The ostéosarcome

Osteosarcomas are the most common primary malignant tumor of the bone. Highly aggressive, they occur mainly in young people between the ages of 10 and 20. The majority of osteosarcomas occur in the knee, the lower end of the femur, or the upper tibia. Other locations are possible, most often on a long bone (humerus, fibula, etc.). The preferred site for metastases is the lung and then the other bones. Currently, the first chemotherapy, by methotrexate mainly allows a reduction of the tumor, followed by a surgical intervention allowing the resection of the diseased part of the bone. Metastatic osteosarcomas (which represent approximately 20% of cases) remain very difficult or even impossible to treat.