Loading...
Mammographic breast density is associated with breast cancer via two mechanisms: (1) dense tissue appears to reflect a biologic predisposition to breast cancer, and (2) dense tissue masks tumors on mammography. In this Canadian study, researchers determined the relative contributions of these two mechanisms to breast cancer risk.
Drawing from mammographic screening studies, researchers assembled 1112 cases (women with newly diagnosed breast cancer) and 1112 age-matched controls. In analyses adjusted for conventional risk factors, women with extremely dense breasts on mammography had a significantly increased risk for mammography-detected breast cancer, compared with women in the lowest-density category (odds ratio, 3.5). During the 12 months…