Breast screening saves far more lives than it harms as study finds mammograms slash cancer deaths by a third
The screening programme costs 96 million a year in England
Mammograms can create 'false positives' leading to needless breast removal
15:21 GMT, 21 March 2012
Breast cancer screening has cut deaths from the disease by almost a third, according to new research.
The programme is also relatively cheap and any harm such as 'false-positives' or over diagnosis has been limited, say scientists.
Mammogram: In the UK all women aged between 47 and 73 are called for breast screening. Younger women are called if a close relative had breast cancer young
In the past decade there has been mounting evidence and controversy surrounding the true cost of mammograms to women. This has included needless breast removal.
But a 20 year study of the national screening programme in The Netherlands – one of the longest of its kind – found it has contributed to a dramatic drop in mortality.
Senior researcher Jacques Fracheboud, of the Erasmus University Medical Centre in Rotterdam, said compared with 1986 to 1988 – the year before screening was introduced – breast cancer deaths among women aged 55 to 79 fell by 31 per cent in 2009.
He told the European Breast Cancer Conference in Vienna: 'We found there was a significant change in the annual increase in breast cancer deaths: before the screening programme began, deaths were increasing by 0.3 per cent a year, but afterwards there was an annual decrease of 1.7 per cent.
'This change also coincided with a significant decrease in the rates of breast cancers that were at an advanced stage when first detected.'
From 1990 to 2009 a total of 16.6 million personal invitations for mammogram screenings were sent to 3.6 million women aged 50 to 75 – in 1998 the programme was extended to the age of 75 from the original cut-off point of 69.
Overall attendance was 80 per cent – increasing from 73.5 per cent in 1990 to 81.5 per cent in 2009. In the same period 13.2 million screenings were performed among 2.9 million women – resulting in 66,562 (0.5 per cent) breast cancer diagnoses.
For a woman who was 50 in 1990 and who had ten screenings over the twenty-year period the cumulative risk of something being detected that turned out not to be breast cancer (a false- positive result) was six per cent.
Over-diagnosis where tumours are detected that would never progress to become a problem was only 2.8 per cent of all breast cancers diagnosed.
The total annual cost of the programme was 43.1million in 2009 or 47.20 per examination. Adjusted for inflation a breast screening cost about 2.92 less than in 1996. In addition the screening programme was accurate with high sensitivity.
Mr Fracheboud said: 'These results provide convincing evidence that the programme contributed to the breast cancer mortality decrease that has been observed in the last 20 years in The Netherlands, and that harms such as the false-positive rates, the interval cancer rate – cancers that are diagnosed in the interval between screenings – and the proportion of over-diagnosed breast cancers were quite limited.
'Our study also shows the programme is of a high quality and is continually improving. It has a high acceptance rate among women aged 50 to 75 and the costs of the programme are reasonable.
'We are convinced that the benefits of the screening programme outweigh all the negative effects.
'These results may also be of value for other mammography breast cancer programmes that are strictly population-based, centrally organised, where quality assurance is guaranteed and that are continuously monitored and evaluated.
'The implementation of our breast cancer screening programme was based on previous practical experience from two regional pilot screening programmes, and on an extensive cost-effectiveness analysis.
'These 20 year results appear to be largely in line with the outcomes predicted around 1990.'
A review of the NHS breast cancer screening programme has been announced by the national cancer director, Professor Sir Mike Richards.
Under the programme, which costs 96 million a year in England, women are invited for three-yearly mammograms, or X-rays, between the ages of 50 and 70. The age limits are being extended to 47 and 73. Almost two million women are screened each year.
Conference chair Professor David Cameron, of the University of Edinburgh, said: 'This study reports the findings of a twenty-year national screening programme.
'Many of the pivotal randomised studies of breast screening did not directly assess the benefit of twenty years’ screening, as is increasingly being used in many national programmes.
'Therefore, these data will help inform the current debate about the risks and benefits of many of the current national screening programmes implemented around the world.'