Breast Cancer: Anti-Estrogen treatment Flashcards
What is the typical responsiveness of anti-estrogen treatment in Estrogen sensitive tumors?
The tumors are typically responsive to treatment within 8-12 weeks. The average remission lasts 6-12 months
What drug is a Selective Estrogen Receptor Downregulator?
Fulvestrant
What is the MOA of Fulvestrant?
Fulvestrant is a pure antagonist of Estrogen. It binds to the ER and prevents dimerization which in turn prevent nuclear localization and increases degradation.
What is the ADME of Fulvestrant?
Monthly IM injections
Hepatic metabolism
What adverse effects are associated with fulvestrant?
Essentially symptoms of menopause: nausea asthenia vasodilation (hot flash) Headache
What Drugs belong to the SERM group?
Tamoxifen
Raloxifen
Toremifene
What is the MOA of the SERMs?
Location dependent agonistic/antagonistic effects on estrogen receptors.
What is the effect of SERMs on bone?
SERMs have an agonistic effect on bone. Thus they increase bone density.
What effect do SERMs have on breast and other tissues?
They are antagonistic in breast tissue thus inhibiting tumor growth. In other tissues they increase apoA1 and decrease LDL, cholesterol, and lipoproteins.
What are some common and serious adverse effects of SERMs?
Teratogenic
Retinal degeneration
DVT/PE/stroke
What is the ADME of tamoxifen?
Daily PO,
metabolized by CYP2D6
What are some effects unique to tamoxifen?
Can cause endometrial hypertrophy
Vaginal bleeding
Endometrial cancer
What is the ATLAS study?
The ATLAS study showed that the benefit of 10yr adjuvant therapy with tamoxifen outweighed the potential risk of endometrial cancer.
What is the ADME of Raloxifene?
Monthly IM injections
No agonism in the Endometrium.
What is the ADME of Toremifene?
Derivative of tamoxifen
Daily PO
CYP3A4
What adverse effects are unique to Toremifene?
Prolongation of QT interval
Agonizes ER in endometrium