On Wednesday, Katie Couric revealed that she had breast cancer.
In an essay on her website, she wrote about the “heart-stopping, suspended animation feeling” she had upon receiving her diagnosis in June; she also noted that she had dense breasts — a common classification that can increase the risk of developing the disease.
About half of women who are 40 years old or older have dense breast tissue, said Dr. Laura Esserman, director of the Breast Care Center at the University of California, San Francisco. Here’s what to know about what breast density means and how dense breasts can influence cancer risk.
What does having dense breasts mean?
Density isn’t related to breast size or firmness, said Dr. Sarah Friedewald, chief of breast imaging at the Northwestern Feinberg School of Medicine. It is a measure of how much fibrous and glandular tissue is in your breasts compared with the amount of fatty tissue, as viewed on a mammogram. These tissues include the glands that create milk, the tubes that ferry milk to the nipples and the fibrous tissue that binds them together.
Every mammogram report includes an assessment of a woman’s breast density, which falls into one of four categories: almost entirely fatty; some areas of scattered density; evenly dense; or extremely dense. Dense breasts is an umbrella term that refers to the latter two categories.