A Swedish study published this month maintains that mammograms for women in their 40s saves lives. It contradicts numerous studies done over the past 20 years, as well as recommendations from The American College of Physicians in 2007 and from the expert U.S. Preventive Services Task Force in 2009 which concluded that the benefits of mammography screening before age 50 do not outweigh the risks, something that has been widely acknowledged in public health circles since mammography became big business in the late 1980s.
First, the Swedish study. You’d never know it to listen to the TV docs and their cheering section, but the Swedish study has been widely criticized by scientists for its lack of internal consistency. The research group that received mammograms was not similar to the comparison group, there were no age categories so no comments can be made that would refute other, better done studies, and did not weigh risks against benefits. No conclusions of any kind can be drawn from such a hodgepodge.
Next: that cheering section. It’s understandable that 24 hour news channels require something to fill air space and that they will glom on to anything that might hold a viewer’s attention. It is not so understandable that they would ignore a study published a week or two earlier from Norway and Harvard that not only confirmed the findings of the Task Force but questioned whether mammograms actually benefit woman of any age. In other words, a direct contradiction to the Swedish study that also, remarkably, questioned the screening value of mammograms for anyone and received no media attention at all.
By far the worst of the cheerleaders for the Swedish study was Dr Richard Besser, formerly director of the Centers for Disease Control and Prevention and now an expert talking head on all things medical for ABC. On air, his opinion was that mammograms should continue for women in their 40s because of this apparently “well done study” which he had clearly neither read nor had vetted for him. He said that there was no reason to question the findings of the Swedish article and that women should ask “Why not? Why shouldn’t I have a mammogram?”
OK, Dr. Besser. Let’s talk about why not.
1. Overdiagnosis. Because screening tests are often based on imprecise measurements and are subject to human error, like the mammogram and the PSa test for prostrate cancer, a great many people are misdiagnosed as having a life threatening condition when they don’t. Once a diagnosis of breast cancer is made, the next steps are preordained. What follows is enormous anxiety on the part of the patient, discussions with radiologists, oncologists, surgeons and other doctors about how to treat, the order of treatment and the side effects at each step. There is enormous expense involved at each level of discussion.
And consider this: approximately 1300 women over age 50 must be screened for years to avert one death. In the 40s that figure is 1900 screened. That’s thousands of mammograms, hundreds of biopsies, and many cancers treated as if they were life-threatening when they are not.
What no one is likely to tell the patient is that some cancers are slow growing, or will not expand, or might clear up by themselves as the woman’s immune system comes to the rescue. These cancers need to be just watched; no immediate action necessary. It has been estimated that 25%-30% of breast cancer found on mammograms is the result of overdiagnosis. Further, an estimated 6% of the time the finding of breast cancer from a mammogram is a false positive. Translated, that means that more than one patient in 20 is told she has breast cancer when she does not.
There is a huge emotional and financial cost associated with overdiagnosis and mis-diagnosis, part of the reasoning of the 2009 U.S. Preventive Services Task Force. The down side hazards of mammograms make them unsuitable for women in their 40s who are at low risk for breast cancer, anyway.
2. Radiation: Every dose of radiation from chest xrays, dental xrays, mammograms and other sources is cumulative. When it comes to radiation, nothing is for free. Radiation damages DNA and has been a known to cause serious disease since the scientist who discovered it, Madame Curie, died of aplastic anemia. Changes to the DNA resulting from xrays may later cause cancer. That is a major reason for the deep concern and criticism among many scientists regarding mammograms. It’s a reason to avoid unnecessary xray exposure (and to reject dental xrays for routine visits.) One study showed a much higher incidence of invasive breast cancer in women who had been subject to routine mammograms than those who had not. The suspicion among some scientists is that the mammograms themselves are responsible.
What the experts have said:
Dr. Otis Brawley, chief medical officer of the American Cancer Society.
We don’t want people to panic, but I’m admitting that American medicine has over-promised when it comes to screening. The advantages to screening have been exaggerated.
Dr Brawley, under pressure from his employer, immediately withdrew his comment but could not remove it from the record.
From Drs. Epstein (UCLA) and Bertell, (International Physicians for Humanitarian Medicine):
Mammography facts are in stark contrast with what is most publicized about the screening, namely that “mammography saves lives.”
Routine mammography delivers an unrecognized high dose of radiation. If a woman follows the current guidelines for premenopausal screening, over a 10 year period she would receive a total dosage of about 5 rads. This approximates the level of exposure to radiation of a Japanese woman one mile from the epicenter of atom bombs dropped on Hiroshima or Nagasaki.
Why the one-sided emphasis on a screening tool of such questionable value? For the same reason that your rheumatologist doesn’t know that diet can be used to control RA: Big business.
Outpatient mammogram suites, both free standing and in hospitals, generate billions of dollars each year for their owners. Some of these clinics scan hundreds of thousands of women a year. Advocacy groups like the American Cancer Society (ACS) receive major funding from the makers of xray and mammography equipment and are intensely resistant to changing the screening recommendations for mammograms.
Drs. Epstein and Bertell, again:
The mammography industry conducts research for the ACS and its grantees, serves on its advisory boards, and donates considerable funds.
DuPont also is a substantial backer of the ACS Breast Health Awareness Program; sponsors television shows and other media productions touting ACS literature for hospitals, clinics, medical organization, and doctors; produces educational films; and aggressively lobbies Congress for legislation promoting the nationwide availability of mammography services.”
The incidence of breast cancer diagnosis and death has been dropping like a rock since 1999. Between 2000 and 2006, the last year for which I could find data, the death rate dropped by almost 13%. Between 1990 and 2006, the rate dropped by almost 30%.
There were several things happening during those years which may have contributed. Although advocacy groups would like to credit mammography for these trends, the fact is that the number of women having mammograms declined in tandem with the change in the diagnosis and death rate. So it is not possible that screening is the cause of the decline. In fact, the opposite may be true, as some scientists believe. Maybe the decline in screening means less breast cancer.
In 2002 a major study was published connecting the use of Hormone Replacement Therapy (HRT) to breast cancer after which the use of HRT by menopausal women dropped precipitously. At the moment, no one knows exactly what the statistical effect of this change had on breast cancer deaths, but it has no doubt contributed to the decline.
There is another important hazard and that is the polycarbonate plastics found in water bottles, canned food, and everywhere else. Some of these plastics are carcinogens and others are active endocrine disrupters, causing such things as early puberty in our 7 year old daughters, as well as breast cancer.
The way to defeat breast cancer, it seems to me, is to eliminate as many cancer causing agents as possible from our lives, and that includes environmental chemicals like the plastics we live with and inadvertently ingest, as well as xrays from all sources
In this post, I’ve linked to just a few of the many sources available on the internet that discuss mammography, breast cancer, and reasons for the decline in death rates. I hope the take-away message is that we should be careful of tampering with the fragile miracle that is our healthy body.
This web site is not a substitute for medical advice.