1. ¹Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
2. ²Department of Public Health, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
3. ³Association of Laboratory Pathology and Cytology (Pathan), Rotterdam, The Netherlands
4. ⁴Association of Nation-wide Screening South-west Netherlands, Vlaardingen, The Netherlands
5. ⁵Comprehensive Cancer Centre, Rotterdam, The Netherlands
6. ⁶Internal Medicine, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands

Correspondence: Dr L Hol, Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Centre Rotterdam, 's-Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands. E-mail: l.hol.1@erasmusmc.nl

Received 21 October 2008; Revised 30 January 2009; Accepted 8 February 2009.

Abstract

Immunochemical faecal occult blood testing (FIT) provides quantitative test results, which allows optimisation of the cut-off value for follow-up colonoscopy. We conducted a randomised population-based trial to determine test characteristics of FIT (OC-Sensor micro, Eiken, Japan) screening at different cut-off levels and compare these with guaiac-based faecal occult blood test (gFOBT) screening in an average risk population. A representative sample of the Dutch population (n=10 011), aged 50–74 years, was 1 : 1 randomised before invitation to gFOBT and FIT screening. Colonoscopy was offered to screenees with a positive gFOBT or FIT (cut-off 50 ng haemoglobin/ml). When varying the cut-off level between 50 and 200 ng ml^-1, the positivity rate of FIT ranged between 8.1% (95% CI: 7.2–9.1%) and 3.5% (95% CI: 2.9–4.2%), the detection rate of advanced neoplasia ranged between 3.2% (95% CI: 2.6–3.9%) and 2.1% (95% CI: 1.6–2.6%), and the specificity ranged between 95.5% (95% CI: 94.5–96.3%) and 98.8% (95% CI: 98.4–99.0%). At a cut-off value of 75 ng ml^-1, the detection rate was two times higher than with gFOBT screening (gFOBT: 1.2%; FIT: 2.5%; P<0.001), whereas the number needed to scope (NNscope) to find one screenee with advanced neoplasia was similar (2.2 vs 1.9; P=0.69). Immunochemical faecal occult blood testing is considerably more effective than gFOBT screening within the range of tested cut-off values. From our experience, a cut-off value of 75 ng ml^-1 provided an adequate positivity rate and an acceptable trade-off between detection rate and NNscope.