The risk of developing estrogen receptor (ER)-positive breast cancer increases in post-menopausal women if the gene Esr1 (estrogen receptor 1) is expressed excessively in glandular cells of the breasts, reports a study from the Georgetown Lombardi Comprehensive Cancer Center published in the American Journal of Pathology. Another study by the same group, in the same issue of the journal, reports preclinical evidence that administration of anti-hormonal drugs such as tamoxifen and letrozole, can reduce the risk of developing breast cancer due to overexpression of Esr1. The studies use a new mouse model of aging that mimics breast cancer development in ER-positive post-menopausal women.
