Osteosarcoma

Question 1

where do 75% of osteosarcomas occur?

Answer 1

axial skeleton

Question 2

what is the most common bone tumor in dogs?

Answer 2

osteosarcoma

Question 3

does late spay/neuter decrease orthopedic disease?

Answer 3

yes- clearly

Question 4

in which dog breeds are there heritable forms of osteosarcoma?

Answer 4

greyhounds
irish wolfhounds
scottish deerhounds

Question 5

what value on bloodwork is associated with shorter survival with osteosarcoma?

Answer 5

elevated ALP

Question 6

what is the most common site of metastasis of osteosarcoma?

Answer 6

lung

Question 7

what location of osteosarcoma is associated with poorer prognosis?

Answer 7

humeral location

Question 8

what does cytology of osteosarcoma look like?

Answer 8

characteristic large spindle cells with multinucleated large osteoclasts

Question 9

what is the amputation done in the front?

Answer 9

forequarter amputation with removal of scapula

Question 10

what is the adjunctive chemotherapy drug of choice?

Answer 10

carboplatin

Question 11

who are limb spare surgeries reserved for?

Answer 11

dogs with severe orthopedic conditions

Question 12

what is a concern with stereotactic radiosurgery?

Answer 12

pathologic fracture

Question 13

what percentage of dogs will eventually develop metastasis?

Answer 13

90%

Question 14

what is osteosarcoma in the ribs like?

Answer 14

very aggressive, highly metastatic
similar survival to long bone

Question 15

what is osteosarcoma like in cats?

Answer 15

complete excision curative for most pets

Question 16

when are dogs most susceptible to osteosarcoma?

Answer 16

1-3 years
8-10 years

Question 17

what is the cause of osteosarcoma likely related to?

Answer 17

genetics associated with breeds with a large skeletal frame

Question 18

what is the most common site of osteosarcoma?

Answer 18

distal radius

Question 19

what is codman’s triangle?

Answer 19

elevation of periosteum from new bone growth

Question 20

how large must metastases be to be detected with radiographs?

Answer 20

5 mm to 8 mm

Question 21

how long must surgery be delayed if you do a bone biopsy?

Answer 21

7-10 days

Question 22

what will osteosarcoma stain positive with?

Answer 22

ALP
high specificity for OSA

Question 23

what is median survival with amputation?

Answer 23

4-5 months

Question 24

what is surgery on a hindlimb osteosarcoma like?

Answer 24

amputation with high transection of femur
avoid femoral disarticulation
trauma to pelvis
loss of muscle to pad area- risk for decubital ulcers

Question 25

why is cisplatin not used that much?

Answer 25

highly nephrotoxic

Question 26

which location can limb spare surgery be used for?

Answer 26

only radial

Question 27

what percentage of animals have improvement with palliative radiation therapy?

Answer 27

70% for 2-4 months

Question 28

what do biphosphonates do?

Answer 28

destroys osteoclasts

Question 29

do small dogs or large dogs do better with flat bone osteosarcoma?

Answer 29

small dogs

Question 30

how common are bone tumors in cats?

Answer 30

rare