STS Flashcards
What are some factors that can influence local recurrence of STS?
- tumour size
- tumour infiltration
- degree of surgical resection
- tumour grade
Which is the most important factor for risk of metastasis for STS?
tumour grade
Which breeds may be predisposed to FSA?
Golden and Doberman pinchers
What are some interesting features of FSA?
- tend to be in younger dogs (vs the general population for STS)
- more likely to recur after incomplete resection
- may have more mitotic counts versus other STS
- but are also more likely to be low grade
Which breeds may be predisposed to pleomorphic undifferentiated sarcoma?
- flat coated retriever
- Rotties
- Goldens
Which IHC can be used for undifferentiated pleomorphic sarcoma?
vimentin (+)
CD18 (-)
What’s the biological behaviour of undifferentiated pleomorphic sarcoma in dogs?
Aggressive.
- Often found with metastasis to SQ, LNs, liver and lungs
- 1 study reported MST of 61 days
Where are the most common locations for undifferentiated pleomorphic sarcoma?
- trunk
- pelvic limbs
- spleen
What markers are expressed by periocytes? myoperiocytes? smooth muscles?
-Periocytes: vimentin, variable degree of smooth muscle actin
- myoperiocytes: (also) desmin, calponin
- smooth muscles: smoothlin, heavy caldesmon
What’s the general cause of death for peripheral nerve sheath tumour?
patients generally die from the local disease rather than metastasis
What’s the outcome for peripheral nerve sheath tumour amendable for amputation?
- if completely removed, MST = 2227 days (6y), which is significantly better than incomplete removal (487 days, 1.3y). The overall MST = 1303 days (3.5y)
What’s the outcome of brachial plexus tumour treated with SRT?
- PFI = 240 days
- OST = 371 days
- 90% of the dogs had disease progression
- complete or partial neurological resolution
Which IHC stains can help to differentiate between well-differentiated liposarcoma and de-differentiated liposarcoma?
MDM2 and CDK4
What’s the outcome of surgical removal of liposarcoma?
- complete removal: MST = 1188 days (3.25y)
-marginal surgery: MST = 649 days (1.7y) - Incisional biopsy: MST = 183 days (6 months)
What it’s the prognostic value of histo subclassification of rhabdmyosarcoma?
- Botryoid tumours: grape-like clusters, more commonly found in the urinary bladder, may be more female, large breeds (St. Bernard). Metastatic rate = 27%
- Embryonic tumours: tend to be in younger dogs, head/neck/ retrobulbar. Metastatic rate = 50%. MST for young dogs = 2 months
- Alveolar tumours - also has a met rate of 50%
What’s the outcome of dogs with lymphangiosarcoma treated with Sx +/- RT versus no treatment?
- Sx: MST = 487 days (16m)
- Sx + RT: ST = 547 days (18m)
- No Tx: MST = 168 days
What’s the reported outcome of splenic mesenchymoma?
MST = 1 year
What’s the diagnostic yield of FNA for STS?
63-97%
What’s the dis-concordance rate of pre-op biopsy vs post-op histology?
41%:
29% underestimated, 12% overestimated
What’s the recurrence rate of incompletely removed grade I, grade II and grade III STS?
- Grade 1 = 7%
- Grade 2 = 34%
- Grade 3 = 75% (3/4 dogs)
Generally, what is the recurrence rate of low-grade STS?
- PWT: 11%, 18-20% (60-63% were incompletely removed in the entire sample)
- 28% (when <10% resected with 3cm margins)
- 21% (only 5% had wide surgical margins in the entire sample)
What are some prognostic factors predictive of local recurrence after surgery?
- large primary tumour size (>5cm)
- high grade (III)
What’s staging surgery for STS?
Can be done if the initial STS was incompletely removed. Aim for <1cm lateral margin around the scar to determine if further (larger) resection margin is needed.
- One study found only 22% of 39 incompletely removed STS had residual disease on staging surgery
What’s the outcome of incompletely removed STS treated with metronomic cyclophosphamide with piroxicam?
The DFI is significant longer in treated vs control group (but the control group had very high rate of progression)
