Randomized trial of the addition of flexible sigmoidoscopy to faecal occult blood testing for colorectal neoplasia population screening

Abstract

Background: Published data suggest that screening might reduce the mortality rate from colorectal neoplasia. Faecal occult blood (FOB) testing suffers from poor sensitivity and significant numbers of interval cancers, both of which should be improved by the addition of flexible sigmoidoscopy (FOS).

Methods: This prospective, randomized study aimed to assess the compliance and neoplasia yield of FOB testing and FOS compared with that of FOB testing alone. From general practitioner registers, 6371 asymptomatic patients (3124 men, 3247 women; age range 50-74 years) were invited for screening by means of FOB testing (3128 patients) performed at home, or a combination of FOB testing and FOS (3243 patients).

Results: Compliance with FOB testing alone was 50 per cent. In the FOB testing/FOS group, 48 per cent returned the FOB test but only 20 per cent went on to FOS. Despite the poor compliance, the neoplasia yield was four times greater in the FOB testing/FOS group.

Conclusion: FOS increase the neoplasia yield but strategies to improve compliance must be identified for this to become a population screening test.