Osteosarcoma Flashcards
What is the most common primary bone tumor of dogs?
Osteosarcoma
Which dog breeds are most commonly affected by OSA?
Large and giant breed dogs
Which part of the skeleton is most often affected by OSA in large/giant breed dogs?
Appendicular skeleton
If a small breed dog is affected by OSA, which part of the skeleton is most often affected?
Axial skeleton
Where is OSA most commonly seen?
Distal radius, proximal humerus, distal femur, proximal tibia (away from the elbow, close to the knee)
What is the onset of OSA?
Chronic progressive or acute after inciting incident
What is the most effective way to eliminate pain assoc. w/OSA?
Limb amputation
Why is limb amputation only considered a palliative treatment for OSA?
90% of OSA develop mets
What is the most common site of OSA mets?
Lungs
By how much does chemotherapy extend MST assoc. w/OSA?
10-12mo
How will OSA radiographs appear?
Lytic and productive lesion @ metaphysis of bone
If the diaphyseal region of a bone appears to be affected by OSA, what should you consider instead?
Mets from a primary tumor elsewhere in the body
Does OSA cross joints to adjacent bones?
No
How do you dx OSA?
FNA/biopsy of the affected bone
What is a complication assoc. w/FNA/biopsy of an OSA bone?
Pathologic fracture
In what % of OSA cases are pulmonary mets actually visible on radiographs?
Only 10% (even though 90% are metastatic)
What liver enzyme will be elevated with OSA that is a poor prognostic indicator?
ALP
What is one of the complications of a limb-sparing OSA procedure?
Chronic resistant infections
What is a complication if radiation therapy is used to treat an OSA?
Pathological fractures
What chemotherapy drugs are useful for OSA?
Platinum drugs or doxorubicin
What other medication can help palliate pain in patients where OSA surgery is not an option?
Bisphosphonates
What is the MoA of bisphosphonates?
Osteoclast inhibitors
What is the MST for OSA w/amputation alone?
4-6mo
What is the MST for OSA w/amputation and chemo?
10-12mo
What is the MST for OSA when mets are visible in the lungs?
1-3mo
What are common locations for axial OSA?
Mandible and maxilla, ribs, spine, pelvis
Which axial OSA site has the best prognosis with surgery alone?
Mandible (70% 1yr)
