What Does it Mean to Have Dense Breast Tissue?

What Does Dense Breast Tissue Mean?

Did you know that about 50% of women have dense breasts?

Dense breasts are fairly common, and they can make it more difficult for doctors to detect cancer on a mammogram. Once you know what having dense breasts means and how it may affect your risk, you can confidently take the right steps for early detection.

How Do I Know If I Have Dense Breasts?

Breast density isn’t something you can feel or notice on your own. It's only visible on a mammogram and impossible to tell whether you have dense breast tissue without first having a mammogram. A mammogram provides you with an X-ray of your breast tissue. Once completed, your healthcare professional can observe these images to determine whether your tissue is dense.

Your breasts are composed of several types of tissues. These include:

• Fatty - Fatty breast tissue is mostly made up of fat cells. It appears dark on mammograms and presents the lowest risk of breast cancer.
• Glandular - This tissue consists of ducts, lobules and fibrous tissue. Glandular tissue produces milk.
• Fibrous - Fibrous tissue is connective tissue that holds the ducts and lobules in place.

If you have dense breasts, this means that they contain more fibrous and glandular tissue instead of fatty tissue. According to the Breast Cancer Research Foundation, almost half of women over age 40 who receive a mammogram are found to have dense breast tissue.

What Causes Dense Breast Tissue?

Some people are more likely to have dense breasts. People who are younger have denser breast tissue. For this reason, it’s important to consider having additional screening, such as a breast ultrasound screening, done. Mammograms typically aren’t covered by insurance until a woman is 40 or older. 

As you age, your breast tissue tends to become less dense and more fatty, especially after menopause. Other people who may have denser breast tissue are those with a lower body mass index and women receiving hormone therapy for menopause.

Everything You Need To Know About Dense Breast Categories

Levels of breast density are categorized by using the American College of Radiology's Breast Imaging Reporting and Data System. This is also known as BI-RADS. These levels are scored from A to D and describe the level of density.

• A - The breast is made up of nearly all fatty tissue.
• B - There is mostly fatty tissue, but some pockets of dense tissue exist in the breast.
• C - Most of the tissue is dense, but there are some scattered areas of fatty tissue.
• D - Almost all of the breast tissue is dense with little fatty tissue.

Generally speaking, if you receive a mammogram report that says your breasts are heterogeneously or extremely dense, then you are considered to have dense breast tissue.

Do Dense Breasts Increase My Cancer Risk?

Although having dense breast tissue is very common, you may be wondering, "What does dense breast tissue mean?" A more specific question is, "Do dense breasts increase my cancer risk?"

Dense breast tissue is common and not considered abnormal or a disease. Dense breast tissue does not turn into cancer. However, having dense breast tissue puts you at a 4 to 6 times higher risk of developing breast cancer compared to women who do not have dense breast tissue. Additionally, dense breast tissue makes it more difficult to detect any areas of concern on a mammogram.

It's important to note that genetic factors are behind only 5-10% of breast cancers. For this reason, early screening for breast cancer is critical.

Key takeaway: Dense breast tissue does not turn into cancer. However, having dense breast tissue puts you at up to 6 times higher risk of developing breast cancer compared to women who do not have dense breast tissue. 

FDA Dense Breast Reporting

Beginning on September 10, 2024, all mammography facilities must give every patient who receives a mammogram accurate information regarding breast density. Breast density must be described as either "dense" or "not dense."

In addition, mammogram reports that are then sent to the referring provider have to include an overall assessment of the patient's breast density using the four official categories. This information gives providers additional information to discuss with their patients regarding whether they may benefit from other types of imaging tests to locate anomalies and other actions they can take.

Is Ultrasound Better for Dense Breasts?

When combined with mammography, breast ultrasound increases breast cancer detection rates up to 96% in women who have dense breast tissue. Breast ultrasound is important for women who have dense breasts. This can increase the chances of detecting breast cancer early. 

Both mammograms and breast ultrasounds are screening tests that can help detect breast cancer. However, these tests work differently. They also look for different things.

• Mammogram: When you receive a mammogram, you are getting an X-ray of your breast. Screening mammograms take two views of each breast. If abnormalities are present, a diagnostic mammogram may be performed to further examine any areas of concern. However, it can be difficult to detect any abnormalities when you have dense breast tissue. On a mammogram, both breast cancer and dense breast tissue show up white in color. This makes cancer much more difficult to find.
• Ultrasound: A breast ultrasound uses sound waves, which reflect off your breast tissue. These sound waves create detailed images of your breast. There is no radiation involved in a breast ultrasound. In an ultrasound, dense breast tissue will appear white, but any areas of cancer will appear darker gray. This provides a better contrast that allows for easier detection.

If a woman's breast tissue ranks as a category C or D, then she should get additional essential screening alongside an annual mammogram. Additionally, studies have shown that undergoing a breast ultrasound (and perhaps even MRI imaging) can help detect some types of breast cancers that may not be seen on mammograms. By undergoing multiple types of imaging tests, there is a higher likelihood of catching any areas of concern.

Breast ultrasound is crucial for all women to increase their chances of detecting breast cancer early. This is especially true for those with dense breast tissue. HerScan is on a mission to provide women with accessible and preventive breast ultrasound screening. If you're ready to do more for your breast health, a non-invasive breast ultrasound screening with a certified sonographer can play an important role in your healthcare routine.