Metastatic osteosarcoma: Results of two consecutive therapeutic trials at St. Jude Children's Research Hospital

BACKGROUND. The outcome of patients with metastatic osteosarcoma treated in two consecutive trials from 1986 to 1997 was analyzed to evaluate the efficacy of carboplatin-based multiagent chemotherapy and to identify prognostic factors. The initial study (OS-86) used ifosfamide, cisplatin, doxorubicin, and high-dose methotrexate, and the subsequent study (OS-91) used the same agents at similar doses, but carboplatin was substituted for cisplatin. METHODS. Twelve patients (median age, 15.1 yrs) were treated in OS-86 for osteosarcoma metastatic to the lung only (11 patients) or bone only (1 patient), and 17 patients (median age, 15.1 yrs) were treated in OS-91 for osteosarcoma metastatic to the lung only (12 patients), bone only (2 patients), lung and bone (2 patients), or other site (1 patient). RESULTS. Patients with metastatic disease enrolled in OS-86 and those with metastatic disease enrolled in OS-91 did not differ in terms of demographic features, histologic subtype, site of primary tumor, or site of metastases. There was a difference in survival according to treatment protocol (P = 0.054). All survivors (four of whom were enrolled in OS-86 and one of whom was enrolled in OS-91) had lung metastases only. Five-year survival estimates for patients with lung metastases only were 45.5 ± 13.7% (OS-86) and 8.3 ± 5.6% (OS-91) (P = 0.084). Unilateral lung metastases (P = 0.006), no more than three lung nodules (P = 0.014), and surgical remission (P = 0.001) were associated with improved survival probability. CONCLUSIONS. The poor outcome of patients with metastatic osteosarcoma treated in OS-91 justifies the use of cisplatin with its associated toxicity in patients with high-risk disease.