FDA: Mammogram facilities must tell women if they have dense breast tissue

Dense tissue and a tumor can look similar on a mammogram; it’s possible to miss small tumors

Half of women have dense breast tissue, with 40% evenly dense throughout and 10% extremely dense, according to the Centers for Disease Control and Prevention.

Why does this matter? Because women with dense breasts have a higher risk of breast cancer, the CDC states. And because dense tissue and a tumor can look similar on a mammogram, it’s possible to miss small tumors.

Now, the Food and Drug Administration will require mammogram facilities to tell women if they have dense breasts.

“Dense breast tissue is a common finding on mammograms, especially in younger women,” Dr. Hal Burstein, a breast oncologist at Dana-Farber Cancer Institute, told ABC News.

“It does not mean that a woman has breast cancer,” Burstein added. “It means she might be at slightly greater risk of breast cancer, and that the mammogram is slightly less helpful for early detection.”

Before the new rule, more than half of U.S. states required facilities to inform women of dense tissue, FDA Chief Medical Officer Dr. Hilary Marston told ABC. The others have 18 months to comply.

In Georgia, patients whose mammogram shows heterogeneously or extremely dense breasts are sent a letter letting them know. The required notification reads:

“Your mammogram shows that your breast tissue is dense. Dense breast tissue is very common and is not abnormal. However, dense breast tissue can make it more difficult to detect cancer through a mammogram. Also, dense breast tissue may increase your risk for breast cancer. This information about the result of your mammogrm is given to you to increase your awareness. Use this information to talk with your health care provider about whether other supplemental tests in addition to your mammogram may be appropriate to you, based on your individual risk. A report of your results was sent to your ordering physician. If you are self-referred, a report of your results was sent you in addition to the summary.”

Having this knowledge might help women decide to get more frequent screenings or additional imaging to ensure a tumor isn’t missed, Marston said.

“It has been known for a long time that (dense breast tissue) makes it more difficult to see a cancer on a mammogram when it exists,” Marston told ABC News. “What’s evolved more recently in the science is an understanding that having dense breast tissue in and of itself is an independent risk factor for breast cancer.”

Marston added that women can’t tell if they have dense tissue just by how their breasts feel. “This is really a finding that is seen on mammography,” she said.