Chemotherapy Flashcards
what are the possible therapeutic methods used to treat cancer? (5)
- surgery
- radiotherapy
- chemotherapy (systemic delivery/absorption, IV or oral)
- targeted therapies
- immunotherapy
what 3 things cause cell proliferation?
- growth factors
- oncogenes
- Cyclins and CDKs
what 2 things stop cell proliferation?
- tumour suppressor genes
2. CDK inhibitors
why does chemotherapy need to be closely administered?
the right line needs to be drawn between chemo administration to kill cancer and not giving too much chemo which will cause cancer
how is chemotherapy delivered? (2)
- orally
- intravenously
what is the timing and regular cycles of chemotherapy dependent on?
Pharmacokinetics (half life, excretion)
why might chemotherapy cycles be delayed?
if toxicities develop (in bone marrow especially)
Chemotherapy (systemic therapy) is better for what type of tumours?
non-solid tumours
what objective methods can be used to asses drug activity? (4)
- CT scans
- PET scans
- clinical examination
- RECIST criteria in radiology
what 3 categories can “improved” method of drug activity be split into?
- overall survival
- progression-free survival ( time before tumour starts to grow again)
- improved quality of life
what is adjuvant treatment?
prevents recurrence of disease especially at distant sites, often if tumour is invasive or has unfavourable prognostic outcomes
what is neoadjuvant treatment?
administered before a surgery as drugs could possibly shrink tumour and give more surgical options
what are the main cytotoxic agents?
- alkylating agents
- anti-metabolites
- mitotic inhibitors
- antibitoics
5 others
where do antimetabolites work at cellular level?
on DNA synthesis
where do alkylating agents work at cellular level?
on DNA directly
where do intercalating agents work at cellular level?
on DNA transcription and duplication
where do spindle poisons /mitotic inhibitors(vinca alkaloids and taxanes) work at cellular level?
mitosis
what do alkylating agents do specifically in DNA?
- alkyl group allows for other covalent bods with other molecules to be made
- attach to free guanines at N6 on separated DNA strands
- can’t act as templates for new DNA formation
- DNA strands linked and will not separate
- DNA unwinding doesn’t happen because of these DNA changes (no new DNA formation, replication impaired)
Can tumours develop resistance to alkylating agents?
Yes
what are the 3 forms of resistance that tumours can develop against alkylating agents?
- Decreased entry or increased exit of agent from the cell (drug is pumped out or not allowed in)
- inactivation of agent in cell (glutathione deactivates drug)
- enhanced repair of DNA lesions produce by alkylation (enzymes repair damaged DNA)
what do antimetabolites do on DNA synthesis?
- may be incorporated to new nuclear material or bind irreversibly with vital enzymes to inhibit cell division
e. g. methotrexate inhibit thymidylate synthase
what does antimetabolite, methotrexate act on?
FH4 production which is needed for purine production. Instead 5-FU is incorporated instead of uracil in the RNA
what does the spindle poison, vinca alkaloids do?
- metaphase arrest agents
- bind to tubuli and block microtubule/spindle formation
what does the spindle poison, taxanes do?
-promotes spindles and “freeze” cells at the stage of cycles
