Results of the first round of a demonstration pilot of screening for colorectal cancer in the United Kingdom.

OBJECTIVE To assess the feasibility of introducing into the UK's NHS a national screening programme for colorectal cancer based on faecal occult blood testing. DESIGN Demonstration pilot. SETTING Two English health authorities and three Scottish health boards. PARTICIPANTS People aged 50-69 years. RESULTS 478,250 residents of the pilot areas were invited to take part in the screening programme. Uptake (the proportion in whom a final faecal occult blood test result was available) was 56.8% (n = 271,646). The overall rate of a positive test result was 1.9% and the rate for detecting cancer was 1.62 per 1000 people screened. Both these values were higher in Scotland than in England, higher in men than in women, and increased with age. The positive predictive value was 10.9% for cancer and 35.0% for adenoma. 552 cancers were detected by screening; 92 (16.6%) were polyp cancers. 48% of all screen detected cancers were Dukes's stage A, and 1% had metastasised at the time of diagnosis. CONCLUSIONS Screening for colorectal cancer by testing for faecal occult blood is feasible within the context of the United Kingdom's NHS. Screening should lead to a reduction in deaths from colorectal cancer in the population offered screening.