There are several types of plasma cell neoplasms. These diseases are all associated with a monoclonal (or myeloma) protein (M protein). They include monoclonal gammopathy of undetermined significance (MGUS), isolated plasmacytoma of the bone, extramedullary plasmacytoma, and multiple myeloma.
Incidence and Mortality
Estimated new cases and deaths from multiple myeloma in the United States in 2012:
New cases: 21,700.
Clinical Presentation and Evaluation
Multiple myeloma, other plasma cell dyscrasia, or lymphoma will develop in 12% of patients by 10 years, 25% by 20 years, and 30% by 25 years.
All patients with MGUS should be kept under observation to detect increases in M protein levels and development of a plasma cell dyscrasia. Higher levels of initial M protein levels may correlate with increased risk of progression to multiple myeloma.[1,2] In a large retrospective report, the risk of progression at 20 years was 14% for an initial monoclonal protein level of 0.5 g/dL or less, 25% for a level of 1.5 g/dL, 41% for a level of 2.0 g/dL, 49% for a level of 2.5 g/dL, and 64% for a level of 3.0 g/dL.
Treatment is delayed until the disease progresses to the stage that symptoms or signs appear.
Patients with MGUS or smoldering myeloma do not respond more frequently, achieve longer remissions, or have improved survival if chemotherapy is started early while they are still asymptomatic as opposed to waiting for progression before treatment is initiated.[3,4,5,6] Newer therapies have not been proven to prevent or delay the progression of MGUS to a plasma cell dyscrasia.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with monoclonal gammopathy of undetermined significance. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
Kyle RA, Therneau TM, Rajkumar SV, et al.: A long-term study of prognosis in monoclonal gammopathy of undetermined significance. N Engl J Med 346 (8): 564-9, 2002.
Bird J, Behrens J, Westin J, et al.: UK Myeloma Forum (UKMF) and Nordic Myeloma Study Group (NMSG): guidelines for the investigation of newly detected M-proteins and the management of monoclonal gammopathy of undetermined significance (MGUS). Br J Haematol 147 (1): 22-42, 2009.
Bladé J, Dimopoulos M, Rosiñol L, et al.: Smoldering (asymptomatic) multiple myeloma: current diagnostic criteria, new predictors of outcome, and follow-up recommendations. J Clin Oncol 28 (4): 690-7, 2010.
He Y, Wheatley K, Clark O, et al.: Early versus deferred treatment for early stage multiple myeloma. Cochrane Database Syst Rev (1): CD004023, 2003.
Riccardi A, Mora O, Tinelli C, et al.: Long-term survival of stage I multiple myeloma given chemotherapy just after diagnosis or at progression of the disease: a multicentre randomized study. Cooperative Group of Study and Treatment of Multiple Myeloma. Br J Cancer 82 (7): 1254-60, 2000.
Kyle RA, Remstein ED, Therneau TM, et al.: Clinical course and prognosis of smoldering (asymptomatic) multiple myeloma. N Engl J Med 356 (25): 2582-90, 2007.