Breast Cancer Screening for Women With Dense Breasts

Having dense breast tissue is normal for approximately 40% of the female population. If you are found to have dense breasts during your annual mammogram, the Breast Health Center will inform you in writing.

What Does Having Dense Breasts Mean?

Dense breast tissue means there is more fibroglandular tissue (ducts and lobules for milk production) than fatty tissue. Breast density is not something you can feel. It is not related to the size of your breasts or your age. Dense breast tissue can only be determined on your mammogram.

After the childbearing years, some women hold on to the fibroglandular tissue while other women do not. Much of this is genetic.

Why Does Breast Density Matter?

The issue with dense breast tissue is that it can mask the appearance of tumors. Proper compression during mammograms and the use of tomosynthesis (or 3D) mammograms dramatically improves the radiologist’s ability to find tumors hiding within the dense tissue. For some women, a mammogram alone may not be enough to detect disease at its earliest stages. In these instances, your physician may provide a referral for an Automated Breast Ultrasound System (ABUS) screening.

“Mammography continues to be the gold standard for the detection of breast cancer; however, it doesn’t work equally well in all women, particularly those with dense breast tissue,” says Dr. Phillip Blalock, chief of radiology at Beaufort Memorial Hospital. “Using ABUS screening in addition to mammography improves breast cancer detection and is another tool we can use to give women with dense breasts peace of mind.”

Read More: 5 Questions About Mammograms Answered

Why Get Both a Screening Ultrasound And Mammogram?

Supplemental screening ultrasounds are offered at the Beaufort Memorial Breast Health Center (Beaufort location only) because the combination of mammograms and ultrasounds have been shown to increase breast cancer detection by 36%.

The Invenia™ Automated Breast Ultrasound System (ABUS) uses sound waves to penetrate the breast tissue and can differentiate differences within the breast – unlike mammograms which uses radiation. The two modalities complement one another to provide the radiologist the most information.

You can have both the ABUS and mammogram exams during the same visit to the Beaufort Breast Health Center. However, some women find it beneficial to separate these exams into two visits in 6-month intervals. This option provides women with peace of mind during the year that their breast tissue continues to appear healthy.

Speak with your primary care provider or OBGYN about ordering a screening ultrasound and which timing option is best for you. Currently, a screening ultrasound requires a physician order (having a mammogram alone does not).

Read More: For Women, Health Care Is Self-Care

Breast Density: What’s Your Grade?

In South Carolina, mammography results are required to include a letter grade that identifies a woman’s level of breast density and the amount of breast tissue and fat in her breasts. Here is what the letters may mean:

• A: Almost entirely fatty (not very dense)
• B: Scattered fibroglandular densities (primarily fat with some breast tissue)
• C: Heterogeneously dense (mostly breast tissue with some fat)
• D: Extremely dense

Women with letters C and D are considered to have dense breasts.




Dr. Blalock says that the need to have an automated breast ultrasound in addition to an annual mammogram depends on a woman’s personal risk factors for breast cancer. It may not be appropriate in all situations.

We recommend women begin annual mammograms at age 40, regardless of breast density. Schedule your mammogram today by calling 843-522-5015. If you have no insurance or a high-deductible plan, you may save money on your screening by purchasing a voucher through MDsave.