, a cumulative total of 36,284 persons underwent the IFOB test, and 2,719 persons (7.5%) were determined to be positive. (We measured IFOB levels, and set a level of 80 ng/ml or greater as positive.) Among the IFOB-positive persons, the findings from 617 who agreed to undergo total colonoscopy at Nissay hospital were analyzed regarding a relationship between IFOB levels and colorectal cancer incidence.
Results: Thirty-one persons (19 men and 12 women)(5% of all examined by colonoscopy) were diagnosed as histologically confirmed colorectal cancer. IFOB levels of persons with colorectal cancer were found to be significantly higher than those without colorectal cancer (504±332 vs 326±285, p=0.001). Among persons with an IFOB level of 900 ng/ml or over, colorectal cancer was found in 12.5%. The incidence of colorectal cancer in patients with such high IFOB levels was significantly higher than that for all persons.
Conclusions: The IFOB level was higher in persons with colorectal cancer than those without colorectal cancer. However, we considered that not only positivity but also the actual IFOB level should be taken into consideration when determining if colorectal cancer is present or not.
