Sarcomas Flashcards
What are sarcomas?
Connective tissue/mesenchymal tumors
Spread by blood
Different behaviors depending on tissue of origin and grade
Primary Bone Tumors
Kind
80% Osteosarcoma
Fibrosarcoma
Chondrosarcoma
Hemangiosarcoma
Primary Bone Tumors
Signalment
Mid to older aged dogs; also peak at 18-24 months
Large/giant breeds (rare in toy breeds)
Males > Females
Neutered > Intact (Rotties)
Primary Bone Tumors
Presenting Complaint
Lameness
+/- swelling
Canine Osteosarcoma
Bones inolved
Long Bones (Appendicular)
75% metaphyseal
Front legs > back legs
Away from the elbow and towards the knee (sometimes distal tibia)
Flat Bone (Axial) Bones of the head, ribs, pelvis, vertebrae
Canine Osteosarcoma
Diagnosis
Radiographs (must differentiate from fungal or bacterial osteomyelitis)
Cytology (Alk Phos staining; takes up stain suggesting osteosarcoma)
Histopathology (definitive diagnosis)
Canine Osteosarcoma
Staging
Look at lungs! -> high potential for metastasis to lung (essential to look here)
Metastasis most likely to grow after primary tumor removed!
CT is far more sensitive and recommended if considering amputation (can pick up on smaller sized mets)
1 lung lesion is alright but when there are multiple be careful
Canine Osteosarcoma
If see mets in lung what should you consider?
Possibly not amputating the leg
If leg is amputated then do something to decrease lung tumor size (chemotherapy)
Canine Osteosarcoma
Poor prognosis with
Lung or bone metastasis (especially if large masses)
Lymph node metastasis
Elevated Alk Phos
Monocytosis
Young age
Canine Osteosarcoma
Treatment and Prognosis
No therapy
Painful!
Should at least give NSAIDs and pain meds
Canine Osteosarcoma
Treatment and Prognosis
Amputation/No Chemo
3-4 months
Canine Osteosarcoma
Treatment and Prognosis
Radiation for pain control
4-6 months
Canine Osteosarcoma
Treatment and Prognosis
Pain Meds (NSAIDs, Opioids)
4-6 months
Canine Osteosarcoma
Treatment and Prognosis
Bisphosponates
4-6 months
Canine Osteosarcoma
Vaccine?
New therapy
Target: Her-2/Neu Listeria
Canine Osteosarcoma
Aggressive therapy for appendicular tumors
Amputation and chemotherapy (9-12 months)
Cisplatin (high toxicity)>Carboplatin>Doxorubicin
Carboplatin alternating with Doxorubicin
NSAIDs
Note: can start chemo prior to amputation; just closely monitor wound healing post-sx
Canine Osteosarcoma
Axial tumors
Treatment
Difficult due to inability to remove surgically (vertebrae, pelvis)
Palliative radiation (cannot damage CNS) Pain medication
Local recurrence is common
Surgical removal of mandible/ribs + chemotherapy
Feline Osteosarcoma
Background
Rare but it happens
Metastasis seems to come much slower than in dog (takes years)
Amputation = treatment of choice
Soft Tissue Sarcomas
What are they?
Tumors arising from supportive tissues, variety of types, all behave very similarly
Soft Tissue Sarcomas
Examples
Fibrosarcoma Hemangiopericytoma Nerve sheath tumor Leiomyosarcoma Synovial cell sarcoma Liposarcoma Malignant fibrous histiocytoma
Soft Tissue Sarcoma
What is important to know?
Tumor grade!
Soft Tissue Sarcomas
Signalment
Larger, older dogs
Any breed or any age really
Soft Tissue Sarcomas
Presentation
Usually a mass (SQ)
Tumor can arise from internal soft tissue
Soft Tissue Sarcomas
Biologic Behavior
Locally aggressive, invasive, poorly defined margins
Slow to metastasize:
Spread to lungs more than lymph nodes
Grade should be predictive
Mitotic index (most important prognostic indicator): > 20 is grade III (poor prognosis and need large margins)
Soft Tissue Sarcomas
Diagnosis
Cytology suggestive
Incisional biopsy; required for true diagnosis and grade
Excisional biopsy; be sure you know margins
Soft Tissue Sarcomas
Diagnostics
Imaging:
Radiographs and ultrasound
CT and MRI best for surgery planning
Evaluation of lymph nodes
Metastasis (thorax)
Radiographs
CT for high grade
Soft Tissue Sarcomas
Surgery
Aggressive!
3 cm in all directions (dog)
5 cm in all directions (cat)
Submit for histopathology
Soft Tissue Sarcomas
Radiation
Best for minimal disease (incomplete surgical margins)
Gross tumor may require higher dose
High dose difficult to achieve in some locations
Soft Tissue Sarcomas
Chemotherapy
Doxorubicin (most common)
VAC (Vincristine, Doxorubicin, Cyclophosphamide)
DTIC and Doxorubicin
Soft Tissue Sarcomas
Metronomic Chemotherapy
Low dose alkylators (cyclophosphamide, lomustine, chlorambucil) and NSAID
Soft Tissue Sarcomas
Treatment
Low Grade Tumor
Surgery alone can be curative (5-6 years)
Surgery with follow-up radiation when margins not adequate
Soft Tissue Sarcomas
Treatment
High Grade Tumors
High potential for metastasis (at least 40%)
Surgery +/- radiation +/- chemotherapy
Soft Tissue Sarcomas
Treatment
Non-resectable tumors
Palliative radiation + metronomic therapy
Soft Tissue Sarcomas
Feline (common one)
Cause
Vaccine Associated Sarcomas
Iatrogenic; aluminum oxide crystals in tumor (from adjuvant)
Can come about months to years after vaccine administration (record where you have given injections)
Soft Tissue Sarcomas
Feline Characteristics
Every sarcoma on cats is high grade
Vaccine Associated Sarcomas
Rule of 1, 2, 3
Remove a mass at a vaccine site when:
Still growing after 1 month
Greater than 2 cm in size
Still present at 3 months post vax
Same for other injections (not necessarily just vax)
Soft Tissue Sarcomas
Feline-Signalment
Any vaccinated cat
May be genetic; if parent has had a reaction keep that in mind and perhaps stop breeding that cat
Soft Tissue Sarcomas
Feline-Biologic Behavior
Locally aggressive (extremely) 10-25% metastasize
Soft Tissue Sarcomas
Feline-Staging
Advanced imaging nearly always required
CT or MRI (Sx planning needed due to aggressive nature) - margins are important
Soft Tissue Sarcoma
Feline-Therapy
Surgery; remove with margins (5 cm required for potential cure)
Radiation most helpful as follow-up when margins are clean but could not get 5 cm margins
Soft Tissue Sarcoma
Feline-Margin Importance
Bad surgery = prematurely dead cat
If first Sx leaves dirty margins the cat may have no hope for long term tumor control
Soft Tissue Sarcoma
Feline-Chemotherapy Effectiveness
10-25% metastasis potential
Chemotherapy has not been documented to help overall survival but may shrink tumor
Soft Tissue Sarcomas
Feline-Prevention
Give all vaccines low on leg
Decrease use of vaccines (every 3 years opposed to every year) or give intranasal
Never use killed virus vaccines in a cat which has had VAS (write a letter as to why)
Hemangiosarcoma
Background
Arises from vascular endothelial cells (may be of bone marrow origin)
5% of non-skin primary malignant tumors in the dog
Hemangiosarcoma
Signalment
Large breed dogs; German Shepherd, Golden Retriever, Labrador Retriever but any dog can get them
Mean age: 8-13 years
Male > Female
Hemangiosarcoma
Sites
Anywhere blood is: Spleen Liver Right atrium Kidney Subcutaneous tissue Muscle Oral cavity Urinary bladder Pericardium Peritoneum Bone
Hemangiosarcoma
Bleeding
Sudden collapse Weakness Pallor Sudden enlargement of mass Cardiac tamponade; weakness and arrythmia
Hemangiosarcoma
Biological behavior
Extremely aggressive tumor has a high rate of early development of metastasis
Endothelial cells can go anywhere they want
25% have right atrial involvement
14% have brain metastasis
Hemangiosarcoma
Diagnosis
Histopathology but may have suggestive features that suggest Hemangiosarcoma
Splenic lesions Right atrial mass Ultrasound: fluid filled masses Aspiration: may only get blood Plasma troponin 1 found in pericardial fluid
Hemangiosarcoma
Splenic lesions rule (Sys Path)
2/3 are malignant and 2/3 of those are hemangiosarcoma
Hemangiosarcoma
CBC, Chem, UA
Normocytic, normochromic anemia
Nucleated RBC
Fragmented cells (schistocytes) = highly suggestive
Neutrophilic leukocytosis
Thrombocytopenia
Hemangiosarcoma
Thoracic rads
78% of metastasis identified
47% cardiac lesions present identified
Met in lung or heart do NOT take to Sx
Hemangiosarcoma
Cardiac ultrasound
92% of cardiac lesions detected
25% have right atrial involvement
Hemangiosarcoma
Surgery Goal
Get bleeding to stop so the patient has a little bit longer with family :(
Hemangiosarcoma
Surgical Removal
Spleens and some subcutaneous masses
Right atrial mass; removal reported to extend survival but difficult to assess
Hemangiosarcoma
Chemotherapy
Single agent doxorubicin (once every 2-3 weeks); helps stop growth and bleeding!
Combination:
Doxo + Vincristine + Cyclophosphamide
Doxo + DTIC
Hemangiosarcoma
Anti-angiogenesis therapy
Minocycline (not much improvement)
Low dose chemotherapy/metronomic therapy: Cyclophosphamide daily or Cyclophosphamide, Lomustine daily, Chlorambucil daily
NSAIDs (not a COX-2 issue though)
Tyrosine Kinase inhibitors
Hemangiosarcoma
Prognosis
Poor
Hemangiosarcoma
Prognosis
Surgery
2-3 months
Hemangiosarcoma
Prognosis
Surgery + Chemotherapy
4-6 months
Hemangiosarcoma
Right atrial
Doxorubicin (116 days)
Surgery (4 months)
Surgery + Doxo (175 days)
Hemangiosarcoma
WSU Protocol
Control local disease: surgery and palliative radiation
Doxorubicin x 4
Metronomic chemotherapy follow-up
Cutaneous Hemangiosarcoma
Background
Light coat color, thin skin dog and cat disease
Likely sunlight induced
Surgically curable if does not invade deeper tissues
