Breast cancer screening – is it worth it?

All women aged between 50 and 70 are offered screening for breast cancer. But how effective is it at stopping deaths - and might it actually do more harm than good?

Many of us will know someone who had breast cancer found at screening. The cancer seen on a mammogram may have been microscopic, so early in its malignant life that it hadn't broken through the wall of its milk duct. Thank heavens, then, for breast screening, which is offered to all women between 50 and 70 in the UK and other countries. It is promoted enthusiastically as lifesaving, but does it deliver on its promise? And are the randomised controlled trials that persuaded governments to offer it, carried out in the 1970s and 80s, still valid?