COMMUNITY‐BASED MASS SCREENING FOR COLORECTAL CANCER BY A COMBINATION OF FECAL OCCULT BLOOD TESTING AND FLEXIBLE SIGMOIDOSCOPY

Abstract

Background: There have only been a few large‐scale community‐based reports on the combination of immunological fecal occult blood testing (IFOBT) and flexible sigmoidoscopy (FS). Based on the results of mass screening at our hospital, we investigated the utility of combining IFOBT with FS to detect colorectal cancer (CRC) and analyzed the detection rates of CRC.Subjects and methods: The subjects comprised examinees during mass screening for CRC from 1992 to 2002. Only examinees that underwent the 2‐day IFOBT method were enrolled. During the 11 years, 117 644 subjects had negative 2‐day IFOBT and underwent FS. Cancers that were directly found by FS or by work‐up examinations with negative 2‐day IFOBT were designated as IFOBT‐FS‐detected cancers.Results: The detection rate of CRC was 0.16% (mucosal cancer, 0.13%; invasive cancer, 0.03%) by negative 2‐day IFOBT and FS. It was 0.27% (mucosal cancer, 0.22%; invasive cancer, 0.05%) in first‐time examinees. The detection rate was significantly higher in males than in females, and rates increased with age in both genders. Adverse events included eight cases of ischemic colitis that occurred after FS (incidence rate, 0.0068%). There were no cases of perforation, hemorrhage or infection after endoscopy.Conclusion: Although there are problems in introducing FS into mass screening for CRC, such as cost‐effectiveness, speed of examinations and lack of manpower, FS is expected to prevail because preparation is easier, and it is a shorter and safer procedure than colonoscopy. In particular, a combination of IFOBT with FS is effective and recommended in first‐time examinees and for individuals 50 years and older. Mass screening using the combination of IFOBT and FS provides limited benefit in those who are below 50 years of age.