Screening for breast cancer is one of a number of carefully developed health screening initiatives that have been put in place in health systems across the world. Despite its widespread popularity, a stream of research continues to emerge questioning the absolute benefits of breast screening programmes.
The latest study has just been published in the Journal of the Royal Society of Medicine. Researchers from the University of Oxford's department of public health analysed mortality trends before and after the 1988 NHS introduction of breast cancer screening. Focusing primarily on mortality statistics from Oxford, they concluded there is "no evidence" that screening women has an effect on mortality at a population level. But lead researcher Toqir Mukhtar said the results did not rule out a benefit for individual screened women .
The Oxford study contradicts a major review of breast cancer screening research published last year and was undertaken by a panel chaired by the distinguished public health physician Prof Sir Michael Marmot. On reviewing the evidence, it concluded that there was a 20 per cent relative reduction in mortality from breast cancer in women invited to screening.
However, the panel also found that for each breast cancer death prevented about three over-diagnosed cases will be identified and treated. Other trials have indicated that several years have to elapse between the start of screening and the emergence of a reduction in mortality, and that the benefit of screening persists many years after screening stops.
While there has been concern for some time that some women will suffer from unnecessary intervention as a result of false positive mammograms, the overall benefit in reducing breast cancer mortality from screening programmes is generally seen as trumping this caveat. The most recent research has enough methodological limitations to suggest it should not overly influence the informed decision facing a woman when she is invited to participate in the Republic’s BreastCheck programme.