Breast Density Frequently Asked Questions

Breast density can affect the kind of breast screening you need. Here are some answers to frequently asked questions that may help you and your physician as you try to decide whether to add automated whole breast ultrasound for dense breasts to your annual routine for breast cancer screening.

1. How do I know if I have dense breast tissue?

Your mammogram report will show one of the following:

  • Mainly fatty tissue – NOT DENSE
  • Scattered fibroglandular tissue – NOT DENSE
  • Dense tissue – DENSE
  • Extremely dense tissue – DENSE

The radiologist will interpret your mammogram and indicate if your breasts are 1) fatty tissue, 2) scattered fibroglandular tissue, 3) dense tissue, or 4) extremely dense tissue. Dense breast tissue may make it more difficult for your radiologist to detect a cancer in your breast. You may wish to consider an additional screening test to improve cancer detection because of your dense breasts.

The radiologists at The Breast Center, a MANA Clinic, believe that you should be aware of your breast density. We want you to understand breast density and especially want you to know if your mammograms could be less effective because of this dense tissue.

For women with dense tissue, your radiologist may suggest you consider supplemental or additional screening with automated breast ultrasound. We encourage you to discuss this further with your primary physician. You may also contact one of our nurses at the Breast Center (479-442-6266) to ask questions about automated breast ultrasound and if it is a good option for you.

2. What is breast density?

Breast density refers to the amount of fibroglandular tissue in the breast compared to the amount of fatty tissue. Both fibroglandular tissue and fat are normally found in the breasts and the amount of each is different for each woman. Breast density is not a disease. It is a common condition, found in as many as 40% of women. Aging, taking hormones and weight gain or loss can all affect breast density.

3. How does my radiologist determine if my breasts are dense?

Breast Tissue
The image on the left is fatty tissue and the right is dense tissue.

Determining breast density is a subjective assessment of the radiologist who is reading your mammograms. This means that experienced radiologists may not always agree on whether a woman’s mammograms should be classified as dense or not.

There are obvious cases where almost all of the breast is made up of fatty tissue or cases where all of the tissue is dense. Radiologists will almost always agree on the density classification in these cases.

However, many cases show a moderate amount of dense tissue. In these cases, one radiologist might say your mammograms are dense and another might classify your mammograms as showing scattered tissue, or not dense. Because of the subjective nature of breast density assessment, it is sometimes difficult to be consistent in assigning a breast density classification each year.  The National Cancer Institute shows examples of dense breasts, fatty breasts and those that are in between or moderately dense.

4. Why is breast density important?

Dense breast tissue may hide cancers on mammograms. The more dense tissue that a woman has, the more the radiologist worries about not being able to find a small cancer. Mammograms have been shown to save lives by finding cancers when they are small, at an earlier stage, when treatments are easier and more effective. Dense tissue may mask or cover up the cancer and this can delay the diagnosis. Having dense breast tissue also increases the risk of developing breast cancer. Experts consider dense tissue to be a risk factor for breast cancer.

In some states, laws have been passed that require the radiologist to notify a woman if she has dense tissue. Radiologists in Arkansas are not required to do this, but at The Breast Center – A MANA Clinic, the radiologists have decided that each woman ought to be informed about her breast density. We are making every effort to educate our patients and referring doctors about the importance of breast density.

5. Is there anything I can do about my dense breasts?

There is really no way to decrease breast density. Dense tissue often decreases with age and with weight gain, but in general, there are really no practical ways to decrease your breast density if you have dense tissue.

6. If mammograms are limited, should I stop having them?

No, ABUS is recommended in addition to your mammogram. The exams can easily be scheduled together.

Even though mammograms may not be as sensitive or find cancers as well in dense tissue, they still are valuable. Some cancers may initially show up on mammograms as calcifications and these can often be seen in spite of dense tissues. Although a woman’s breast tissues may be dense, yearly mammograms beginning at age 40 are still the best way to decrease the chance of dying from breast cancer.

7. Do I need other tests in addition to mammograms?

Experts do not agree about whether additional tests are needed. Research is showing that performing a breast ultrasound examination to screen for cancers in addition to getting routine yearly mammograms will find more cancers. Ultrasound has been used for years to evaluate patients with breast lumps and breast pain. It is also used to investigate an area in the breast that may appear abnormal on a mammogram. It is a very useful tool in diagnosing breast cancer, but experience in using ultrasound to screen for breast cancer is limited.

There generally is agreement among experts in recommending a screening test if it can be shown to decrease cancer deaths. This type of data is not yet available for screening ultrasound, which makes some researchers hesitant to recommend it for everyone with dense breasts. Until there is more data, controversy will continue about whether women should have screening ultrasound in addition to screening mammograms.

However, since beginning our screening ultrasound program in 2012, the radiologists at the Breast Center of Northwest Arkansas – A MANA Clinic, have been successful in finding small cancers on ultrasound that were not visible on mammograms. In these women, screening with ultrasound allowed them to be diagnosed at an earlier stage, with easier treatment and a better prognosis.

8. What is automated breast ultrasound screening?

Automated breast ultrasound (ABUS) is a screening ultrasound examination offered to women with dense breast tissue.   As a screening test, it is for women who are not currently having problems such as a breast lump or pain in a particular area. The exam uses the same ultrasound technology that radiologists use for evaluating lumps and abnormal mammograms. However, the ABUS technique images both breasts entirely and even scans into the lower part of the axilla or armpit region. The transducer is attached to an automatic arm that then completely scans the breasts.

A video of the exam is saved and the radiologist reviews the images at a separate time. With this technique, the images can be saved and used in subsequent years for comparison.

If there appears to be an abnormality on the ABUS exam, the patient is asked to return for a diagnostic ultrasound. The diagnostic ultrasound exam enables the technologist and the radiologist to focus on a particular area, view the abnormality in “real-time” and use all the sophisticated tools available on the ultrasound machine to determine if there is an abnormality that is suspicious for cancer. This is very similar to the diagnostic mammograms that are performed when a screening mammogram shows an area of concern.

9. What are the pros and cons of additional or supplemental automated breast ultrasound?

Like any medical test or treatment, there are advantages and disadvantages to consider.

The strongest argument for performing automated whole breast ultrasound screening is that additional cancers will be found, cancers that are not visualized on mammograms. The negatives are the lack of agreement among experts and the lack of a recommendation from organizations like the American Cancer Society. Screening with ultrasound in addition to mammograms increase the chance of what is called a “false positive.” This means that the screening ultrasound or ABUS identifies what appears to be an abnormality and the patient is asked to return for additional tests. If those additional tests do not show cancer, then the original screening ultrasound identified a false positive finding. False positives occur with all screening exam, such as PAP tests for cervical cancer or PSA tests for men looking for prostate cancer. False positives may cause anxiety and contribute to added costs, but many patients are willing to accept the possibility of false positives if it means that cancer will be found earlier.

Insurance is currently not paying for the ABUS and that is a negative for patients. For some patients, the $275 for the ABUS exam is worth the peace of mind that comes from more complete screening. Other patients prefer the standard recommendation of screening with mammograms alone.

The technologists, nurses and radiologists at The Breast Center would be happy to speak with you about the pros and cons of ABUS and help you decide if it is the right choice for you. We encourage you to speak with your primary care physician as well.

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