Women's Services

Do you have dense breasts? What you need to know.
Do you know the density of your breast tissue? Chances are the answer is no - because no one has told you and you didn't know it was important to your health. But there is increasing awareness that women with dense breasts can be at greater risk for breast cancer.

What is dense breast tissue?
Breast tissue is comprised of fat, glandular and connective tissue. Women with dense breasts have more fibrous and glandular tissue and less fat. About 40 percent of women have dense breast tissue.

Breast density is determined through a woman's mammogram and described as one of four categories: (A) Fatty; (B) Scattered fibroglandular density; (C) Heterogeneously dense; or (D) Extremely dense Breasts which are (C) Heterogeneously dense; or (D) Extremely dense are considered "dense breasts."

Why does breast density matter?
On a mammogram, dense breast tissue can hide abnormalities like cancer. Unlike fatty breast tissue that shows up dark on a mammogram, dense breast tissue appears white. Cancer and other abnormalities also appear white, so we say it is like looking for a snowball in a snowstorm. Mammography misses nearly 50 percent of breast cancers in women with dense breast tissue. Finding cancers early, when they are smaller, often means they are more treatable.

How do I know if I have dense breasts?
How a woman's breasts look or feel has nothing to do with her breast density. A radiologist can determine breast density by examining a mammogram. While this information has generally been included in radiology reports, it hasn't been clearly understood that density mattered, so it typically hasn't been shared. In recent years, there has been more attention given to the risk of dense breast tissue and its importance in assessing a woman's risk for breast cancer.

What should I do?
Learn your breast density. At St. Luke's, breast density is included in the radiologist's report and is provided to every patient with her mammogram results.

Talk with your doctor or healthcare provider. Mammography has proven time and again to be the best screening tool in the early detection of breast cancer. Women with dense breasts should still get regular mammograms. However, mammography alone may not be enough. In dense breasts, abnormalities like cancers can be hidden on mammography and may go undetected until they are larger and more likely to have spread. There are various tools available to further assess a woman with dense breasts, including whole breast ultrasound or breast MRI. When added to mammography, they can increase the detection of early stage breast cancer. Recommendations vary for each woman based on her level of breast density and individual risk.

For more information on whole breast ultrasound (including SonoCiné) and breast cancer risk assessment options, visit our breast health services section.

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