Why Breast Density Matters to Your Health

I thought I knew what I needed to know about breast cancer.

For years, I volunteered with the American Cancer Society. Since I was teenager, I’ve viewed cancer as Public Enemy Number One (or at least in the top five) and have tried to raise awareness on my own and promote measures known to lower one’s risk of either getting the disease or dying from it.

But, just last week, during the 30th annual National Breast Cancer Awareness Month, I learned something new. I didn’t learn it from a billboard or yogurt carton or tinted lights shining on the White House. No, I learned it from the form letter sent to me by my hospital’s breast health center where I had gone for my annual mammogram.

The first line of the letter contained the good news. My screening showed no signs of breast cancer. The next was a bit more confusing. “The mammogram shows that your breast tissue is comprised of scattered fibroglandular densities (type B).


What does that mean? And why are they telling me this? Is it bad?

I kept reading. The next part of the letter looked like a multiple choice question from a standardized test.

“Breast tissue is described in one of four patterns of increasing density:”

My anxiety is already up so I’m scanning the text quickly to get to the point. Did the radiologist find something or not?

“A. Almost entirely fat
B. Scattered figroglandular densities
C. Heterogeneously dense
D. Extremely dense
Having type C or type D tissue means you have dense breast tissue. Dense tissue is very common and not abnormal.”

But I’m not a C or D which is “very common and not abnormal.” I’m a B. Does that mean my tissue is uncommon and abnormal?

The letter continues, stating the above information is given to me to raise my awareness. At this point, my blood pressure was raised more than my awareness.

I should talk to my doctor about the report, the letter states, as well as my risks for breast cancer including family history. If I have dense breasts or other risk factors, I may benefit from additional screening methods next year and in the future.

I folded the letter, put it back in it’s envelope, and tucked it in my desk drawer until I had a chance to read it more carefully. Later, I did and it still didn’t make sense. So, I did what I usually do.

I went online and typed “scattered fibroglandular densities” into the URL box. One of the first links on the page that appeared went to http://staceyvitiellomd.com/what-breast-density-means-to-you.

After reading Dr. Vitiello’s blog post, I understood the meaning of the my hospital’s form letter.

Having dense breasts means you have more breast and connective tissue than fatty tissue in your breasts, making any tumor or cyst harder to detect.

On a mammogram, fat tissue shows up as black while breast, connective, and harmful tissue all show up as white. It’s extremely difficult if not impossible for radiologists to decipher bad tissue from good tissue in breasts that are dense as opposed to fatty.

As a result, half of all cancers in dense breasts escape detection. Women who happen to have dense breasts have gotten a clean bill of health while cancerous tumors hid in the tangled web of whiteness.

No wonder there are still woman dying (40,000 Americans per year) from breast cancer. By the time the cancer is detected, it’s often too late. Women are doing what they’re told to do – getting their annual mammograms – but many miss out on the benefits of early detection all because their breasts were dense.

There is good news, however.

Fortunately, a grassroots effort is well underway to pass legislation requiring medical professionals to include information regarding patients’ breast density along with their mammogram results.

Giving women with dense breasts the information they need for an early diagnosis of breast cancer is part of the mission of AreYouDense.org. Dr. Vitiello, a radiologist, is another strong advocate. Connecticut was the first state to adopt this legislation in 2009. Many, but not all, states have followed.

Statistics-wise, having dense breasts is a higher risk factor for getting breast cancer than having two 1st degree relatives (mother, sister, daughter) with the disease but that risk should be reduced when women with high breast density seek alternative diagnostic screenings to catch what a regular 2D test might miss.

Below is a video of a 2013 press conference held by sponsors of the New York Breast Density Information Law where cancer survivor and an advocate for the legislation, JoAnn Pushkin is honored.


What do you think? Should sharing breast density information with mammogram results be required by law? Is it in your state? Find out here and leave your comments below.