Combination Chemotherapy With or Without Cyclophosphamide and Prednisone in Treating Older Patients With Multiple Myeloma

DISEASE CHARACTERISTICS: Diagnosis of multiple myeloma, defined by at least 2 of the following conditions: Neoplastic cell infiltrate and/or microplasmacytomas by bone marrow sections or smears Plasma cell infiltrates greater than 20% of marrow nucleated cells or, if less than 20%, objective evidence of monoclonality of the plasma cells required Paraprotein in blood or urine Definite lytic bone lesions (not osteoporosis) Nonsecretory disease allowed in the presence of 1 of the following conditions: Microplasmacytomas Monoclonal plasmacytosis with immunoglobulin light-chain expression in cytoplasm No equivocal myelomatosis, defined by the following criteria: Minimal or no symptoms attributable to myelomatosis Pretransfusion hemoglobin greater than 10 g/dL Post-hydration creatinine less than 1.47 mg/dL No osteolytic lesions except minimal lesions that do not threaten pathological fracture and are not associated with pain Plasma cells less than 30% of marrow nucleated cells and marrow showing normal hematopoietic activity Serum beta-2 microglobulin less than 4 mg/L Less than 1 g of free light-chain excretion per 1 g of creatinine No objective factors indicating progressive myelomatosis PATIENT CHARACTERISTICS: Age: 65 to 74 If under 65, higher priority is given to protocol MRC-LEUK-MYEL-VII unless entry into this study would be more appropriate Performance status: Not specified Life expectancy: Not specified Hematopoietic: See Disease Characteristics Neutrophil count at least 1,300/mm^3 Platelet count at least 75,000/mm^3 Hepatic: Not specified Renal: See Disease Characteristics Other: Ability to tolerate fluid intake of at least 3 L/day beginning at least 2 days before study entry Afebrile and free of infection No contraindication to therapy PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Endocrine therapy: Prior or concurrent prednisolone at 30 mg/m2/day or less (or equivalent doses of other corticosteroids) for relief of fluid-unresponsive hypercalcemia allowed Radiotherapy: Prior or concurrent minimal local radiotherapy to relieve persistent bone pain or cord compression allowed Surgery: Not specified