DISEASE CHARACTERISTICS: Histochemically proven primary systemic amyloidosis (AL) No presence of non-AL amyloidosis No amyloid-specific syndrome (e.g., skin purpura or carpal tunnel syndrome) as only evidence of disease No vascular amyloid only in a bone marrow biopsy specimen or in a plasmacytoma Must have symptomatic organ involvement with amyloid (e.g., liver, mild cardiac, renal, or soft tissue involvement, or grade 1 or 2 peripheral neuropathy) Demonstrable M-protein in the serum/urine OR Clonal population of plasma cells in the bone marrow OR Immunohistochemical stain with anti-light chain antisera of amyloid fibrils No clinically overt multiple myeloma (i.e., monoclonal BMPC greater than 20% and at least one of the following: bone lesions, anemia, or hypercalcemia)

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-3 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Total bilirubin less than 2.0 mg/dL OR Direct bilirubin no greater than 1.0 mg/dL Alkaline phosphatase no greater than 4 times upper limit of normal (ULN) ALT or AST no greater than 3 times ULN Renal: Creatinine clearance greater than 40 mL/min Cardiovascular: Echocardiographic ejection fraction greater than 50% At least 3 years since prior enzyme documented myocardial infarction Interventricular septal thickness no greater than 20 mm No New York Heart Association class III or IV heart failure No grade 2 or 3 A-V block No chronic atrial fibrillation No sustained (greater than 30 seconds) ventricular tachycardia or frequent episodes (greater than 20 in 24 hours) of nonsustained ventricular tachycardia or ventricular pairs, detected by 24-hour ambulatory electrocardiographic monitoring Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception HIV positive allowed No uncontrolled infection No severe diarrhea not controllable with medication or that requires total parenteral nutrition No other concurrent active malignancy except nonmelanoma skin cancer or cervical cancer

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 6 weeks since prior interferon alfa Chemotherapy: No prior anthracyclines greater than 120 mg/m2 At least 6 weeks since prior melphalan or other alkylating agents

Endocrine therapy: At least 6 weeks since prior high dose dexamethasone Radiotherapy: Not specified Surgery:

Not specified