BREAST SCREENING SAVES TWICE AS MANY LIVES
2010.04.07

Two deaths will be prevented for every woman overdiagnosed by breast screening, according to a study published today* (Wednesday 31 March 2010).

Following numerous, highly controversial debates in recent months over the risks and harms of screening for breast cancer, the researchers - including a member of The London Breast Institute research board - set out to uncover how effective the programme is at saving lives.
Some reports had estimated that for every life saved, six women were overdiagnosed. Overdiagnosis describes cancers picked up and treated as a result of screening which would not have been diagnosed in a woman's lifetime had screening not taken place.

Stephen Duffy, based at Queen Mary, University of London, said: “This shows that the benefits of screening outweigh the harms.“
Unfortunately, we haven't yet got a flawless screening test, and some cases that are picked up wouldn't have needed treatment. But for every case like this, screening saves two women who would have otherwise died from breast cancer.

“If a tumour is detected through screening it is important to consider a range of options before treatment begins. Women should be given the opportunity to understand the implication of their screening results and discuss their treatment options with a specialist.”

The researchers carried out two studies. One study predicted the number of women who would have died from breast cancer in the UK if the screening programme had not been introduced.
The other study looked at the number of deaths from breast cancer in over 133,000 women in Sweden, comparing those who were screened with those who were not.

Nick Perry, Director of The London Breast Institute at The Princess Grace Hospital says: “The London Breast Institute is extremely proud that the author of this paper, Professor Stephen Duffy, is a member of our research board and a contributor to our numerous research presentations. Diagnosis of breast cancer through screening results in treatment of some breast cancers that would not have proceeded to kill the patient if undiagnosed, however, early diagnosis of even these cancers allows the possibility of less surgery with a better cosmetic result. It is now extremely reassuring to know that for every 'over-diagnosed' breast cancer through screening, at least two other women will have their lives saved”.


* Absolute Numbers of Lives Saved and Overdiagnosis in Breast Cancer Screening, from a Randomised Trial and from the Breast Screening Programme in England. Duffy et al. Journal of Medical Screening.