From the Guidelines
Multiple myeloma diagnosis requires a combination of blood tests, urine tests, bone marrow biopsy, and imaging studies, with diagnostic criteria including evidence of clonal bone marrow plasma cells ≥10% or biopsy-proven plasmacytoma, plus at least one myeloma-defining event, as outlined in the International Myeloma Working Group (IMWG) diagnostic criteria 1. The diagnostic workup for multiple myeloma should include:
- Initial testing with complete blood count, comprehensive metabolic panel, serum protein electrophoresis with immunofixation, serum free light chain assay, 24-hour urine protein electrophoresis, and bone marrow aspiration and biopsy
- Advanced imaging such as whole-body low-dose CT, PET/CT, or MRI to detect bone lesions
- Cytogenetic testing of bone marrow plasma cells to determine prognosis, with high-risk features including del(17p), t(4;14), t(14;16), and t(14;20) 1 Key considerations in the diagnosis of multiple myeloma include:
- The presence of end-organ damage, such as hypercalcemia, renal insufficiency, anemia, or bone lesions, which is a key component of the CRAB criteria 1
- The use of serum free light chain assay to monitor disease response and progression, particularly in patients with nonsecretory myeloma 1
- The importance of early diagnosis, as treatment outcomes are better when initiated before significant end-organ damage occurs, and modern therapies have significantly improved survival rates for multiple myeloma patients 1
From the Research
Multiple Myeloma Diagnosis
- Multiple myeloma is a hematologic malignancy characterized by the presence of abnormal clonal plasma cells in the bone marrow, with potential for uncontrolled growth causing destructive bone lesions, kidney injury, anemia, and hypercalcemia 2.
- The diagnosis of multiple myeloma involves the evaluation of patients with possible multiple myeloma, including measurement of hemoglobin, serum creatinine, serum calcium, and serum free light chain levels; serum protein electrophoresis with immunofixation; 24-hour urine protein electrophoresis; and full-body skeletal imaging with computed tomography, positron emission tomography, or magnetic resonance imaging 2.
- Serum protein electrophoresis (SPEP) is an easy-to-perform laboratory test that can be used for detection and quantification of monoclonal gammopathy and should be recommended as a preliminary test for suspected cases of multiple myeloma 3.
- Immunofixation electrophoresis detection technique can be used for screening M protein in patients with atypical multiple myeloma, and can increase the diagnosis accuracy in patients with atypical multiple myeloma 4.
Diagnostic Techniques
- Serum protein electrophoresis is used to identify patients with multiple myeloma and other serum protein disorders, and can help differentiate multiple myeloma from other causes of monoclonal gammopathy 5.
- Urine immunofixation is not always necessary for defining complete response in multiple myeloma patients, other than those with light-chain-only disease 6.
- The detection rate of M protein by immunofixation electrophoresis detection is better than that of serum protein electrophoresis, and can be used to detect M protein in patients with atypical multiple myeloma 4.
Diagnosis and Staging
- The Revised International Staging System combines data from serum biomarkers and malignant plasma cell genomic features to assess estimated progression-free survival and overall survival 2.
- At diagnosis, 28% of patients are classified as having Revised International Staging stage I multiple myeloma, and these patients have a median 5-year survival of 82% 2.
- Approximately 34,920 people in the US and 155,688 people worldwide are diagnosed with multiple myeloma each year, with an estimated 73% having anemia, 79% having osteolytic bone disease, and 19% having acute kidney injury at the time of presentation 2.