Why the Latest Advice About Mammograms May Not Be for You
New recommendations released last year by the American Cancer Society advise most women to get fewer mammograms, not more. What’s going on here?
We’ve all come to equate screening for breast cancer with saving lives. In fact, research has repeatedly shown screening mammograms are associated with a decrease in breast cancer mortality. But when to begin and how often to have screening mammograms is controversial.
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Multiple highly respected medical organizations have released their own recommendations, which certainly creates confusion, says diagnostic radiologist Laura Shepardson, MD.
For example, the American Cancer Society (ACS) guidelines released in October 2015 are based on multiple studies that repeatedly show mammograms reduce a woman’s risk of dying from breast cancer.
The guidelines say:
It’s important to know that the ACS recommendations, which were published in the Journal of the American Medical Association, are directed at women with an average risk of developing breast cancer. That means women who have no history of breast cancer, no genetic mutation (such as BRCA1 or BRCA2) that predisposes them to breast cancer, and no radiation therapy to the chest between the ages of 10 and 30.
The United States Preventive Services Task Force (USPSTF), on the other hand, released their recommendations in 2009, and were subsequently updated in 2016.
Despite significant criticism, their recommendations remain the same, and are as follows:
In contrast, however, there continues to be very strong support for women to begin their annual screening mammograms at age 40 despite the recommendations outlined above.
For example, the American College of Radiology, the American College of Obstetricians and Gynecologists, and the American Society of Breast Disease all recommend women who are at average risk for developing breast cancer should begin their annual screening mammograms at age 40.
So why is there so much controversy?
Chief among the concerns over when to get a mammogram is the “risk” of false positives.
A “false positive” means an abnormality is identified on the screening mammogram that requires additional evaluation, including a possible biopsy to rule out cancer. In many cases, such an abnormality turns out to be benign. Some argue this causes women significant anxiety and should be minimized.
On the other hand, some women say a false positive, despite the inconvenience and sometimes uncomfortable follow-up, is worth it if screening improves the chance of finding a cancer, particularly one that is early and small, which gives the woman more treatment options and better chance at cure.
As Dr. Shepardson notes, “It is important for every woman to discuss with her doctor the very real possibility she may have a false positive on her screening mammogram and how it will affect her.”
This is also why it’s so important for a woman to understand what risk factors she has for developing breast cancer, and to understand the benefits, risks, and limitations of mammograms in the context of her personal medical history and preferences, Dr. Shepardson says.
Another concern about mammograms, Dr. Shepardson says, is that they may result in “over-diagnosis” of disease, meaning a very early or slow-growing breast cancer is detected on a mammogram and then treated, without any certainty whether the disease might have an impact on a woman’s life if left alone.
“Unfortunately, at this time, we are not able to predict which breast cancers are going to progress and which aren’t,” Dr. Shepardson says. “Until our science catches up, we are going to have cases of over-treatment.”
For women who are at average risk of developing breast cancer, Cleveland Clinic physicians recommend a baseline mammogram starting at age 40 and then every year afterward, and that you and your doctor should decide whether you should get a mammogram earlier if you are at high risk, meaning:
“A woman needs to know what her individual risk factors are and what the risks, benefits and limitations of screening mammography are,” Dr. Shepardson says. “Using that information in conjunction with her values and preferences for her own care, a woman and her clinician should be able to come up with an appropriate screening schedule.”