3. Cancer Biology
• A 1-cm tumor: 109 cells
• Lethal tumor burden: 1012 cells
• Chemotherapy can kill a specific fraction of
tumor cells present
– Fraction of cell kill: cell sensitivity & dose of drug
• At least 4 courses of treatment are needed
– 1011108105102almost 0 cell
• What is a “course”?
– Period that is for normal tissue recovery
4. Mechanisms of
antineoplastic drug action
• Some drugs are cell cycle phase
specific (ex. Cytarabine in S phase),
some are not
• Chemotherapy target: DNA
5. Class of Chemotherapy Agents
• Alkylating agent: cross link DNA
– cyclophosphamide,
ifosfamide, melphalan
• Cisplatin and its analogue: inhibit
DNA formation
– cisplatin, carboplatin
• Antimetabolites: inhibit purine or
pyrimidine synthesis
– Ara-C, methotrexate,
fludarabine
6. Class of Chemotherapy Agents
• Topoisomerase inhibitor: binding to DNA &
interfere with mitosis
– adriamycin, etoposide
• Antimicrotubule: spindle damage, absent
metaphase
– vincristine, vinblastine,paclitaxel
• L-asparaginase
– hydrolyzes asparagine into aspartic
acid,Destroy extracellular
asparagine stores
– kills those unable to synthesize
asparagine
17. Drug specific toxicity -1
• Cyclophosphamide: general side
effects of C/T
– HD- Cyclophosphamide : for stem cell
harvest
• Hemorrhagic cystitis
• Mesna use and keep high urine output
• Mesna = 0.6 to 1.5 dose of
Cyclophosphamide (before ,during & after
4hr/8hr)
• Ifosfamide:
– Hemorrhagic cystitis/Renal tubular
18. Drug specific toxicity -2
• Adriamycin:
– A vesicant
– Congestive Heart Failure :
• rare if doxorubicin < 450 mg/m2
– 550 ,600 ,700 mg/m2 7% ,15% ,30%
• Vincristine: peripheral neuropathy,
ileus
• Steroid: candidiasis, GI upset, edema
Principles of chemotherapy
19. Drug specific toxicity -3
• High-dose Ara-C:
• Cerebellar toxicity
• Skin rash
• Conjunctivitis
– Prophylactic steroid use for skin rash
and conjunctivitis
20. Drug specific toxicity -4
• L-asparaginase:
– Hypersensitivity
– Low albumin
– Low coagulation factors
– Pancreatitis
21. Drug specific toxicity -5
• Etoposide:
– General side effects of chemotherapy
– Hypersensitivity
– 泡製濃度要<0.4 mg/ml,濃度高較不穩定而且容
易發生沈澱
– 腎功能異常要減量
Principles of chemotherapy
22. Drug specific toxicity -6.1
High dose MTX : MTX > 500mg/m2
need hydration and urine alkalinization
Leucovorin (folinic acid) LV rescue
Toxicity :
Myelosuppression , Mucositis
Renal toxicity and liver toxicity
Neurotxicity :
systemic : acute cerebral dysfunction
intrathecal : acute/subacute arachnoiditis, chronic
encephalopathy
Monitor serum level
23.
24. Drug specific toxicity -6.2
Hydration : 12 hours before MTX , 24-48 hrs after
stopping MTX , keep u/o 1500-2000cc/day
Urine alkalinization : keep PH>7.0
LV rescue : 12-24 hours after finishing MTX
10-15mg (60-100mg) iv q6h
Keep LV rescue to MTX < 0.05μmol/ L.
MTX level (48hr) LV dose (mg)
0.5 uM 15mg q6h * 8
1.0 uM 100mg q6h * 8
2.0 uM 200mg q6h * 8
25. Drug specific toxicity
• 高劑量5FU+Leucovorin骨髓抑制
與黏膜發炎的副作用減輕
• 長時間輸注,5FU會使細胞代謝產
生ATP的克氏循環受到抑制
• ATP不足時,Urea cycle無法進行,
使NH3在血液裡堆積。
• 營養不良,肝功能太差的病人會發
生腦病變