Breast Density Tied to Specific Types of Breast Cancer

Extract

Women with breasts that appear dense on mammograms are at a higher risk of breast cancer and their tumors are more likely to have certain aggressive characteristics than women with less dense breasts, according to a study published online July 27 in the Journal of the National Cancer Institute.

Mammographic breast density—a reflection of the proportions of fat, connective tissue, and epithelial tissue in the breast—is a well-established risk factor for breast cancer. Women with higher amounts of epithelial and stromal tissue have higher density and higher risk. However, it has not been clear whether breast density was associated with specific tumor characteristics and tumor types.

To explore this issue, Rulla M. Tamimi, Sc.D., at Harvard Medical School and Brigham and Women’s Hospital, Boston, and colleagues, compared breast density in 1,042 postmenopausal women with breast cancer and 1,794 matched control subjects (women who were similar in terms of age, postmenopausal hormone use, and other factors, but did not have breast cancer).