PATIENT CHARACTERISTICS: Age: 18 and over Performance status: SWOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count at least 1500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater than 1.5 mg/dL SGOT/SGPT no greater than 3 times upper limit of normal No nonmalignant hepatic disease Renal: Creatinine no greater than 2.0 mg/dL Potassium and magnesium at least lower limit of normal (LLN) Calcium at least LLN Cardiovascular: QTc interval on echocardiogram less than 450 milliseconds No myocardial infarction within past 6 months No uncontrolled congestive heart failure No unstable angina No active cardiomyopathy No unstable ventricular arrhythmia No uncontrolled hypertension Other: Not pregnant or nursing Fertile patients must use effective contraception Must have functional central venous access device or percutaneous intravenous catheter No known hypersensitivity to intoplicine or its analogs No active alcoholism or drug addiction No uncontrolled, unstable psychotic disorders No serious infections No underlying medical conditions that may be aggravated by treatment