PATIENT CHARACTERISTICS: Age: Any age Performance status: ECOG 0-3 Life expectancy: At least 3 months Hematopoietic: WBC at least 3,000/mm3 Absolute granulocyte count greater than 1,500/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin no greater than 3.15 mg/dL Renal: Creatinine less than 2.26 mg/dL Serum calcium no greater than 3.1 mmol/L Cardiovascular: Patients with history of angina pectoris, previous cardiac infarction, hypertension, or valvular or congenital heart disease must have baseline measurement of LVEF exceeding 50% Other: No other malignancy within 5 years except nonmelanomatous skin cancer No active infection or any other contraindication to chemotherapy with mitoxantrone No spinal cord or nerve root compression No unstabilized impending pathological fractures