As of April 1, 2013, California law requires that all women receive a notification if their mammogram reveals dense breast tissue.

While receiving this notification may lead to confusion at first, the information is provided to empower women. Dense breast tissue has been shown to be associated with a slight increase in breast cancer, and it is important for women to be aware of their risk factors.

What are dense breasts?

The breasts are composed of glandular tissue and ligaments that create the dense tissue within the breasts. These appear white on a mammogram. Breasts are also composed of fat cells, which appear black on mammogram. When the dense breast tissue exceeds the fat density the breasts are dense. About 50 percent of women have dense breasts. Regardless of size or shape, breasts that are dense have an overall increase in risk of developing breast cancer than breasts that are predominantly fatty.

How is breast density determined?

The breast density is determined by a radiologist when interpreting a woman’s mammogram. It cannot be predicted by a physical examination. Breast density is categorized into four categories:

  1. Predominantly fatty
  2. Scattered fibroglandular tissue
  3. Heterogeneously dense
  4. Extremely dense

California women receiving a mammogram will now be informed if they have heterogeneously or extremely dense breasts.

How does breast density affect screening?

Mammography remains the gold standard for breast cancer screening; however, some cancers may not be detected in high breast density. That’s because on mammograms, dense breasts are white as are tumors. It’s similar to the challenge of finding a polar bear in a snowstorm. Mammograms in less dense individuals are less likely to obscure any potential tumors.

Which imaging study is best?

For women with dense breasts and a normal mammogram, there are additional imaging studies available including ultrasound and magnetic resonance imaging (MRI).

The study chosen will depend on a woman’s complete risk profile. Most insurance plans do not cover additional imaging for women with low risk, as the new law does not require that they do.

Breast MRI has the highest sensitivity for detecting cancers that may be missed on mammograms. Breast MRI may be a suitable adjunctive screening for high risk women or women with dense breast tissue. Annual MRI studies for women that have a greater than 20% lifetime risk of developing cancer are usually covered by their insurance plans.

The goal of screening with mammograms and any supplemental imaging is to detect cancer in its earliest stage. This leads to better survival and saves lives. Women should begin annual mammographic screening at age 40. Women that are at increased lifetime risk (>20%) or gene carriers may need to start earlier and this should be discussed with their breast care specialist or physician.

The Chrysalis at Breastlink in Rancho Mirage is a comprehensive breast health center providing individualized treatment plans including risk management, imaging, surgery and oncology. 760.324.4466.

For more information on this new law:

Read or write a comment

Comments (0)


Living Wellness with JenniferNaturopathic Family Medicine with Dr. ShannonThe Paradigm Shift in Medicine Todaybanner your financial health michelle sarnamentoring the futureConventionally Unconventional with Kinder Fayssoux, MD