Oncology

Question 1

What is the most common malignancy that causes hypercalcemia?

Answer 1

Lymphoma

Question 2

What is the most common clinical manifestation of hypercalcemia?

Answer 2

• PU/PD
• Calcium inhibits vasopressin receptors in kidney and prevents free water absorption, creating a nephrogenic DI
• The hypercalcemic pt is often dehydrated due to inability to concentrate urine; dehydrated pts have a decreased GFR which further exacerbates hypercalcemia

Question 3

Hypercalcemia primarily affects what 4 body systems?

Answer 3

• Renal
• GI
• Neuro
• Cardiovascular

Question 4

What is calcitriol?

Answer 4

• The active product of Vit D metabolism
• Leads to increased GI absorption of Ca and increased release of Ca from bone

Question 5

What drugs can be used to promote Ca excretion?

Answer 5

• Furosemide (Na utilizes the same pump as Ca)
• Glucocorticoids
• Bisphosphonates (inhibit bone osteoclast activity)
• NaHCO3 (correction of acidosis will result in increased binding of Ca to albumin)
• Calcitonin (inhibits osteoclasts)
• EDTA (chelates Ca)
• Mithramycin (cytotoxic to osteoclasts)

Question 6

What complication can arise from L-asparaginase administration?

Answer 6

Lspar is a protein so a reaction is more likely after 1st use

Question 7

What complications can arise from doxorubicin administration?

Answer 7

• Head shaking, salivation
• Reactions secondary to degranulation of mast cells
• Cardiotoxic

Question 8

What is the antidote that should be instilled in the case of extravasation of doxorubicin?

Answer 8

• Vesicant
• Dexrazoxane or DMSO

Question 9

What is the antidote that should be instilled in the case of extravasation of vincristine/vinblastine?

Answer 9

• Vesicants
• Hyaluronidase

Question 10

What is the antidote that should be instilled in the case of extravasation of mechlorethamine?

Answer 10

• Severe vesicant
• Thiosulfate

Question 11

What is the antidote that should be instilled in the case of extravasation of cisplatin?

Answer 11

• Irritant
• Thiosulfate

Question 12

What is the nadir?

Answer 12

The point at which chemo has its greatest effects on the number of circulating neutrophils and they are at their lowest population

Question 13

How long after chemo administration does neutropenia commonly occur?

Answer 13

5-10 days

Question 14

Neutropenia grading scale in chemo

Answer 14

• Grade 1 = normal to 1500/uL
• Grade 2 = 1500 - 1000/uL
• Grade 3 = 1000 - 500/uL
• Grade 4 = <500/uL

Question 15

Which chemo drug is most commonly associated with vomiting?

Answer 15

Cisplatin

Question 16

What drug blocks both the CRTZ and vomiting center?

Answer 16

Butorphanol

Question 17

What chemo drug is most commonly associated with anorexia?

Answer 17

Doxorubicin

Question 18

What chemo drug causes paralytic ileus?

Answer 18

Vincristine

Question 19

Tachyarrhythmia is an early sign of toxicity of which chemo drug?

Answer 19

Doxorubicin

Question 20

Which chemo drug can cause a sterile hemorrhagic cystitis?

Answer 20

Cyclophosphamide

Question 21

Which chemo drug is nephrotoxic?

Answer 21

Cisplatin

Question 22

Which chemo drug is hepatotoxic?

Answer 22

CCNU/Lomustine

Question 23

Cardiac HSA are almost always found on the ___?

Answer 23

Right atrium

Question 24

Female dogs are more at risk than male dogs for which type of cancer?

Answer 24

TCC

Question 25

What is tumor lysis syndrome?

Answer 25

• Rupture of the cancer cells which then releases their intracellular contents into tissues and blood. The rapid release of byproducts overwhelms the body’s ability to clear waste
• Ca, nucleic acids, K, phos
• Tumor cells can contain up to 4x normal quantity of Phos due to their increased need for ATP
• The hyperphos causes hypoCa
• The hyperK + hypoCa can lead to life threatening arrhythmias
• AKI results from Ca + phos precipitation
• English bulldogs and dalmations more at risk

Question 26

What is paraneoplastic syndrome (PNS)?

Answer 26

• Any systemic illness that is induced by neoplasia but occurs in a body system from from, and unrelated to, the primary tumor
• Most common PNS in dogs are caused by production of hormones (insulin, calcitonin, PTH etc) that leads to endocrine-like effects

Question 27

Which cancer is a common cause of PNS?

Answer 27

Lymphoma

Question 28

What are the most common chemistry abnormalities from PNS?

Answer 28

• Hypercalcemia and hypoglycemia

Question 29

What is the most common metabolic emergency seen in veterinary cancer patients?

Answer 29

Hypercalcemia