The Big 5

Question 1

What are the big 5 tumors?

Answer 1

Osteosarcoma
Lymphoma
Mast cell tumor
Melanoma
Mammary carcinoma

Question 2

Signalment of Osteosarcoma

Answer 2

Older
Males
Large giant breeds

Question 3

Which breeds are predisposed to osteosarcoma?

Answer 3

CDKN2A gene in rotties, Scottish deerhound
Great Dane, St. Bernard, greyhound

Question 4

Where is osteosarcoma most common?

Answer 4

Metaphysis long bones: distal radius

Question 5

Other places where osteosarcoma is common

Answer 5

Mandible better behavior: 70%- 1 yr survival sx alone, 20% met rate
Rib worst behavior (MST sx 3-4 m) + chemo 8 m

Question 6

How is osteosarcoma dx?

Answer 6

FNA cytology and core bx (Combined (94%) and Jamshidi (92%))

Question 7

Appendicular OSA Metastasis

Answer 7

> 90% micrometastases
<10% clinical met @ dx
Remove whole leg with tumor —> met to lungs
Leave primary tumor in place —> delay met

Question 8

MST OSA with amputation alone

Answer 8

4-6 months

Question 9

MST OSA with amputation + chemo OR limb- salvage + chemo

Answer 9

10-12m
Meds: cisplatin, carboplatin, doxorubcin, combo/ alternating

Question 10

MST OSA with radiation, palliatively

Answer 10

4-6m
Pain management in 2-4m
Pathological fracture risk with use (patient uses leg more)

Question 11

Medical tx for OSA

Answer 11

Biphosphanates: pamidronate (improvement in pain control in 4/10 dogs) and zoledronate (more potent)

Question 12

Samarium

Answer 12

Medical tx of OSA
60% PR (mean ST 5m), 17% CR (mean ST 27 m)
Effect: BM suppression

Question 13

What factors allow for Limb salvage in OSA

Answer 13

No Met
Location: distal radius/ ulna
<50% bone affected
Absence of pathologic fracture
<360° involvement soft tissues
15% catastrophic failure

Question 14

OSA- stereotactic radiosurgery

Answer 14

High dose: 1-2d
Risk of fracture (50%)

Question 15

Anatomic classification for K9 lymphoma

Answer 15

Multi-centric (80-85%)
GI: 5-7%
Mediastinal: 5%
Cutaneous: epitheliotropic and non
Atypical anatomical forms: hepatosplenic (aggressive), Intravascular, CNS, renal, ocular

Question 16

Immunophenotypic Classification

Answer 16

B cell LSA: 60-80% K9 LSA
T cell LSA: 10-38%
Mixed B & T cell LSA: 22%
Null cell tumors (neither): <5%

Question 17

Immunophenotyping

Answer 17

CD34: hematopoietic stem cells
CD45: LEUKOCYTES
CD3: T lymphocytes
CD4: T helper
CD8: T cytotoxic
CD21, CD79a/B: B lymphocytes
CD14: monocytes

Question 18

Tx of choice for K9 lymphoma

Answer 18

C (cyclophosphamide)
H (hydroxydaunoribicin)
O (oncovin/ vincristine)
P (Pred)
12m for B cell, 6-8m for T cell

Question 19

Other tx for lymphoma

Answer 19

None: 4-6w
Pred alone: 3-4m
Dox alone: 6-9m

Question 20

Low grade lymphoma tx

Answer 20

if needed tx!
+/- Chlorambucil and pred if needed
Wean pred first then q 48-72 hrs Chlorambucil

Question 21

Anatomic classification of feline lymphoma

Answer 21

Alimentary/ GI (large cell/ high grade or small cell/low grade)*
Extranodal (nasal*, renal, CNS, laryngeal & tracheal)

Question 22

Large cell alimentary feline lymphoma

Answer 22

CHOP, COP protocols
30-60% remission
MST: 1.5-3 m

Question 23

Small cell alimentary feline lymphoma

Answer 23

More common
Chlorambucil + prednisolone
70% remission
T cell is better
MST: >2 years

Question 24

Nasal feline lymphoma RT

Answer 24

Mass effect in front sinus (local) responds to RT
CR: 75-95%
MST: 1.5-3 years (4m if not CR)

Question 25

Nasal feline lymphoma CT

Answer 25

Systemic tumor Response rate:75% MST 2 yrs if CR

Question 26

Most common cutaneous tumors in dogs

Answer 26

Mast cell Lipoma Histiocytoma

Question 27

Most common cutaneous tumors in cats

Answer 27

Basal cell tumor Mast cell tumor Fibrosarcoma

Question 28

Breeds predisposed to mast cell tumors

Answer 28

Boxers, labs, Boston terriers, pugs, beagles, schnauzers

Question 29

C-kit mutations (mast cell)

Answer 29

Gain of function mutations in the extracellular domain of KIT, common in K9 MCT Exon 8 &11(histologic high grade and high mitotic count) Tandem duplications involving exon 11 and 12

Question 30

CT for mast cell tumors

Answer 30

Vinblastine + pred Lomustine + pred Pallida

Question 31

Stelfonta

Answer 31

Tx for MCT Wound heals via seconds intention (necrotic tissue falls off) No mets

Question 32

Prognosis of mast cell tumors

Answer 32

1: 100% survival with sx resection 2: median survival 500 days 3: 24% @ 1 yr 2 years for low grade and <4m for high grade

Question 33

What is the significance of splenomegaly in a cat?

Answer 33

Can causes V/D, WL → met to the skin

Question 34

What is the MST for a cat that undergoes splenectomy for a cat?

Answer 34

1.5 yr survival

Question 35

Oral melanoma

Answer 35

Must take bone to achieve complete margins

Question 36

Oral melanoma RT

Answer 36

Response rate 80% MRT: 18 m MST: 7-12m Higher stage, shorter remission and survival Die of mets

Question 37

Oral melanoma immunotherapy (oncept)

Answer 37

Transdermally IM and not preventative- xenogeneic DNA vaccine that targets tyrosinase Dogs with stage 2 or 3 oral melanoma

Question 38

Oral melanoma immunotherapy (oncept) tx repsonse

Answer 38

MST not reached stage 1-3 with local control and vx (>3yr) W/o local control MST 553d

Question 39

Oral melanoma prognosis

Answer 39

Sx alone: 6-8m Radiation alone: 6-12 m CT alone:6m Radiation + chemo: 1 y Sx or radiation + vx: >3y

Question 40

What causes mammary tumors?

Answer 40

Hormonally influenced Spay b4 first heat (incidence 0.5%) B4 seconds estrus (incidence 8%) After second (incidence 26%)

Question 41

Dogs with mammary tumors

Answer 41

50% benign, malignant and met Surgical tx- as much as needed To remove tumor + OHE if intact

Question 42

Cats with mammary tumors

Answer 42

10-15% benign, 85-90% malignant Sx tx bilateral: complete mastectomy + OHE if intact Prevents recurrence

Question 43

Dog tx with mammary tumors

Answer 43

CT or RT offered when mets present, high grade, invasion lymphatics or blood vessels

Question 44

Cat tx with mammary tumors

Answer 44

Doxorubicin improved CT always offered

Question 45

Inflammatory mammary carcinoma DD

Answer 45

Mastitis (litter or pseudopregnancy) No sx