Session 10 Chemotherapy Flashcards
Examples of tumours that have highly sensitive chemo sensitivity? i.e. we only need to give chemo to treat
Lymphomas Germ cell tumours Small cell lung Neuroblastoma Wilm’s tumour
Examples of tumours that have modest sensitivity chemo sensitivity? i.e. can’t use chemo alone - combine with radiotherapy or surgery
Breast Colorectal Bladder Ovary Cervix lung
Examples of tumours that have low sensitivity chemo sensitivity? i.e. not very responsive to chemo
Prostate
Renal cell
Brain tumours
Endometrial
How do alkylating agents work?
Impair DNA replication
How do antimetabolites work?
5-fluorouracil (5-FU)
Methotrexate
Impair DNA synthesis
5-FU
* inhibits thymidylate synthase enzyme
Methotrexate
* inhibits dihydrofolate reductase so that purine’s can’t be made
Spindle poisons mode of action?
Once chromosomes are aligned at metaphase plate, spindle microtubles depolymerize, moving sister chromatids toward opposite poles
Nuclear membrane re-forms and cytoplasms device
Taxoids
* promote assembly of spindle and prevent disassembly
= cells are too rigid to divide
Vinca alkaloids
* Prevent spindle formation
How do microtubule binding agents work?
They disrupt microtubule dynamics In 2 ways:
Inhibit polymerisation
Stimulate polymerisation and prevent depolymerisation
What is the fractional cell kill hypothesis?
fractional kill hypothesis states that a defined chemotherapy concentration, applied for a defined time period, will kill a constant fraction of the cells in a population, independent of the absolute number of cells.
we basically use it to work out how often to give chemotherapy
cells of bone marrow - recover more quickly
need an overall reduction of tumour cells whilst minimising the reduction of bone marrow cells
Alkylating agents are vulnerable to resistance. How does this come about?
- decreased entry or increased exit of agent
- inactivation of agent in cell
- Enhanced repair of DNA lesions produced by alkylation
What is the predicted response (within the same cancer) based on?
- performance score
i. e. someone that is bed bound will have a performance score of 4 whilst someone who is fit and healthy will have one of 0 - clinical stage
- prognostic factos or score (involves biological factors)
- molecular or cytogenetic markers
What are two types of IV pumps used for chemotherapy?
PICC line
Hickman line
What are some side effects of chemotherapy?
mucosistis (can involve whole length of gut) nausea and vomiting diarrhoea cystitis sterility myalgia neuropathy alopecia pulmonary fibrosis cardiotoxicity renal faliure myelosuppression phlebitis
What are some adverse effects that are due to the effect of treatment on the tumour?
Acute renal failure
* hyperuricaemia caused by rapid tumour lysis leads to precipitation of urate crystals in renal tubules
GI perforation at site of tumour - reported in lymphoma
DIC
* acute myeloid leukaemia
Describe the pattern of vomiting (emesis) that can occur due to chemotherapy
acute phase = 4-12 hours
delayed onset = 2-5 days later
chronic phase = can persist up to 14 days
What are some local and general problems that involve the skin due to chemotherapy side effects?
from bleomycin..
from busulphan, doxorubicin, cyclophosphamide, actinomycin D..
local
- irritation and thrombophlebitis of veins
- extravasation
general
- from bleomycin (treatment)
- hyperkeratosis = thickening of the stratum corneum
- hyperpigmentation
- ulcerated pressure sores
- busulphan, doxorubicin, cyclophosphamide, actinomycin D
- hyperpigmentation
