Lecture 7 Flashcards
Route of spread for sarcomas
blood/hematogenous
sarcoma definition
Connective tissue / mesenchymal tumors
80 percent of bone tumors are what kind of tumors?
•80% Osteosarcoma
–Others include Fibrosarcoma, Chondrosarcoma, Hemangiosarcoma
–Rare in cats
signalment for OSA patient
–mid to older aged dogs, also peak at 18-24 months
–Large / giant breeds
–males > females
–neutered > intact (in Rotties)
appendicular OSA means what?
long bones affected
location of appendicular OSA
–Most common location, > 75% metaphyseal
–Front legs > back legs
–Away from the elbow and towards the knee
axial OSA means what?
flat bones
axial OSAs develop where?
Bone of the head, ribs, pelvis, vertebrae
cytological stain to dx OSA
Alk Phos staining
gold standard diagnostic for OSA
histopath
organ with high potential for metastasis
lung
most sensitive dx tool to determine if mets to the lung have occured
–Lung radiographs -3 views
•< 5% have radiographic evidence at outset
•Metastasis most likely to grow after primary tumor is removed
–CT is far more sensitive
indicators of a poor prognosis
–Lung or bone metastasis at outset
–Lymph node metastasis
–Elevated Alk Phos
–Monocytosis
treatment for osteosarcoma
no real treatment; palliative only
•Amputation / no chemo 3-4 mths
•Radiation for pain control 4-6 mths
–External Beam or Radionuclide (Samarium)
•Pain medication (NSAID’s, Opiods) 4-6 mths?
•Bisphosphonates (Alendronate- Fosamax, Pamidronate, Zoledronate)
chemo for appendicular osa
•Cisplatin > Carboplatin > Doxorubicin
•Carboplatin alternating with Doxorubicin
Single agent Carboplatin
treatment for axial OSA
–When removal is possible + chemotherapy
•survival is probably longer than for long bone tumors because metastasis comes slower
feline OSA characteristics
- Rare but it happens
- Metastasis seems to come much slower than in dog
- Amputation is treatment of choice
for soft tissue sarcomas, grade is ____ than type
more important
signalment of dogs with soft tissue sarcomas
Usually larger, older dogs- but any age and breed
biologic behavior of soft tissue sarcomas
–Locally aggressive, invasive, poorly defined margins
–Slow to metastasize
•Spread to lungs more than LN’s
important consideration of soft tissue sarcomas
Grade should be predictive
•Mitotic index (mitosis per 10 high per field) may be most important prognostic indicator
–10-19 grade II
–>20 is grade III
interpretation of the mitotic index for SSA
–10-19 grade II
–>20 is grade III
Dx of SSA
Cytology suggestive
•Incisional biopsy
–Required for true diagnosis and grade
•Excisional biopsy- be sure you know margins
parameters for surgical removal of SSA
•Surgery- aggressive
–3 cm in all directions
–Submit all tissue for histopathology !!!
How to use radiation for SSA
– Best for minimal disease (incomplete surgical margins) – Gross tumor may require higher dose – High dose difficult to achieve in some locations
chemotherapeutics for SSA
– Doxorubicin
– VAC (Vincristine, Doxorubicin, Cyclophosphamide)
– DTIC and Doxorubicin
metronomic therapy
VAC stands for what
(Vincristine, Doxorubicin, Cyclophosphamide)
treatment for low grade SSA
– Surgery alone can be curative (done properly!)
– Surgery with follow-up radiation when margins not
adequate
treatment for high grade SSA
– High potential for metastasis (at least 40%)
– Surgery +/- radiation +/- chemotherapy
rule of 1,2,3 for SSA
remove a mass at a vaccine site when – Still growing at 1 month – Greater than 2 cm in size – Still present at 3 months post vaccination
biologic behavior of SSA in cats
– Locally extremely aggressive
– 10-25 % metastasize
treatment for feline SSA
•Surgery- remove with margins the first time!
–5 cm or 2 facial planes required for cure
•Radiation most helpful as follow-up when margins are clean but < 5 cm
