In a perspective piece published in the New England Journal of Medicine,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 Outdated Clinical Trials
The ongoing debate over mammography screening is based on a “series of re-analyses of the same, predominantly outdated trials.”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.
Furthermore, more than 200 women will experience important psychological distress including anxiety and uncertainty for years because of false positive findings.”
3. Women’s Perceptions of Mammography Benefits Do Not Match Reality
The experts also said they were “disconcerted” by the profound discrepancy between women’s perceptions of mammography benefits and the actual benefits.
In one survey, most women said they believed mammography reduced the risk of breast cancer deaths by at least half and prevented at least 80 deaths per 1,000 women screened. In reality, mammography may, at best, offer a relative risk reduction of 20 percent and prevent in absolute terms only one breast-cancer death per 10,000 women. The experts asked a long overdue question:
“How can women make an informed decision if they overestimate the benefit of mammography so grossly?”
The sad reality of course, is that they can’t. Many women are still unaware that the science backing the health benefits of mammograms is sorely lacking. Instead of being told the truth, women are guilt-tripped into thinking that skipping their yearly mammogram is the height of irresponsibility. It can be hard to stand your ground against such tactics. After all, you expect health professionals to know what they’re talking about, and to give you the best advice possible.
When it comes to cancer prevention, however, many doctors are just as confused and manipulated as the average person on the street because of the relentless industry and media propaganda that downplays or ignores research that dramatically contradicts their profit-based agenda.
Indeed, mounting research shows that more women are being harmed by regular mammograms than are saved by them. In light of such facts, avoiding an annual mammogram is hardly an irresponsible act.
Ditto for saying “no thanks” to 3D tomosynthesis, which exposes you to an even greater amount of cancer-causing radiation for virtually no additional benefit. Please understand that there are other screening options, each with their own strengths and weaknesses, and you have a right to utilize those options. Also remember that in order to truly avoid breast cancer, you need to focus your attention on actual prevention and not just early detection.