Breasts come in different shapes, sizes and densities.
In some cases, dense breast tissue can be associated with an increased risk of breast cancer.
A 2017 U.S. study revealed that four in 10 cases of breast cancer in younger women can be blamed on high breast density. The results show that breast density is a much more important breast cancer risk factor to be aware of than a person’s family history.
But having dense breasts is not an abnormal condition. In the United States, 46% of women have dense breast tissue. It’s basically a physical attribute of the body and there’s little anyone can do to actively change or improve the density of their breast.
Annual screenings are important
Karen Builta, BS, RT (R) (CT), manager of Medical Imaging at OSF HealthCare St. Joseph Medical Center in Bloomington, Illinois, said it’s important to remember that the density of a woman’s breasts can change over time. That’s why it’s important to get annual mammogram screenings to stay up-to-date on the condition of your breasts.
Breast tissue consists of fatty and fibroglandular tissue. Dense breast tissue is defined as having a higher percentage of fibroglandular tissue within your breasts. If more than 50% of your breasts is made of fibroglandular tissue, then your breasts are classified as “dense.”
The more fibrous and glandular tissue absorbs more radiation during mammography, reducing the accuracy of the test and making it more difficult to properly diagnose breast cancer. Dense breast tissue shows up white on a mammogram, as do tumors, which makes it more difficult to identify the difference.
According to the American Congress of Obstetricians and Gynecologists, a mammogram will identify 88% of cancers in a breast that is almost entirely fat, or low in density. That’s compared to 62% in high-density breasts.
“On January 1, 2019, the state of Illinois began requiring notification to mammography patients that they have dense breast tissue. Michigan has had the law since 2015,” Karen said. “Dense breast tissue may obscure or hide breast cancers on a 2D mammogram – described at times as looking for a snowball in a snowstorm from the bright white tissue appearance on films.
“If you happen to be a patient that has been identified as having dense breast tissue, it is important to understand your options to ensure the best possible imaging studies are performed for confidence in imaging results.”
Two of the best imaging techniques for screening dense breast tissue include having 3D (tomosynthesis) yearly with your annual screening mammogram and ABUS (Automated Breast Ultrasound) once identified as having dense breasts.
3D imaging allows the radiologist to view the breast anatomy like pages in a book. These exams can assist in limiting the overlapping of tissues to provide a clearer image for the radiologists to review. The clearer images produced allow radiologists to obtain a more detailed look at the breast tissue; alleviating the need for additional imaging in some cases and identifying small cancers early.
Once having a screening mammogram, the radiologist may recommend an ABUS as an additional form of imaging for dense breast tissue. The ABUS exam uses 3D ultrasound. Using sound waves instead of radiation, a picture of the breast tissue is created. A radiologist reviews those pictures along with the mammogram images. ABUS complements mammography but does not replace it. They work in different ways, and each has it owns attributes, Karen said.
ABUS exams provide a clearer image of breast tissue to find even the smallest cancers. When used in addition to mammography, ABUS can improve breast cancer detection by 55% over mammography alone. With an order from a primary care provider, ABUS can be scheduled to be completed during the same setting as an annual mammogram.
What to do
If you receive a report indicating you have dense breast tissue, speak with your doctor about your breast tissue density and family history of breast cancer to determine the best imaging options. Additionally, you should check with your insurance provider for coverage on 3D (tomosynthesis) and ABUS.