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letrozole![Patient Information Patient Information](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/btn-patient-info.gif) A nonsteroidal inhibitor of estrogen synthesis that resembles paclitaxel in chemical structure. As a third-generation aromatase inhibitor, letrozole selectively and reversibly inhibits aromatase, a cytochrome P-450 enzyme complex found in many tissues including those of the premenopausal ovary, liver, and breast; aromatase catalyzes the aromatization of androstenedione and testosterone into estrone and estradiol, the final step in estrogen biosynthesis. In estrogen-dependent breast cancers, anastrozole may inhibit tumor growth. Check for active clinical trials or closed clinical trials using this agent. (NCI Thesaurus)
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US brand name: | ![](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/spacer.gif) | Femara | | ![](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/spacer.gif) | Abbreviation: | ![](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/spacer.gif) | LTZ | | ![](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/spacer.gif) | Code name: | ![](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/spacer.gif) | CGS 20267 | | ![](https://webarchive.library.unt.edu/eot2008/20090114221229im_/http://www.cancer.gov/images/spacer.gif) |
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