OBJECTIVES: I. Evaluate the complete and partial response in multiple myeloma patients receiving peripheral blood stem cells supported by gemcitabine and high dose carmustine and melphalan followed by consolidation therapy with gemcitabine plus cyclophosphamide/dexamethasone/etoposide/cisplatin (DCEP) and dexamethasone/paclitaxel/cisplatin. II. Evaluate the incidence of early death in comparison with historical data in this patient population. III. Evaluate the feasibility of chemotherapy with gemcitabine plus DCEP and dexamethasone/paclitaxel/cisplatin following autotransplantation in these patients.