Many women find out they have dense breasts after their first mammogram. This simply means that the makeup of their breast tissue can hide some breast cancers on mammogram. Learn more about what it means to have dense breasts and how it might impact your breast cancer screening.
What is dense breast tissue?
The phrases “dense breasts”, “heterogeneously dense breasts” or “extremely dense breasts” in mammography reports refer to how the breast tissue appears on mammogram images. Breasts are made up of three different kinds of tissue:
- fibrous tissue that supports the breasts and keeps structures in place
- glandular tissue that is made of glands that produce and store milk
- fatty tissue that fills the spaces between the fibrous and glandular tissue
Fatty tissue is easy to see through on a mammogram, but fibrous and glandular tissue are denser (or more opaque) and harder to see through on a mammogram. Having dense breasts just means having more areas of fibrous or glandular tissue within the breasts. Some women have extremely dense breasts with very little fat, while other women have heterogenous or more patchy areas of dense breast tissue. There is no way to know if you have dense breast tissue without a mammogram because how breasts feel and how they look on a mammogram can be very different, with some completely fatty breasts being thick and feeling very firm.
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Is dense breast tissue concerning?
Having dense breast tissue is normal, occurring in roughly 40 percent of women. The density of a woman’s breast tissue is largely genetic, although certain conditions can change your breast density. As we age and go through menopause, our glandular tissue decreases, leading to a decrease in breast density. On the other hand, losing weight often reduces the amount of fatty tissue within the breasts, increasing the overall proportion of dense breast tissue and making the breasts denser on mammogram.
Because some women with dense breast tissue have more glandular breast tissue than women with fatty breasts, dense breast tissue is considered one of many factors (including reproductive history, family history, obesity and alcohol consumption) that increases the risk of breast cancer. However, having dense breast tissue by itself is not enough to put a woman at high risk for breast cancer.
Dense breasts and cancer screening
When your mammogram shows that you have dense breasts, you will be informed by your mammogram result letter. In addition, a report will be sent to your provider and to your portal. Women with dense breasts should consider having additional screening with ultrasound or MRI. Typically, in women with dense breasts but without significant additional risk factors, ultrasound is indicated, while women at high risk because of a strong family history will be recommended for MRI.
It is vitally important to get regular, routine mammograms even if you have dense breast tissue. While some lumps can be harder to see on mammography in women with dense breasts, there are other signs of breast cancer that only mammography can find. Having an ultrasound or MRI is not a replacement for mammography.
The importance of staying up to date on breast cancer screenings
Early detection of breast cancer through regular screening ensures the best possible outcome. For some women, the best screening method is mammography alone and for others it means mammography with the addition of ultrasound or MRI. Make sure you talk to your provider about any family history of cancer. All women, including those with no family history are at risk of getting breast cancer and should have regular mammograms. However, women with a family history of cancer may be at increased risk and may need early or additional screening. If you have an area of concern, such as a new lump, make sure you discuss the problem with your provider as you may need a specialized diagnostic mammogram.
Newer mammogram guidelines recommend that women start breast cancer screening at 40. If you need to schedule a mammogram, call our breast imaging specialists in Rhode Island and southeastern Massachusetts.
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