New research questions 40 years of routine mammography

Research shows routine mammography doesn’t prevent deaths from breast cancer, as I have been reporting for years.

The latest study appeared in the “gold standard” of medical journalism, the New England Journal of Medicine, on October 12. Researchers hailed from the Dartmouth Institute for Health Policy and Clinical Practice and the National Cancer Institute’s Division of Cancer Prevention (my old group). And their findings should finally set to rest the many myths and misrepresentations about mammography.

Massive study finds conclusive evidence of over-diagnosis

The new study covered a long period of time from 1975 to 2012. It used cancer statistics for women 40 years and older in the U.S. from the Surveillance, Epidemiology and End Results (SEER) cancer registry.

According to the investigation, mammography resulted in the discovery of 162 more cases of small breast tumors for every 100,000 women subjected to the screening. However, only 30 of these small tumors — just 18.5 percent — were of the kind that would potentially enlarge and become a danger.

In fact, we now know many small breast tumors — once considered “cancerous” or “pre-cancerous” — do not grow, invade, metastasize, or kill the patient. Therefore, as I have been reporting for years, we need more accurate and precise standards for using the word “cancer” in a diagnosis.

So — over this time frame, mammography did not detect greater numbers of large tumors, which are more likely to be dangerous. Instead, it detected greater numbers of smaller tumors, which are less likely to be dangerous.

This finding means radiologists over-diagnosed an astounding 81.5 percent of these small breast tumors as “cancer” when they weren’t really cancer. This over-diagnosis led to needless worry and the dangers and expense of overtreatment.

Has the bottom line improved?

Statistics and statistical analysis can be complicated. So, I always say look at the bottom line of cancer mortality. Statisticians can’t manipulate mortality. And you can’t cheat the grim reaper.

Years ago, studies from Canada and Switzerland found mammography does NOT reduce mortality from breast cancer. Based on these findings, Switzerland has stopped subjecting women to “routine” mammography screening altogether. And both Switzerland and Canada have a higher healthcare quality ranking than the U.S.

In the new study, mortality rates in the U.S. clearly fell between 1975 and 2012.

And, of course, oncologists claim we have increased mammogram screening to thank for this improvement.

But that’s just not the case.

According to the researchers, increased mammography did not cause the improvements in death rates. Rather, death rate improvements occurred because of some improvements in treatments. (Treatments include Taxol, which derives from the Pacific yew tree, as known to Native Americans of the Pacific Northwest.)

So, here’s the good news…

Over the past nearly 40 years, there have been some improvements in breast cancer treatments and mortality. That is, more women are surviving longer.

But the improvements have NOT been due to routine mammography screening.

Plus, women are much more likely to be over-diagnosed since the introduction of routine mammography 40 years ago. For all the women who have been convinced that routine mammography saved their lives, this study shows that their lives were never at risk.

But the government-industrial-medical complex doesn’t go down without a fight. Especially when it comes to the huge cash cow behind their lucrative careers and massive profits.

So, even though we’ve had conclusive evidence about the limitations of mammography for years, the academic medical centers keep receiving funding to do MORE research on it with your tax dollars.

And, according to the American Medical Association’s news service, many experts still urge women to get mammograms as currently recommended.

A lot of women have talked about moving to Canada or Switzerland depending on the outcome of the election. Indeed, they will be better off in at least one way: doctors won’t hound you to get routine mammograms there.


“Breast-Cancer Tumor Size, Overdiagnosis, and Mammography Screening Effectiveness,” N Engl J Med 2016; 375: 1,438-1,447