How to navigate dense breasts—before, during and after your mammogram

When it was time for my annual mammogram, I didn’t know what to do.

As an oncology nurse, I was used to having the information I needed to make my own medical decisions. But after finding out I had dense breasts, I was confused about what to do next. Here’s what happened and how I made the decision that was best for me.

Like many others, I have a family history of multiple cancers. My mother had breast cancer in her 60s and that puts me at increased risk. This always motivated me to make sure I stay on top of my routine breast cancer screening. But after a routine mammogram, I received a letter from the radiologist recommending I follow up with my primary care provider due to my dense breasts.

What are dense breasts? All breasts are made up of two types of tissue—dense and fatty. Dense breast tissue includes milk ducts, glands and other supportive tissue; fatty tissue is made of fat cells. Someone with “dense breast tissue” has more dense breast tissue than fatty breast tissue. On a mammogram, fatty breast tissue is transparent. But dense breast tissue appears solid white and is harder to see through. Breast cancer, which also appears solid white on a mammogram, could therefore be missed. It is important to keep in mind that dense breast tissue is completely normal and common—half of all women ages 40 and over have dense breasts.

In the past, you might not even know if you had dense breasts (you can’t necessarily tell just by feeling). But thanks to updated U.S. Food and Drug Administration (FDA) regulations, as of the end of 2024 it became a national requirement for the facility where you had the screening performed to notify you of your breast density in the report following your mammogram. That’s why I received that letter from my radiologist informing me of my dense breast tissue.

So what did all this mean for me and my dense breast tissue? I knew I may need additional imaging in order to make sure cancer was not missed on the mammogram. But there are no official screening guidelines for people with dense breasts to tell you what to do next.

I started with my primary care provider, like the letter suggested, with a plan to discuss my family health history and mammogram results. My provider then recommended that I meet with my gynecologist, who does my annual Clinical Breast Exam (CBE), for recommendations.

After giving my OB-GYN the whole story, she was able to provide some helpful next steps.

My OB-GYN explained that I could do any of the following:

• Get a breast magnetic resonance imaging (MRI) test or a breast ultrasound as supplemental screening

• Increase the frequency of my mammograms (go more often)

• Get a breast MRI or ultrasound as supplemental screening AND increase the frequency of my mammograms

An MRI takes detailed images of the breast and is the most sensitive test for finding breast cancer. Ultrasound is a tool that uses sound to create images of the breast, and like an MRI, can detect abnormalities even with dense breast tissue present. Because these tests are not standard for everyone, they are not always covered by insurance.

Even as someone who is well-versed in the medical field, I felt uneasy making this decision. The reality is that none of the three providers I communicated with had strong feelings about which route I decided to take.

Ultimately, I decided to get an MRI as a baseline screening due to my personal philosophy: I would rather take a more conservative approach when it comes to screening and preventive care for peace of mind. Moving forward, I will get an ultrasound at each mammogram—but not at an increased frequency. When I got the baseline MRI, I was already glad I did it—it resulted in a suspicious finding, and I ended up having to get a biopsy, which fortunately came back as not cancerous.

The most important thing for women to know is that you should get your annual mammogram beginning at age 40 (if you are at average risk). If you are told you have dense breast tissue, make sure to take action—consider supplemental or more frequent screening, and talk to your full health care team to make a decision.

It is also important to remember: Any supplemental tests (like a breast MRI or ultrasound) do not replace your routine mammogram but can increase the chance of finding early-stage breast cancers in dense breasts. This is important because Early Detection = Better Outcomes!