Chemo from WM

Question 1

Definition: Partial response/remission?

Answer 1

Partial remission/response: decreased tumor volume by 50% or decreased max tumor diameter by >30%

Question 2

Definition: Progressive disease?

Answer 2

Progressive disease: Increase in tumor volume > 25% or increase in tumor max diameter of > 20%; new lesion(s)

Question 3

When do PFI/PFS begin counting?

Answer 3

PFI/PFS begins counting at the start of treatment.

Question 4

Chemosensitivity of a cell depends on a number of factors including what?

Answer 4

Chemosensitivity depends on:

1. Drug uptake into cell
2. Interaction with a cellular target
3. Generation of lethal damage to nb cell mols
4. Repair of potentially lethal damage
5. Cell’s response to generated damage

Question 5

Name 4 chemotherapeutics actively transported into cells:

Answer 5

Actively transported into cells:

1. Melphalan (two AA transporters)
2. Cytosar (nucleoside transporter)
3. Gemzar (nucleoside transporter)
4. Methotrexate (reduced folate carrier)

Question 6

Increased levels of which enzyme will increase 5-FU resistance?

Answer 6

Increased thymidylate synthetase decreases 5-FU sensitivity (increases resistance)

Question 7

Definition: Therapeutic index

Answer 7

Therapeutic index: The ratio between toxic dose and therapeutic dose

Question 8

Drug dosages are based on what?

Answer 8

Maximum tolerated dose (MTD), not efficacy

Question 9

Definition: Radiosensitization

Answer 9

Radiosensitization: enhancement of cytotoxicity when irradiation and chemo are combined so therapeutic gain is achieved

Question 10

Radiosensitization may involve: (1-3)

Answer 10

Radiosensitization may involve:

1. enrichment of tumor cell pop in more sensitive cell cycle phase
2. increased tumor oxygenation through cytoreduction or alterations in tumor vascularization
3. selective killing of inherently radioresistant hypoxic cell fractions

Question 11

Definition: partial remission/partial response

Answer 11

PR: decrease in tumor volume by 50% or more - OR - decrease in tumor max diameter of >30%

Question 12

Definition: Progressive disease

Answer 12

PD: increase in tumor VOLUME >25% or increase in tumor max diameter of >20%; new lesions

Question 13

Definition: DFI/DFS

Answer 13

DFI - amt of time that elapses w/o disease recurrence (or survival) or patient following therapy

Question 14

Definition: PFI/PFS

Answer 14

PFI/PFS: Amt time elapsed w/o evidence of progressive tumor growth (PFI) or survival w/o progressive growth of tumor from treatment START (PFS)

Question 15

Increased levels of this enzyme will decrease 5FU sensitivity

Answer 15

Increased levels of THYMIDYLATE SYMTHASE decrease 5FU sensitivity

Question 16

Which enzyme metabolizes gemcitabine from a pro-drug?

Answer 16

deoxycytidine kinase transforms gemcitabine from a pro-drug to its di- and tri-phosphate forms

Question 17

The ABCB1 mutation is expressed in which tumors?

Answer 17

ABCB1 expressed in…
Canine LSA, mammary, pulmonary carcinoma
Feline pulmonary carcinoma

Question 18

Which ABC transporter/MDR mutations are expressed in canine mammary tumors?

Answer 18

Canine mammary tumors express:

ABCC1, ABCC2, ABCC10, ABCG2

Question 19

What dose reduction is recommended for ACBC1 substrates in mut/mut patients?

Answer 19

Dose adjustments of 30-40% are recommended for ACBC1 substrates in mut/mut dogs

Question 20

Vehicle induced mast cell degranulation is associated with which chemotherapeutics?

Answer 20

Vehicle-induced mast cell degranulation:

Paclitaxel and etoposide

Question 21

Infusion hypersenstivity dt histamine release is associated with which chemotherapeutic?

Answer 21

Infusion hypersensitivity dt histamine release is associated with LSPAR

Question 22

Definition: elimination half-life

Answer 22

Elimination half-life: time required for concentration of drug to reach half its original value

Question 23

Cmax:

Answer 23

Cmax: the peak plasma concentratin of the drug after administration

Question 24

Tmax:

Answer 24

Tmax: time to reach Cmax

Question 25

Cmin:

Answer 25

Cmin: the lowest concentration of a drug before the next dose is administered

Question 26

Steady state typically equals X-X times the half life

Answer 26

SS typically equals 4-5 times the half life