When women get their mammogram results, they may be notified that they have “dense breast tissue.” Starting in April 2013, California law requires that patients be informed if they have dense breasts, and if they do, they may want to consult with their doctor about additional screening options.
Density is apparent only in mammograms and has nothing to do with firmness. Breasts appear dense if there is a great deal of fibrous or glandular tissue, and less fatty tissue. According to the American Cancer Society, about 40 percent of women in the U.S. over age 40 have dense breasts.
Having dense breasts increases your risk of getting breast cancer—the second-leading cause of cancer death in women, with lung cancer as the number one-leading cause. A February 2017 University of California, San Francisco, study showed that women with dense breast tissue are at a greater risk for breast cancer compared to women with a family history of the disease, their own history of benign lesions, or a first full-term pregnancy over age 30. However, it’s still not understood why there is a link. But what is clear is that dense breast tissue makes it more difficult to see tumors in mammograms.
If you do receive notice that you have dense breasts, be sure to discuss with your doctor about what follow-up tests (e.g., an MRI, ultrasound, or 3D mammography) may be necessary. To check the license of a doctor, visit the Medical Board of California website at www.mbc.ca.gov.