This report presents the planning, projected costs, and manpower requiremen
ts for a possible national colorectal cancer screening programme. Screening
would be offered to all those aged 50-69, who comprise 20% of the United K
ingdom population. The initial screening test would be faecal occult blood
testing every two years. A local programme, administered by a screening cen
tre 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 i
nformed compliance would require the active support of primary care. The in
vitation and test kit would be sent by post, and completed tests returned t
o the screening centre, for reading and reporting.
Those with a positive initial screen (about 2%) would be recalled for asses
sment. 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 t
he cancer unit, as recommended in recent NHS executive guidance.
The best method for investigation is colonoscopy. When completed successful
ly this allows visualisation of the whole bowel. However, performance varie
s widely across the UK, and there is insufficient skilled manpower to under
take this additional workload. Most significantly the technique has a morta
lity rate of 0.02%, so the programme might expect 12 deaths a year, which w
ould not be acceptable. Alternatively, assessment of screen positive cases
could be by a combination of double contrast barium enema and flexible sigm
oidoscopy, with a comparable sensitivity. Both procedures have much lower m
orbidity and mortality rates. Colonoscopy would then only be required for a
smaller number of patients, with cancer or suspicious lesions, or after un
satisfactory investigations.
Quality assurance should be an integral part of the programme, as in the ot
her NHS cancer screening programmes, involving all professional groups and
coordinated by a regional quality assurance reference centre.
Cost estimates are over pound 40 million a year, together with any allowanc
e for general practitioners, with additional capital and training costs at
the start of the programme. Given a 60% overall uptake rate, a test sensiti
vity 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 detec
ted each year. As this would also depend on maintaining good compliance, a
continuing value of 4000 cases is more realistic. Appreciable savings on co
sts of treatment are unlikely as aggressive curative treatments would be ex
pensive.