(HealthDay News) – County-specific mortality statistics from Sweden indicate little benefit of mammography screening on breast cancer mortality.
To examine whether the gradual implementation of breast cancer screening in Sweden was reflected in county-specific mortality patterns, Philippe Autier, MD, MPH, from the International Prevention Research Institute in Lyon, France, and colleagues analyzed breast cancer mortality trends in women aged >40 years. During the 18 years of follow-up after the introduction of nationwide screening, observed mortality trends were compared with expected trends.
The researchers found that, from 1972–2009, there was an annual decrease of 0.98% in breast cancer mortality, from 68.4 to 42.8 per 100,000. The decline was continuous in 14 of 21 Swedish counties. Breast cancer mortality decreased sharply during or soon after screening implementation in three counties; there was a sharp decrease at least five years after implementation in two counties; and there was an increase after screening started in two counties. For counties that implemented screening in 1974–1978, during the following 18 years, trends were similar to those before screening started, while counties that started screening in 1986–1987 experienced about a 12% increase in mortality after screening began, compared with previous trends. After the introduction of screening, mortality decreased by approximately 5 and 8% for counties that implemented screening in 1987–1988 and 1989–1990, respectively.
“The Swedish breast cancer mortality statistics are consistent with studies that show limited or no impact of screening on mortality from breast cancer,” the authors write.
One author is a consultant for Advanced Medical Diagnostics.