To screen or not to screen
That is the question women are asking (well, I’m asking). But there is no clear answer.
October is Breast Cancer Awareness Month, aka Pinktober. The news and social media are already broadcasting the message “Mammograms save lives.”
That simplistic platitude isn’t enough. Do screening mammograms really save lives? What do the numbers tell us?
Cancer screening has become a huge business in our for-profit healthcare system. As a result, marketing for these tests can be pretty aggressive.
Related post: Do you need an annual mammogram?
We’ve been doing annual screening mammograms for several decades now, and more evidence is piling up that they may do more harm than good, at least when patients and physicians (and social media and marketers) continue to advocate for annual mammograms starting at age 40 for all women.
Such a one-size-fits-all approach leads to overdiagnosis and overtreatment.
Overdiagnosis is the detection of breast cancers that grow so slowly they would never cause health problems during a woman’s lifetime.
Overtreatment is the unnecessary treatment (surgery, chemo or radiation) that exposes a woman to side effects with minimal health benefits.
In 2014, the Journal of the American Medical Association (JAMA) published this nifty infographic that helped explain some numbers.
If 10,000 women have annual mammograms over 10 years, 10 lives will be saved. But almost 1,000 will be overdiagnosed or overtreated. That’s costly both financially and emotionally.
In 2015, JAMA Internal Medicine wrote:
…the clearest result of mammography screening is the diagnosis of additional small cancers. Furthermore, there is no concomitant decline in the detection of larger cancers, which might explain the absence of any significant difference in the overall rate of death from the disease. Together, these findings suggest widespread overdiagnosis.
Another statistic I see a lot is that annual mammograms lower a woman’s risk of dying of breast cancer by 20%. Watch this YouTube for another excellent visual to explain why that number is not so significant as you might think.
In short, if five out of 1,000 women who don’t get mammograms die, but only four out of 1,000 women who do get annual mammograms die, that one life saved is the 20%. And that doesn’t count the number of women who will be overdiagnosed and overtreated.
It doesn’t help that the major medical groups that produce screening mammogram guidelines don’t agree with each other.
The American Cancer Society (ACS), the United States Preventive Services Task Force (USPSTF), the American College of Obstetricians and Gynecologists (ACOG), the American College of Radiologists (ACR) and others all have a different starting age, stopping age, and mammogram interval.
Some start at 40, some at 45, some at 50. Some recommend annual mammograms, some every other year. Some suggest stopping at age 74 or 75; others say to continue as long as the woman is in good health.
If these professionals can’t agree on the best approach to breast cancer screening, how are patients supposed to be confident that they are getting the best care for their money?
Be informed and ask questions
What your care provider recommends for you will be based on several things:
- His or her professional society’s guidelines
- Guidelines generated by the clinic’s electronic health system
- Personal and professional experiences with mammograms (good or bad)
- Personal judgement and opinions
- Your input
You can’t change the first few factors, but you can insist on a more shared-decision making approach to find a breast cancer screening program that fits YOU. (If you want one at all.)
A recent study showed that the vast majority of women don’t realize there is any risk with annual mammograms. Physicians obviously aren’t doing a very good job communicating harms and benefits to their patients.
I know care providers are swamped with paperwork and have little face-to-face time with patients. And one-size-fits all medicine is fast, easy and profitable.
But simply being told to get a mammogram because it will save your life is not good medicine.
Mammograms are a useful tool when used wisely. For myself, I would rather have a discussion with my doctor and discuss the evidence-based benefits and harms, my personal risk factors (age, family history, etc.) and my personal comfort level, and then make an informed decision about screening mammograms that suits my health care goals.
Interested in learning more about overdiagnosis and overtreatment (and hopefully avoiding both)? Here are some of my favorite books on the topic: