A mammogram is the only screening test proven to reduce deaths from breast cancer. But sometimes, it doesn’t give doctors the full picture—especially for women with dense breasts.
What Are Dense Breasts?
Breasts are made up of 2 main types of tissue:
- Fibroglandular tissue, which includes milk glands, milk ducts and connective tissue, and appears white on a mammogram
- Fatty tissue, which appears dark on a mammogram
“If your breast tissue is more than 50% fibroglandular tissue, your breasts are considered dense,” explains Christin Martino, MD, a breast imaging radiologist at Carilion Clinic. “This is very common. About 40 – 50% of women in the U.S. have dense breasts.”
Why It Matters
Here’s the thing: Like dense tissue, breast cancer also appears white on a mammogram. That means it can blend into the rest of the tissue and be harder to spot.
Having dense breasts also raises your risk of developing breast cancer. That’s because there’s more of the glandular tissue where cancers tend to grow.
The good news? Advanced screening measures like 3D mammograms and breast ultrasounds can help find tumors hidden in dense tissue.
Who Is Most Likely to Have Dense Breasts?
Younger women tend to have denser breasts. As women age, breast tissue typically becomes fattier, making changes easier to detect.
Dr. Martino notes that some women stay dense into their 70s. Breast density is checked as part of every mammogram.
How Do You Know If You Have Dense Breasts?
A radiologist will measure breast density when they review your mammogram. The results are sent to your doctor and can also be found in your MyChart patient portal.
If you do have dense breasts, talk to your OB/GYN or primary care doctor. Together, you can decide if you need more advanced screening based on your personal risk factors.
When Should You Start Screening?
In general, it’s recommended to start getting mammograms at age 40. If you have a family history of breast cancer or other risk factors, you might need to start sooner or get additional screenings.
“The earlier cancer is detected, the better the outcome,” says Dr. Martino. “It’s often smaller, easier to treat and less likely to have spread. That’s why it’s so important to keep up with regular mammograms every year.”
Schedule your mammogram if you’re due, and don’t hesitate to reach out to your doctor if you have questions or concerns.
