5. Tumor Cell Heterogeneity
Drug sensitive
subpopulation
Drug resistant
subpopulation
Drug resistant
subpopulation
Drug sensitive
subpopulation
Chemotherapy
6. Mechanisms of drug resistance
Single drug
Resistance
Multiple drug
Resistance
C a t a b o l i c
enzymes
GSH & its
enzymes
Resistance to
Topoisomerases
inhibitors
Transport
proteins
mdr‐ 1 gene
P170
Loss of
apoptosis
8. Clinical uses of cytotoxic agents
Contra-indications
Inable to assess
response to therapy or
toxcity
Short
survival
Poor
Performance
status
Asymptomatic slow-
growing & incurable
(Indolent)
9. Clinical uses of cytotoxic agents
Timing of
chemotherapy
Induction
cheomotherapy
Post-remission
cheomotherapy
Salvage
Neoadjuvant Adjuvant
10. Clinical uses of cytotoxic agents
Clinical end points in
evaluating response
Complete Response
Partial Response
Stable disease
Progressive disease
Relapse Free
Survival
Progression Free
Survival
Pathogical
Response
CLinical
Response
11. Clinical uses of cytotoxic agents
Responsiveness of tumors to
chemotherapy
Curable
Choriocarcinoma
Improved Survival
Aggressive NHL
Palliation
Prostate cancer
Occasional responses H&N cancer
12. Treatment Approach
Low dose Therapy
High dose Therapy
Dose-dense Therapy
Alternating therapy
Dose intensification
More
frequent
Highest
tolerated
dose
Palliative
To target different
subpopulation
13. Monitoring of cytotoxic agents
Toxicity
Disease extent
Time of toxicity
Chemotherapy
Flow Sheet
14. Administering cytotoxic agents IV
Vein selection
Large
forearm
veins
Metacarpal
veins on
dorsum of
hand
Antecubital
fossa
Wrist
Freely
flowing
intravenous
line
Extravasation
16. Adverse effects of chemotherapy
General
effects
Fatigue & Malaise Fever & ChillsAlopecia
Modifying
drug
dosage
Postpone
Infection
Toxicity
Debiliated
100%
Effective
17. Adverse effects of chemotherapy
Mylosuppressive
drugs
Nadir
ANC 2000
Plt 120,000
Increase interval
Dose reduction
Different Nadir
Different Recovery
18. Adverse effects of chemotherapy
Diarrhea
Recovery
Mucositis
100%75%50%
Creatinine clearance
< 55 mL/min
Abnormal liver function
Hepatoxic
Nephrotoxic