Do you have dense breasts?

Take charge of your breast health by determining how dense your breasts are and which screening tools are right for you.

Why is breast density important?

Did you know that women with very dense breasts are four times more likely to develop breast cancer during their lifetime versus women with low density breasts? 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.

A page of images from the “Are You Dense” website presents a simple, clear description of why breast density matters when trying to evaluate healthy vs. cancerous breast tissue, and why mammograms often miss cancerous growths.  Dense tissue appears white on a mammogram. Lumps, both benign and cancerous, also appear white. Therefore, mammograms can be less accurate in women with dense breasts.

What are dense breasts?

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. Each woman’s breast is made up of different proportions of tissue and fat. High density breasts are made up of more than 75% tissue than fat whereas low density breasts have more fat than tissue. Density may decrease with age, but there is little, if any, change in most women. (American College of Radiology)

How do I know if my breasts are very dense?

Ask your doctor. If you have had a mammogram in the past, your doctor will have the measurement of your breast density in his written report from the radiologist.  Find Out How Dense You Are (George Washington University Hospital)

If it is not included in the mammography report, a radiologist or qualified mammography technician can also determine your breast density by viewing a prior mammogram. While standard film mammography is very good, it is less sensitive for women with dense tissue because dense tissue is light, like tumors, which makes it hard for radiologists to spot a cancer.

Digital mammography is a much more accurate screening tool for women with very dense breasts. If your doctor determines that your breasts are very dense, ask your doctor to refer you for a digital mammogram instead of a standard film mammogram.

Take charge of your breast health by determining how dense your breasts are and which mammography-screening tool is right for you. It’s very important to know the answer to this question.

Are any tests better than a mammogram for dense breasts?

According to the American College of Radiology, 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 findings 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.

An article in the Wall Street Journal, 5/16/13 lists options for breast-cancer screening, each of which is generally covered by insurance (check with your insurance provider before being tested as all of those listed below can be expensive. However, if your doctor thinks you are in a high risk category, his/her recommendation may be sufficient to have the cost covered:

1.    A digital mammogram. There are two types of regular mammograms: the traditional analog kind and newer "digital" mammograms. For women with dense breasts, it's best to get a digital scan, which is more accurate, says Karla Kerlikowske, a professor of medicine at the University of California in San Francisco.

2.    3-D mammography. Also called tomosynthesis. It delivers twice as much radiation as a conventional mammogram, but some radiologists say it gives a clearer image. Some facilities charge an extra fee—often about $50—for the 3-D mammogram.

3.    Sonogram in addition to a mammogram. The cost, about $100 to $350, is often covered by insurance. Typically, a hand-held wand is used to take the image, which takes between five and 45 minutes.

4.    Another option, especially for women with a high risk of breast cancer, an MRI (magnetic resonance imaging) is yet another test option. MRI is a procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). MRI does not use any x-rays.

MRI is used as a screening test for women who have one or more of the following:

MRIs find breast cancer more often than mammograms do, but it is common for MRI results to appear abnormal even when there isn't any cancer. (From National Cancer Institute)

Additional tests and equipment available for breast cancer screening:

5.    Dilon Gamma Camera (BSGI). The Dilon Gamma Camera is designed to perform Breast-Specific Gamma Imaging/Molecular Breast Imaging (BSGI/MBI), which provides a high-resolution metabolic approach to imaging the breast: that is, BSGI looks at the breast tissue from the perspective of how it functions, and not just how it looks, as mammography and ultrasound do. A BSGI/MBI exam can identify early breast cancer—as small as 1 mm, especially in difficult-to-diagnose patients. Used in addition to mammography, BSGI allows the physician to see the breast more clearly and may find cancers which would otherwise not be seen as well as may distinguish between benign and malignant tissue.

In comparison to existing gamma camera technology, the Dilon 6800 is able to detect smaller cancers and those in portions of the breast not well imaged with the currently available technology. (George Washington University Hospital)

6.    Scintimammography. A specialized radiology procedure sometimes used to assess the breasts when other examinations have not been clear. Scintimammography, or a molecular breast scan, is a type of nuclear radiology procedure. This means that a tiny amount of a radioactive substance is used during the procedure to assist in the examination of the breasts. The radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is absorbed by certain types of body tissues. the exact role of scintimammography is unclear at this time. (Johns Hopkins University)

If I have dense breasts, do I still need a mammogram?

It’s best to discuss this question with your medical provider. However, depending on your age and physical health, you may wish to use a second testing method every other year – for example, have a digital mammogram one year and MRI/sonogram the following year. Medical imaging screening has been proven to reduce breast cancer deaths. Many cancers are seen on mammograms even if you have mildly dense breast tissue, but at the same time, they can be missed.

How often and what type of screening should I have if I’ve:


  • Had breast cancer,
  • Have a higher risk of getting breast cancer, or
  • Have dense breasts? (MD Anderson Cancer Center)


How often you should get tested for breast cancer depends on your chances for getting the disease.

Having one or more risks for breast cancer does not mean you will definitely get the disease. It means that you may be more likely to get breast cancer. If you are at increased risk for breast cancer, you may need to start screening exams at an earlier age, get additional tests or be tested more often. Look at the lists below to find out if you are at average or increased risk for breast cancer.

Women at increased risk have a higher chance of getting breast cancer than women at average risk. The exams you get and how often you are tested depends on what puts you at increased risk for breast cancer.
Increased risks include:

  • History of radiation treatment to the chest (for example: tanning booths and x-rays)
  • Genetic mutation, including an abnormality in the BRCA 1 or BRCA 2 genes, Li-Fraumeni Syndrome, CDH1, Cowden's Syndrome or Bannayan-Riley-Ruvalcaba Syndrome
  • History of LCIS (lobular carcinoma in situ)
  • Age-1. Being over 50. Five-year risk of breast cancer 1.7% or greater at age 35 or older, as defined by a Gail Model calculation. Calculate your risk using the Gail Model
  • Family history of breast cancer. A life-time risk of breast cancer 20% or greater, as defined by models dependent on family history. Women with a strong family history of breast cancer should consider speaking with a genetic counselor to learn more about these models and have their risk determined.
  • Personal history of ovarian cancer
  • History of taking birth control pills
  • Postmenopausal hormone replacement therapy
  • Long term exposure to estrogen and progesterone
  • Being overweight
  • Not getting regular exercise
  • Excess alcohol consumption (more than 2 drinks per day)
  • Race and ethnicity

NOTE: If you have symptoms, you should see your health care provider as soon as possible.

What should I do if I have dense breasts?

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 treatment for cancer and previous 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 breasts, you should still get an annual mammogram starting at age 40. (American College of Radiology)

Women with dense breasts have more glandular tissue. This results in mammogram images that are harder to read. If you have dense breasts, you may be worried that your yearly screening exam won’t find an unusual spot. Not to fear.

“Yes, it’s harder for mammograms to detect abnormalities in women with dense breasts. But, it’s not impossible,” Therese Bevers, M.D., medical director of MD Anderson’s Cancer Prevention Center says. “With digital mammograms, it’s easier to find anything unusual in your breasts.”

Women with dense breasts can choose to get a yearly breast ultrasound as an extra screening precaution. Ask your health insurance provider if such a test would be covered under your benefits. Not all providers cover the costs of screening ultrasounds or MIRs for women with dense breasts. (MD Anderson Cancer Center)

IMPORTANT INFORMATION FOR FEMALE VIRGINIA RESIDENTS: On July 1, 2012, a new Virginia law went into effect making it mandatory for all doctors and testing facilities to tell any woman with dense breasts that the condition can interfere with the effectiveness of a mammogram. It also requires doctors and providing facilities to advise their patients that ultrasound or MRI might yield better test results.

The law was modeled after existing laws in CA and NY. Additional states with similar laws in place are: OR, NV, TX, AL, CT, TN, MD, HI, and TX. States in the process of drafting their versions to enact: IA, UT, OH, MN, PA, NJ, MA, ME, SC, GA, FL.

On July 1, 2013, an updated amendment to the Virginia law went into effect. Language in the Virginia law has been changed from: "Your mammogram demonstrates that you may have dense breast tissue," to "Your mammogram demonstrates that you have dense breast tissue." The original law also made no mention of breast density as an independent risk factor. The amended law informs a patient that density "May also be associated with an increased risk of breast cancer."

The information on this page was compiled by Adrienne C., July, 2013. Adrienne is a breast cancer survivor with a family history of breast cancer.