Oncology - Osteosarcoma and Hemangiosarcoma Flashcards
What is an osteosarcoma?
It is a malignant mesenchymal tumor of primitive bone that produces an extracellular osteoid matrix
True or False: Osteosarcoma is the most common skeletal malignancy in dogs.
True
What type of age distribution does osteosarcoma have?
Bimodal - young dogs, and old dogs
What breeds more commonly get osteosarcomas?
Large/Giant Breed dogs
What legs usually get osteosarcomas more commonly?
Front legs
Where do osteosarcomas more commonly happen?
at the metaphysis
What are the developmental factors that can lead to osteosarcoma?
Large, fast growing dogs
Dogs who get ionizing radiation
How are osteosarcomas diagnosed?
Radiographs primarily
Is cytology or a biopsy necessary for osteosarcoma diagnosis?
It has decent accuracy of determining malignancy and an average accuracy of determining tumor type Can fracture
Long story short - not entirely necessary
Is a definitive diagnosis of osteosarcoma needed before treatment?
no - any other lesion that could be caused there may be treated similarly
If you are doing radiation - no
What should be done for staging?
3 view chest rads
LN aspirate
Bone scan is not helpful
What percentage of cases have micrometestatic disease at diagnosis of osteosarcoma?
90%
What is osteosarcoma grading based on?
Amount of pleomorphism, tumor cell appearance, MI, and necrosis
What grade of osteosarcoma has the highest risk of death
Grade III
What are subclassifications of osteosarcoma based on?
the type and amount of matrix, may impact survival
What is a stage I OSA?
Low grade, no metastasis
What is a stage II OSA?
high grade, no metastasis
What is a stage III OSA?
Low or high grade, mets
What is a stage A OSA?
Intracompartamental
What is a stage B OSA?
Extracompartamental
What stage and grade are most dogs that we diagnose with OSA?
Stage IIB
What are the treatment options for OSA?
Surgery, radiation, chemotherapy, and pain control
What is the recommended surgery for OSA?
Amputation - this does nothing for the metastasis
Limb spare
What is limb spare?
You take the tumor out and replace it with something - can only do for distal radial osteosarcoma
What radiation therapy options are there for osteosarcoma?
Palliative and stereotactic
What is something important to keep in mind about stereotactic therapy and OSA?
The leg will fracture within a year
What is the chemotherapy of choice for OSA?
Carboplatin (less side effects) or doxorubicin
What can be done to remove pulmonary metastatic disease associated with OSA?
pulmonary metastasectomy
What criteria are there for pulmonary metastasectomy?
Stable primary disease for 300 days
3 lesions or less
Radiographic doubling time for >40 days
No other evidence of disease
What pain control can be given to manage OSA?
NSAIDs, Opioids, Gabapentin, and bisphosphonates
What do bisphosphonates do?
Prevent oseoclastic activity - bone break down
What is a risk with pain management of OSA?
When they are feeling better they may end up fracturing their bone
What is the median survival time for OSA with one of the treatments if done alone?
5 months
What is the median survival time for OSA when multiple treatments are done together?
9-12 months
True or False: Pathologic fracture in a patient with OSA does not impact prognosis.
True
What are negative prognostic factors for OSA?
Large tumor, humeral location, high tumor grade, high MI, stage III, elevated ALP, monocytosis, and lymphocytosis
True or False: Osteosarcoma is not painful and aggressive.
It is very painful and aggressive
If you see anisocytosis, polychromasia, or acanthocytes, what should you be worried about?
Something is going on in the spleen
What differentials should you consider with hemangiosarcoma (HSA)?
Hematoma, hemangioma, sarcomas, other tumors, and extramedullary hematopoiesis
What is a HSA?
Aggressive vascular endothelial cell tumor
What percentage of splenic neoplasias are hemangiosarcomas?
50%
What is the typical signalment for HSA?
middle aged to older
Breeds - GSH, goldens, labs, large breed dogs, lightly pigmented breeds
What can cause cutaneous HSA?
UV light or radiation therapy
What can cause visceral HSA?
Ionizing radiation pre or postnatally or genetic predisposition
Where are the primary sites of HSA in dogs?
Spleen, right auricular, skin, subcutis, and muscle, liver, and kidney
What percentage of HSAs present with overt metastasis at presentation?
80%
True or False: HSA are the number one neoplasia that goes to the brain.
True
What clinical signs are associated with HSA?
Weakness and collapse, signs associated with hypovolemia, abdominal distension, weight loss, signs of right hearted failure, seizures, and lameness
What will you see on CBC/Chem/UA in patients with HSA?
Regenerative anemia, neutrophilic leukocytosis, thrombocytopenia, schistocytes, acanthocytes, and hypoglycemia
What will you see on coagulation profile in patients with HSA?
Elevations in PT/PTT - 50% will have coagulation abnormalities meeting the criteria for DIC
What other diagnostics and staging tests should be done for HSA?
Three-view thoracic rads. abdominal ultrasound, ECG, EKG
What will you see on an EKG in patients with HSA?
VPCs and ventricular tachycardia
What is the gross pathology of HSA?
Solitary or multifocal, disseminated pale grey to dark red/purple Soft, gelatinous, blood filled, necrotic nonencapsulated friable
What is staging for HSA based on?
Primary tumor, regional lymph nodes, distant metastasis
What is the only chemotherapy agent effective in hemangiosarcomas?
Doxorubicin
What is the survival time for chemotherapy in patients with HSA?
6 months
What does I’m Yunity do?
It contains polysaccharides that are immunomodulatory, inhibit tumor cell growth, and free radical scavenger
What does Yunnan Baiyao do?
It stops bleeding and can be helpful in HSA cases
What is the most effective treatment for HSA?
splenectomy with doxorubicin
True or False: All splenic masses are malignant.
False - but 2/3 are
