[Surgery and adjuvant chemotherapy of osteosarcoma]

The primary site of metastasis of osteosarcoma is the lung. In the past, even if the primary lesion was completely removed by radical surgery, more than 90% of patients of died pulmonary metastasis with in one to two years. Control of osteosarcoma therefore depends upon the prevention and treatment of its pulmonary metastasis. The introduction of chemotherapy consisting mainly of Adriamycin and high-dose methotrexate with Leucovorin rescue, dramatically improved the prognosis of osteosarcoma. In the past where systemic chemotherapy was not available, the five-year survival rate was around 19%. The majority of patients developed bilateral pulmonary metastasis within one year after onset, and died. These patients exhibited numerous micro-metastases as well. In patients receiving surgical adjuvant chemotherapy with current combination of chemotherapeutic agents (ADM, HD-MTX, VCR, CPM, CDDP), the incidence of pulmonary metastasis was low, and the five-year survival rate increased to 65%. In patients who receive chemotherapy, pulmonary metastasis may be either delayed, a single metastasis appearing after the termination of treatment, or early and multiple, appearing resistant to treatment. Surgery is indicated in the former situation while some therapeutic system must be devised for the latter. Recently, preoperative chemotherapy for limb-saving is given to patients with osteosarcoma of the extremities (NSH-3, 4, 5). The adjuvant of chemotherapy proved to be of great significance for improving the survival rate of osteosarcoma and for achieving limb salvage.