Breast cancer death rates have dropped over the last few years in Europe, however, researchers from France, Norway and the UK say this is due to better treatment and health systems rather than breast cancer screening. In an article in the BMJ (British Medical Journal), the authors wrote that “..breast cancer screening has not played a direct part in the reductions of breast cancer mortality in recent years.”

In most developed nations breast cancer mortality has been dropping over the last few years. The authors add that it is very hard to determine what proportion of that reduction over two decades of mammography screening is due to early detection or better management.

As far as cervical cancer is concerned, the evidence is clearer that screening programs have brought about lower death rates. From 1965 to 1980 Nordic countries implemented screening programs before their European neighbors, and experienced earlier falls in cervical cancer death rates.

In this study the researchers decided to use a similar approach. They compared breast cancer mortality trends within three pairs of countries:

  • Northern Ireland vs. The Republic of Ireland
  • The Netherlands vs. Belgium (and Flanders)
  • Sweden vs. Norway

All the investigators had expected to see death rates dropping earlier in the countries that implemented breast cancer screening programs first. The pairs of countries had similar peoples, similar breast cancer risk factors, and pretty much the same levels of healthcare services. The only real difference was that in each pair, one country started mammography screening much later than the other.

The authors gathered data from the WHO (World Health Organization) mortality database on causes of death from 1980 to 2006. They also collected information on risk factors, death, mammography screening and cancer treatment.

Between 1989 and 2006, death rates from breast cancer fell by the following rates in the three pairs of countries:

  • 29% in Northern Ireland, compared to 26% in the Republic of Ireland
  • 25% in the Netherlands, compared to 20% in Belgium (25% in Flanders)
  • 16% in Sweden compared to 23% in Norway

The death rates in the pairs of countries were not that different, even though mammography screenings were implemented many years apart, the authors explained. The researchers also pointed out that the greatest reductions were among females aged 40 to 49, whether or not they had screening available appeared to make no difference.

The authors concluded:

“The contrast between the time differences in implementation of mammography screening and the similarity in reductions in mortality between the country pairs suggest that screening did not play a direct part in the reductions in breast cancer mortality.

Improvements in treatment and in the efficiency of healthcare systems efficiency may be more plausible explanations. “

Written by Christian Nordqvist