How Breast Density Affects Your Breast Cancer Risk...

August 21, 2024

If your mammogram report says you have dense breast tissue, you may be wondering what that means

about your breast cancer risk.

Breast density describes how much fibrous and glandular tissue there is in the breast compared to the

amount of fat tissue. Dense breast tissue—less fat tissue and more fibrous and glandular tissue—can

make it harder to see cancer on a mammogram. Dense breast tissue may also be linked to a higher risk

of developing breast cancer.

“Having dense breast tissue does not necessarily mean you have a higher risk of developing cancer, or

that any potential cancer would not be found on a mammogram,” said [Physician] at [Practice]. “But

knowing you have dense breasts can help you and your healthcare provider make proactive decisions

about breast cancer screening.”

How Do I Know if I Have Dense Breasts?

Breast density isn’t related to breast size or firmness and cannot be determined by external look or feel.

When you are screened with a mammogram, your radiologist will look at your breast density, which is

described by four categories:

• Category A breasts are almost all fatty tissue.

• Category B breasts have scattered areas of dense tissue.

• Category C breasts are made of more dense tissue and are described as heterogeneously dense.

• Category D breasts are extremely dense.

Category C and D breasts are considered dense. The US Food and Drug Administration requires

mammogram facilities to include breast density as described by dense or not dense.

How Does Breast Density Affect Cancer Screening?

Fibrous and glandular breast tissue looks white on a mammogram. Because breast masses can also look

white on a mammogram, it can be difficult to see them in an image of a dense breast. However,

mammograms still detect most cancers in women with dense breasts and those women should still be

regularly screened with a mammogram. For some women, additional screening may also be

recommended.

The US Oncology Network is supported by McKesson Specialty Health. © 2024 McKesson Specialty Health. All rights reserved.

Your physician may recommend a three-dimensional mammogram. Multiple X-ray images are taken of

each breast at multiple angles without compressing the breast to avoid causing the tissue to overlap.

These images are then digitally assembled to produce a clear three-dimensional image that makes any

potential cancer easier to detect. Your physician may also recommend an ultrasound or MRI to further

improve breast cancer detection.

If I Have Dense Breasts, What Should I Know About My Cancer Risk?

Researchers have linked dense breast tissue to a higher risk level of developing breast cancer, but it is

unclear why this link exists. If you have dense breasts, it’s important to talk to your doctor about your

personal risk of getting breast cancer. They will look at any other potential risk factors you may have,

including:

• Age

• Height and weight

• Any past breast biopsies

• Personal or family history of breast or ovarian cancer

• Hormone use

• Ashkenazi Jewish heritage

• Age of your first menstrual period

• Age when you first gave birth

• Age at menopause

• Age of any other cancer diagnosis

These factors tell your physician whether you are at an average, intermediate, or high risk of developing

breast cancer. Knowing your risk level can help your physician decide on the most appropriate and

beneficial screening for you.

Ask Your Physician About Screening Recommendations

If you have questions about breast cancer screening, your mammogram report, or any risk factors you

may have, please consult your physician. They can help you determine the most appropriate screening

guidelines for you.