Chemotherapy Flashcards
Explain why cancer kills people so soon after detection. (2)
The difference between detectable cancer and cancer that will kill you is only three orders of magnitudes in terms of cell number.
Explain the type of drug commonly given with chemotherapy / radiotherapy. (3)
Chemo and radiotherapy only work if the cell is replicating (ie not in stage G0), so drugs are commonly given to keep cells in the replicatory phase.
Describe the fractional kill hypothesis. (2)
The next dose of chemo needs to be times when the bone marrow has had enough time to recover, but the cancer has not.
Name one example of a cancer that is highly sensitive, moderately sensitive and not sensitive to chemotherapy. (3)
High - lymphomas
Moderate - lung
Low - prostate
Describe the clinical indications for chemotherapy. (2)
Cancer, but also other inflammatory conditions eg RA.
Describe how the predicted response to chemotherapy is worked out. (4)
Depends on malignancy type, clinical stage, cytogenetic markers, performance score (4= bedbound, 0= active).
Describe the MoA of antimetabolites. (3)
Interfere with DNA synthesis by inhibiting synthesis of bases by changing folate metabolism.
Describe the MoA of alkylating agents. (3)
Interfere with the DNA within the cell by forming inter-strand bonds and attaching bulky side groups to mess up future replications.
Describe the MoA of spindle poisons. (3)
Interfering with mitosis by inhibiting spindle polymerisation or preventing depolymerisation.
Describe the MoA of intercalating agents. (2)
Interfere with DNA transcription or DNA replication.
Describe the mechanisms of resistance to alkylating agents. (3)
Decreased entry of increased exit of the agent.
Inactivation of the agent within the cell (eg by glutathione)
Enhanced repair of DNA lesions.
Describe the methods of administration of chemotherapy. Explain the indications for each. (7)
IV - most common - bolus, bag, pump PO - only if bioavailability is high SC - convenient in community Body cavity - pleural, bladder Intralesional - directly into cancer Intrathecal - into CSF Topical - onto skin.
Describe the renal side effects of chemotherapy. (3)
Acute renal failure - hyperuricamia cause by rapid tumour cell lysis leading to urate precipitation in renal tubules.
Describe the GI complications of chemotherapy for GI cancer. (3)
Perforation and peritonitis - all the tumour cells get listed and there is a hole.
Describe the commonest cause of chemotherapy-induced DIC. (1)
Acute myeloid leukaemia.