Hormones and the breast: Local and environmental interactions

Abstract

A woman's reproductive history affects her risk to get breast cancer. In particular, the number of menstrual cycles she experiences correlates with risk. We use tissue recombination experiments and different mouse mutant models to discern the roles of the ovarian hormones estrogens and progesterone act in the mammary gland. While estrogens drive pubertal development, progesterone is the major driver of proliferation in the adult mammary epithelium. Both steroids rely strongly on paracrine signaling to elicit cell proliferation and other biological effects.