Monitoring multiple myeloma.

Multiple myeloma (MM) is a B-cell malignancy characterized by the accumulation in bone marrow of terminally differentiated plasma cells. MM is a slowly growing, heterogeneous disease with no known cure. Patients with MM have a median survival of approximately 5 years, during which they may experience significant morbidity. More reliable and rapid determination of changes in the clinical status of patients with MM is becoming increasingly important because of the increasing number of available treatments for these patients. Currently available tests for monitoring patients with MM most often include assessments of monoclonal paraprotein and serum free light chain levels, but the tests have several limitations. Measurement of serum B-cell maturation antigen level may overcome these limitations and improve outcomes for patients with MM. Newer radiologic procedures such as positron emission tomography/computed tomography are superior to plain radiographs, but are costly and inconvenient. Bone marrow examination directly identifies malignant cells, but the heterogeneous nature of the disease makes it problematic to use routinely to follow patients with MM. The development of new markers and approaches to more accurately and quickly assess changes in tumor burden in patients with MM should result in better outcomes for these patients.