Breast Density and Its Effect on Your Cancer Screening
August 7, 2018
If you’ve had a mammogram and were told you have dense breast tissue, you may be wondering what that means. While having dense breasts is normal and common, many women are left feeling uncertain regarding whether there is anything they should do differently or how it affects the risk of getting breast cancer.
What Does it Mean to Have Dense Breasts?
Breasts contain glandular, connective, and fat tissue. Breast density is a term that describes the relative amount of these different types of breast tissue as seen on a mammogram. Dense breasts have more glandular tissue and fibrous connective tissue and than fatty breast tissue. Dense breasts can be inherited.
Younger women, more than older women, tend to have dense breasts since breast density typically decreases with age. According to Susan G. Komen, approximately 50-60 percent of women ages 40-44 have dense breasts, compared to 20-30 percent of women ages 70-74.
The Breast Imaging Reporting and Database Systems (BI-RADS), which reports mammogram findings, classifies breasts into four groups:
- Mostly fatty: The breasts are made up of mostly fat and contain little fibrous and glandular tissue, which means the mammogram would likely show anything that was abnormal.
- Scattered density: The breasts have quite a bit of fat, but there are a few areas of fibrous and glandular tissue.
- Consistent density: The breasts have many areas of fibrous and glandular tissue that are evenly distributed through the breasts, making it harder to see small masses in the breast.
- Extremely dense: The breasts have a lot of fibrous and glandular tissue, which may make it hard to see a tumor on a mammogram since breast cancer can blend in with the normal tissue.
The Connection Between Breast Density and Cancer
Women with dense breasts have a higher risk of breast cancer than women with fatty breasts, and the risk increases with increasing breast density. Research has shown that women who have dense breasts are 6 times more likely to develop breast cancer. In addition to that, dense breasts can make it harder for mammograms to detect breast cancer. This is because there is not enough fatty tissue surrounding the tumor to make it easily visible.
This does not mean women with dense breasts are more likely to die from breast cancer. In fact, studies have found that women who have dense breasts are no more likely to die from breast cancer than breast cancer patients who have fatty breasts, after accounting for other health factors and tumor characteristics.
What Does that Mean for Your Mammogram?
Only a mammogram can show if a woman has dense breasts. However, because dense breast tissue appears white on a mammogram, as do some abnormal breast changes like calcifications and tumors, it can make it more difficult to find cancer on a standard screening. Because of this, women with dense breasts have more false-negative results, which indicate that there is no disease present even though it really is.
If you have dense breasts, you may be called back for follow-up tests more often than women with fatty breasts. In some cases, your doctor may recommend breast ultrasound and/or magnetic resonance imaging (MRI). Studies have shown that both can help detect some breast cancers that can’t be seen on mammograms. Insurance may not always cover these procedures, but it could be important, especially if you have dense breasts or other risk factors.
Steps You Can Take to Lower Your Risks of Breast Cancer
One important step you can take is to make certain lifestyle changes that could help lower your risk for developing breast cancer. These may include:
- Keeping a healthy weight
- Exercising regularly
- Eating a nutritious diet
- Quitting smoking
- Reducing your alcohol intake
In addition to lifestyle changes, another important step is keeping up with your regular breast screenings. According to the American Cancer Society, this includes:
- Monthly self-exams of the breast
- Yearly breast exams by your doctor
- Yearly mammogram for women ages 40-54 and mammograms every two years for women age 55 and older
Talk to your doctor about developing a screening plan that is tailored to your unique situation so you can have peace of mind.