It’s easy to think of breasts as simply mounds of fat on a woman’s body, but they’re much more complex structures than that. Within the breast are a network of glands and ducts that produce and move milk to the nipple for feeding a baby. There’s also lots of fibrous and fatty tissue in between these structures, and how much of this fatty tissue you have can play a part in whether you develop breast cancer.
If you have less fatty tissue, your breasts are considered dense, and density is both a risk factor of its own and can be a hindrance for diagnosing cancer in some women. According to the Susan G. Komen foundation, high breast density is a common occurrence in American women; between 40 and 50 percent of women ages 40 to 74 in the U.S. have dense breasts.
Regardless of the individual genetic and lifestyle factors that contribute to a woman having dense breasts, the Susan G. Komen foundation reports that these “women with high breast density are four to five times more likely to get breast cancer than women with low breast density.”
How Density is Measured
Breastcancer.org reports that “no one method of measuring breast density has been agreed upon by doctors. Breast density is not based on how your breasts feel during your self-exam or your doctor’s physical exam.” Although there isn’t an exactly quantifiable measure for what makes a breast dense, there are gradations of density that can be determined by looking at a mammogram. The Breast Imaging Reporting and Database Systems, a reporting database supported by the American College of Radiology, classifies density into four categories: mostly fatty, scattered density, consistent density and extremely dense.