PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: At least 3 months Hematopoietic: WBC greater than 3,000/mm3 Absolute neutrophil count at least 1,500/mm3 Platelet count greater than 100,000/mm3 Hemoglobin at least 10 g/dL Hepatic: Bilirubin less than 2.0 mg/dL AST and ALT no greater than 3 times upper limit of normal (ULN) Alkaline phosphate no greater than 3 times ULN (no greater than 5 times ULN if liver metastases present) Renal: Creatinine less than 2.0 mg/dL Cardiovascular: No myocardial infarction within the past 3 months No symptomatic coronary artery disease or heart block No uncontrolled congestive heart failure Pulmonary: No moderate or severe pulmonary dysfunction Other: Not pregnant or nursing Negative pregnancy test Fertile women must use effective contraception Body weight greater than 50 kg No active infection No mental deficits and/or psychiatric disorders that would preclude study No other life-threatening illness No bleeding disorder (except occult blood from gastrointestinal cancer)