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
What cardiovascular and endocrine side effects of GnRH agonists warrant concern in select patients?
QT prolongation (a side effect of androgen deprivation), dyslipidemia, and hyperglycemia
What is abiraterone? What drug must it always be given with, and why?
Abiraterone is a CYP17A1 inhibitor, which is the enzyme responsible for a large part of the metabolic conversion of cholesterol to cortisol and DHT. Since cortisol production is blocked, prednisone is given to both replace the lost steroid and provide some negative feedback on the pituitary gland to prevent further aldosterone production.
Which classes of traditional chemotherapy agents are cell-cycle independent?
Alkylating agents (eg cyclophosphamide) Anthracyclines (eg doxorubicin) Platinum compounds (eg cis/carboplatin)
Chemotherapy is most often dosed by _______ or _______.
weight (mg/kg) or BSA
What is the Mosteller equation for BSA calculation?
sqrt [(ht in cm x wt in kg) / 3600]
What is the name of the toxic metabolite of cyclophosphamide and ifosfamide? Where does this accumulate? How can patients be protected from this adverse effect?
Acrolein is a metabolite that accumulates in the bladder, causing hemorrhagic cystitis. Since ifosfamide causes this at any dose, it is always given with mesna, while only higher doses of cyclophosphamide require mesna.
Among the alkylating agents: pulmonary toxicity, neurotoxicity, and hepatic necrosis are boxed warnings of _______, _______, and _______, respectively.
carmustine, ifosfamide, dacarbazine
While it does not have a boxed warning for pulmonary toxicity, this alkylating agent is well known to cause it.
busulfan (remember the B’s are often pulmonary toxicity - busulfan/bleomycin)
Which alkylating agent should be protected from light and turns pink when it has decomposed?
dacarbazine
Which chemotherapy drug is associated with the highest incidence of nephrotoxicity and CINV?
cisplatin (boooooo)
Other than CINV, what are the two biggest concerns with cisplatin? Which of them can be reduced with a chemoprotectant?
Nephrotoxicity and ototoxicity
Nephrotoxicity can be reduced by giving IV fluids and amifostine (ethyol).