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NCI Drug Dictionary


letrozole  Patient Information
A nonsteroidal inhibitor of estrogen synthesis with antineoplastic activity. As a third-generation aromatase inhibitor, letrozole selectively and reversibly inhibits aromatase, which may result in growth inhibition of estrogen-dependent breast cancer cells. Aromatase, a cytochrome P-450 enzyme localized to the endoplasmic reticulum of the cell and found in many tissues including those of the premenopausal ovary, liver, and breast, catalyzes the aromatization of androstenedione and testosterone into estrone and estradiol, the final step in estrogen biosynthesis. Check for active clinical trials or closed clinical trials using this agent. (NCI Thesaurus)
US brand name:Femara
Abbreviation:LTZ
Code name:CGS 20267
Chemical structure:4,4'-(1H-1,2,4triazol-1-ylmethylene)dibenzonitrile