Breasts are made up of fibroglandular tissue and fat. The amounts of each varies from person to person. The more fibroglandular tissue there is the more dense a mammogram appears to a radiologist.
Dense breasts can make it harder to see breast cancer on a mammogram. The denser tissue can mask or hide a small cancer. In addition to other factors, breast density can increase the risk of developing breast cancer.
Breast density is determined by the radiologist who reads your mammogram. There are four categories of mammographic density. Breast density is determined by the radiologist who reads your mammogram. There are four categories of mammographic breast density. The radiologist assigns each mammogram to one of the categories (see diagram below). This will be included on your mammogram report.
If you have dense breasts, continue getting an annual screening 3D (tomosynthesis) mammogram. A mammogram is the only screening test proven to reduce breast cancer deaths. Many cancers are seen on a mammogram, even with dense breast tissue.
Yearly screening breast ultrasound or MRI are supplemental screening tests that can be performed in addition to an annual mammogram. These have been proven to detect smaller cancers that may not be visible on a mammogram. They can also uncover other findings which tends to lead to more workups and biopsies. So it’s important to talk to your provider on whether the additional supplemental imaging tests such as ultrasound or MRI are right for you. Insurance coverage may vary.
