Musculoskeletal & Integumentary tumors (sarcoma): slides 3, 15, 16, 18, 37, 40 - 43.

Question 1

What type of tumor??

Diverse group of tumors accounting for 15% (dogs) & 7% (cats) of cutaneous & SQ tumors
– 1% of all malignancies

Answer 1

Soft tissue Sarcoma

Question 2

Over 20 different histologic subtypes of STS but are considered as a collective group because why?

Answer 2

similar biologic behaviour and histologic features

Question 3

Behavior is characterized by?

Answer 3

a propensity for local invasiveness w/ a low to-moderate risk of metastasis (grade dependent)

Question 4

Most STS are _____ and present in ______age dogs and cats?

Answer 4

Most are solitary and present in middle-aged to older dogs & cats

Question 5

What is the specific breed and sex predilection for STS?

Answer 5

No specific breed or sex predilection

large breed dogs in general may be overrepresented for STS development

Question 6

What is the age predilection for STS?

Answer 6

No general age predilection except for rhabdomyosarcoma variant which tends to develop in younger dogs

Question 7

Describe the capsule and margins of STS and if it’s infiltrative or not?

Answer 7

• Pseudo-encapsulated soft-to firm masses w/ poorly defined margins

– Infiltrative into surrounding tissue

Question 8

Is recurrence common?

Answer 8

Local recurrence after
conservative excision is common

– exemptions

Question 9

What route of metastasis?

Answer 9

Hematogenous route of metastasis (generally < 20%)

Question 10

Is regional LN metastasis uncommon or common?

Answer 10

• Regional LN metastasis
uncommon

• Synovial cell exemption*

Question 11

Grade predictive of metastasis and resected margins predictive of _______ ______

Answer 11

local recurrence

– 1, 2, 3 —> 10, 20, 30 RULE

Question 12

Measurable/bulky tumors (>___cm)

tend not to respond to

Answer 12

chemotherapy or RT; >5 cm

Question 13

For tumor assessment what can you do to rule out DDX of lipoma, seroma, inflammation & abscess

Answer 13

FNA

Question 14

If a sarcoma is confirmed then you need to ask yourself?

Answer 14

how important is knowledge of the GRADE for me to develop a therapeutic strategy?

Question 15

What are some things to consider with STS with local tumor assessment?

Answer 15

Location of the tumor, size & invasiveness, owner’s position (would they do multiple surgeries for curative intent, are they up for adjunctive RT) and patient characteristics (age/comorbidities)

Question 16

If grade information is required what can you obtain?

Answer 16

Incisional biopsy (tru-cut vs. wedge not usually punch since they are often hypodermal)

Question 17

What do we need todo for pulmonary metastasis?

Answer 17

Thoracic radiographs

Question 18

Is abdominal U/S for presurgical staging needed?

Answer 18

– Abdominal u/s for presurgical staging is generally not indicated for most STS’s

Question 19

What kind of excisions should be considered when performing surgery?

Answer 19

Wide excision (3cm radial & 1 fascial plane or 2 muscle planes deep)

– All biopsy tracts and areas of fixation (including bone/fascia/tendon) are removed en bloc

Question 20

With STS radical surgery such as ______ may be required

Answer 20

(amputation/pelvectomy)

Question 21

What is indicative about the first surgery for STS?

Answer 21

Remember the 1st surgery provides the best change for local control and cure

Question 22

Incompletely resected tumors increase….?

Answer 22

increase patient morbidity, tx $$, increases risk of further local recurrences and decrease survival

– So plan thoroughly and execute properly

Question 23

What is unique about the prognosis of STS?

Answer 23

Px is usually determined by local disease control rather than distant metastasis

Question 24

What are the 3 main negative prognostic indicators for local control?

Answer 24

– Large tumor size
– Incomplete sx margins
– High histologic tumor grade = Higher met. Rate and more invasive locally

Question 25

Global recurrence rate of STS following incomplete resection = 28%, recurrent STS is more difficult than?

Answer 25

recurrent STS = More difficult to control than primary tumors w/ shorter DFI ±
increased metastatic rate

Question 26

What is the metastatic rate for grade 1 grade 2 and grade 3

Answer 26

10% (Gr I), 20% (Gr II), 30 – 50% (Gr III)

Question 27

What is the MST with surgery alone?

Answer 27

MST = 1,416 d (~4 y) w/ sx alone (do worse w/ aggressive variants)

Question 28

Circa late 1980’s – Pennsylvania law established that all cats must be?

Answer 28

rabies vaccinated

Question 29

Simultaneous changes to 2 vaccines developed around same time: what are the 2 vaccines?

Pathologists at UPENN then started seeing increased incidence of these 2 things?

Answer 29

– Killed RV & FeLV vaccines for SQ admin. developed

increased incidence of reactions and formation of tumors at vaccination sites

Question 30

When path at upenn started seeing increased incidence of rxns and formation of tumors at the injection site, it was suspected that _____ adjuvant in vaccine was contributing to massive inflammatory rxn. that leads to?

Answer 30

aluminum

leads to uncontrolled fibroblast and myofibroblast proliferation and eventual tumor formation

Question 31

Incidence of the development of sarcomas at site of rabies or FeLV
vaccination site: is?

Answer 31

1/1,000 to 1/10,000

Question 32

Time to tumor development for feline injection site sarcomas post vaccination is?

Answer 32

4 weeks – 10 YEARS

Question 33

What is unique about feline injection site sarcomas compared to typical soft tissue sarcomas?

Answer 33

These sarcomas are histologically and biologically more aggressive than typical STS’s!

Question 34

What did the studies conclude on feline injection site sarcoma?

Answer 34

Based on studies it is still unclear if non-adjuvanted vaccines are any
safer

– Renamed syndrome from vaccine associated sarcoma to ISS b/c other etiologies implicated (interferon injection/microchip)

Question 35

Feline ISS

What is reasonable todo to give you a sarcoma dx? Ideally would like to confirm…..?

Answer 35

Cytology very reasonable to do

– Ideally like to confirm ISS vs. typical STS to justify higher surgical dosing which requires INCISIONAL biopsy

Question 36

With Feline ISS, please DON’T do an ______ _______

Answer 36

excisional biopsy!

Question 37

With Feline ISS

-Accurate pretreatment knowledge of the extent of disease is important:

• Tumors are very _______
• ____ may be performed for surgical margin planning

Answer 37

– Tumors very infiltrative

– CT may be performed for surgical margin planning

Question 38

What is the current treatment recommended for Feline ISS? What do you include? What is the recurrence rate? What is the preferred technique for establishing local control?

Answer 38

Current recommendation is surgical excision w/ 5cm radial margins and 2 muscle planes deep

– Including body wall, soft-tissue or bone (i.e. dorsal scapula/spinous processes or limb)

– Recurrence rate = 14%
– Complication rate = 11% w/ 8% sustaining dehiscence of the incision

• Historically reported rates of local recurrence for feline ISS after treatment range from 26% to 59%
• Validates surgical model (i.e. 5 cm margins) as the preferred technique for establishing local control of feline ISS’s