Swiss panel calls for an end to mammography screening programs

A Swiss medical ethicist and a clinical epidemiologist reveal in the New England Journal of Medicine that the Swiss Medical Board has called for a moratorium on any new screening mammography programs in Switzerland and a time limit on those that currently exist.

The panel also called for quality evaluation of all forms of mammography screening, as well as an effort to re-educate women about the modality’s harms and benefit, the latter of which is grossly over-estimated by women, they conclude.

The recommendation was made on February 2 by the panel, which also included a clinical pharmacologist, an oncologic surgeon, a nurse scientist, a lawyer, and a health economist. Unlike the United States Preventive Services Task Force, the recommendations of the Swiss Medical Board are not legally binding. The Swiss Medical Board is an independent health technology assessment initiative that operates under the auspices of the Conference of Health Ministers of the Swiss Cantons, the Swiss Medical Association, and the Swiss Academy of Medical Sciences.

The authors acknowledge that their recommendation caused “uproar” in Switzerland and was rejected by Swiss cancer experts and organizations, some of which called the findings unethical. The American College of Radiology concurred, criticized the NEJM for publishing the paper, and stating that an additional 15,000 to 20,000 women would die of breast cancer each year if screening mammography were ended in the U.S.

“The deadly consequences of the authors’ breast cancer screening recommendations to the Swiss government may take years to become evident, may yet affect women in the United States, and were minimized—if included in the article at all,” read the statement from the ACR. “The lack of a counterbalancing perspective, in such 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.”

The authors describe three main findings on which the board’s decisions were made. Recognizing that the ongoing debate in mammography is based on multiple “reanalyses of the same, predominantly outdated trials,” the authors wondered if the same modest benefits of mammography would be found if a trial were repeated using modern technology.

Secondly, they acknowledged being “struck by how nonobvious it was that the benefits outweighed the harms.” The authors used the modest risk-reduction figure of approximately 20% in breast-cancer mortality, and a 21.9% overdiagnosis number, both from the recently published Canadian National Breast Screening Study, initiated in the 1980s and criticized for a lack of rigor, poor design, and obsolete data.

The third finding was the aforementioned gap between women’s perception of the benefits of mammography and what benefits and protection mammography can be expected to provide in reality. The authors cite a study of U.S. women in which 71.5% believed that mammography reduced the risk of breast cancer by half.

In minimizing the benefits and emphasizing the harms of overdiagnosis, the panel recommended that “no new systemic mammography programs be introduced and that a time limit be placed on existing programs.” It additionally recommends that the quality of all forms of mammography be evaluated and that women are provided clear and balanced information about mammography’s benefits.

In an odd and unsettling observation near the end of their short paper, the authors make a distinction between Italian- and French-speaking cantons, or member states of Switzerland, where mammography is favored, and German-speaking cantons, where mammography is less in favor, suggesting that “cultural factors” should be taken into consideration.

The authors conclude by saying that it is easy to promote mammography if women believe it prevents or reduces the risk of getting breast cancer, which the authors flatly deny. “From an ethical perspective, a public health program that does not clearly produce more benefits than harms is hard to justify,” they write. “Providing clear, unbiased information, promoting appropriate care, and preventing overdiagnosis and overtreatment would be a better choice.”

The article was published online first on April 16.