Oncology II - Common Cancers and Treatment Flashcards
Which parts of the body have the most rapidly dividing cells, and thus are most susceptible to side effects from chemotherapy?
GI tract (vomiting/diarrhea) hair follicles (hair loss) bone marrow (suppression)
What are two clinically valid scales used for assessment of side effects by a patient’s level of physical functioning?
Karnofsky and ECOG
What is the function of BRCA genes in healthy individuals? Mutation in these genes increases the risk of what kind of cancer?
BRCA genes function as tumor suppressor genes by repairing damaged DNA. Mutations render them ineffective, and increase a woman’s odds of breast cancer.
Describe the genetic nature of Klinefelter’s syndrome, who it effects, and the cancer risk it imposes.
Klinefelter’s syndrome affects males and occurs when an extra X chromosome is present (XXY). These men produce more estrogen than normal and are at an increased risk of breast cancer, which frequently feeds on estrogen.
How does the treatment of hormone sensitive breast cancer differ in pre- and post-menopausal women?
Since premenopausal women produce estradiol (the most potent estrogen), they receive a SERM (tamoxifen) to block the hormone dependent tumor. Post-menopausal women do not produce estradiol, and instead receive an aromatase inhibitor that blocks the production of weaker estrogens in the periphery.
Why is an aromatase inhibitor not effective for hormone sensitive BC treatment in premenopausal women?
Aromatase inhibitors do not block the production of estradiol, which feeds the tumor in pre-menopausal women.
Which SERM is indicated for BC prophylaxis, but not treatment?
raloxifene
Where is raloxifene an estrogen inhibitor? agonist?
Raloxifene is an estrogen inhibitor in the ovaries - giving it some cancer prophylactic use. It is an agonist in bone, which is why it can be used for osteoporosis. However, its agonism in the CNS and blood make it not first line - it can cause hot flashes (CNS) and clots (blood).
Which SERM is an injectable?
fulvestrant (Faslodex)
Which SERM is a prodrug that requires conversion for activation? Which enzyme does this?
tamoxifen - 2D6 (don’t take with 2D6 inhibitors)
Describe the issues associated with treating hot flashes caused by tamoxifen.
Since tamoxifen requires activation by CYP2D6, and fluoxetine and paroxetine (typically used for hot flashes) are 2D6 inhibitors, venlafaxine is preferred for initial treatment.
What are some side effects of SERMs used for breast cancer treatment or prophylaxis? What are two unique to tamoxifen?
hot flashes, vaginal bleeding/spotting, vaginal discharge or dryness, decreased libido
unique to tamoxifen - cataracts and decreased bone density (supplement with calcium and D)
Tamoxifen carries a boxed warning for increased risk of what cancer?
endometrial (acts as an estrogen agonist in the uterus)
brand name and drug class of anastrozole
Arimidex - an aromatase inhibitor
Should patients be counseled to take two doses of a SERM/AI if they miss a dose one day?
no - take as soon as you remember, but not if it is close to time for your next dose, just skip dose entirely
Which SERM is a known teratogen?
tamoxifen
How should patients be counseled for oral administration of SERMs regarding food?
These may be taken with or without food.
The first-line treatment mode for prostate cancer is (think broad) _______.
androgen deprivation therapy (ADT)
How can testosterone depletion (or chemical castration) be accomplished?
A GnRH agonist may be used in combination with an antiandrogen (for a few weeks) or a GnRH antagonist/antiandrogen alone.
If a GnRH agonist is used for chemical castration, what must be used with it? Why?
An antiandrogen must be used - since the GnRH will initially cause increased testosterone production and a tumor flare, an antiandrogen must be given until the negative feedback in the pituitary shuts off GnRH release.
What are the two most commonly used GnRH agonists?
leuprolide (Lupron depot) and Goserelin (Zoladex)
What is the most significant side effect that can be partially prevented with GnRH agonists and antagonists?
a decreased in BMD - tell patients to supplement with Ca/D
Which medication is a GnRH antagonist?
degarelix (firmagon)
What are the side effects of the GnRH agonists and antagonists?
hot flashes, impotence, decreased BMD, gynecomastia, bone pain