RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more that one drug may kill more tumor cells. Chemoprotective drugs, such as amifostine, may protect normal cells from the side effects of chemotherapy.

PURPOSE: Phase II trial to study the effectiveness of combination chemotherapy plus amifostine chemoprotection in treating patients who have metastatic or unresectable cancer and who are undergoing peripheral stem cell transplantation.

OBJECTIVES: I. Describe the toxic effects of ifosfamide, carboplatin, and etoposide (ICE) with amifostine in patients with metastatic or locally unresectable malignancies who are undergoing peripheral stem cell transplantation. II. Describe the pharmacokinetic profile for ifosfamide and its metabolites in patients receiving the maximum tolerated dose of ICE with amifostine. III. Compare the toxic effects of this study with the toxic effects observed on protocol 94-078. IV. Compare the pharmacokinetics of ifosfamide on this study with the pharmacokinetics observed on protocol 94-078.

OUTLINE: Patients undergo peripheral blood stem cell (PBSC) harvest on day -8, followed by ifosfamide IV, carboplatin IV, and etoposide IV (ICE) by 96 hour continuous infusion on days -7 to -4. Patients receive amifostine IV twice a day on days -7 to -3. PBSCs are reinfused on day 0. Filgrastim (G-CSF) is administered subcutaneously beginning on day 0 at least 2 hours after infusion of the stem cells and continuing until blood cell counts recover. Patients are followed monthly for the first 2 months and then for survival.

PROJECTED ACCRUAL: A total of 25 evaluable patients will be accrued for this study within 19 months.

• Bladder Cancer
• Brain and Central Nervous System Tumors
• Carcinoma of Unknown Primary
• Extragonadal Germ Cell Tumor
• Head and Neck Cancer
• Kidney Cancer
• Lung Cancer
• Ovarian Cancer
• Sarcoma
• Testicular Germ Cell Tumor
• Unspecified Adult Solid Tumor, Protocol Specific

• Biological: filgrastim
• Drug: amifostine trihydrate
• Drug: carboplatin
• Drug: etoposide
• Drug: ifosfamide
• Procedure: peripheral blood stem cell transplantation

DISEASE CHARACTERISTICS: Histologically proven metastatic or locally unresectable malignancy Patient may be responding to therapy: Stage IIIC/IV or recurrent/refractory ovarian carcinoma (ineligible for other bone marrow or stem cell transplant protocols) Recurrent or refractory germ cell carcinoma Extensive disease small cell lung cancer in partial or complete remission Stage IIIB non-small cell lung cancer responding to chemotherapy Sarcomas in or near complete remission after induction chemotherapy Responsive bladder, head and neck carcinoma, or carcinoma of unknown primary Other tumors without curative or first line therapy (not eligible for phase II or III studies) No active brain or bone marrow metastases

PATIENT CHARACTERISTICS: Age: 18 to 55 Performance status: PS 0-1 Life expectancy: Not specified Hematopoietic: WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT less than 2.5 times ULN Renal: Creatinine no greater than 1.5 times ULN Creatinine clearance at least 60 mL/min Cardiovascular: No uncontrolled or severe cardiovascular disease No myocardial infarction within 6 months No congestive heart failure Other: Not pregnant No other serious medical or psychological illnesses No active uncontrolled bacterial, viral, or fungal infection No active duodenal ulcer

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: Greater than 3 weeks since prior chemotherapy See Disease Characteristics No other concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: Greater than 1 week since prior radiotherapy No concurrent radiotherapy Surgery: Greater than 1 week since prior surgery (except for biopsies) Other: No barbiturates, dilantin, or cimetidine within 3 weeks of high dose chemotherapy No antihypertensive medications within 24 hours prior to amifostine administration