PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3,000/mm3 Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater than 2 mg/dL AST or ALT no greater than 2 times upper limit of normal (ULN) (no greater than 5 times ULN if liver metastases) Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No atrial or ventricular arrhythmias requiring medication No atrial fibrillation (with or without medication) No ischemic event within past 6 months No history of congestive heart failure Other: Not pregnant or nursing Fertile patients must use effective contraception No significant psychiatric disorders No active infection No other prior malignancies within past 5 years, except: Basal or squamous cell skin cancer Carcinoma in situ of the cervix No concurrent serious systemic disorder