Osteosarcoma: a multidisciplinary approach to diagnosis and treatment.

The treatment of osteosarcoma requires a multidisciplinary approach involving the family physician, orthopedic oncologist, medical oncologist, radiologist and pathologist. Osteosarcoma is a mesenchymally derived, high-grade bone sarcoma. It is the third most common malignancy in children and adolescents. The most frequent sites of origin are the distal femur, proximal tibia and proximal humerus. Patients typically present with pain, swelling, localized enlargement of the extremity and, occasionally, pathologic fracture. Most patients present with localized disease. Radiographs commonly demonstrate a mixed sclerotic and lytic lesion arising in the metaphyseal region of the involved bone. Computed tomography and bone scanning are recommended to detect pulmonary and bone metastases, respectively. Before 1970, osteosarcomas were treated with amputation. Survival was poor: 80 percent of patients died from metastatic disease. With the development of induction and adjuvant chemotherapy protocols, advances in surgical techniques and improvements in radiologic staging studies, 90 to 95 percent of patients with osteosarcoma can now be treated with limb-sparing resection and reconstruction. Long-term survival and cure rates have increased to between 60 and 80 percent in patients with localized disease.