Autologous Peripheral Blood Stem Cell Transplant for Germ Cell Tumors

OBJECTIVES: Primary * Determine overall survival (OS) of patients with germ cell tumors treated with tandem autologous stem cell transplantation with non-cross-resistant conditioning regimens. Secondary * Determine disease-free survival (DFS) of patients treated with this regimen. * Determine the toxicity of tandem transplants * Determine the time to engraftment of neutrophils and platelets in patients treated for each transplant * Determine the number of patients unable to adequately mobilize sufficient peripheral blood stem cells (PBSC) for tandem transplantation. * Identify prognostic factors of patients unlikely to mobilize sufficient PBSC for tandem transplantation. * Compare OS and DFS of patients undergoing single vs tandem transplantation. OUTLINE: * Peripheral blood stem cell (PBSC) mobilization with filgrastim (G-CSF): Patients receive G-CSF subcutaneously (SC) beginning on day 1 and continuing until stem cell collection is complete. Patients undergo stem cell collection beginning on day 5 of G-CSF administration and continuing for at least 3 collections until the collection goal is met. * Second PBSC mobilization with chemotherapy: Patients not meeting the collection goal receive cyclophosphamide IV over 2 hours on day 1 and G-CSF SC beginning on day 4 and continuing until stem cell collection is complete. Patients meeting the collection goal after PBSC mobilization via G-CSF alone or in combination with chemotherapy will undergo tandem autologous transplantation. If collection goal is not met but the patient has collected \> or = 2 x 10\^6 CD34 cells/kg, a single autologous transplant will be performed. * Single stem cell transplantation (SCT): Patients receive paclitaxel IV over 3 hours on day -7 and ifosfamide IV on days -6 to -4. Patients undergo reinfusion of stem cells on day 0. Patients also receive G-CSF SC or IV beginning on day 1 and continuing until blood counts recover. * Tandem SCT: Patients receive treatment as in single SCT. Beginning 30-90 days later, patients receive carboplatin IV over 60 minutes and thiotepa IV over 30 minutes on days -6 to -4 and etoposide IV over 60 minutes on days -6 to -3. Patients undergo reinfusion of stem cells on day 0. Patients also receive G-CSF SC or IV beginning on day 5 and continuing until blood counts recover. After completion of study treatment, patients are followed at 6, 9, and 12 months and then every 6 months for up to 2 years. PROJECTED ACCRUAL: A total of 25 patients will be accrued for this study.