Chemotherapy Flashcards
What is the definition of complete remission?
- No evidence of tumour on physical exam, haematology, biochemistry, or imaging
What is the definition of partial remission?
Reduction in the sum of the longest diameters of more than 30% with no new lesion at 4 weeks
What is the definition of stable disease?
No change at 4 weeks
What is the definition of progressive disease?
Increase of 20% or more in longest diameter at 3 weeks, or new lesions.
What is the definition of MTD?
Maximum tolerated dose of an agent at one time or cumulatively
What is the definition of adjuvant chemotherapy?
Adminisatered after surgery or radiotherapy, usually to limit metastasis formation (neoadjuvant is given before surgery or radiotherapy to shrink mass)
Which cancers are highly sensitive to chemo?
Lymphoma
Myeloma
Leukaemia
(mostly haemolymphatic cancers)
What cancers are not very sensitive to chemo?
- Most slow growing sarcomas
- Some carcinomas
- Melanomas
What done cell cycle non specific chemo drugs do?
Disrupt the DNA double helix
What do cell cycle specific chemo drugs do?
Affect mitosis and interfere with spindle formation
What are the implications for phase specific drugs?
- Need actively replicating cells
- Can be altered by administering drug multiple times/ continual infusion
How are cytotoxic drugs administered?
- They kill cell using first order kinetics (the number of cancer cells killed by the drug is proportional to the dose)
- So you want to use highest dose possible. BUT you cannot go above normal tissue toxicity
- Single dose unlikely to be effective. Repeated doses with recovery times between are usually needed.
When are phase non specific drugs active?
In G0
Which class of drugs have a narrow therapeutic index?
Non specific drugs- they kill all cells
Have to aim for MID
Describe biological mechanisms of drug resistance
-Kinetic: too many cells in G0 so minimal kill, problem in cell cycel specific agents
