Screening has benefits in terms of lives saved that outweigh the harms caused by over-diagnosis, according to a major review of breast cancer screening services in Europe. The review was jointly led by researchers at Queen Mary, University of London and published in a special supplement to the Journal of Medical Screening.
“This is the only comprehensive review of the results of breast screening services in Europe. It reports results from screening millions of women, and confirms that the screening services are delivering the benefits expected from the research studies conducted years ago. In particular, it is good news that lives saved by screening outweigh over-diagnosed cases by a factor of two to one,” explained Stephen Duffy, co-author of the supplement and Professor of Cancer Screening at Queen Mary, University of London.
Estimates of benefit in published European studies in terms of breast cancer deaths prevented and the major harms, in terms of over-diagnosed cancers, were reviewed by the European Screening Network (EUROSCREEN). Over-diagnosed cancers are those that were diagnosed as a result of screening, would never have given any symptoms during a woman’s lifetime, and would not have been diagnosed if she had not been screened. The members of EUROSCREEN come from nine European countries.
A second working group, European Network for Indicators on Cancer (EUNICE), reviewed 26 screening programs in 18 countries involving 12 million women. Their review was based on organization, participation rates, and main performance parameters.
For every 1,000 women screened, 170 women would have at least one recall followed by a non-invasive assessment before the absence of cancer could be confirmed (a negative result). Also, 30 women would have at least one recall followed by invasive procedures, such as biopsy, before confirming a negative result. These “false positives” cause women stress and anxiety until the negative result is confirmed.
Dr Eugenio Paci, Director of the Cancer Prevention and Research Institute in Florence, Italy, who is a second EUROSCREEN coordinator and co-author, said, “By weighing up the pros and cons of breast cancer screening programmes we hope to ensure that women are fully aware of the chief benefits and harms and can make a fully informed choice when they decide whether or not they wish to attend screening. There has been quite a lot of discussion recently over the worth of breast cancer screening and for this reason it is timely that the international group of experts has assessed the impact of population-based screening in Europe and has found that it is contributing to the reduction in deaths from the disease.
“We believe that not only should our conclusions be communicated to women offered breast screening in Europe, but that, in addition, communication methods should be improved in order to raise women’s awareness, and to make information more accessible, relevant and comprehensible.”