Survey says: Most women don’t know about breast cancer overdiagnosis and overtreatment

By | October 5, 2017

Breast Cancer Awareness MonthOctober is here, so along with the fall foliage, prepare yourself for a deluge of pink ribbons, umbrellas, bumper stickers, and billboards: it’s Breast Cancer Awareness Month.

Started as a well-intentioned campaign to raise awareness about breast cancer and fundraise for breast cancer research, some have said that the movement commodifies a deadly disease at the expense of other cancers and conditions. Furthermore, the emerging subtleties of the evidence on breast cancer screening are rarely communicated in earnest reminders to get a mammogram.

The fact is, mammography is an essential tool in reducing mortality from breast cancer: it is estimated to reduce mortality from breast cancer by about 20%. But it also comes with significant risks for over-diagnosis and over-treatment, meaning women may undergo biopsies, procedures, or be diagnosed and treated for abnormalities noted on mammograms that may not be cancerous or even harmful. As evidence of this has emerged, the influential USPSTF revised their guidelines in 2009, and now urge women under age 50 to discuss their individual risk with primary care providers to determine their plan of care rather than starting mammography at age 40. Women without genetic or other risk factors should get a mammogram every two years between the ages of 50 and 74.

In the 8 years since this change in guidelines, have public health and primary care professionals have had any success in communicating the risks of over-diagnosis and over-treatment attendant with breast cancer screening? Nagler et al make an important contribution to this discussion with their October publication in Medical Care, entitled: Women’s Awareness of and Responses to Messages About Breast Cancer Overdiagnosis and Overtreatment: Results from a 2016 National Survey.

Nagler and colleagues found that most of the 429 women they surveyed found factual statements about overdiagnosis and overtreatment not believable, and most would not consider such statements as part of their own individual decision making about whether or not to undergo a mammogram. The women had very low awareness of the concepts of overdiagnosis (17%) and overtreatment (18%), and almost half of them either disagreed or strongly disagreed with statements such as:

  • “Some breast cancers found by mammograms are so slow-growing that they would not have caused any health problems for women in their lifetime” (overdiagnosis)
  • “Some breast cancers that are treated (such as with surgery or medications) would not have needed such treatment after all” (overtreatment)

Interestingly, women who had undergone mammography within the year prior to the survey found the factual statements about overdiagnosis and overtreatment particularly objectionable when compared to women who had never had a mammogram (overdiagnosis OR=-0.57; overtreatment OR= -0.29).

We haven’t done an adequate job of communicating the intricacies of mammography risks and benefits to women.

These findings are not surprising to me as a clinician. Usually, I start conversations about mammography with the question: “What do you understand about mammograms?” Often women say things like “They prevent breast cancer,” “They find it early,” or “They really hurt!” But I have never had a patient say anything close to: “They often lead to unnecessary biopsies, procedures, surgeries, and treatments, which have a very real emotional and physical toll on an otherwise healthy woman.”

I think that there are a few reasons for this. The first is, simply, we (primary care and public health professionals) haven’t done an adequate job of communicating the intricacies of mammography risks and benefits to women. It’s not a conversation that can be printed on a poster or bumper sticker, and it’s a complex message that can’t compete with the annual parade of pink ribbons.

Also, talking about the benefits and harms of mammograms requires numeracy and literacy on the part of both parties – providers and patients. Yet studies have shown that even physicians often do not fully understand [PDF] the statistics in these studies. It’s very difficult to have a conversation about why mammography may harm a woman based on complex statistics if one does not fully understand them. And, given the emphasis on productivity and limited time with patients in primary care, it is simply easier to place the order for a mammogram rather than have a long conversation about the risks and benefits of screening for each individual woman.

Another reason is far more basic. Breast cancer is the most common cancer among women. The actress Julia Louis Dreyfus recently revealed a breast cancer diagnosis on social media, pointing out that 1 in 8 women will get the disease in their lifetimes. Almost everyone knows someone who has had breast cancer. Few enjoy contemplating our mortality or the idea that we cannot control our fate. A mammogram seems like one way to take control and protect ourselves from such a terrible disease.

It is hard to both understand and accept that the mammogram, so long held up as a shield from breast cancer, may in in fact harm us. But it is time to come to terms with it – the evidence requires that we do.

Audrey Provenzano

Audrey Provenzano

Audrey M. Provenzano, MD, MPH is a General Internist in the Boston area. She cares for patients in a community health center and works in quality improvement. She is interested in primary care practice reform and quality improvement and healthcare policy. She is the host and producer of the primary care and health policy podcast Review of Systems, which can be found at
Audrey Provenzano

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