17 and 18 Antineoplastics Flashcards
(103 cards)
Cancer causes over how many deaths annually in the USA?
500,000 second only to heart disease
What is the % of diagnosed patients cured?
What percentage cured by chemotherapy?
What % cured by local measures?
- 50%
- 17%
- 33%
What are the 5 shortcomings mentioned of chemotherapies?
- cancer is a group of diseases
- cancers result from genetic alterations
- No foreign organism to target
- Harm to normal host
- low therapeutic indices
T-F—chemotherapeutic agents have high therapeutic indices?
False–a low index means its more toxic at lower doses
What 3 ways do conventional chemotherapeutic agents act?
inhibit metabolism (RNA synthesis)
Damage DNA
Interfere with mitotic machinery
T-F–chemotherapeutics do not attack the host cell?
False–they do
Does activation or inactivation of oncogenes overrides G_ arrest?
Activation, G1 arrest
Inactivation of tumor suppressor genes overrides what cell cycle arrest?
G2
When is the DNA replication checkpoint?
End of G2 phase
When is the restriction point checkpoint?
End of G1
What does S phase stand for?
synthetic phase, DNA replication
What is the order of the cell cycle starting from G0?
G1–>S—>G2—>M
What is the tumor cell growth fraction?
Fraction of cells not in G0
Are differentiated tumor cells responsive to chemotherapy?
not responsive they are in G0
[cycling cells are sensitive to cytotoxic drugs attacking cell cycle]
Which tumor cells are are responsive to conventional chemotherapy?
non G0
What is micro metastases derived from what does it lead to?
presumably derived from tumor stem cells, generally the ultimate cause of lethality
Is micrometastases susceptible to chemotherapeutic agents?
yes
Toxic side effects are most pronounced on what types of cells?
Noncancerous proliferating cells
- bone marrow
- intestinal epithelial cells
- oral mucosa
- gonadal cells
- hair follicles
according to the log kill hypothesis how many cells does each intervention kill?
eradicates the same percentage of tumor cells (you have to stop to take breaks to relieve the adverse effects in which the cancer cells grow again)
What are the 4 primary applications for chemotherapy?
1- metastatic/hematopoietic cancer
2- surgical adjuvant
3- lymphomas, leukemias
4- palliative/prolong life
What are the 3 major alkylating agents/classes of alkylating agents?
bischloroethyl amines, nitrosoureas, procarbazine
What drug was the nitrogen mustard that was used in mustard gas World War 1?
mechlorethamine
What less highly reactive derivative has been developed to replace mechlorethamine? What does it require?
cyclophophamide
-activation in liver or tumor tissues
Dechlorination of the bischloroethyl amines leaves what energy state?
+ state- electrophile
[this is what attacks neutrophils nitrogen in DNA bases]