Study: Breast cancer deaths drop in Europe, partly due to mammo screenings
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Philippe Autier, MD, of the International Agency for Research on Cancer in Lyon, France, and colleagues retrospectively examined changes in breast cancer mortality trends in women living in 30 European countries from 1989 to 2006.
While the authors noted that mammography screening continues to vary throughout Europe, “since the 1990s, profound changes have taken place in the clinical presentation and management of breast cancer due to mammography screening, implementation of effective hormone treatments and chemotherapy and progress in radiotherapy and surgery. These innovations have probably contributed to the observed improvements in breast cancer survival in Europe,” they wrote.
The researchers leveraged the World Health Organization mortality database on causes of deaths to review female deaths from breast cancer from 1989 to 2006. Changes in breast cancer mortality for all women and changes adjusted by the age groups of women less than 50 years old, women aged 50-69 and women greater than 70 years old were used as the main outcome measures. Joinpoint analysis was used to identify the year when trends in all age mortality began to change, explained the authors.
From 1989 to 2006, there was an average reduction in breast cancer mortality of 19 percent, with the largest reduction seen in Iceland, at 45 percent, found Autier and colleagues. The researchers noted that breast cancer mortality decreased by greater than 20 percent in 15 countries and the reduction tended to be greater in countries with higher mortality in 1987 to 1989. England and Wales experienced a decrease of 35 percent, Northern Ireland decreased 29 percent and Scotland decreased 30 percent, marking the second, third and fourth largest decreases in Europe. Moreover, France, Finland and Sweden saw decreases in mortality rates of 11 percent, 12 percent and 16 percent, respectively.
However, the authors also found that the mortality for central European countries did not decline and increased for some countries during the period, with Romania increasing 17 percent.
In countries with the highest mortality reduction, the decline was found to slow during the last eight years of observation and in most other countries, the persistent reduction from 1999 to 2006 indicates that these trends may continue, the authors speculated.
For the age groups, the average changes were -37 percent in women less than 50 years old, -21 percent in 50 to 69 year olds and -2 percent in women greater than 70 years old.
“Women aged less than 50 years showed the greatest reductions in mortality,” said Autier and colleagues. “The increasing mortality in some central European countries reflects avoidable mortality.”
However, in an accompanying editorial, Valerie Beral, professor of epidemiology and Richard Peto, professor of medical statistics and epidemiology at the University of Oxford in England, noted that cancer registration throughout the United Kingdom is known to be incomplete and that defects in these data make cancer survival rates appear significantly worse. By contrast, the registration of death is complete and deaths from breast cancer are well recorded. As a result, population-based mortality trends in middle age are fairly reliable, they wrote.
“Clearly, improving the collection of relevant screening and management data is warranted for understanding the strong variations in breast cancer mortality in Europe,” the Autier and colleagues concluded. “Efforts should be made to reduce the avoidable breast cancer mortality in central European countries.”