Osteosarcoma
Osteosarcoma is a primary malignant tumour of the skeleton characterised by the direct formation of immature bone or osteoid tissue by the tumour cells.
Epidemiology
Classic osteosarcoma is a rare (0.2% of all malignant tumours) highly malignant tumour, with an estimated incidence of 3 cases/million population/year.
Clinical description
Osteosarcoma arises predominantly in the long bones and rarely in the soft tissues. The age at presentation ranges from 10 to 25 years of age.
Diagnostic methods
Plain radiographs, computed tomography, magnetic resonance imaging, angiography and dynamic bone scintigraphy are used for diagnosis, evaluation the extent of tumour involvement and for making decisions about the type of operation and, if necessary, the type of reconstruction required.
Management and treatment
In the past, all patients with osteosarcoma were treated by amputation but the cure rate was under 10% and almost all patients died within a year from diagnosis. At present, the percentage of patients cured varies between 60% and 70% for localised osteosarcoma at onset (80% of cases) treated in specialised bone tumour centres with pre- and postoperative chemotherapy associated with surgery. Surgery is conservative (limb salvage) in more than 90% of patients.
Prognosis
Prognosis is more severe (cure rate about 30%) for tumours located in the axial skeleton and in patients with metastasis at onset.