Update: This piece has been updated to reflect the correct number of states with breast density notification requirements at 37. A previous version stated 38.

In the past 10 to 15 years, researchers have directed increased attention toward breast density as both a risk factor for breast cancer and a potential obstacle to optimal mammographic assessment. “Dense” breasts contain more connective tissue and less fat, which means they appear differently on mammograms. Whereas non-dense breast tissue typically appears dark on a mammogram, dense tissue appears white, which may obscure small breast tumors. Extremely dense breasts are linked to a higher risk of developing breast cancer.

For an average-risk woman, the lifetime risk of breast cancer is about 12 percent. Although study results vary, a woman with extremely dense breasts has about 1.5 to 2 times the risk of developing breast cancer compared to a woman with average breast density. Some studies suggest dense breasts may be more common in black women compared to white women. Although results have been mixed, a 2015 study evaluating breast density in black and white women revealed that black women had significantly higher density breast tissue than white women.

Breast cancer awareness interest groups such as Are You Dense Inc. have championed the cause of breast density, lobbying state governments to enact legislation mandating that women are informed of their mammographic breast density. Today, 37 states require some level of breast density notification after a mammogram, but the distribution and content of such notifications varies. While some states require that a patient be informed about her own breast density, others require only general information about breast density. Certain state statutes mandate that all patients be notified, while others require that notification be sent only to patients who are determined to have dense breasts. Even the notifications themselves vary by state: some mention the terms “cancer” or an “abnormality masking effect,” and others mention breast density as a risk factor or include information about supplemental screening tests. Although some states’ notifications include all of this information, there is currently no nationwide consensus on what proper notification entails.

In an effort to address these variations in the content of patient notifications, Congress enacted legislation on February 15, 2019, as part of the federal government appropriations package, directing the Food and Drug Administration (FDA) to ensure that mammography reports and summaries received by patients and their providers include appropriate information about breast density. The legislation specifies that this information should include, at a minimum, “the effect of breast density in masking the presence of breast cancer on a mammogram, the qualitative assessment of the provider who interpreted the mammogram, and a reminder to patients that individuals with dense breast tissue should talk with their providers if they have any questions or concerns about their summary.”

On March 28, 2019, following the passage of the legislation, the FDA published a notice of proposed rulemaking regarding updates to the regulations that were issued under the Mammography Quality Standards Act of 1992 and the Federal Food, Drug & Cosmetic Act. Among other changes, the FDA plans to “[r]equire reporting to patients and healthcare providers to include an assessment of breast density...so they and their healthcare providers can make informed healthcare decisions.” Comments on the proposed regulatory changes are due by June 26, 2019. The new regulations will apply on a national level with the hope of bringing consistency to notification requirements. Until these new FDA guidelines take effect, however, patients must still rely on the notification requirements (if any) mandated by their respective state governments.

There are arguments both in favor of and against mandatory notification of breast density. Advocates of breast density notification laws suggest that a woman should know if her breasts are dense because the information may prompt her to speak to her physician about her risk of breast cancer and her screening program. Those who argue against mandatory notification emphasize that no research has definitively shown that it improves any population-based outcome in breast cancer, such as decreasing breast cancer incidence or mortality rate. In fact, medical guidelines for how to manage dense breasts are vague and differ depending on the source of the recommendation.

Consider the hypothetical situation of a 54-year-old white college professor who has her annual mammogram. The mammogram is normal, but the radiologist reports that she has dense breasts. This finding is included in the mammography report mailed to the patient. Upon reading the report, the patient notes her family history of breast cancer and decides to talk to her primary care physician about her dense breasts and family history. Ultimately, she is referred to a “high-risk” breast clinic, where she learns about additional screening modalities and other methods for reducing her risk of breast cancer. In this situation, an educated, health-literate woman with access to primary medical care was able to potentially modify her breast cancer risk.

But not all women have this level of access to health education and health care services. Black women comprise a patient group that has historically experienced inequities in health care access—a disparity clearly evidenced by the troubling fact that the breast cancer mortality rate is 40 percent higher in black women than in white women. Contributors to this disparity are varied and complex, and include a combination of relative lack of access to primary care and health insurance, increased rates of poverty and comorbidity, and medical mistrust.

Simply mandating that breast density information be provided to all women does nothing to address the underlying disparities in health education and health care services that already exist among different patient populations. Providing such information to a patient who does not have the opportunity to talk to a trusted health care provider and understand its implications may be of little benefit—and may even result in unnecessary stress and confusion on the part of the patient. One study reported that only about half of women surveyed knew the implications of dense breasts, which suggests that many women may not understand what to do with this information.

Over the past 30 years, new diagnostic modalities and therapeutic options have drastically improved outcomes from breast cancer. Based on national surveillance data from the CDC, almost 90 percent of patients diagnosed with breast cancer will survive at least five years after diagnosis. From a public health perspective, some of the greatest strides in breast health have been made by improving the rate of mammogram screening and enhancing access to primary medical care. Yet, sizeable differences in breast cancer outcomes persist, especially along racial and class lines. Mandatory breast density notification laws will likely only be effective if they are coupled with an increase in public health funding and policies to increase access to primary and specialty medical care.  

To accomplish the FDA’s stated goal of helping patients and their healthcare providers “make informed healthcare decisions,” all women must have the opportunity to not only receive information about breast density, but also understand that information in the appropriate context. In the wake of current legislation, many questions remain: Will mandatory notification legislation create positive changes in breast cancer outcomes? Will these laws lead to better breast health for any individual woman? Could these laws increase costs by adding potentially unnecessary radiologic exams to screening programs? And could they create increased anxiety for women with dense breasts without providing any clinically meaningful benefit?

Health care providers, patients, and advocates should take the opportunity to pose these questions and provide comments to the FDA, and regulators should consider this feedback in developing the new guidelines. Sharing breast density information with women could be a powerful tool in empowering them to seek medical care as early as possible, if access to such care is available. Hopefully, more early interventions will result in improved outcomes for all women.

Resources

Breast Density Notification - State Laws

Federal eRulemaking Portal: Submit Comments on the Mammography Quality Standards Act

Breast Density and Your Mammographic Report

Risk Factors for Breast Cancer

Dense Breasts: Answers to Commonly Asked Questions