Onco Q's. 3. Flashcards
In addition to chest x-rays and abdominal U/S, what else is necessary in order to stage HSA?
Echocardiogram.
Staging hemangiosarcoma is used for predicting what outcome?
Prognosis.
What protocol is the treatment of choice and offers the longest MST in dogs with splenic HSA?
Splenectomy + doxorubicin.
What is the MST of using a splenectomy and doxorubicin as treatment for a splenic HSA?
4-6 months.
What is the MST of using a splenectomy as treatment for a splenic HSA?
1-2 months.
Cutaneous hemangiosarcoma has been associated with what?
UV light exposure.
Based on what you know about splenic masses.
What percent are malignant and what percent are
HSA?
2/3 are malignant.
2/3 of malignancies are HSA.
Which cutaneous form of HSA is least likely to metastasise?
Dermal (stage I).
Which of the following is not a natural behaviour of an osteosarcoma in dogs?
Commonly invades the loco-regional lymph nodes.
What is diagnostic of OSA in dogs?
Cytology of the lesion centre with ALP(+) stain.
Which is a positive prognostic indicator of OSA in dogs?
OSA of the orbit/mandible.
What is the prognosis of amputation alone in OSA?
MST of 4-5 months.
Which of the following is not a method of local disease control that may be offered for OSA in dogs, apart from surgery?
Chemotherapy.
How do we treat a dermal stage 1 form of HSA?
Wide surgical excision alone.
How do we treat a subcutaneous stage 2 form of HSA?
Wide surgical excision + doxorubicin.
What are the 3 toxicities caused by chemo?
Bone marrow (myelo) suppression.
Alopecia.
Gastrointestinal upset.
Why does radiation therapy sometimes take a while?
The cells die just before dividing.
Sometimes it takes a while to get to M phase, so the tumour may not subside until months later.
What are the 4 R’s of radiation therapy?
Repair of sublethal damage.
Repopulation with tumour cells.
Reoxygenation of hypoxic cells
Redistribution of cells throughout the cell cycle.
What is a stage 2 lymphoma?
More than 1 lymph node affected on the same side of the diaphragm.
What is a stage 3 lymphoma?
Multiple lymph nodes are affected on both sides of the diaphragm.
What is a stage 4 lymphoma?
The liver or spleen are involved (+/- Stages I-III).
What is a stage 4 lymphoma?
There is bone marrow or extranodal involvement (+/- Stages I-III).
What does substage A mean with lymphoma?
There are no clinical signs.
What does substage B mean with lymphoma?
There are clinical signs.
What kind of tumours are mast cell tumours?
Round cell tumours.
What kind of mast cell tumours are undifferentiated and what kind are well differentiated?
Histamine (undifferentiated).
Heparin (well-differentiated).
What breed tends to get low grad MCTs?
Boxers.
Do we ever stick a cats spleen?
No.
What are the 3 most common locations for a hemangiosarcoma?
Spleen (28 to 50%).
Right Atrium (3 to 50%).
Subcutaneous (13%).
What is the double 2/3rds rule with hemangiosarcomas?
Approximately 2/3 of dogs with splenic masses will have a malignant tumour.
Approximately 2/3 of those malignancies will be a hemangiosarcoma.
How does the size of a hemangiosarcoma affect the prognosis?
The bigger the mass, the more likely it is benign.
How does the size of a osteosarcoma affect the prognosis?
The bigger the mass the worse it is.
A dog has suspected lymphoma, but the owner only has enough money for one diagnostic test.
What do you want to check?
Calcium.
Hypercalcemia of malignancy is a negative prognostic indicator.
An 8-year-old female Rottweiler has hindlimb lameness.
What is the most likely tumour?
Osteosarcoma.
Which of the 3 families of tumours have the BEST exfoliation?
Round cell.
With what 2 masses do we not do an FNA?
Cavitary mass.
Bladder mass.
What is the mechanism of alkylating agents?
Cross-link DNA and prevent replication.
What is cyclophosphamide (Cytoxan) used to treat?
Sterile hemorrhagic cystitis.
What are the 4 signs of cystitis?
Vocalising.
Change in urine colour.
Straining to pee.
Increased pee frequency.
What is lomustine (CCNU) used to treat?
Delayed myelosuppression.
What is the mechanism of anti-metabolites?
They interfere with DNA synthesis.
What drug causes a fatal neurotoxicity in cats?
5-Fluorouracil (5-FU).
What is the mechanism of anti tumour antibiotics?
DNA damage via free radical formation or interference with activity of topoisomerase II.
What are the side effects of doxorubicin/adriamycin in dogs?
Dose cumulative cardiotoxicity and anaphylaxis.
What are the side effects of doxorubicin/adriamycin in cats?
Nephrotoxicity and anorexia.
How must a vesicant be administered?
IV, it must go into the vein.
What is the mode of action of heavy metals?
They cross-link DNA and prevent replication.
What drug causes fatal pulmonary oedema in cats?
Cisplatin.
What cats are most likely to be affected by FeLV?
Young cats = positive for FeLV-associated disease.
Old cats = negative for FeLV.
