Last year the Swiss Medical Board conducted a review of mammography screening and their findings exposed something rather unexpected. They assessed that these screenings cause more harm than good. In fact, via their studies, they found that the screenings really only saved 1 in 1000 women who died. On the contrary, the failure of the process, or unsafe side effects, were the actual greater concern.
From the study:
3 Primary Reasons the Swiss Medical Board Recommended No More Systematic Mammograms
In a perspective piece published in the New England Journal of Medicine,2 two members of the Swiss Medical Board’s expert panel explained how they reached their conclusions. Three primary factors came into play:
1. Outdated Clinical Trials
The ongoing debate over mammography screening is based on a “series of re-analyses of the same, predominantly outdated trials.” The first mammography trial began more than 50 years ago and the last trial was in 1991.
The mammography benefits that were supposedly found during these trials were prior to the era of modern breast cancer treatment, in which the prognosis of women with breast cancer has improved significantly from even two decades ago. The expert panel questioned:
“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?”
2. The Benefits Did Not Clearly Outweigh the Harms
The experts noted they were “struck by how nonobvious it was that the benefits of mammography screening outweighed the harms.”
They cited a recent study published in British Medical Journal (BMJ)3 — one of the largest and longest studies of mammography to date — involving 90,000 women followed for 25 years. It found that mammograms have absolutely NO impact on breast cancer mortality.
Over the course of the study, the death rate from breast cancer was virtually identical between those who received an annual mammogram and those who did not, while 22 percent of screen-detected invasive breast cancers were over-diagnosed, leading to unnecessary treatment. The experts noted:
“This means that 106 of the 44,925 healthy women in the screening group were diagnosed with and treated for breast cancer unnecessarily, which resulted in needless surgical interventions, radiotherapy, chemotherapy, or some combination of these therapies.”
A Cochrane Collaboration review also found no evidence that mammography screening has an effect on overall mortality,4 which, taken together, seriously calls into question whether mammography screening really benefits women. According to the authors of the Cochrane review:
“If we assume that screening reduces breast cancer mortality by 15% and that overdiagnosis and overtreatment is at 30%, it means that for every 2000 women invited for screening throughout 10 years, one will avoid dying of breast cancer and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily.