Information About Breast Density
What is Breast Density?
Breast density is a common topic when it comes to screening mammography. If you have questions about breast density, you are not alone. Breast density is determined from your mammogram. Each time you have a mammogram, your radiologist checks your breast density for two reasons. First, dense breasts have a higher chance of developing breast cancer. Second, it is more difficult to find breast cancers in dense breasts compared with fatty breasts. For these reasons, some states, including New York, now require that radiologists include your breast density with your mammography results (LEGISLATION AND REGULATIONS – WHAT IS REQUIRED- by State). Your report from our office will include your breast density type:
A. Almost entirely fatty
B. Scattered areas of fibroglandular density
C. Heterogeneously dense
D. Extremely dense
The new law requires patients with heterogeneously dense and extremely dense tissue to be informed as they may be candidates for additional screening tools such as ultrasound or MRI (patients with family history and other risk factors may qualify). The denser the tissue, the more difficult it can be for a radiologist to interpret.
All breasts contain fibro-glandular tissue and fat. The amount of fibro-glandular tissue a breast has compared with the amount of fat is called breast density. A breast with more fibro-glandular tissue and little fat is considered a dense breast, and a breast with lower fibro-glandular tissue and more fat is considered a fatty breast. Dense breasts are very common and normal. About 40% of women over age 40 have dense breasts. Dense breasts are more common before menopause, and breast density generally decreases with age. Your breast density can change as you age, or as your bodyweight changes so your density could be different year to year
If we find you have a dense pattern (Heterogeneously dense OR Extremely dense), your result letter will recommend that you talk to your referring health care provider about your breast cancer risk and discuss whether you may benefit from additional testing. If you and your primary care physician wish to have a screening ultrasound because your breast tissue is dense, EWBC can provide that service at any of our five locations. Patients may be responsible for payment, depending on insurance coverage.
Women with breast density of “heterogeneously dense” or “extremely dense” have been shown to be at increased risk for breast cancer by several studies on breast density published over the last 20 years. The degree of risk is controversial as studies to date have reported drastically different results. We believe there is a considerable risk for these women, even without any other risk factors present (such as family history of breast cancer). The risk is based on the masking of breast cancer (the inability to identify an abnormality that may be a malignancy) in dense breast tissue as well as the inherent higher risk of cancer for women with this type of tissue.
The percentage of women we care for yearly with this type of breast density is approximately 43% of women of all ages having a routine mammogram. In January of 2013, New York State adopted the law of informing patients and their practitioners of breast density. In the last year we have seen a trend of women with this type of breast tissue return for a screening breast ultrasound after notification was given to them by our staff and our radiologists.
In the women that do return, we are discovering mammographically non-visible cancers at three per 1000 women, which is comparable to published studies performed on screening ultrasound in average risk women. We believe screening ultrasound is a reasonable, accessible tool for breast cancer detection to be used in addition to the screening mammogram.
American College of Radiology Breast Density brochure
Breast Density:Are You Informed? By: Wendie A. Berg, M.D., Ph.D., FACR and JoAnn Pushkin
This page is intended as an educational resource only. It is not a substitute for professional care.
Please see your physician if you have any concerns about your own health.