I Have Dense Breasts. What Does That Mean For My Cancer Risk?

“If you have dense breasts, you’re not alone,” said Jamie Murphy, MD, a breast surgeon with Franciscan Physician Network in Indianapolis. “About half of all women do, and it can raise questions about mammograms and breast cancer screening.”

Dense breast tissue is common, but it can make mammograms more difficult to read and small cancers harder to spot. Starting in 2024, new federal guidelines require mammography centers to tell patients if they have dense breasts and explain what that means for screening. Understanding your breast density helps you make informed choices about follow-up tests and take steps to protect your health. 

Key Takeaways: Dense Breasts

• Nearly half of women over 40 have dense breasts.
• Dense breast tissue can make it harder for mammograms to find small cancers.
• Dense breasts can make cancer harder to detect and raise your overall dense breast cancer risk .
• Supplemental screening tests, like ultrasound, MRI or molecular breast imaging, can help find cancers that a regular mammogram might miss.
• Starting in 2024, mammography centers must notify women about their breast density categories and explain what it means for screening.

What Are Dense Breasts?

“Breast density describes how much fibrous and glandular tissue is in your breast compared with fatty breast tissue. 

Only imaging, such as a mammogram, can measure density. Doctors classify breast density into four categories.

How is breast density measured?

“Dense breasts simply have more glandular tissue, which appears white on a mammogram — the same color as cancer,” Dr. Murphy explained. “That’s why dense tissue can sometimes hide small abnormalities.” It’s like trying to see a cloud against a cloudy sky — it blends in.

Breast density falls into the following categories:

1. Almost entirely fatty: Breasts with mostly of fatty tissue make mammograms easier to read.
2. Scattered areas of fibroglandular density: A few dense areas mixed with mostly fatty tissue.
3. Heterogeneously dense: Many areas of dense tissue can make small cancers harder to see.
4. Extremely dense: Almost all dense tissue, which can make it difficult to spot cancer on a mammogram.

Women in the heterogeneously dense or extremely dense category have dense breasts.

Why Dense Breasts Raise Cancer Risk

Dense breasts don’t cause cancer, but they are linked to a higher chance of developing it. According to the National Cancer Institute, women with dense breasts are four to six times more likely to develop breast cancer than women with mostly fatty tissue.

“When we see extremely dense breasts, we know there’s a slightly higher risk for breast cancer,” said Dr. Murphy. “We don’t know if that’s because of the tissue itself or because it’s harder to see through that dense tissue.”

Breast density can also change over time. It can decrease with age, after pregnancy or during menopause. But not always. That’s why your mammogram report includes your density level each year.

Why Does Breast Density Matter?

That’s why 3D mammography, ultrasound and MRI play a crucial role for women with dense breasts. They help doctors see what a traditional mammogram might miss.

How Do You Know If You Have Dense Breasts?

You can’t feel dense tissue and it doesn’t change the way your breasts look or feel.

The only way to know if you have dense breasts is through your mammogram results.

If your mammogram shows you have dense breasts, talk with your doctor about what kind of follow-up dense breast screening is right for you.

What Should You Do If You Have Dense Breasts?

• Get your mammogram every year. Even if your last one was normal, regular screening helps find changes early, when treatment works best.
• Talk with your provider. Ask what your breast density means and whether an extra test, like an ultrasound or MRI, could give a clearer picture.
• Understand your risk. Your doctor can review your family history, genetics and lifestyle to help you decide if more frequent or advanced breast screening makes sense.
• Know what’s normal for you. If you notice a new lump, thickening, redness or a change in skin texture, call your healthcare provider right away.

Dense breasts are just one piece of your overall health story. The most important step is to stay consistent with screening and speak up about any changes you notice.

What Screening Options Are Available For People With Dense Breasts?

Mammograms are the most important tool for early breast cancer detection. But if you have dense breasts, your doctor might recommend supplemental screening for dense breasts to help see through the tissue. These can include:

• 3D mammography (tomosynthesis): Creates layered images of the breast, improves accuracy in dense tissue and is now considered the standard screening tool for women with dense breasts.
• Breast ultrasound: Uses sound waves to find small lumps that might not appear on a mammogram.
• Breast MRI (magnetic resonance imaging): Offers highly detailed images and is especially helpful for women at higher risk.
• Molecular breast imaging (MBI): A newer, advanced breast screening that uses a small amount of radioactive tracer to highlight cancer cells. Studies show that combining MBI with 3D mammography can double cancer detection rates in women with dense breasts.

Your healthcare provider can help decide which test makes sense based on your risk factors, age and health history.

Where Can You Get Advanced Screening For Dense Breasts?

Franciscan Health offers 3D mammography and supplemental screening options to help detect breast cancer early, even in women with dense breast tissue. Our breast specialists can help you understand your mammogram report, discuss your personal risk and guide you to the right next step.

If you’re not sure where to start, take our quick Breast Cancer Risk Assessment. It’s a simple way to learn more about your risk factors and start a conversation with your healthcare provider about your screening plan.

Talking To Your Doctor About A Screening Plan

Your doctor can help you create a breast screening plan that fits your personal risk, age and breast density. “In most cases, women should continue with yearly mammograms,” Dr. Murphy said. “For women with extremely dense breasts or other high-risk factors, your doctor may recommend alternating mammograms and MRIs every six months.”

If you’re unsure what type of dense breast screening is best for you, ask your provider to explain your mammogram results and discuss whether additional imaging could help you get a clearer picture.

Schedule your mammogram today at your nearest Franciscan Health Breast Center. And if you’ve been told you have dense breasts, ask if additional dense breast screening could help you get the clearest possible results.