A new FDA ruling requires mammogram facilities to include information about breast density in mammogram reports. Dense breasts are a common and normal condition in which there is more fibrous and glandular tissue (called fibroglandular tissue) than fatty tissue in the breast. Almost half of women over the age of 40 have dense breasts. While this is perfectly normal, it’s important to understand what having dense breasts means for your health.

Dense breast tissue can make it challenging for doctors to spot signs of breast cancer on a mammogram. It may also slightly increase your risk of developing breast cancer. This doesn’t mean you should worry, but it does mean you should be informed.

Why Is Breast Density Important?

Breast density is important for two key reasons:

1. Can Make Mammograms Challenging to Read 

Dense breast tissue shows up as white on a mammogram. The problem is that cancer also shows up as white, making it difficult for doctors to tell the difference between healthy tissue and potential cancer.

2. Slightly Increases Cancer Risk 

Women with dense breasts have a modestly higher risk of developing breast cancer compared to women with less dense breasts. The higher the density, the higher the risk, though having dense breasts does not increase the risk of dying from cancer.

How Do You Know If You Have Dense Breasts?

 You can’t tell if your breasts are dense by how they feel. Dense breasts don’t feel any different from non-dense breasts. The only way to know if you have dense breasts is by getting a mammogram. When you have a mammogram, the radiologist (a doctor who reviews the images) will categorize your breast density into one of four categories:

1. Almost entirely fatty (Category A): Mostly fatty tissue, which makes it easier to detect any signs of cancer.

2. Scattered areas of dense tissue (Category B): Some dense tissue but mostly fat.

3. Heterogeneously dense (Category C): A large portion of the breast is dense, making it harder to detect cancer.

4. Extremely dense (Category D): Almost all of the breast is dense, making it very hard to detect cancer.

Women in categories C and D are considered to have dense breasts. About half of all women who get mammograms fall into one of these two categories.

Breast Density Categories and Risk Levels

Breast Density and Cancer Risk

While women with dense breasts may be at a slightly higher risk of breast cancer, breast density is just one part of the picture. Other factors, like your family history, genetics and lifestyle, may also play a role in your overall risk. 

Screening Options for Women With Dense Breasts

If you have dense breasts, your doctor may suggest additional screening methods to help detect any signs of cancer more accurately. Here are some options:

• Standard Mammography: This is still the most common and useful screening method, but it may miss some cancers in dense breast tissue.
• 3D mammography (tomosynthesis): This creates a clearer image by taking multiple pictures from different angles, which helps doctors see through dense tissue better than with standard mammograms.
• Ultrasound: Uses sound waves to create images of the breast tissue and may help find cancers that a mammogram can’t. However, it can also lead to false alarms, meaning the test might suggest cancer when there is none.
• MRI (magnetic resonance imaging): Provides a more detailed picture than a mammogram or ultrasound, particularly for women at higher risk of cancer.
  

What To Do If You Have Dense Breasts

If you’ve been diagnosed with dense breasts, don’t panic. Have a conversation with your doctor about what your breast density means and whether you need additional screening. Make sure to keep up with your mammogram appointments. Based on your individual risk, your doctor may recommend other tests like 3D mammography, ultrasound or MRI.