This randomized phase III clinical trial studies combination chemotherapy with high dose cyclophosphamide and recombinant interferon alfa-2b to see how well it works compared to combination chemotherapy alone in treating patients with previously untreated stage I-III multiple myeloma. Drugs used in chemotherapy, such as vincristine sulfate, carmustine, melphalan, cyclophosphamide, and prednisone, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Recombinant interferon alfa-2b may interfere with the growth of cancer cells. It is not yet know whether giving combination chemotherapy with or without alternating high-dose cyclophosphamide and recombinant interferon alfa-2b is more effective in treating multiple myeloma.