PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-1 Life expectancy: At least 12 weeks Hematopoietic: Platelet count at least 100,000/mm3 Absolute granulocyte count at least 1,500/mm3 No known bleeding disorder Hepatic: Bilirubin no greater than 2 times upper limit of normal (ULN) AST less than 5 times ULN PT/PTT normal (except when elevated due to therapeutic coumadin) Renal: Creatinine no greater than 2 times ULN Cardiovascular: No significant cardiac dysfunction Neurologic No history of significant neurologic disorder No significant psychiatric disorder Other: Not pregnant or nursing Fertile patients must use effective contraception At least 5 years since prior malignancy and no evidence of recurrence No other serious illness or medical condition No active uncontrolled infection No complete bowel obstruction