Breast cancer screening is effective, appropriate and reduces deaths from the disease in women aged up to 75 years old, according to new research in over 860,000 women aged 70-75.
The research was presented today at the 6th European Breast Cancer Conference (EBCC-6) in Berlin.
In another study of nearly 100,000 women aged 50-62, also presented at EBCC-6 today, researchers found that the best interval for screening was every three years – a finding that counters arguments that women should have mammograms more frequently.
Many countries that run breast cancer screening programmes offer it to women aged between 50 and 70. However, in 1998 in The Netherlands, the programme was extended to women aged up to 75. The results presented today suggest that this is an appropriate upper age limit and saves lives without causing substantial harm by subjecting older women to over-diagnosis and over-treatment.
This is the first study to provide firm support for the idea that offering mammograms to women up to the age of 75 is effective, as, until 1998, very few women were screened at this age.
Mr Jacques Fracheboud, a senior researcher at the Erasmus Medical Center, Rotterdam, and his colleagues found that from 2003, five years after screening was extended to women aged 70-75, there was a steady decline in deaths from breast cancer among women aged 75-79.
By 2006 breast cancer mortality was 29.5% lower than the average for the period 1986-1997 for this age group – a time when breast cancer mortality in women aged 75-79 had remained stable.
In 1986-1997 the average was 166 deaths per 100,000 women aged 75-79, and in 2006 it was 117 per 100,000.
It takes some years before a significant effect from screening can be seen, therefore breast cancer mortality was analysed for the ages 75-79.
That means that women, aged 70-75 at the time that screening was extended to this age group, have become five years older and the reduction in breast cancer mortality shows that the screening has started to have a statistically significant effect, Mr Fracheboud told a news briefing.
One of the authors of the study, Professor Roger Blamey, a breast surgeon at Nottingham City Hospital (Nottingham, UK), told the news briefing: “There was a lot of criticism of the UK for having a three-yearly interval when breast screening was set up screeners and advocacy groups said, without evidence, that it was too long an interval. Population screening in the UK costs around £100 million a year. These results indicate that our earlier predicted mortality figures were accurate and that there is no evidence in favour of shortening the current three-year screening interval.”