The mantra “early detection saves lives” has been the driving force behind the mainstream breast cancer movement. But increasingly, the data has shown that many small, slow-growing tumors don’t endanger a woman’s life. And patients and providers increasingly view the harms of medical treatment to be an important part of decision-making.
The harms of breast cancer treatments are wide-ranging and common. Of course, many people have long known about immediate toxicities of treatment, like pain, scarring, disfigurement, radiation burns, digestive problems, hair loss, etc., But there is growing concern about the longer term health harms of breast cancer treatments—things like physical disability and lymphedema, secondary cancers, heart disease, and more. The term “financial toxicity” has also been coined recently to refer to the devastating financial impact of medical treatment in an era of exorbitant costs.
There can be an understandable reluctance to consider scaling back on treatment—particularly at a time when Republicans in Congress are proposing a plan that would strip millions of people to life saving healthcare access. Breast Cancer Action has long worked to ensure access to evidence-based, affordable, culturally competent health care for all. At the same time, we have worked since our founding to ensure that women have unbiased information in order to make their own treatment decisions, including revealing the prevalence and true impact of overdiagnosis and overtreatment.
Identifying Breast Cancers That Don’t Need Extensive Treatment
Many people associate the term “precision medicine” with the development of innovative, new therapies to successfully treat disease. However, another goal of precision medicine should also be to better understand and identify which patients will not benefit from treatment and can safely forego treatments that may be physically and/or financially toxic.
Several genomic tests have been used for more than a decade to inform breast cancer treatment decisions by predicting the benefit of systemic therapy after surgery, as well as estimating the risk of recurrence. Oncotype DX was the first of these tests to be widely used. MammaPrint was the first genomic test to seek FDA approval for its use to predict the risk of recurrence after a breast cancer diagnosis and was approved by the FDA in February 2007.
MammaPrint measures the activity of 70 genes associated with breast cancer recurrence from a sample of a surgically removed breast tumor. Women with a low-risk score can safely forego chemotherapy without decreasing likelihood of disease free survival. It should be noted that the test is better at predicting low-risk than high-risk of recurrence. Even within the low-risk group, researchers have found a sub-set of patients that they are calling “ultralow risk” breast cancers for which “death from breast cancer after surgery alone is exceedingly low.”
A new study published in JAMA builds on prior studies by identifying women with this “ultralow risk” of recurrence and whose risk of death from breast cancer a full 20 years after surgery alone is exceedingly low. The study looked at 652 postmenopausal women whose early stage breast cancer had not spread to any lymph nodes and randomized them after surgery to either receive no further treatment or the standard hormone therapy tamoxifen. The majority (377 or 58%) of these early stage breast cancers were categorized as low-risk, while 275 (or 42%) were MammaPrint high-risk. Of the low-risk group, 98 (or 15% of the total) were deemed to be “ultralow risk.”
In the ultralow-risk group that was treated with tamoxifen, there were no deaths at 15 years, and these patients had a 20-year disease-specific survival rate of 97%. By comparison the survival rate for the untreated group was 94%, demonstrating that even without systemic therapy the long-term risk of dying from breast cancer for these women is exceedingly low.
Even with the advances in identifying which patients may not need extensive treatment, there are inevitably some cases of overtreatment. The use of a genomic test, like MammaPrint, to evaluate individual breast cancers may help to reduce, but cannot fully eliminate, this harm. Each woman should have the opportunity to weigh the harms and benefits of treatment options and the treatment decision that is right for her based on her values, priorities, and individual life circumstances.
Mammography Screening May Result In Overtreatment
Overtreatment stems in part from detection of non-life threatening breast cancers, which is increasingly recognized as a significant harm from widespread mammography screening. Another research letter was published in JAMA this month that shows women are much more likely to know about the potential benefits of mammography screening than the harms associated with it. This imbalance in perceived benefit flies in the face of the “growing scientific consensus that mammography has a modest impact on averting deaths from breast cancer, while exposing women to a number of harms.” And the imbalance makes it difficult, if not impossible, for women to make informed, evidence-based medical decisions.
Researchers present 2016 data on women’s beliefs about mammography screening and found that few women know about the potential harms from routine mammography screening, and most of the women who do know, don’t view these as “very important.” In contrast to the underestimation of the harms, more than 90% of women knew the 4 benefits of mammograms listed in a recent study. Women who recently had a mammogram in the last year were significantly more likely to view the benefits as “very important.”
And yet a Cochrane review of breast cancer screening published in June 2013 estimates that a woman who undergoes 10 years of routine screening for early signs of breast cancer is 10 times more likely to undergo unnecessary treatment than to have her life saved. In addition to the risk of overtreatment—that is the treatment of a cancer that never would have grown and is therefore unnecessary—more than 10% of women who are screened will “experience important psychological distress including anxiety and uncertainty for years because of false positive findings.” The skewed perception of the benefits of breast cancer screening are a result of simplistic, paternalistic messaging and corporate marketers who are focused on selling pink ribbon “solutions” to the breast cancer epidemic.
All treatments, tests, and procedures come with both potential harms and potential benefit. The benefits may be seen to outweigh the harms when they are rare and not serious. But for breast cancer treatments, the side effects are extremely common and are often life altering, with both short and long term tolls. Many women when presented with balanced information decide that the rarity of the benefits don’t outweigh these harms of routine screening.
Informed consent is considered to be an essential part of our modern health system. Whether women are considering routine screening or making treatment decisions after a diagnosis, we all need full information about the harms and benefits. None of this is possible if lack of access constrains our choices. Which leads us right back to what we’ve been fighting for the past several months—access to healthcare.
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