Antiandrogenic actions of medroxyprogesterone acetate on epithelial cells within normal human breast tissues cultured ex vivo

Abstract

In a subset of postmenopausal women, MPA exerts an antiandrogenic effect on breast epithelial cells that is associated with increased proliferation and destabilization of AR protein. This activity may contribute mechanistically to the increased risk of breast cancer in women taking MPA-containing EPT.