Understanding Dense Breast Tissue and Your Screening Options

Breasts are made up of glandular, fibrous, and fatty tissue. When you have more fibrous and glandular tissue than fat, your breasts are considered dense.

Dense tissue appears white on a mammogram and so do most cancers — which can make it harder to detect abnormalities. About 40–50% of women over 40 have dense breast tissue. Women with dense breasts may have up to two times higher risk of developing breast cancer than women with mostly fatty breasts. This increased density can make it harder for mammograms to identify tumors.

However, density alone isn’t the only reason to consider additional screening. Other important risk factors include a personal or family history of breast cancer, genetic predisposition, or prior chest radiation. It’s important to talk with your doctor about whether additional screening may be beneficial, especially if you have multiple risk factors.

What additional screening may help if I have dense tissue?

3-D Mammography (Tomosynthesis):

A preferred standard that improves cancer detection and reduces recall rates compared with 2-D mammography. Many guidelines now recommend 3-D as the standard screening method.

Breast MRI:

Offers the highest supplemental detection rate and is recommended for certain higher-risk women and those with dense breasts. It is more costly and may lead to additional follow-up tests.

Contrast-Enhanced Mammography (CEM):

An emerging option shown in recent studies to detect additional cancers in dense-breast populations. It’s being evaluated as an alternative to MRI in certain settings.

Whole-Breast Ultrasound:

Can find cancers that mammography may miss, but it can also result in more false positives and unnecessary biopsies.

Recommendations from Dr. Shelley Nakamura, breast surgical oncologist at Arizona Center for Cancer Care, who explains how to reduce breast cancer risk:

Know your breast density

Mammogram reports now routinely state your BI-RADS density category; FDA rules and many state laws require centers to notify patients. If you haven’t been told, ask your doctor.

Get mammograms as recommended

Discussing age and frequency with your clinician. Mammography remains the foundation of screening.

Discuss your overall risk

Family history, genetics, prior biopsies, age, hormone exposures. Density is only one risk piece, decisions about adding additional screening like an MRI or an ultrasound should include global risk.

If you’re at higher risk or have dense breast tissue

Ask whether supplemental MRI, CEM, or whole-breast ultrasound is appropriate.

Supplemental imaging can find cancers missed by mammography, but it can also increase false positives, anxiety, and downstream procedures. That’s why personalized risk discussion is essential: the women most likely to benefit (very dense + other risk factors) should be prioritized while avoiding unnecessary tests in low-risk women with density alone.

Knowing your breast density and understanding your screening options can make a real difference in early detection and outcomes. Do you have concerns about dense breasts or your breast cancer risk? Request an appointment online today.