Dense Breast Tissue -- What Does it Mean?

This summer, New York became the fourth state (after Connecticut, Texas and Virginia) to mandate that women be notified if their mammogram reveals that they have dense breasts -- but what does "dense breasts" actually mean, and how does it affect you?

Mammograms can show whether breasts are made up of mostly dense (meaning milk producing or connective tissue) or fatty tissue. Fatty tissue shows up dark on mammograms, while dense tissue shows up white. The problem is that potentially cancerous spots also show up white, making them harder to spot in dense breasts. The purpose of informing women if they have dense breasts is so they and their physicians can discuss whether additional imaging procedures, such as ultrasound, MRI, or 3D breast tomosynthesis (also known as 3D mammography) would be beneficial to help identify potential problems.

Does having dense breasts mean a reduced chance of surviving cancer if cancer is discovered? The answer, according to a recent study, is no.

The study, published in the Journal of the National Cancer Institute, followed over 9,000 breast cancer patients and found that patients with dense breasts were no more likely to die from breast cancer than those with less dense breasts. So, while tumors in dense breast tissue may be harder to detect, once detected they are no more aggressive or harder to treat than tumors in less dense breasts.

What does this mean to you?  If you are notified that you have dense breasts, speak to your physician about whether additional testing might be useful for you, such as 3D breast tomosynthesis. Patients who are classified as having dense breasts benefit the most out of this new technology. Ultimately, take comfort in knowing that breast cancer patients with dense breasts do not have worse outcomes than those without dense breasts.

For more information about the study, visit http://jnci.oxfordjournals.org/content/104/16/1218.abstract