If you are a Vermont woman, there is some new legislation taking effect this January that you should know about. It’s called Act 139, and it requires all mammogram facilities to include information identifying the patient’s breast tissue density in the patient’s report. If the patient has uniformly dense or extremely dense breasts, the patient must receive a notice.
“Whoa,” you say. “What does all that mean?” Basically, if you receive a mammogram and are found to have dense breast tissue, we have to let you know. “But why?” It’s important information to know, because women who have dense breasts are at a slightly higher risk of developing breast cancer. In addition, the character of their breast tissue makes breast cancer harder to find.
Think of your breast density in the same way that you think about your blood pressure, cholesterol reading, and body weight. These numbers help you understand your risk for diabetes and heart disease. Knowing your breast density is one way to make sense of your risk for breast cancer. Just like the risk factors for other common diseases, knowing your risk of breast cancer can help you make good decisions regarding prevention and screening.
First, you likely need a little more information. Below is a list of the most common questions and their answers.
What is dense breast tissue?
Breasts are made up of four different parts: milk glands, milk ducts, connective tissue, and fat. Breast that contain a lot of fat are penetrable or light. They are easy to see through during a mammogram. Fibrous connective tissue is dense. Women with more connective tissue are said to have dense breasts.
On a mammography reading, fat appears almost black. Fibrous tissue shows up white. One of the main problems with high breast density is that cancer also appears white. So, if a woman has a lot of fibrous tissue, the radiologist reading the test may find it difficult to detect cancer.
What causes dense breast tissue?
Dense breast tissue is completely normal and not a concern in and of itself. And there are not many behavioral causes, apart from some forms of hormone therapy, which does increase breast density. Dense breasts are inherited, mostly. Although Asian women are more likely to have dense breasts and recent studies conflict regarding increased likelihood among African American women, breast density affects women of all races.
Breast density does decrease with age. More than half of women under age 50 have dense breasts, while only 40 percent of women in their 50s and only 25 percent 60 and older do.
How do I know if I have dense breast tissue?
You might guess if your breasts are firm that they are dense. But that is not always the case. Breast density cannot be detected by how your breasts look or feel. It is not linked to firmness or size. The only way to tell if you have dense breasts is by having a mammogram. At the same time your radiologist looks for abnormal areas, he or she will also evaluate breast density.
Your radiologist will assign density to your breasts. The density descriptions were created by the American College of Radiology as a part of their Breast Imaging Reporting and Data System. There are four types: least dense, scattered, more dense, and densest. The denser the tissue, the more difficult it may be to identify a tumor.
Staring January 15, 2017, mammogram reports issued from facilities in Vermont must note breast density in a way that is easy for patients to understand. Look for the words, “Fatty,” “Scattered,” “Heterogeneously Dense,” or “Extremely Dense.” Those with Heterogenous dense or Extremely dense breasts will receive the notification letter saying they have dense breasts.
How does dense breast tissue affect my breast cancer risk?
More than half of all women who develop breast cancer have no additional risk factors other than being female and aging; however, dense breast tissue can increase your risk of getting breast cancer above and beyond obscuring cancers on mammography. As density increases, risk increases. Women with the densest breasts have a risk for breast cancer that is 4- to 6-times higher than that of women with the least dense breasts.
What should I do differently if I find out that I have dense breasts?
For most women, no additional screening will be recommended. Depending on your age, other risks, and your breast density, your provider may recommend an additional screening, like ultrasound or MRI. While combining screening methods does increase the likelihood of finding cancers, it also increases the number of false positives, including perhaps unnecessary biopsies. That’s why it is wise to consider additional testing with your provider.
The website densebreast-info.org is an excellent resource for answers to more common breast density questions and helpful screening images that make it easy to see the differences between breasts of different densities.
John Wade, MD, is a radiologist with Radiology Associates of Bennington. Rebecca Hewson-Steller, RN, CN-BN, is the breast health navigator at SVMC Women’s Imaging and the Southwestern Vermont Regional Cancer Center. “Health Matters” is a column meant to educate readers about their personal health, public health matters, and public policy as it affects health care.