Breast cancer is one of the leading causes of cancer-relatedmortality among women worldwide from different age groups.
The vast majority of breast cancers in postmenopausal women are
deriving from estrogens production.
1–3
Estrogens are biosynthesized from androgens catalyzed by aromatase (CYP19), an enzyme
belonging to the P450 family of monooxygenase heme proteins.
Two main strategies to control or block breast cancer progression include binding of the estrogen receptors (ERs) with receptor antagonists (ERAs such as tamoxifen), and inhibiting the production of estrogen with aromatase inhibitors (AIs).
3
AIs were found to have less side effects than ERAs owing to the the lack of estrogenic activity on uterus and vasculature.