Having dense breasts—that is, breasts that have less fatty tissue and more fibroglandular tissue, which includes milk glands and ducts as well as fibrous connective tissue—increases the likelihood that you’ll develop breast cancer, and it also makes cancer more difficult to detect.
Experts In This Article
- Wendie Berg, MD, PhD, researcher, radiologist, and distinguished professor of radiology at University of Pittsburgh School of Medicine
Here’s the thing, though: Having dense breasts is normal, and quite common—about half of women ages 40 and older have dense breast tissue, according to the National Cancer Institute, although your density can change over time. You’re also more likely to have dense breasts if you’re pregnant or breastfeeding, taking hormone replacement therapy, or if you have a lower body weight, per the Centers for Disease Control and Prevention.
While learning that you are at an increased risk of breast cancer may trigger panic and confusion at first, Wendie Berg, MD, PhD, says the information should be “viewed as empowering.”
“It provides a woman with information to discuss with her provider and to consider having additional screening beyond the mammogram alone, depending on her other risk factors and tolerance for additional testing,” Dr. Berg, a distinguished professor of radiology at the University of Pittsburgh School of Medicine, tells Well+Good.
Why understanding your breast density is important
There are four categories when it comes to breast tissue density: fatty, scattered, heterogeneously dense, and extremely dense. The latter two are both considered “dense,” but the higher the density category, the higher the breast cancer risk, Dr. Berg says, adding that up to half of cancers can be missed on a mammogram of dense breasts.
That’s because on a mammogram, dense tissue appears as either white or gray. Unfortunately, so does cancer. This creates a “masking effect,” where malignancies can essentially hide and go undetected until they have grown larger and the cancer has progressed to later stages.
This was the case for JoAnn Pushkin.
When Pushkin was diagnosed with breast cancer at age 46, she was shocked, confused, and angered. She had been getting her recommended annual mammograms since age 40, but her cancer was missed until it had reached a later stage and required more aggressive treatment.
When she found out why her cancer evaded the watchful eyes of her doctors, she was even more upset. Pushkin was told, very nonchalantly by an ultrasound tech, that she had dense breast tissue that would make spotting cancer on routine mammograms “a hard find.”
Although her increased breast density was obvious on her prior mammograms, no one ever made her aware of it. Had she been informed about her dense tissue or its associated risks, she could have consulted with physicians about her options for additional testing that might have identified her cancer much sooner.
“I remember thinking, ‘How is it that I don’t know about this when it seems so routine?’” Pushkin tells Well+Good. “How do you have a conversation about something you don’t know that you need to? Not knowing this effectively denied me of an early diagnosis.”
Thankfully, Pushkin is now a breast cancer survivor. Since becoming cancer-free, she has used her experience to educate women about breast density. She is now the executive director of DenseBreast-info.org, an educational hub meant to arm people with information and resources on all things breast density.
She has also stood before lawmakers on numerous occasions to champion laws that would require providers to tell patients about their breast density status—something that was not mandated in every state until now.
Under the FDA’s new rules, people who get mammograms will be informed of their breast density category in easy-to-understand language, and that information can then be used to guide their decisions around further testing or supplemental imaging.
What to do after finding out you have dense breasts
Dr. Berg recommends every person planning to be screened for breast cancer seek a 3D (rather than 2D) mammogram, regardless of breast density. Also known as digital breast tomosynthesis or DBT exams, 3D mammograms provide radiologists with much more detailed imaging. Rather than the standard four to eight views included in 2D exams, radiologists view hundreds of slides in DBT exams, without having to take additional views that would expose you to more radiation.
If your mammogram reveals you have dense breasts, you may also benefit from additional supplemental imaging. This can include breast MRI, ultrasound, and sometimes contrast-enhanced breast CT scans.
Dr. Berg says MRI is the preferred supplemental exam for identifying difficult-to-detect cancers. Research backs this recommendation—numerous studies have determined that supplemental breast MRI is the best way to spot cancer in dense breast tissue.
“It detects more cancers than any other screening test,” she says. “Among 1,000 women having a screening mammogram, about 100 will be called back for more testing, and five or six will be found to have cancer. On average, another one to three women will be found to have cancer after adding screening ultrasound.”
If these women had MRIs, an average of 16 more would be found to have cancer the first year, Dr. Berg says, and seven more would be diagnosed with cancer on subsequent screening MRI exams. In other words, MRIs can catch breast cancer at earlier stages than other screening tests, so it’s worth talking to your doctor about this option, especially if you have dense breast tissue.
Hurdles for people with dense breasts
Although the new mandate is a step in the right direction, there is the matter of affording supplemental screening. Currently, the Affordable Care Act requires insurers to fully cover screening mammograms. The same cannot be said for supplemental imaging.
Some states have laws in place that mandate coverage of supplemental screening when it is recommended, but these exams could still come with out-of-pocket expenses depending on the insurer, which might deter people from seeking additional imaging. MRIs in particular can sometimes cost thousands of dollars.
In a situation when a person wants to pursue additional imaging but is worried about the cost, Dr. Berg recommends looking into facilities that offer a shortened version of breast MRI exams.
“There are over 200 facilities that offer ‘abbreviated MRI’ with direct-to-patient billing at lower cost, usually $250 to $600,” she says. “Abbreviated MRI uses fewer sequences and takes less time, but performs very well.”
She adds that now that breast density is considered a risk factor for cancer, supplemental exams are more likely to be covered. What’s more, there are currently many discussions related to insurance coverage of supplemental imaging circulating on a federal level.
Pushkin has been working alongside Congresswoman Rosa DeLauro (D-Conn.) to lend her support to the development of a federal law that would require insurance providers to offer coverage of breast cancer screening, supplemental or otherwise, at no additional cost. The Find It Early Act was introduced to Congress in December of 2022 and reintroduced in May 2023.
Katie Couric, who was diagnosed with early stage breast cancer after undergoing a breast ultrasound due to having dense tissue, has also lent her support to the proposal. Couric, who sometimes refers to herself as “dense breasts Katie” in her social media posts advocating for greater awareness of breast density, was present when the bill was reintroduced.
Pushkin says that, if passed, the new law, in addition to the FDA’s new notification requirements, will prevent “unnecessary tragedies.”
“The additional screening recommended needs to be affordable and accessible,” she says. “It’s important that when we get everyone educated and have a plan of action that the plan of action can happen.”
