PATIENT CHARACTERISTICS: Age: 18 and over Performance status: 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 2,000/mm3 WBC at least 4,000/mm3 Hepatic: ALT and AST less than 2.5 times upper limit of normal (ULN) (less than 5 times ULN if liver metastasis present) Bilirubin less than 1.25 times ULN Renal: Creatinine less than 1.5 times ULN Creatinine clearance greater than 60 mL/min Cardiovascular: No evidence of severe or uncontrolled cardiovascular disease Pulmonary: No evidence of severe or uncontrolled pulmonary disease