Studies show that as breast density increases, so does the risk of breast cancer. Breast density refers to the proportions of fat and tissue in the breasts as seen on a mammogram. High density breasts are those that have a greater proportion of tissue than fat. Low density breasts have a greater proportion of fat than tissue. Women with very dense breasts, as assessed by mammography, are four to five times more likely to develop breast cancer than women with low density breasts [33,34].
Although these findings have been consistent, health care providers do not yet regularly use a woman's breast density to assess her breast cancer risk. This is mainly due to the lack of an agreed-upon standard for assessing breast density.
Screening for Women with High Breast Density
For women with high breast density, digital mammography may offer screening benefits over standard mammography [35]. Tumors in women with very dense breast tissue can be easier to find with digital mammography. For more on digital mammography, click here. Both ultrasound and MRI are being studied to determine whether or not, when combined with mammography, they improve detection compared to mammography alone among women with dense breast tissue. For more on emerging screening and early detection methods, click here.
For more on screening options for women at higher risk of breast cancer, visit the Screening and Early Detection chapter.
Updated 09/14/09
