PHARM: Breast Cancer Flashcards
How does estrogen mediate non-genomic actions?
Membrane-bound ER ALSO mediates nongenomic action through its interaction with growth factor receptor tyrosine kinases or downstream molecules
What implications do non-genomic estrogen actions have on breast cancer treatment success?
explain treatment failure with drugs that target only estrogen’s classical genomic pathway
What is the source of estrogen in pre-menopausal women?
ovaries
What is the source of estrogen in post-menopausal women?
adrenal cortex
What are the two major treatment options for pre-menopausal women with breast cancer?
Removal of ovaries Chemical castration (GnRH agonists)
What is commonly seen with the use of GnRH agonists in breast cancer?
Because they are agonists, it will initially increase estrogen release so that things get worse (bone pain, hypercalcemia, breast tenderness) before getting better.
What are the three major treatment options for post-menopausal women with breast cancer?
SERMs, Aromatase inhibitors, SERDs
Why do SERMs, aromatase inhibitors, and SERDs have only a 6-12 month effect?
due to alternative estrogen (non-genomic) pathways
How do progesterone receptor negative cells spread?
can spread the “negativity” via a paracrine mechanism
What type of HRT has been show to increase risk of invasive breast cancer?
Estrogen + Progesterone can increase risk of breast cancer while estrogen alone shows a significant reduction in breast cancer
What types of drugs can target HER2 + tumors?
mAbs adn RTKIs
How are triple negative breast cancers managed?
conventional therapy/chemotherapy
What conventional chemotherapy is commonly used for triple negative breast cancer that often leads to cardiac issues in the years following treatment?
doxirubicin
What are the major consequences of BRCA1/2 mutations?
DNA strand breaks, dysfunctional break repair and uncontrolled cell cycling through abrogation of the normal checkpoint machinery
What clinical features warrent BRCA gene testing?
- Breast cancer <45-50
- Ovarian, fallopian tube or primary peritoneal cancer
- 2+ primary breast cancer
- Breast + ovarian cancer
- Male breast cancer
- 2+ family members with breast and/or ovarian cancer
- Ashkenazi Jewish ancestry
What preventative treatment is available for women with BRCA mutations that decreases breast cancer risk by 90%?
prophylactic double mastectomy
What SERMs are used in BRCA carriers?
Tamoxifen
Raloxifene (post-menopausal only)
ONLY FOR BRCA2!!!!!
What percentage of BRCA1 carriers are ER+?
only 10-30%
What percentage of BRCA2 carriers are ER+?
60-75%
List the aromatase inhibitors. ROD?
Anastrozole
Exemestane
Letrozole
(all daily oral)
Which aromatase inhibitor is steroidal (irreversible)?
Exemestane
What are the indications for aromatase inhibitors?
ER+ metastatic BC in post-meno women for 5 years or swapping from AIs to tamoxifen, for a total period of 5 years
MOA of Aromatase inhibitors.
Aromatase inhibitors bind to heme center of CYP protein to block CYP19A1 mediated production of estrone and estradiol, thereby starving the tumor cell of continued proliferative signaling.
AEs of aromatase inhibitors.
Hot flashes, nausea, hair thinning (no effect on adrenal steroids, thyroid hormone and other hormones); more arthralgia and diarrhea but fewere gynecologic symptoms than SERMs
List the SERMs.
Raloxifene (monthly IM)
Tamoxifen (daily PO)