In the UK and many other countries, women are advised to have routine screening (mammography) for breast cancer in the hope that early detection of a breast cancer and prompt treatment will cure the disease. A report in The Lancet in January 2000, by Peter Gøtzsche and Ole Olsen from the Nordic Cochrane Center In Copenhagen, Denmark, suggested that this may not be the case. This report was widely criticised in the medical and non-medical press.
Gøtzsche and Olsen re-analysed their data according to a rigorous protocol developed by the Cochrane Collaboration, an organisation committed to using the best evidence to help doctors and policy makers make reliable decisions about patient care.
The results of this second analysis are published in The Lancet this week (a summary of this analysis is published as a Research letter in the print journal and the full analysis is available on The Lancet’s website, www.thelancet.com). Their conclusions are unchanged, "The two best trials failed to find an effect of screening on deaths ascribed to breast cancer after 13 years… We have also confirmed …that screening leads to more aggressive treatment"…
The editor of The Lancet, Richard Horton, in a commentary, argues that "… women should expect doctors to secure the best evidence about the value of screening mammography. At present there is no evidence from large randomised trials to support screening mammography programmes."
Contacts : Ole Olsen, Nordic Cochrane Centre, Rigshospitalet Dept 7112, Blegsdamasveg 9, DK-2100 Copenhagen, Denmark. E) o.olsen@cochrane.dk
Dr Richard Horton : E) richard.horton@lancet.com
Journal
The Lancet