Chemotherapy Flashcards
What is the major advantage of chemotherapy for treating cancer, compared to localised treatments like surgery
Systemic cancer treatment
Chemo will kill cancer cells, wherever they are - so will kill metastasised cancer
Surgery only removes the main tumour, so if the cancer has metastasised (and they don’t know) then it will not actually be cured
What 2 ways is chemotherapy administered?
Oral & intravenous
How is a patients response/progress to chemotherapy treatment assessed?
Imaging (CT, PET etc) & general examination
Varies with different cancers/progressions
What is PFS?
Progression-free survival:
In cancer care, the time during which a patient shows no signs or symptoms of the growth or the spreading of a tumour
What is the difference between adjuvant and neoadjuvant treatment?
Adjuvant treatment is applied after the main treatment, to suppress secondary tumour formation
Neoadjuvant treatment is applied before the main treatment
What is the purpose of neoadjuvant treatment?
Aims to reduce the size or extent of the cancer before using radical treatment intervention, thus both making procedures easier and more likely to succeed
What are the main types of cytotoxic chemo agents
Antimetabolites
Alkylating agents
Intercalating agents/antimitotic antibiotics
Spindle poisons
What are the main features of alkylating agents?
- How they work
- What they target
- example
Prevent DNA synthesis
Attaches alkyl group to DNA strands leading to a covalent bond forming between the two DNA strands
Can not act as templates ∴ synthesis goes tits up
Cisplatin
What 3 ways are tumour cells able to be resistant to alkylating agents?
1) Decreased entry/exit of alkylating agent in/out of the cell
2) Inactivation of the alkylating agent within the cell
3) Enhance ability of the tumour cell to repair DNA lesions causes by the alkylating agent
What are the main features of antimetabolites?
Chemicals with similar chemical structure to essential metabolites required by the cancer cells, prior to division
Basically trick the cell into incorporating them into different things which they stop from working
What are common antimetabolites used clinically?
Methotrexate
6-mercaptopurine
6-thioguanine
5-flouroacil
What part of the cell cycle do spindle poisons target?
Mitosis
What are the 2 main types of spindle poisons, and how do they work?
Vinca alkaloids & taxanes
Vinca alkaloids
- Bind to tubuli and block microtubule formation ∴ preventing spindle formation
- Metaphase arrest agents
Taxanes
- Promote spindles ∴ over production ∴ freeze cells at that stage of the cell cycle
- (promote assemby - prevent disassembly)
What are the 2 types of intercalating agents/antimitotic antibiotics?
Anthracylines & non-anthracyclines
What do intercalating agents do?
- Intercalate and inhibit DNA & RNA synthesis
- Inhibit enzymes needed in DNA transcription
- Bind to membranes and increase permeability to various ions
- Generate free radicals that damage DNA, proteins and membranes
- Involved with production of cytotoxic compounds through metal ion chelating
