Tumor volume change after chemotheraphy as a predictive factor of disease free survival for osteosarcoma.

Change in tumor volume after chemotherapy appears to have a prognostic significance for the outcome of osteosarcoma. A newly developed volume measurement method based on three-dimensional summation with a proved reproducibility was utilized to measure osteosarcoma tumor volume. This retrospective analysis included 38 patients with biopsy- proven, nonsurface, skeletal high-grade osteosarcoma. The treatment was started by using three cycles of preoperative chemotherapy with cisplastin (100 mg/m2) and adriamycin (30 mg/m2). The tumor volume was measured before and after preoperative chemotherapy using three-dimensional magnetic resonance image measurement. The percentage of tumor necrosis was assessed by pathologic exam. After three cycle of postoperative chemotherapy, the patients were followed up at regular interval. For the 23 good responder patients, the mean survival time was 73.2 months (95% confidence interval 61.9-84.5 months), and for the 15 poor responder patients, the mean survival time was 50.8 months (95% confidence interval 38.6-63.1 months) (p<0.05). For the 14 patients with increased tumor volume after chemotherapy, the mean survival time was 47.5 months (range: 36.3-58.6 months) and for the 24 patients with stable or decreased tumor volume, the mean survival time was 74.3 months (range: 63.79-84.88 months) (p<0.05). Among the various factors, histopathologic response and tumor volume change after chemotherapy predicted disease free survival (p<0.05). Change in the tumor volume that was measured with a reproducible method and the histopathologic response after chemotherapy were the important predictors of disease free survival for osteosarcoma patients.