Detection of colorectal cancer in symptomatic outpatients without visible rectal bleeding: Validity of the fecal occult blood test

• Published in: Clinical epidemiology 2009-08, Vol.1 (default), p.119-124
• Main Authors: Bjerregaard, Niels Christian, Tøttrup, Anders, Sørensen, Henrik Toft, Laurberg, Søren
• Format: Article
• Language: English
• Subjects: Blood tests; Clinical medicine; Colorectal cancer; Epidemiology; Health risk assessment; Original Research
• ISSN: 1179-1349; 1179-1349
• DOI: 10.2147/CLEP.S7097

In 2002, a new diagnostic strategy in symptomatic outpatients without known established colorectal cancer risk factors aged 40 years or older was implemented in Denmark. Fecal occult blood test (Hemoccult Sensa®) was a part of that strategy in patients without visible rectal bleeding. The aim was to assess the validity of the Hemoccult Sensa® test in detecting colorectal cancer in the above-mentioned outpatients. Symptomatic outpatients without known established colorectal cancer risk factors and without visible rectal bleeding. Hemoccult Sensa® was performed before endoscopic examination. Colorectal cancer was identified at histopathological examination. Patients completed a questionnaire about their symptoms before their first hospital appointment. Eight of 256 patients were found to have colorectal cancer. Median patient age was 63 years. The positive predictive value, negative predictive value, sensitivity, and specificity of Hemoccult Sensa® for colorectal cancer were 10.5% (95% confidence interval [CI]: 6.8-14.3), 99.0% (95% CI: 97.8-100.0), 75.0% (95% CI: 69.7-80.3), and 79.4% (95% CI: 74.5-84.4). Hemoccult Sensa® as the initial examination in symptomatic outpatients without known established colorectal cancer risk factors presenting without rectal bleeding has to be used with caution. We did not find Hemoccult Sensa® test to be an acceptable alternative to flexible sigmoidoscopy.