Salvage surgical resection after high-dose ifosfamide (HDIF) based regimens in advanced soft tissue sarcoma (ASTS): a potential positive selection bias--a study of the Spanish group for research on sarcomas (GEIS).

ABSTRACT

PURPOSE: To assess the impact of different factors on response rate (RR), time to tumor progression (TTP), and overall survival time (OS) in patients with locally advanced or metastatic soft tissue sarcoma (ASTS), included in three protocols with high-dose ifosfamide (HDIF). PATIENTS AND METHODS: One hundred fifty six ASTS patients included in three consecutive phase II trials with HDIF (>10 g/m(2)), alone or in combination with doxorubicin (DX), were analyzed. Cofactors were institution, trial, gender, age, performance status, histologic type, grade of malignancy, prior radiotherapy, presence of locoregional disease, metastatic site, salvage surgery, number of organs involved, and disease-free interval. RESULTS: By multivariate analysis performance status >0 and lack of salvage surgery correlated with a poorer survival. A good-risk and a poor-risk group were identified, with median survival time (OS) of 29, 5, and 10 months, respectively (P = 0.00001). The 1-, 2-, and 3-year OS for 83 good-risk patients (either with PS = 0 or receiving salvage surgery) was 83, 44, and 29%, respectively, those figures being 37, 7, and 3% for 73 poor-risk patients. CONCLUSION: The design of randomized trials in ASTS including HDIF should consider those prognostic factors as stratification variables.