Breast density and breast cancer

Abstract

Breast density is increasingly recognized as an independent risk factor for the development of breast cancer. It has been shown to be associated with a four-to sixfold increase a woman's risk of malignant breast disease. Increased breast density, as identified on mammography, is known to decrease the diagnostic sensitivity of the examination, which is of great concern to women at increased risk for breast cancer. Dense tissue has generally been associated with younger age and premenopausal status, with the assumption that breast density gradually decreases after menopause. However, the actual proportion of older women with dense breasts is unknown. Unfortunately, mammography is less accurate on dense breast tissue compared to fattier breast tissue. Multiple studies suggest a solution to this by demonstrating the ability of supplemental screening ultrasound to detect additional malignant lesions in women with dense breast tissue but with negative mammography. Improved screening methods for women with dense breasts are needed due to their increased risk of breast cancer and of failed early diagnosis by screening mammography.