Flashcards in Pharm 1: Endocrine Therapies used in Breast Cancer Deck (6)
What must you do before you start Endocrine Therapies used in Breast Cancer ?
• Make sure the patient is estrogen receptor +
o Endocrine therapy is the treatment of choice for patients with hormone receptor-positive tumors who exhibit the first sign of metastatic disease in soft tissue, bone, or pleura.
What are the goals of Endocrine therapy?
• Decrease circulating levels of estrogen
• Prevent the effects of estrogen at the breast cancer cell (targeted therapy) by blocking the hormone receptors or down regulating the presence of those receptors.
• Examples: Anastrozole, Letrozole, and Exemestane
• MOA: block the binding of estrogen to the receptor
o Aromatase is responsible for peripheral conversion of androstenedione, produced by the adrenal gland, into estrone and estradiol.
first line therapy for advanced Breast CA in post-menopauseal women
• nonsteroidal compounds : Anastrozole and letrozole are nonsteroidal compounds that exhibit reversible, competitive inhibition of aromatase while
• Exemestane is steroidal and irreversible.
•Anastrozole and letrozole are for first-line therapy indicated for advanced breast cancer in postmenopausal women. Uterine cells will stop producing the estrogen at this point so it will target the other cells
SERMs and Pure antiestrogen
• MOA: Binds to estrogen receptors, which inhibit receptor-mediated gene transcription and therefore block the effect of estrogen on the end target
SERMs and pure antiestrogens
o SERMs include tamoxifen and toremifene (and raloxifene for breast cancer risk reduction in high-risk women. They inhibit cell proliferation in breast cells, but stimulate the proliferation of uterine endometrial cells.
o Pure antiestrogens also called selective estrogen receptor downregulators (SERDs). These molecules bind to the ER, inhibit estrogen binding, and degrade the drug-ER complex, thus decreasing the amount of ER on the tumor cell surface. Fulvestrant is the only drug in this class