PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3,000/mm3 Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9.0 g/dL Hepatic: Bilirubin normal SGOT/SGPT no greater than 3 times upper limit of normal (ULN) PT/PTT less than ULN OR International normalized ratio (INR) less than 1.1 Renal: Creatinine no greater than 2.0 mg/dL OR Creatinine clearance greater than 60 mL/min Cardiovascular: No clear evidence of acute ischemic heart disease on EKG No history of myocardial infarction within past 6 months No history of angina No peripheral vascular disorder Neurologic: No active seizure disorder Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No evidence of hematemesis, melena, or hematochezia No history of inflammatory bowel disease, autoimmune disease, or bleeding disorders No Type I diabetes mellitus or Type II diabetes with peripheral vascular disorders No active infections or any serious concurrent systemic disorders incompatible with study