Jul 15 2004
An epidemiological study in this week’s issue of THE LANCET highlights the success of the UK’s national screening programme for cervical cancer introduced in 1988.
Authors of the study outline how the programme has prevented an epidemic of cervical cancer—around 5000 deaths are prevented every year and 100 000 (one in 80) of the 8 million British women born between 1951 and 1970 will be saved from premature death by the cervical screening programme.
Recent reports have suggested that the reduction in deaths achieved by the UK national cervical screening programme is too small to justify its costs, except perhaps in a few high-risk women. Julian Peto (Cancer Research UK) and colleagues analysed trends in deaths from cervical cancer before 1988 (when the British national screening programme was launched) to estimate what future trends in cervical cancer deaths would have been if national screening had not been introduced.
The investigators report how Cervical cancer deaths in England and Wales among women younger than 35 years rose three-fold from 1967 to 1987—largely due to increases in the transmission of human papilloma virus associated with the acquisition of sexually transmitted diseases. By 1988, incidence in this age-range was among the highest in the world. Since national screening was started, this rising trend has been reversed.
Professor Peto comments: "Cervical screening has prevented an epidemic that would have killed about one in 65 of all British women born since 1950 and culminated in about 6000 deaths per year in this country. The cervical screening programme will prevent about 5,000 future deaths each year in Britain at a cost per life saved of less than £40,000, or about £2,000 per year of extra life. Despite occasional but widely publicised failures the British cervical screening programme is already remarkably successful and is still improving."
In an accompanying commentary (p 224), David B Thomas (Fred Hutchinson Cancer Research Center, Seattle, USA) states: “Funds for disease-control programmes are often reduced or withdrawn in response to success. However, just because a disease becomes rare does not mean that control of it should stop. It might be rare because of the success of the programme being assessed. Modelling allows us to not only project the effect of an ongoing programme, but also to project what would happen to disease rates if that programme were terminated. If, as Peto and colleagues conclude, the population effect of the national screening programme is indeed great, then screening for cervical cancer should continue-even though it is no longer a major public-health issue in the UK-until a vaccine against HPV, or some other means of primary prevention becomes available. However, if the screening programme is less successful, or the costs outweigh the benefits, funds for control of the disease might be more usefully directed elsewhere.”