Osteosarcoma
Osteosarcoma is the most common primary malignant bone tumour, excluding myeloma and lymphoma. It accounts for 20% of primary bone tumours. It has a bimodal distribution, with 75% occurring in patients below the age of 20, with a predilection for the metaphyseal region of tubular long bones. 50% of cases occur around the knee.
A second peak in incidence occurs in the elderly, usually associated with an underlying bone pathology such as Paget's disease, medullary infarct, or prior irradiation.
Standard therapy is a combination of surgery and chemotherapy.
Osteosarcoma also occurs in dogs and typically afflicts middle aged dogs with long limbs (i.e., Greyhounds, German Shepherds, and the like). One key difference between osteosarcoma in dogs and humans is that the cancer is far more likely to spread to the lungs in dogs.
