You Should Have a Mammogram. You Don't Need a Mammogram. Which Is It?
The New England Journal of Medicine recently published a study by a couple of noted medical school professors questioning the benefits of mammograms. Are too many women being "over-diagnosed" and "over-treated" for breast cancer? The answer may depend on whether you're a professor - or a woman.
Dr. Gilbert Welch, a professor of medicine at the Dartmouth Institute of Health Policy and Clinical Practice in Hanover, N.H. has been railing for years against the increasing ubiquity in American society of mammography as a widely accepted tool for the prevention of breast cancer deaths.
Dr. Welch isn't particularly concerned about the mammogram's effectiveness, which is increasingly being called into question as ever more sophisticated screening devices make their way into mainstream use. Most medical professionals agree that while mammography isn't perfect, it's the best balance of cost effectiveness and accuracy we've got at the moment.
No, Dr. Welch is questioning yet again, as he's done in previous studies and papers, the accepted practice of women at no known risk for breast cancer being routinely screened for the disease: whether beginning every year at age 40, as is common; every other year beginning at age 50, as recommended by the U.S. Preventive Services Task Force in 2009; or ever.
In a paper published Nov. 21 in the New England Journal of Medicine, Welch and co-author Archie Bleyer, a professor at the Knight Cancer Institute at Oregon Health & Science University, point out that despite a large increase in the number of diagnoses of early-stage breast cancer over the past 30 years, there hasn't been a correspondingly large decrease in the number of cases of advanced disease - cases often resulting in death.
In other words, mammograms don't save lives. Or at least as many lives as Dr. Welch thinks would be reasonable, given their cost - in time, money, and anxiety - to both society in general, and women specifically.
Arriving at this conclusion involves some rather "tricky calculations," as well as an "admittedly imprecise" attempt to sort out the impact on the study's results of hormone replacement therapy (HRT), commonly used in the 1980s and 1990s. (Kotz, 2012).
Still, Welch and Bleyer estimate that nearly one-third of all diagnosed breast cancers would never become life-threatening, even if left untreated. Therefore, the study concludes, as many as 1 million American women over the past 30 years have been treated for breast cancer needlessly - undergoing surgery, radiation, and sometimes even chemotherapy, all to fight cancers that would never have become dangerous.
Ah, but here's the question: WHICH one-third of those women were "over-treated"? Surgeons and doctors can identify tumors; but they have no way of telling, in breast cancer's early stages (when it's often caught by mammogram), which cancers will disappear on their own, and which will grow into killers.
On paper, it makes sense to reduce the number of women receiving regular mammograms, since just a small fraction actually have life-threatening cancer, while many go through the emotional distress of a false-positive result, with ensuing biopsy; or "needless" treatment of a cancer that would never have progressed.
But women aren't just numbers on a piece of paper; they're wives and sisters, mothers and daughters. Their impact on friends and family spreads like a stone dropped in water. One woman dying of breast cancer destroys or diminishes not just one life - her own - but the world that revolves around her. And it's this cost - the price of loss - that simply can't be measured.
The American Cancer Society is warning the public that Welch and Bleyer's study "must be viewed with caution." The American College of Radiology writes that the study is spreading "misinformation" and "the cost may be lost lives." (Aizenman, 2012). Dr. Daniel Kopans, senior radiologist at Massachusetts General Hospital, simply calls it "junk science," and questions why it was ever printed in the respected New England Journal. (Kotz, 2012).
To be fair, both Welch and Bleyer say they aren't calling for an end to mammograms; simply a clearer message to women that by having one, they're putting themselves at risk for medical interventions they might not need.
And perhaps it's even accurate to say that mammograms are responsible for many women being over-diagnosed and over-treated for breast cancer. But that's like saying the routine vaccinations we receive as infants are responsible for vast hordes of us being "over-treated" for polio and diphtheria because, really, how many people would actually ever get polio or diphtheria?
Not many. But one of them could be you - or your son, or sister. That's where statistics and humanity part ways. And that's why I have a hard time agreeing that too many women are receiving mammograms.
Kotz, D. (2012, November 22). Mammograms may be used too much, study says. Retrieved from http://bostonglobe.com/lifestyle/health-wellness/2012/11/21/study-links-mammograms-overtreatment/G3IHzOEkkqRig4KjW4ElhP/story.html
Aizenman, N. (2012, November 21). Mammograms leading to unnecessary treatment, study finds. Retrieved from http://www.washingtonpost.com/national/health-science/mammograms-leading-to-unnecessary-treatment-study-finds/2012/11/21/269fc076-33f0-11e2-bb9b-288a310849ee_story.html