Detection of Circulating Osteosarcoma Tumor Cells in the Blood of Patients Using the Polymerase Chain Reaction

Peripheral blood samples (6-9 ml) will be collected in purple top tubes, when routine laboratory tests are being drawn. The blood will be drawn through central venous catheters, whenever possible. Blood will be drawn once from patients with malignant diagnoses other than osteosarcoma, neuroblastoma, Ewing's sarcoma or synovial sarcoma. In patients with osteosarcoma we will obtain blood when baseline laboratory tests are obtained, after every two cycles of treatment (approximately every six weeks), at the end of planned surgery and chemotherapy, every three months for the first year off therapy and yearly thereafter. We will also obtain blood if the patient relapses.