Aromatase Inhibitors in Gynecology

as androstenedione and testosterone. These corticosteroids then move across to the granulosa cells where aromatase, stimulated by FSH, converts the androstenedione to estrone and, to a lesser extent, testosterone to estradiol.2 Subsequently, estrone is converted to estradiol by 17-β hydroxysteroid dehydrogenase (Figure 2). The conversion of androgens to estrogens is called aromatization and is inhibited by aromatase inhibitors. Aromatase inhibitors have 2 primary mechanisms of action. First, they reduce estradiol levels, which in turn blocks estradiol’s impact on estrogen-sensitive end organs. Second, a reduction of estradiol levels decreases the feedback inhibition of the hypothalamic-pituitary-ovarian (HPO) axis, leading to an increase in GnRH secretion and therefore an increase in pituitary gonadotropins (Figure 1B). This article reviews a variety of potential uses of aromatase inhibitors in the field of gynecology. It is important for obstetricians/gynecologists to understand the current evidence around their use and apply it toward potential treatment options for their patients.