Find out what it means if your mammogram report says you have dense breast tissue. Learn about additional breast cancer screening tests to consider.
If a recent mammogram showed you have dense breast tissue, you may wonder what this means for your breast cancer risk. Doctors know dense breast tissue makes breast cancer screening more difficult and it increases the risk of breast cancer.
Review your breast cancer risk factors with your doctor and consider your options for additional breast cancer screening tests. Together you can decide whether additional screening tests are right for you.
Dense breast tissue refers to the appearance of breast tissue on a mammogram. It's a normal and common finding.
Breast tissue is composed of milk glands, milk ducts and supportive tissue (dense breast tissue), and fatty tissue (nondense breast tissue). When viewed on a mammogram, women with dense breasts have more dense tissue than fatty tissue.
On a mammogram, nondense breast tissue appears dark and transparent. Dense breast tissue appears as a solid white area on a mammogram, which makes it difficult to see through.
The radiologist who analyzes your mammogram determines the ratio of nondense tissue to dense tissue and assigns a level of breast density.
Levels of density are described using a results reporting system called Breast Imaging Reporting and Data System (BI-RADS). The levels of density are often recorded in your mammogram report using letters. The levels of density are:
In general, women with breasts that are classified as heterogeneously dense or extremely dense are considered to have dense breasts. About half of women undergoing mammograms have dense breasts.
Breast tissue is composed of milk glands, milk ducts and supportive tissue (dense breast tissue) and fatty tissue (nondense breast tissue). Radiologists use mammogram images to grade breast tissue based on the proportion of dense to nondense tissue. According to the BI-RADS reporting system, the levels are (from left to right) A: almost entirely fatty, B: scattered areas of fibroglandular density, C: heterogeneously dense, and D: extremely dense.
It's not clear why some women have a lot of dense breast tissue and others do not.
You may be more likely to have dense breasts if you:
Having dense breasts affects you in two ways:
Most medical organizations recommend women with an average risk of breast cancer consider regular mammogram testing beginning at age 40 and consider repeating the screening annually.
Women with dense breasts, but no other risk factors for breast cancer, are considered to have a higher risk of breast cancer than average. They may benefit from annual breast cancer screening.
Dense breast tissue makes it more difficult to interpret a mammogram, since cancer and dense breast tissue both appear white on a mammogram. Very dense breasts may increase the risk that cancer won't be detected on a mammogram.
Despite concerns about detecting cancer in dense breasts, mammograms are still effective screening tools. The most common type of mammogram — digital mammogram — saves images of your breasts as digital files instead of film and allows for more detailed analysis. This is more effective at finding cancer in dense breast tissue than older film mammogram technology.
There's some evidence that additional tests may make it more likely that breast cancer is detected in dense breast tissue. But additional tests carry additional risks, and no additional testing method is proved to reduce the risk of dying of breast cancer.
You and your doctor may consider additional or supplemental testing based on your other risk factors and your personal preferences.
Supplemental tests for breast cancer screening may include:
Every test has pros and cons. While each test is proved to find more breast cancers than a mammogram, none of these newer imaging tests is proved to reduce the risk of dying of breast cancer, as has been done with the standard film mammogram.
|Supplemental screening test||Pros||Cons|
|Molecular breast imaging||