OUTLINE: This is a dose escalation study. Patients undergo apheresis over 2-4 days to mobilize peripheral blood stem cells (PBSC). They then receive amifostine IV over 15 minutes. Fifteen minutes later, carboplatin is administered over 30 minutes on days -6 through -3. Cyclophosphamide IV is administered 1 hour after the carboplatin infusion is completed on days -6 through -4. PBSC are infused on day 0. Filgrastim (G-CSF) is administered beginning on day 4. Cohorts of 3-6 patients are treated at each dose level. At least 15 days must pass between the day of PBSC infusion and the next dose escalation. The dose limiting toxicity (DLT) is defined as the dose producing grade 3 or 4 nonhematologic toxicity in 2 of 6 patients. The maximum tolerated dose (MTD) is defined as one dose level below the DLT dose. At least 6 patients are treated at the MTD. Patients are followed monthly for 6 months, every 2-3 months for 1 year, and annually until death.