The (surprising) Truth About Mammograms
There are many sacred cows in Medicine.
SACRED COW (n) – One that is immune from criticism, often unreasonably so.
In this case, a sacred cow refers to an idea, belief or procedure that is accepted as fact, even in the presence of an abundance of contradictory evidence.
One of the most often striking examples of this is the idea of yearly mammograms. It is currently recommended that all women over age 40 or age 50 (depending on the source) get a yearly mammogram despite the fact that there are significant questions about its effectiveness (How well do they find cancers?), cost effectiveness (Is it the best use of our health care dollars?) and their side effects (Do the benefits outweigh the negative effects?).
In this article, I will share researched medical opinions answering these three questions. In the process, I hope to share with you helpful resources you can discuss with your doctor to make the best decision for you.
What are Mammograms?
Mammograms are a diagnostic test to evaluate the breast for cancerous growth. They use ionizing radiation to create a 2D or 3D picture of the breast tissue. This then allows for the earlier detection of certain cancers of the breast. Sounds good right?
Now lets see how the evidence supports or refutes this claim.
Are Mammograms Effective?
According to the Lancet, one of the most prestigious medical journals in the world:
“For women under 50, there is a reluctant consensus that screening is not beneficial”
In this study, the researchers concluded that, for women under 50, the yearly mammogram was not effective as a screening tool for breast cancer.
Ok, well how about for the female populate in general, how well do mammograms detect cancer?
The Lancet article continues:
“About 5% of screening mammograms are positive or suspicious, and of these 80-93% are false positives that cause much unnecessary anxiety and further procedures including surgery.”
This hits on a key point in research, the idea of specificity.
An everyday example of this would be cold weather and snow. We could say that cold weather is a indicator of snow but, even with the crazy weather we have had recently, cold weather would not be a very good predictor of snow. If we wanted to know if there was snow on the ground, only by looking at the thermometer, we would be wrong more than we are right.
The research here is saying much the same with mammograms, they predict or are suspicious of breast cancer 5% of the time, but are wrong 80-93% of the time.
In fact, a second study referenced in the info graphic below confirms this same finding.
Returning again to the Lancet study:
False reassurance by negative mammography occurs in 10-15%
of women with breast cancer that will manifest clinically within
This is example of being wrong the other way. Sadly, in 10-15% of patients who will be diagnosed breast cancer within 12 months their latest mammogram was negative for cancer, giving them a clean bill our health
Is Mammography Cost-effective?
Continuing from the Lancet article:
“Our calculations confirm others that the mean annual cost per life
“saved” is around $1·2 million (£558 000).”
Said simply, to save one person from dying from breast cancer, we have to spend 1.2 million dollars to screen a bunch of people who will never get it (while risking the false positives and false negatives referenced above along with potential side effects).
This is not to say that it is not worth it to do anything we can to save someone’s life or prevent a death from cancer, because this is clearly a noble goal, but there are many more cost effective ways to save lives for a lot less than 1.2 million. For example, if everyone consumed a few servings of organic broccoli and a good iodine source each week (such as seaweed), we could save lives and prevent breast cancer death MUCH more cost effectively.
Do the benefits outweigh the negative effects?
The Lancet article concludes:
“Since the benefit (of mammograms) is marginal, the harm
caused is substantial, and the costs incurred are enormous, we
suggest that public funding for breast cancer screening in any
age group is not justifiable.”
Bottom line, this article concludes it is not justifiable to recommend mammograms as a breast cancer screening method to groups of any age.
Confirming this finding, last month the New York Times reported on a recent study from the British Medical Journal. As reported by the New York Times:
“One of the largest and most meticulous studies of mammography ever done, involving 90,000 women and lasting a quarter-century, has added powerful new doubts about the value of the screening test for women of any age.
It found that the death rates from breast cancer and from all causes were the same in women who got mammograms and those who did not. And the screening had harms: one in five cancers found with mammography and treated was not a threat to the woman’s health and did not need treatment such as chemotherapy, surgery or radiation.”
Further the ionizing radiation used in plain film and
digital mammograms are known to increases the risk of breast cancer by actually causing the disease in women who otherwise would not be affected.
While there are benefits to having a mammogram, there are also shortcomings to the procedure as well. This is a decision I encourage you to further research and discuss with your doctor to make the best decision for you.
Also, on Thursday, I will share with you a safer natural alternative to mammography and 10 key lifestyle changes you can make to maximize your health and minimize your breast cancer risk.
I encourage you to share this article with all the women in your life who would benefit from this vital information.