{"meta":{"totalResults":2,"from":0},"results":[{"aliases":[{"type":"CodeName","name":"CGS 20267"},{"type":"ForeignBrandName","name":"Fempro"},{"type":"USBrandName","name":"Femara"},{"type":"ChemicalStructureName","name":"4,4'-(1H-1,2,4triazol-1-ylmethylene)dibenzonitrile"},{"type":"CASRegistryName","name":"112809-51-5"}],"definition":{"html":"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.","text":"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."},"drugInfoSummaryLink":{"uri":"https://www.cancer.gov/about-cancer/treatment/drugs/letrozole","text":"Letrozole"},"nciConceptId":"C1527","nciConceptName":"Letrozole","termId":42086,"name":"letrozole","firstLetter":"l","type":"DrugTerm","termNameType":"PreferredName","prettyUrlName":"letrozole"},{"aliases":[{"type":"Synonym","name":"letrozole-palbociclib"},{"type":"Synonym","name":"palbociclib + letrozole"},{"type":"Synonym","name":"letrozole + palbociclib"},{"type":"Synonym","name":"letrozole/palbociclib"},{"type":"Synonym","name":"Femara/Ibrance"},{"type":"Synonym","name":"letrozole-palbociclib regimen"}],"definition":{"html":"A regimen consisting of letrozole and palbociclib that can be used in the treatment of breast cancer.","text":"A regimen consisting of letrozole and palbociclib that can be used in the treatment of breast cancer."},"drugInfoSummaryLink":null,"nciConceptId":"C142859","nciConceptName":"Letrozole/Palbociclib Regimen","termId":791794,"name":"letrozole/palbociclib regimen","firstLetter":"l","type":"DrugTerm","termNameType":"PreferredName","prettyUrlName":"letrozole-palbociclib-regimen"}],"links":null}