PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 No underlying disease associated with active bleeding Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) Alkaline phosphatase no greater than 3 times ULN AST no greater than 3 times ULN PT and PTT normal Renal: Creatinine no greater than 1.5 times ULN Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 6 months after study