Credit: © Monkey Business Images | Dreamstime.com

It has been assumed that screening has played an important role in the reduction of breast cancer mortality that has been observed in the past two decades. However, a study published in July 2011 in the British Medical Journal indicates that screening does not have a direct impact on breast cancer mortality rates.

In 2010, Philippe Autier and coauthors published a comprehensive analysis of breast cancer mortality trends in European countries. Although they found that there was considerable variability in the mortality trends for different countries, the changes in mortality were similar for countries even when the timing that breast screening was introduced was very different. This finding prompted Autier and colleagues to assess “three pairs of European countries that were highly comparable for cultural background, access to cancer treatment and socioeconomic environment,” explains Autier. The researchers then systematically searched the screening activities of these countries and assessed risk factors that might have influenced the breast cancer mortality rates. The neighboring countries analyzed were Sweden and Norway, The Netherlands and Belgium, and Northern Ireland and the Republic of Ireland. “The most striking finding was the similarity in changes in breast cancer mortality over time between countries forming each pair. Our findings are in sharp contrast with a number of reports that attributed screening to most of the decreases in breast cancer mortality observed in the Netherlands and in Sweden,” says Autier. He further comments, “if screening worked, then with time, one should observe decreases in the incidence of advanced breast cancer in countries where screening has been widespread in the past 7 years or so; however, earlier studies using cancer registry data showed no change over time in the incidence in advanced breast cancer”.