Last year, the Swiss Medical Board was mandated by Swiss health authorities to prepare a review of mammography screening, and based on its findings has recommended that no new systematic screening programs be introduced. What's more, it said, a time limit must be placed on existing programs.
In an article published in the New England Journal of Medicine, Nikola Biller-Andorno, M.D., Ph.D., and Peter Jüni, M.D., explained that after the board reviewed the available evidence and considered its implications, "we became increasingly concerned."
Three things were of particular concern, wrote Biller-Andorno and Jüni. First, they noted that that the ongoing debate on the efficacy of mammography screening was based on the same data from a series of reanalyses of the same "outdated" trials, the first of which began more than 50 years ago. "Could the modest benefit of mammography screening in terms of breast-cancer mortality that was shown in trials initiated between 1963 and 1991 still be detected in a trial conducted today?" the authors asked.
They were also "struck by how nonobvious it was that the benefits of mammography screening outweighed the harms," writing that the relative risk deduction in cancer mortality has come at the cost of repeat mammography, subsequent recalls, and overdiagnosis. Finally, they were "disconcerted" by the difference in the perception of women as to the benefits of mammography screening and what they should expect in reality.
The board's report acknowledged that systematic mammographic screening might prevent one death attributed to breast cancer for every 1,000 women, "even though there was no evidence to suggest overall mortality was affected." This would come at the cost of false positive test results and overdiagnosis.
Consequently the board made its recommendation to phase out existing screening programs and not to start any new programs.
"From an ethical perspective, a public health program that does not clearly produce more benefits than harms is hard to justify," Biller-Andorno and Jüni wrote. "Providing clear, unbiased information, promoting appropriate care, and preventing overdiagnosis and overtreatment would be a better choice."
The American College of Radiology and the Society of Breast Imaging issued a joint statement condemning the article, as well as NEJM's decision to publish it.
"The authors minimized the deadly consequences of their recommendations to the Swiss government," the statement said. "The disastrous results may take years to develop. If breast cancer screening were ended in this country, it would cost the lives of up to 20,000 American women each year. The lack of a counterbalancing perspective, in a major scientific journal, is surprising and concerning. American women should pay close attention to the breast cancer screening policies that may be considered for them."
Two opinion papers published recently in the Annals of Internal Medicine argued that it's time to start thinking differently about the issues associated with breast cancer and mammography screening, particularly with each side of the breast screening debate bringing up the same arguments based on data from old trials.