Your genetics determine if you’ll have dense breasts, which are associated with a higher risk of cancer. But having dense breasts doesn’t mean you will develop cancer in your lifetime.
Having dense breasts is a risk factor for breast cancer.
Your breasts won’t necessarily feel different if they’re dense. The only way to know if you have dense breasts is through a mammogram. The mammogram will show what kind of tissues are dominant in your breasts.
Read on to understand how dense breast tissue is diagnosed and how it relates to the risk of breast cancer.
Language matters
We use the terms “women” and “female” in this article to refer to sex assigned at birth and reflect terms historically used to gender people.
Sex and gender exist on spectrums, and your gender identity may not align with these terms. Your doctor can better help you understand your specific circumstances.
Glandular, fatty, and connective tissue
You can’t tell if breast tissue is dense by feeling it.
For breasts to be considered dense, they need to show higher amounts of connective tissue and glandular tissue than fatty tissue.
Having dense breasts is common, with about
After menopause, breasts are typically composed more of fat than other connective and glandular tissue. This is because the number and size of milk-producing glands decreases.
Research has linked dense breasts to an increased risk of developing breast cancer later on.
Increased risk for cancer
A study of pre and postmenopausal women found that for those who were premenopausal, dense breasts were a risk factor for breast cancer.
Other research states that having extremely dense breasts can increase your risk of advanced breast cancer four times compared to all other women.
Research also suggests that dense breasts have more ducts and glands. This increases risk because cancer often begins in the cells lining the ducts. Researchers are still studying this theory.
Keep in mind that having dense breasts doesn’t necessarily mean you have or will develop breast cancer.
And having
Missed readings
Traditionally, doctors use
If you have dense breasts, that tissue will appear white as well. This makes it more difficult for doctors to see potential breast cancer.
According to the National Cancer Institute, about
About
3D mammograms are the preferred method for detecting cancer in dense breasts because digital images are clearer. These types of machines are becoming more common.
Those with dense breasts may need to undergo MRI screenings or
You may have a higher likelihood of dense breasts if you:
- were older when giving birth for the first time
- have had few or no pregnancies
- are in premenopause or younger in age
- use or have used hormone therapy, especially combined estrogen and progestin
Dense breasts can have a genetic component. Your chances of having dense breasts increase if your mother also has or had them.
Talk with your doctor if you’re concerned about dense breasts and your risk for breast cancer.
When radiologists look at your mammogram, breast tissue will show up as black and white. Glandular and dense connective tissue will show up white on a mammogram because X-rays don’t pass through as easily. This is why it’s called dense tissue.
X-rays pass through fatty tissue more easily, so they appear black and less dense. You have dense breasts if your mammogram shows more white than black.
These tests are also used to help doctors diagnose potential breast cancer:
While most people may only get digital mammograms, additional diagnostic tools may also be recommended based on your:
- medical and family history
- genetics
- existing medical conditions
- tests available to you
Your doctor can help you determine which will work best for you.
A classification system known as the Breast Imaging Reporting and Database Systems (BI-RADS) Breast Composition Categories recognizes four categories of breast composition:
| BI-RADS composition category | Breast tissue description | Ability to detect cancer |
| A: mostly fatty | mostly fatty tissue, very few glandular and connective tissues | cancer will likely show on scans |
| B: scattered density | mostly fatty tissue with few foci of connective and glandular tissue | cancer will likely show on scans |
| C: consistent density | even amounts of fatty, connective, and glandular tissue throughout the breast | smaller cancer foci are difficult to see |
| D: extremely dense | significant amount of connective and glandular tissue | cancer may blend in with tissue and be difficult to detect |
Ask your doctor about the BI-RADS results related to your breast tissue density when you get your mammogram results.
Many states, including California, Virginia, and New York, require radiologists to tell you if your breasts are extremely dense.
While having dense breasts doesn’t necessarily mean you will develop breast cancer, knowing you have dense breasts is a step toward health awareness.
Ask your doctor to suggest a screening plan if you have dense breasts or other risk factors for breast cancer.
It’s suggested that breast cancer develops in areas where the breast is dense. However, more research is needed to see if there’s a direct relationship. Dense breasts mainly increase your risk for a missed diagnosis.
That’s because it’s harder for doctors to spot tumors on mammography. Dense breast tissue and tumors both show up white. Fatty breast tissue shows up as gray and black.
Keep in mind that studies define increased risk by comparing women with the highest breast density to women with the lowest density. The risks don’t necessarily apply to everyone. Dense breasts are a common finding in many mammograms.
If you want to read the latest research and recommendations, the nonprofit organization Are You Dense? advocates for people with dense breasts.