Prognostication including DNA analysis in osteosarcoma

In a retrospective study of 83 osteosarcoma patients treated by surgery and adjuvant interferon from 1971 to 1986, the clinical course was related to different clinicopathologic features and tumor DNA content. DNA analysis was feasible in 60 cases. Four tumors were diploid and 56 hyperploid. The 7-year survival rate, estimated by life-table analysis, was 0.44 for the whole series. Multivariate analysis disclosed that male sex, proximal tumor location, and histologic Grade IV were independent risk factors--all approximately of equal strength. DNA analysis did not provide prognostic information, except for tumors with extreme abnormality of the DNA content, which was associated with a very poor prognosis. A prognostication model was created, based on the number of risk factors present. The 7-year survival rate for patients with none, one, two, or three risk factors was 0.80, 0.59, 0.42, and 0.13, respectively. The estimated 7-year rate of local recurrence was 0.29: 0.07 after ablative surgery and 0.54 after local surgery. Among patients who were free of metastasis 1 year after diagnosis, local recurrence reduced the 7-year survival rate from 0.86 to 0.48. In high-grade osteosarcoma, conventional clinicopathologic features and local tumor control remain the most important prognostic factors.