Oncology Flashcards
Define:
- Transcription
- Translation
Transcription = the formation of RNA from DNA Translation = the formation of proteins from RNA
Molecular components of a DNA nucleotide?
(backbone) Deoxyribose + phosphoric acid bound to a base (pyrimidine/purine).
The base binds to the deoxyribose unit.
Which base is substituted for uracil in RNA?
Thymine
Which enzyme is responsible for transcription?
RNA polymerase
Define complete response (CR)
A complete resolution of the tumour and clinical signs f disease
Define partial response (PR)
Decrease in tumour volume >50% or diameter >30%
Define stable disease (SD)
Neither increase or decrease in tumour size or disease symptoms (+/- 20% diameter change)
Define progression free interval (PFI) vs. disease free interval (DFI)
PFI = the time in which there is no progressive growth of the tumour
DFI = the time in which the patient is free from disease recurrence.
What type of agent is lomustine?
Alkylating agent
What type of agent is cyclophosphamide?
Alkylating agent
What type of agent is chlorambucil?
alkylating agent
What type of agent is doxorubicin?
Anti-tumour antibiotic
What type of agent is vincristine?
Anti-microtubule agent
What type of agent is carboplatin?
Platinum compound that cross links DNA
Pre-treatment considerations for taxanes (e.g. paclitaxel0
These agents can cause marked hypersensitivity reactions so require pretreatment with anti-histamines and corticosteroids as well as a prolonged infusion. For this reason they are rarely used in veterinary medicine.
Unique side effect of vincristine in cats?
Paralytic ileus (it can cause peripheral neurotoxicity)
Vesicant chemotherapy drugs and treatments
Vincristine = HEAT and hyaluronidase, DMSO, flucinolone, flunixin Doxorubicin = COLD and dexraxozane +/- DMSO
Meclorathamine = sodium thiosulfate
Actinomycin D = COLD
Dose limiting toxicity of chlorambucil?
Myelosupression - this occurs after 2-3 weeks of therapy.
Unusual neurological side effect of chlorambucil
Cerebellar toxicity
What is the mechanism of action of cyclophosphamides bladder toxicity?
Acrolein is a metabolite of cyclophosphamide that is toxic to the bladder mucosa.
Why should dacarbazine be avoided in cats?
It is not thought to be converted to enough of its active metabolite.
Unique side effects of lomustine in cats and dogs?
Dogs: hepatotoxicity with chronic use
Cats: pulmonary fibrosis
Specific GI side effect of doxorubicin
Colitis (often haemorrhage)
Side effect of doxorubicin in cats?
Nephrotoxicity
Side effect of rabacfosadine (tanovea)
Idiosyncratic pulmonary fibrosis
Why is cisplatin contraindicated in cats?
It causes severe pulmonary vasculitis and oedema
Weird side effects of hydroxyurea in cats and dogs
Dogs = claw detachment Cats = Methoglobinaemia
MoA of hydroxyurea
It inhibits ribonucleotide reductase leading to a reduction in RNA pools available for new cell production. Therefore it is often used for myeloproliferative diseases and neoplasias.
WHO staging of lymphoma in dogs
I = local lymph node involvement only II = regional lymphatic spread III = more generalised lymphatic spread IV = involvement of the liver and spleen V = bone marrow involvement a = without systemic signs b = with systemic signs
Staging of lymphoma in cats
I = single extra nodal tumour or single anatomic area (nodal) II = same side of the diaphragm or resectable GI tumour (can have LN involvement) III = crossing of the diaphragm, paraspinal or epidural, or extensive/unresectable GI disease IV = stage 1-3 with liver and spleen involvement V = stages 1-4 with involvement of CNS or one marrow or both.
How to differentiate thymic lymphoma vs. thymoma with flow cytometry.
Thymoma is more likely to be double positive for CD4 & CD8.
Where does renal lymphoma tend to metastasise in cats?
CNS
Where does GI lymphoma tend to metastasise to in cats?
Renal system.
Most common neoplasia associated with pulmonary metastatic disease?
Mammary carcinoma.
What is the other name for tignalol tigalate (Stelfonta)
EBC-46
