Purpose: The relative value of increasing ifosfamide dose in combination chemotherapy for patients with soft tissue sarcoma (STS) is unclear. The purpose of this study was to compare the efficacy and toxicity of doxorubicin with high-dose (HD) ifosfamide or standard-dose (SD) ifosfamide in patients with STS.
Patients and methods: Chemotherapy-naive patients with STS were randomly assigned to receive doxorubicin 60 mg/m(2) and either SD ifosfamide (1.5 g/m(2)/d, days 1 through 4) or HD ifosfamide (3.0 g/m(2), days 1 through 4) every 21 days. Patients were stratified by the presence or absence of metastatic disease. End points were overall survival (OS), 1-year disease-free survival (DFS), and toxicity.
Results: The study group consisted of 79 patients (52 patients with localized disease and 27 patients with metastases). Both groups were well-balanced with respect to known prognostic factors. There was no significant difference in 1-year DFS comparing SD ifosfamide with HD ifosfamide (55% v 52%; P = .81). For SD ifosfamide, 2- and 3-year OS were 73% and 52% versus 57% and 49% for HD ifosfamide (P = .34). The incidence of grade 3/4 neutropenia, anemia, and thrombocytopenia were 49%, 23%, and 10%, respectively, on the SD ifosfamide arm, compared with 88%, 58%, and 63%, respectively, on the HD ifosfamide arm. There were five early deaths, all on the HD ifosfamide arm.
Conclusion: When combined with doxorubicin, HD ifosfamide did not improve 1-year DFS and OS. Toxicity was clearly greater with the HD ifosfamide arm, and lack of outcome differences might be explained by toxicities with HD ifosfamide. These results suggest that HD ifosfamide combination regimens should not be used as first-line therapy for patients with STS.