Soft Tissue Sarcoma Flashcards
What infectious organism can cause sarcoma in dogs?
Spirocerca lupi
What’s the % of dogs and cats that have mesenchymal tumours?
Dogs = 15%
cats = 7%
How is canine soft tissue sarcoma graded?
grade I, II, III
How does fibrosarcoma behave compare to other canine STS?
- fibrosarcoma is more likely to recur after incomplete excision
- and have higher mitotic rates than other STS
- BUT, they are more likely to be low grade
Which breeds are predisposed pleomorphic sarcoma?
Flat-coated retriever, Rottweilers, Goldens
Where are the common anatomical locations for pleomorphic sarcoma in the dog?
SQ of the trunk and pelvic limbs, spleen
Which IHC can be used for pleomorphic sarcoma?
vimentin + CD18 - (former name = malignant fibrous histiocytoma)
How does canine pleomorphic sarcoma behave compare to the rest of the STS?
- significantly more likely to be high grade and have metastases at the time of diagnosis compared to the rest of the STS
What’s the typical growth pattern of myxosarcoma?
tend to be infiltratie with ill-defined margins
What’s the ICH stain pattern for perivascular wall tumours?
- vimentin +, pan and alpha-smooth muscle actin +
- smooth muslce cells – smoothelin, heavy caldesmon
- myopericytes - desmin, calponin
How does perivascular wall tumour behave compare to the rest of the canine STS?
they tend to be less aggressive, with significantly lower rates of local recurrence than other histologica subtypes
What are the most common benign canine peripheral nerve sheath tumour?
Schwannoma and neurofibroma
What’s the typical growth pattern and behaviour of malignant peripheral nerve sheath tumour?
SQ, poorly cirucumscribed, invasive
- associated with high local recurrence, and relatively poor survival times
- modest metastatic potential
What’s the IHC stain pattern for peripheral nerve sheath tumours?
positive for: S-100, vimentin, glial fibrillary acidic protein (GFAP), nerve growth factor receptor, neuron-specific enolase
- significantly higher ki-67 index then perivascular wall tumour
What’s the outcome for canine brachial plexus PNSTs treated with limb-sparing compartmental resection?
MST = 1303 days
sig better if completely removed = 2227d vs 487 d if not
Van Stee L, Boston S, Teske E, et al.: Compartmental resection of
peripheral nerve tumors with limb preservation in 16 dogs (1995-
2011), Vet Surg 26:40–45, 2017.
What’s the outcome for canine brachial plexus PNSTs treated with SRT?
in 10 dogs, all had either partial or complete resolution of neurological signs
- PFS = 240d, OST = 371d
progression reported in 90% of dogs
Local disease = limiting factor
Dolera M, Malfassi L, Bianch C, et al.: Frameless stereotactic volumetric
modulated arc radiotherapy of brachial
Where is the most common place of intermuscular lipoma?
between the semitendinosus and semimenbranosus muscles
- can also be in the axilla
What’s the treatment and prognosis of intermuscular lipoma?
Tx = surgical resection, use a negative suction drain to minimize seroma formation
- prognosis = excellent, no recurrence in published studies (n = 27)
Can infiltrative lipomas be distinguished from regular lipoma on FNA?
No
- will need CT – differentiation based on shape, margins, and type of attenuation
What’s the biological behaviour of infiltrative lipoma?
They are considered “benign”, but are locally aggressive/ infiltrative
- can infiltrate adjacent muscle, fascia, nerve, myocardium, joint capsule, and even bone
What’s the treatment of choice for infiltrative lipoma?
Amputation (if possible)
RT
Bergman PJ, Withrow SJ, Straw RC, et al.: Infiltrative lipoma in
dogs: 16 cases (1981-1992), J Am Vet Med Assoc 205:322–324,
1994
McEntee MC, Page RL, Mauldin GN, et al.: Results of irradiation
of infiltrative lipoma in 13 dogs, Vet Radiol Ultrasound 41:554–
556, 2000
T or F. Liposarcoma arise from malignant transformation of lipoma?
False, etiology unknown
one case of foreign-body induced liposarcoma in the dog
What’s the typical physical characteristic of liposarcoma?
firm, locally invasive`
What’s the metastatic potential of liposarcoma?
low, likes to go to lungs, liver, spleen, and bone
Where are liposarcomas commonly located?
along the ventrum, and extremitis
How do you differentiate between liposarcoma and lipoma?
- morphological appearance
- cytological characteristics (Oil Red O)
- CT findings (mixed attenuating, heterogneous, multinodular, contrast enhancing)
What’s the prognosis for liposarcoma?
Good with appropriate treatment
- wide surgical excision, MST = 1188days (~3y)
marginal = 649 days, vs biopsy = 183 days
What’s the cell origin of rhabdomyosarcoma?
myblasts or primitive mesenchymal cells capable of differentiating into striated muscles
What are the most common anatomical location of canine rhabdomyosarcoma?
skeletal muscle of the urinary bladder, retrobulbar musculature, larynx, tongue, and mocyardium
What’s the natural behaviour of rhabdomysarcoma?
locally invasive with low to moderate metastatic potential
Which IHC stains can be used for rhabdomyosarcoma?
vimentin, skeletal muscle actin, myoglobin, myogenin, and myogenic differentiation (MyoD)
What are the 4 histological subtypes of rhabdoymosarcoma?
embryogenic, botryoid, alveolar, and pleomorphic
What are the sites of predilection for embryogenic rhabdomyosarcoma?
head & neck - tongue, oral cacvity, laryng, and retrobulbar musculature
What are the sites of predilection for botryoid rhabdomyosarcoma?
urinary bladder
typically in young, large breeds - St Bernard possibly over-represented
What’s the metastatic rate of botryoid rhabdomyosarcoma?
27%
What’s the metastatic rate for embryonic and alveolar rhabdomyosarcoma?
50%
Which age group is more likely to have metastatic rhabdomyosarcoma?
young
in one report only those <2y had metastasis, and another one found all dogs <4y died of metastatic disease or local tumour recurrence (MST 2.5m)
What’s lymphangiosarcoma?
rare tumour from lymphatic endothelial cells
What are some clinical signs of lymphangiosarcoma?
- extensive edema
- drainage of lymph through the skin
- cystic mass
- non-healing, discharging wound
How do you distinguish between lymphangiosarcoma vs HSA?
use IHC such as factor VIII and CD 31
- lymphatic vessel endothelial receptor-1 (LYVE-1), propsero-related homeobox gene-1 (PROX-1)
What’s the prognosis for dogs with lymphangiosarcoma?
MST = 168 days with no treatment
surgery alone = 487 days
Surgery, RT, Chemo = 574 days
all dogs with incompletely removed tumours were euthanized due to recurrent or progressive local disease
Curran KM, Halsey CH, Worley DR: Lymphangiosarcoma in 12
dogs: a case series (1998-2013), Vet Comp Oncol 14:181–190, 2016.
What’s a malignant mesenchymoma?
rare STS having 2 or more different varieties of other types of sarcoma
What’s the prognosis of splenic mesenchymoma?
MST 12m
What’s the cytological accuracy for correctly diagnosing a STS?
63-97%
What’s the rate of discrepancy of the histological grade of STS based on biopsy vs definitive surgical removal in dogs?
incorrect in 41% of cases
underestimated in 29%, overestimated in 12%
What’s the recurrence rate for incompletely removed SQ STS based on grades in a study with 236 dogs?
Grade 1 = 7%
Grade 2 = 34%
McSporran KD: Histologic grade predicts recurrence for marginally
excised canine subcutaneous soft tissue sarcomas, Vet Pathol
46:928–933, 2009.
What’s the recurrence rate of marginally resected low-grade STS in a study with 35 dogs?
11%
Stefanello D, Morello E, Roccabianca P, et al.: Marginal excision
of low-grade spindle cell sarcoma of canine extremities: 35 dogs
(1996-2006), Vet Surg 37:461–465, 2008
In a study of 104 STS removed in non-referral practices, what’s the recurrence rate?
28%, despite <10% were excised with >3cm lateral margin
Chase D, Bray J, Ide A, et al.: Outcome following removal of
canine spindle cell tumours in first opinion practice: 104 cases, J
Small Anim Pract 50:568–574, 2009.
What was the recurrence rate for dogs with perivascular wall tumours?
18-20%, despite 60-63% were incompletely removed
only prognostic factor was tumour >5cm
What’s the recurrence rate in the study of 350 dogs with STS removed in non-referral practices?
21%, only 5% had complete margins
Describe staging surgery.
for incompletely removed tumour, re-excise <1cm margin around the scar and assess for disease. If there is, then go for wide surgical resection or RT
What’s the local tumour recurrence rate for incomplete removed canine STS treated with CFRT?
16.7-36.8%
4-year local control rate up to 80%
median time to recurrence = 412 to 798+ days
What’s the meidan time to recurrence for grade III incompletely removed canine STS treated with CFRT?
78 days
Which of the following groups have been shown to be a prognostic factor for survival times?
1) AgNOR score 2) Ki067 index 3) Mitotic rate 4) Subtype 5) Grade 6) Location 7) Size
A) 1,2,3,5
B) 1,2,5,6
C) 2,3,6,7
D) 1,2,3,4
A).
Listed in withrow: tumor necrosis, mitotic rate, grade, Ki-67, AgNOR. Others are prognostic factor for local control/mets, not necessary survival
Survival has been significantly associated with mitotic rate in one study (Porcellato et al. 2017) of 24 cats with a 994-day MST for cats with mitotic count greater than __ mitoses per 10 HPFs compared with an MST that was not reached in cats with a mitotic rate less than that number of mitoses.
20
In a neoadjuvant setting, which of the following drug showed an improvement in survival time for FISS?
a. carboplatin
b. doxorubicin
c. gentamicin
d. epirubicin
d
What are some prognostic factors associated with FISS?
b. PCV – >25% had a MST of 760d compared to 308 days
c. Size - <2cm MST = 643d vs > 5cm MST = 394d
d. Histo-subtype – FSA MST = 640d vs MFH MST = 290d
What’s the 3-2-1 rule recommended by VAFSTF?
present for >3m post injection, >2cm in diameter, increasing in size >1m post injection
What’s the control rate for RT alone (cumulative dose of 50Gy) for macroscopic canine STS?
50% @ 1y, 33% @ 2y
What’s the response rate for RT in macroscopic canine STS?
one reported 30% CR
What’s the response rate for hypofractionated RT for macroscopic canine STS?
46-50%
What’s the MST for hypofractionated RT for macroscopic canine STS?
206-513 days
What’s the PFI for hypofractionated RT for macroscopic canine STS?
155-419 days
What are some prognostic factors associated with hypofractionated RT for macroscopic canine STS?
- location, better for limb ( 466d PFI) vs head or trunk (110d); MST = 579d vs 195d
- 1 or no Sx (420d) vs 1+ (105 days)
In the Cancedda 2016 et al on hypofractionated RT for macroscopic canine STS, what was the result with metronomic chemotherapy?
PFI did not improve but MST did - 757d vs 518d
What’s the outcome with doxorubicin for canine STS?
no different in survival outcomes
How effective is metronomic chemotherapy?
effective in decreasing the rate of local tumour recurrence and improving DFI
What’s the relationship between local recurrence and death for canine STS?
5x more likely to die from STS, more difficult to manage a recurred STS
MST 256d
What’s the risk of metastasis for canine STS?
5x more likely if MC >20
With complete resection, what’s the local recurrence rate for FISS?
14% @ 3y
Can doxorubicin improve ST in cats with FISS as an neoadjuvant therapy to surgery?
No
What’s the outcome for macroscopic FISS with RT?
4x8Gy, PFI = 4m, MST = 7m
What’s the outcome of SRT for FISS?
3/11 CR, 5/11 PR. PFI = 242d, MST = 301d
Does local recurrence of FISS influence ST?
No, regardless of timing of RT relative the Sx, MST with 600-1307d still reported
How does post-op chemo influence survival for FISS?
minimal effect in cats treated with curative intent surgery and RT
How dose chemo effect FISS with gross residual disease post-op?
MST 29m if treated with RT and chemo vs 5m with post-op RT alone
Does Palladia work for unresectable FISS?
no
What’s the rate of complete histo resection with 5cm lateral margin?
95-97%
What’s the local recurrence rate for FISS when combined with pre- or post-op RT?
28-45%, median DFI 13-37m
What are some prognostic factors for local recurrence for FISS?
- tumour size
- surgical dose
- histo margin
- histo grade
How common is metastasis for FISS?
uncommon, 0-24%
more likely with grade III ISS
0-17%, 15-19%, 22-100% for grade, I, II, and III, respectively
What’s the overall MST for FISS treated with wide surgical margin?
804-901 days to not reacehd
What’s the overall MST for FISS treated with less aggressive surgery?
MST > 395d to 608 days
What’s the overall MST for FISS treated with surgery and RT?
MST 520-1307d
