PATIENT CHARACTERISTICS: Age: Not specified Performance status: Zubrod 0-1 OR Karnofsky or Lansky 80-100% Life expectancy: At least 3 months Hematopoietic: See Disease Characteristics Hepatic: Bilirubin no greater than 2.0 mg/dL ALT/AST no greater than 4 times normal Renal: Creatinine no greater than 2.0 mg/dL Creatinine clearance at least 50 mL/min Cardiovascular: Shortening fraction or ejection fraction at least 80% of normal for age Pulmonary: FVC and FEV1 at least 60% predicted for age Adults: DLCO at least 60% predicted Other: No active concurrent malignancy No active infections at time of backup bone marrow harvest or pretransplant cytoreduction Not pregnant or nursing Negative pregnancy test HIV negative