A new study published in the journal BMJ has added more evidence that breast cancer screening helps reduce cancer-related mortality rates.
In the study, Norwegian researchers found that screening reduced deaths from breast cancer by about 28 percent--or roughly 27 deaths avoided per 10,000 women who were invited to participate in biennial screening programs over a lifetime.
The researchers evaluated the effectiveness of mammography by comparing mortality rates in women between 1986 and 2009--specifically by looking at data on women between the ages of 50 to 69 who were invited to participate in screening, and those who were not (because the national screening program was just being phased in).
In addition to evaluating the effect of mammography on breast cancer mortality rates, the researchers also determined that 280 women would have to be screened in order to prevent one death.
"Mammography screening saves lives--most likely due to earlier diagnosis of breast cancer--and therefore better effect of treatment," study coauthor Lars Vatten, a professor of epidemiology at the Norwegian University of Science and Technology in Trondheim, told WebMD News.
However, a commentary accompanying the study by Joann Elmore, M.D., from the University of Washington in Seattle, and Russell Harris, M.D., from the University of North Carolina, Chapel Hill, stated that the study "largely confirms what is already known: the benefits of screening mammography are modest at best."
Meanwhile, Elmore and Harris said, the harms of screening are plentiful, and include overdiagnosis, psychological stress and "exorbitant" costs.
Research recently published in Cancer from the University of Michigan Comprehensive Cancer Center determined that since the introduction of mammography, the incidence of late-stage breast cancer has decreased by 37 percent.