Aromatase inhibitors are endocrine agents with a different mode of action than tamoxifen against breast tumors. In postmenopausal women, estrogen concentrations are maintained primarily via aromatase, a cytochrome P-450 enzyme that acts at the final step in the estrogen synthesis pathway. The first clinically available aromatase inhibitor, aminoglutethimide, was introduced for the second-line t...

Exemestane (EXE) treats estrogen receptor positive (ER+) breast cancer in postmenopausal women by inhibiting the estrogen-synthesizing cytochrome P450 CYP19A1. Variability in the severity and incidence of side effects as well as overall drug efficacy may be partially explained by genetic factors, including nonsynonymous variation in CYP19A1, also known as aromatase. The present study identified...

Several large phase III trials have demonstrated that tamoxifen-and more recently, raloxifene-can effectively reduce the incidence of invasive breast cancer by 50%. However, these selective estrogen receptor modulators can also be associated with several rare, but serious, adverse events. Recently, the third-generation aromatase inhibitors (AIS) have demonstrated excellent efficacy in adjuvant ...

Over the past decade several novel aromatase inhibitors have been introduced into clinical practice. The discovery of these drugs followed on from the observation that the main mechanism of action of aminogluthemide was via inhibition of the enzyme aromatase thereby reducing peripheral levels of oestradiol in postmenopausal patients. The second-generation drug, 4-hydroxyandrostenedione (formest...