Planning for a possible national colorectal cancer screening programme

Abstract

This report presents the planning, projected costs, and manpower requirements for a possible national colorectal cancer screening programme. Screening would be offered to all those aged 50–69, who comprise 20% of the United Kingdom population. The initial screening test would be faecal occult blood testing every two years. A local programme, administered by a screening centre serving a population of one million, would be responsible for inviting 100 000 subjects a year. The response rate in Nottingham, the UK trial centre, was below 60%. Good informed compliance would require the active support of primary care. The invitation and test kit would be sent by post, and completed tests returned to the screening centre, for reading and reporting. Those with a positive initial screen (about 2%) would be recalled for assessment. This would result in 60 000 investigations each year across England and Wales, given a screening uptake rate of 60%. Clearly any deviation from this predicted rate would have a major effect on resources. Assessment and any subsequent treatment would be by a multidisciplinary team working at the cancer unit, as recommended in recent NHS executive guidance. The best method for investigation is colonoscopy. When completed successfully this allows visualisation of the whole bowel. However, performance varies widely across the UK, and there is insufficient skilled manpower to undertake this additional workload. Most significantly the technique has a mortality rate of 0.02%, so the programme might expect 12 deaths a year, which would not be acceptable. Alternatively, assessment of screen positive cases could be by a combination of double contrast barium enema and flexible sigmoidoscopy, with a comparable sensitivity. Both procedures have much lower morbidity and mortality rates. Colonoscopy would then only be required for a smaller number of patients, with cancer or suspicious lesions, or after unsatisfactory investigations. Quality assurance should be an integ- ral part of the programme, as in the other NHS cancer screening programmes, involving all professional groups and coordinated by a regional quality assurance reference centre. Cost estimates are over £40 million a year, together with any allowance for general practitioners, with additional capital and training costs at the start of the programme. Given a 60% overall uptake rate, a test sensitivity of 60%, and a recall rate of 2%, about 35% of the cases of colorectal cancer in the eligible population—that is, about 5400 cases, could be detected each year. As this would also depend on maintaining good compliance, a continuing value of 4000 cases is more realistic. Appreciable savings on costs of treatment are unlikely as aggressive curative treatments would be expensive.