Breasts are made up of a mixture of fibrous and glandular tissue and fatty tissue. Your breasts are considered dense if you have a lot of fibrous or glandular tissue but not much fat. Density may decrease with age, but there is little, if any, change in most women.
Breast density if determined by the radiologist who reads your mammogram. There are four categories of mammographic density. The radiologist assigns each mammogram to one of the categories. Your doctor should be able to tell you whether you have dense breast based on where you fall on the density scale. (Scale below)
Having dense breast tissue may increase your risk of getting breast cancer. Dense breasts also make it more difficult for doctors to spot cancer on mammograms. Dense tissue appears white on a mammogram. Lumps, both benign and cancerous, also appear white. So, mammograms can be less accurate in women with dense breasts.
Yes. A mammogram is the only medical imaging-screening test proven to reduce breast cancer deaths. Many cancers are seen on mammograms even if you have dense breast tissue.
In breasts that are dense, cancer can be hard to see on a mammogram. Studies have shown that ultrasound and magnetic resonance imaging (MRI) can help find breast cancers that can’t be seen on a mammogram. However, both MRI and ultrasound, show more finding that are not cancer, which can result in added testing and unnecessary biopsies. Also, the cost of ultrasound and MRI may not be covered by insurance.
What should I do if I have dense breasts? What if I don’t?
If you have dense breasts, please talk to your doctor. Together, you can decide which, if any, additional screening exams are right for you.
If your breasts are not dense, other factors may still place you at increased risk for breast cancer – including a family history of the disease, previous chest radiation treatments for cancer and precious breast biopsies that show you are high risk. Talk to your doctor and discuss your history.
Even if you are at low risk, and have entirely fatty breast, you should still get an annual mammogram starting at age 40.