Q: What is breast density and what should a woman know about it?
A: Women’s breasts are a mixture of dense breast tissue and fatty tissue (which is less dense). Breast density cannot be determined in a physical exam, only by imaging. Even with the best screening digital mammography, dense breast tissue can be hard to “see through.” This means that the ability of mammography to find cancers is somewhat reduced in women with dense breast tissue. Breast density tends to vary over a woman’s lifetime, becoming less dense after menopause. An estimated 66 percent of premenopausal women and 25 percent of postmenopausal women have a breast density that interferes with mammogram accuracy. In addition to this challenge, very dense breast tissue has been shown to put a woman at a small increased risk for developing breast cancer. The bottom line is that extra vigilance is needed in women with dense breast tissue and many believe that, along with her doctor, the woman herself should be routinely informed, in plain language, about her breast density.
Q: If she is told she has dense breast tissue, what should a woman do?
A: Dense breast tissue is very common, not abnormal, and not a reason to become alarmed. If you have dense breasts, you should talk to your doctor about your personal breast cancer risk number and personal risks for breast cancer. You should fully explore the options available to you including asking your doctor if more breast screening tests might be useful, based on your risk. Every woman is different, but your doctor may recommend you consider supplemental screening tests. There is a great resource available from the American College of Radiology.