Faecal occult blood tests--eliminate, enhance or update?
Traditional guaiac-based faecal occult blood tests (FOBT) are commonly performed investigations in laboratories, wards, clinics and general practices. Although there is much evidence that use of FOBT in asymptomatic population screening programmes for colorectal (bowel) cancer does reduce mortality, there is little, if any, evidence of the value of FOBT in symptomatic individuals. In contrast, recent evidence-based guidelines are unequivocal that most of those presenting with symptoms should have bowel visualization and that the only laboratory test required is the full blood count. Moreover, recent literature shows that there are significant problems in sample collection for FOBT and in analysis of FOBT. In view of these facts, it is suggested that FOBT be ceased in all clinical settings except in asymptomatic population screening programmes. An alternative to elimination of FOBT would be laboratory-led improvement of knowledge on the appropriateness of requests, the FOBT used, the quality of FOBT sample collection and the standard of analysis, but this would require significant efforts and resources, which probably could be better spent elsewhere. A favoured option is that FOBT be replaced by faecal immunochemical tests since these undoubtedly have many clinical and laboratory advantages and fewer problems in both performance and interpretation.
Fraser
Callum G
CG
Scottish Bowel Screening Centre Laboratory, Kings Cross, Dundee DD3 8EA, UK. callum.fraser@nhs.net
D015179:Colorectal Neoplasms / Q000175:diagnosis; D006801:Humans; D007120:Immunochemistry / Q000379:methods; D009780:Occult Blood