082614 antineoplastics part one Flashcards
ways to stop tumor growth
kill cells (directly by necrosis or by triggering apoptosis)-many antineoplastics trigger apoptosis
cytostatic-stop growth (induce terminal differentiation, interfere w/ growth signals)
what time should you treat with chemotherapy?
when cells are actively growing (increased sensitivity)
why are leukemias and lymphomas very susceptibel to anti-neoplastic drugs?
have a high percentage of actively dividing cells
0.99 fractional cell kill corresponds to log kill of?
2
what order kinetics does killing tumors follow?
first order (a constant dose will kill a constant fraction of tumor cells)
first order best observed in early stages of tumor growth
does tumor size predict dose?
no, because killing tumors follows 1st order kinetics
does tumor size predict duration of therapy?
yes, because killing tumors follows 1st order kinetics
what is the effect of a shorter treatment interval for chemotherapeutics?
has better therapeutic effect
what log kill is required for chemotherapy to be curative?
2-4 log kill, and repeated for 4-12 cycles
what are the class I cel cycle non-specific drugs (antineoplastic agents)?
target DNA (which every cell has) cytotoxicity is nonspecific and kills cells in any stage including G0 (which is non-cell cycle)
kill normal and neoplastic cells to the same extent, which isn’t good
class II cell cycle specific, phase non-specific drugs
targets cells in the cell cyle without regard for specific phase of cell cycle (all dividing cells but not G0)
administered in single large dose to take advantage of their sparing effect on normal cells that may be in G0 (leads to bigger therapeutic window)
class III cell cycle-specific phase-specific drugs
target a specific phase of the cell cycle (can’t target G0 b/c G0 is not in cell cycle)
given either by continuous infusion or in frequent small doses by at any given time, only some of the cells in a tumor are in one particular phase of the cell cycle
which class of antineoplastics had the best log kill effect on breast tumor cells in cell culture?
alkylating agents
what fraction of the tumors cells do cycle specific phase non-specific drugs kill?
a good fraction of the tumor but not including G0 cells
define therapeutic window
difference between percent of surviving cells in the cancer cells and percent surviving in the normal cells
