October is Breast Cancer Awareness Month. Breast cancer is one of the most common kinds of cancer in women. About 1 in 8 women born today in the United States will get breast cancer at some point.

Regular mammograms are the best way to find breast cancer early. But if your mammogram report says that you have dense breast tissue, you may be wondering what that means. Having dense breasts is very common and is not abnormal. Studies show breast density, which is associated with breast cancer risk, was found to be higher in Black/African-American women than white women 

What is dense breast tissue? Breasts are made up of lobules, ducts, and fatty and fibrous connective tissue.

Lobules produce milk and are often called glandular tissue. Ducts are the tiny tubes that carry milk from the lobules to the nipple. Fibrous tissue and fat give breasts their size and shape and hold the other tissues in place.

Your breasts will be seen as dense if you have a lot of fibrous or glandular tissue and not much fat in the breasts. Some women have more dense breast tissue than others. For most women, breasts become less dense with age. But in some women, there’s little change. 

Women who have dense breast tissue seem to have a slightly higher risk of breast cancer compared to women with less dense breast tissue. It’s unclear at this time why dense breast tissue is linked to breast cancer risk.

We do know that dense breast tissue makes it harder for radiologists to see cancer. On mammograms, dense breast tissue looks white. Breast masses or tumors also look white, so the dense tissue can hide some tumors. In contrast, fatty tissue looks almost black. On a black background it’s easier to see a tumor that looks white. So, mammograms can be less accurate in women with dense breasts.

Most breast cancers can be seen on a mammogram even in women who have dense breast tissue, so it’s still important to get regular mammograms. Mammograms can help save women’s lives.

Even if you have a normal mammogram result (regardless of how dense your breasts are), you should know how your breasts normally look and feel. Anytime there’s a change, you should report it to a health care provider right away.