The treatment of Ewing's sarcoma of bone at the University of Florida: 1969 to 1998.

Since 1969, 144 patients with previously untreated Ewing's sarcoma of bone were entered in prospective protocols at the University of Florida. From 1969 through 1981, three institutional protocols were used, and some patients were entered into the First Intergroup Ewing's Sarcoma Study. Starting in 1982, an attempt was made to intensify treatment, with patients divided according to their primary tumor size into standard-risk (< or = 8 cm in maximum diameter) and high-risk groups. Patients with metastases at diagnosis also were considered high risk. The standard-risk protocols (Number 1 and Number 2 specified treatment with chemotherapy considered to be standard for the era; the patients who were high risk had standard chemotherapy followed by end-intensification. Treatment for patients with metastases at diagnosis was intensified additionally in 1993 with a protocol (high-risk protocol Number 5) specifically designed just for these patients. The absolute survival rate of all patients treated before 1982 was 50% at 5 years for patients without metastases at diagnosis and 18% for patients with metastases. Patients with small primary lesions had a better survival rate than patients with large primary lesions. After 1982, the 5-year survival rate for patients treated on the standard-risk protocols was 53% (1985-1998), whereas for high-risk protocols the 5-year survival rate was 63%. Survival rates were better for younger patients at diagnosis and for patients who responded well to induction chemotherapy, indicating that future trials may need to tailor therapy based on the response to induction chemotherapy.