Multiple myeloma: current therapy and a glimpse of the future.

Patients with benign monoclonal gammopathy or smouldering multiple myeloma should not be treated. The plasma cell labelling index utilizing tritiated thymidine or a monoclonal antibody to 5-bromo-2-deoxyuridine is helpful in differentiating patients with benign monoclonal gammopathy or smouldering myeloma from those with overt myeloma. Although combinations of chemotherapeutic agents seem to produce a greater number of objective responses than does melphalan-prednisone, a significant difference in survival has not been proved. Possibilities for future treatment include chemotherapy with large intravenous doses of melphalan, very small doses of cyclophosphamide or melphalan, the administration of hydroxyurea before chemotherapy, combination of interferon with alkylating agents, autologous bone marrow transplantation, and improvement of the soft-agar colony-forming assay for myeloma cells. The therapeutic use of monoclonal antibodies to plasma cell antigens may be possible in the future. Much more needs to be learned about the biologic basis of myeloma before real progress can be made.