Newer approaches to the management of multiple myeloma.

Patients with multiple myeloma must be distinguished from those with monoclonal gammopathy of undetermined significance and smoldering multiple myeloma. Therapy should be reserved for patients with active or symptomatic multiple myeloma. The pertinent literature on the diagnosis of multiple myeloma, prognostic factors, chemotherapy, and allogeneic bone marrow transplantation, as well as autologous peripheral blood or bone marrow stem cells for rescue, was reviewed. The two most powerful prognostic factors for multiple myeloma are the bone marrow plasma cell labeling index and the beta 2-microglobulin level. Chemotherapy is the preferred initial treatment for overt, symptomatic multiple myeloma. Combinations of alkylating agents produce a higher response rate, but the survival is the same as treatment with melphalan and prednisone. The combination of alpha 2-interferon with multiple alkylating agents produces a good response. alpha 2-Interferon prolongs the duration of the plateau state after a response to chemotherapy, but it apparently does not prolong survival. Allogeneic bone marrow transplantation is possible for only 5-10% of patients with multiple myeloma. Its advantage is that the graft contains no tumor cells that can subsequently produce a relapse. However, there is a significant early mortality, the risk of graft versus host disease is troublesome, and relapse of multiple myeloma is common. Autologous bone marrow transplantation is applicable for more patients because the age limit is higher and a matched donor is unnecessary. However, two major problems exist: (1) eradication of multiple myeloma from the patient may not occur even with large doses of chemotherapy and irradiation, and (2) infused autologous bone marrow or peripheral blood stem cells contaminated by myeloma cells or their precursors may be responsible for relapse.