Aromatase Inhibitors as Chemopreventives of Breast Cancer

  • Mitchell Dowsett
  • Judy E. Garber
Part of the Cancer Drug Discovery and Development book series (CDD&D)


Aromatase is a cytochrome P450 enzyme present in the endoplasmic reticulum (ER) which is responsible for the synthesis of steroidal estrogens. It appears that a single aromatase gene codes for the enzyme in all tissues, but, as discussed here, the control of this gene is tissue-specific according to the usage of a number of different promoters (1). Aromatase catalyzes the conversion of androstenedione (the preferred substrate) and testosterone to estrone, then to estradiol. The conversion of estrone to estradiol the most potent estrogen is reversible, and is catalyzed by the 17(β hydroxysteroiddehydrogenase enzyme system (Fig. 1).


Breast Cancer Breast Cancer Risk Aromatase Inhibitor Advanced Breast Cancer Mammographic Density 
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© Springer Science+Business Media New York 2004

Authors and Affiliations

  • Mitchell Dowsett
  • Judy E. Garber

There are no affiliations available

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