ARTICLE

used to predict risk of invasive breast cancer (including both estro-gen receptor [ER] – positive and ER-negative disease) in women 35 years of age or older ( 1, 2). However, strategies to reduce breast cancer risk, including use of tamoxifen, raloxifene, and aromatase inhibitors, infl uence almost exclusively ER-positive disease, with the use of raloxifene and aromatase inhibitors limited to post-menopausal women ( 3, 4). In addition, although many women could potentially benefi t ( 5), risk – benefi t considerations indicate that a large number of postmenopausal women must be screened to identify a population who gain net benefi t from tamoxifen use ( 6, 7). As a result, methods to rapidly identify a population of post-menopausal women at increased risk of ER-positive breast cancer are needed. We therefore examined models of breast cancer risk in partici-pants of the Women’s Health Initiative (WHI). Our objectiv