What Women Need to Know About Why Breast Density is Important, How to Determine It, and What to Do About It

You’re dedicated to your monthly self-exams and you follow your healthcare provider’s recommendations for breast cancer screenings, given your age and family risk factors. But are you aware that it’s also important to know your breast density?

Breast density is a way to describe the composition of a woman’s breasts. It compares the area of breast and connective tissue, to the area of fat, as seen on a mammogram. Breast and connective tissue are denser than fat, so high breast density means there is more breast and connective tissue as compared to fat. On a mammogram, connective tissue appears as solid white, making it difficult to see through. And therein lies the challenge.

“Breast cancer also is white on a mammogram,” said Michael Macon, MD, FACS, Breast Surgeon and Medical Director of the Breast Care Program at Yavapai Regional Medical Center (YRMC). “The whiter the background, the more difficult it is to identify breast cancer in the white background of a dense breast.”

Who is Susceptible to Breast Density?

Generally, women who are younger and thinner have denser breast tissue, according to Dr. Macon. As a woman ages, she may gain weight, decreasing the density. Genetics also plays a role. If your mother had dense breasts, you are more likely to as well.

Additionally, breast density is more common among women taking hormone therapy to relieve the symptoms of menopause. Women with dense breasts have a higher risk – up to six times, by some estimates – of developing breast cancer. The reason is unknown.




Learn Your Breast Density

How can you learn your breast density? The radiologist administering your mammogram will determine the ratio of your dense to non-dense tissue. Four categories are used in the Breast Imaging Reporting and Database Systems:

  1. Fatty Breast Tissue: This mammogram likely would show any abnormalities.
  2. Scattered Fibroglandular Density: This breast density has quite a bit of fat, but also a few areas of fibrous and glandular tissue.
  3. Heterogeneous Density: When areas of fibrous and glandular tissue are distributed evenly throughout the breasts, it can be difficult to see small masses on mammograms.
  4. Extreme Density: This increases the difficulty of detecting cancerous tissue because it can blend in with other tissue.

What Should You Do About Breast Density?

“If the radiologist determines you have heterogeneous density or extreme density, but you have no other breast cancer risk factors, it is important to have a 3-D mammogram,” said Dr. Macon. “A 3-D mammogram combines multiple breast x-rays to create a three-dimensional picture.”

To assess your risk for breast cancer, Dr. Macon recommends the Tyler Cuzick Model, which can be found online and is based on a woman’s answers to a series of questions. The result is an estimate of the likelihood a woman will develop invasive breast cancer within 10 years of her current age and over the course of her lifetime.

“For women with a lifetime risk of breast cancer greater than 20 percent,” explained Dr. Macon, “alternating 3-D mammograms and breast Magnetic Resonance Imaging (MRI) is the standard.”

To schedule screening mammography, including 3-D mammography, contact:

  • The BreastCare Center at YRMC at 928.442.8900 (www.YRMC.org)
  • Prescott Medical Imaging at 928.771.7577 (www.hometownradiology.org)

And, if you’d like to learn more about your risk for breast cancer? Contact YRMC’s Genetic Clinic at 928.442.8747.