√What are 6 beneficial mechanisms of chemoradiotherapy?
√What are the benefits of combined chemotherapy in general? What are the disadvantages? What is the gold standard?
√What are 6 main roles for chemotherapy in head and neck oncology?
√What is the only subsite that should be treated with chemoradiotherapy as the primary modality?
Nasopharynx
√What are three tumor factors affecting chemotherapy success?
(Not curative alone, act as radiosensitizers)
√What are the general indications for chemotherapy in head and neck cancer? 6
PRIMARY INDICATIONS:
1. Combination with radiation therapy for certain malignancies (nasopharyngeal, oropharyngeal, hypopharyngeal, laryngeal)
2. Lymphoma
3. Not surgical candidate
ADJUVANT INDICATIONS:
1. Positive margins
2. Extracapsular extension
3. Trial drug
√What is the maximum age for consideration of chemotherapy?
70 years old (see MACH trial later for explanation)
√Name 5 general chemotherapy emergencies
FATTO
√What is the general overall mechanism of action of most chemotherapy drugs?
What are the overall side effects of most chemotherapy drugs?
√What are the different classes of chemotherapy agents? 9
√Regarding Akylating agents, discuss:
1. What is the mechanism of action?
2. What are common examples?
3. What are common side effects?
MOA: Cross link DNA, interfere with DNA replication (S phase)
Examples: Cyclophophamide, Chlorambucil, Nitrogen mustard, Dacarbazine
Other types (Platinums):
1. Cisplatin (most effective single-agent chemotherapy)
2. Carboplatin (less oto/neuro/nephro toxic effects, but ++ myelosuppression)
SIDE EFFECTS:
1. Ototoxicity, Neurotoxicity, Nephrotoxicity (Cisplatin more common)
2. Myelosuppression (Carboplatin more common)
3. Mucositis
4. Dermatitis
√What is the mechanism of action and examples of DNA binding chemotherapeutic agents?
MOA: Covalent DNA intercalators - interfere with normal DNA function and alter replication
Platinum containing compounds (-platins)
EXAMPLES:
Platinums:
- Cisplatin - binds to the N7 reactive center on purine residues and as such can cause deoxyribonucleic acid (DNA) damage in cancer cells
- Carboplatin - undergoes activation inside cells and forms reactive platinum complexes that cause the intra- and inter-strand cross-linkage of DNA molecules within the cell.
Antibiotic derivaties:
- Bleomycin (induces DNA strand breaks in G2 phase)
- Mitomycin (inhibits fibroblasts - decreases scar formation; and cross links DNA
√What are 7 side effects of cisplatin? What are relative contraindications of Cisplatin?
Contraindication: Renal Failure
√How does the side effect profile of carboplatin compare to cisplatin?
√What is the standard concurrent chemo-RT regimen for Cisplatin in H&N?
Standard high dose = 100mg/m^2 on days 1, 22, 43 of radiation (for primary CRT, q3wk x3)
- Only for patients with high performance status, < 70 years old, and minimal comorbidities
Alternatively: Weekly dose 40mg/m^2 every 1 week
- Better tolerated by low performance status and patients with comorbidities, but compromised survival overall
———
Adjuvant - ENE+ or margin+
Usually uses the alternate regimen x6 weeks
√Discuss the findings of MAC-NC meta-analysis (2009)
√Regarding antibiotic derivatives, discuss:
1. MOA?
2. Side effects? 2
3. Examples? 3
MOA: Interferes with DNA synthesis and replication
SIDE EFFECTS:
1. Pulmonary fibrosis
2. Myelosuppression
EXAMPLES:
1. Bleomycin
2. Mitomycin
3. Hydroxydaunomycin
√What is the mechanism of action and examples of antimetabolite chemotherapeutic agents? What are the common side effects?
MOA:
- Actively interferes with cellular metabolism, act in S-phase
SIDE EFFECTS:
1. Mucositis
2. Dermatitis
3. Myelosuppression
√What are the side effects of methotrexate? (6)
What can be used to reduce the side effects?
What is the response rate of methotrexate as a single agent?
Leucovorin (Folinic acid - folic acid derivative) can be used as a rescue treatment (because MTX is a folate inhibitor) – can also help 5-FU bind better to thymidilate synthase
30% partial response rate as a single agent
√What are the side effects of 5-FU? What is the % partial response 5
13% single agent partial response
√Regarding vinca alkaloid chemotherapeutic agents, dicuss:
1. What is the mechanism of action?
2. What are common examples?
3. What are the common side effects?
MOA:
- Interfere with mitotic spindle formation (microtubule disruptors) - M phase
Examples:
- Vincristine
- Vinblastine
- Vinorelbine
SIDE EFFECTS:
1. Peripheral neuropathy
2. Alopecia
√What chemotherapy agent can cause vocal fold palsy in children?
Vincristine
√Mechanism of action and examples of taxane chemotherapeutic agents?
MOA:
- Stabilize tubulin polymers & prevent progression of mitosis/cell division, cause cell cycle arrest in G2 (microtubule stabilizers)
- Opposite effect of vinka alkaloids
Examples:
1. Paclitaxel
2. Docitaxel
√What are the side effects of taxanes? 4
What is the % single agent partial response rate?
30-40% single agent partial response rate