First, they found that the scientific validity of the 2005 study doesn’t hold up because the research was deeply flawed. Even more important: the new report shows there’s no evidence mammography itself was the reason behind any reduction in breast cancer deaths. In fact, deaths from breast cancer were lower in areas where women didn’t undergo those screening tests.
The Danish research team looked at annual changes in breast cancer deaths in two Danish regions where breast cancer screening programs were offered to the public and compared this to data collected in non-screened regions throughout the rest of the country. To get a broad picture of the trend toward more or less breast cancer mortality, they analyzed breast malignancy rates in the decade before the screening was started and also looked at the ten years after screening was introduced.
The results showed that breast cancer deaths declined by 1% in women between the ages of 55 and 74 in the areas where regular mammography was frequently used. However, breast cancer rates went down more — 2% per year — in women of the same age living in non-screened areas. And this trend was the same in younger women, too. For those between the ages of 35 and 54, breast cancer mortality went down by 5% per year in the screened areas but it went down more, 6% per year, in the non-screened areas during the same time frame.