Diagnostic Criteria and Treatment Approach for Multiple Myeloma

Diagnostic Workup and Staging

The European Society for Medical Oncology recommends detection of M-protein by serum and urine protein electrophoresis, quantification of immunoglobulins and characterization of heavy/light chains, bone marrow aspiration and biopsy, and skeletal imaging for diagnostic workup 1
The International Myeloma Society suggests risk stratification using the International Staging System combining β2-microglobulin and serum albumin levels 2

The European Society for Medical Oncology recommends peripheral blood progenitor cells as the preferred stem cell source and high-dose melphalan 200 mg/m² as the preferred preparative regimen prior to transplantation 1
Oral melphalan (9 mg/m²/day for 4 days) and prednisone (30 mg/m²/day for 4 days) is a standard treatment option for transplant-ineligible patients, with cycles repeated every 4-6 weeks until stable response 3
Long-term administration of bisphosphonates should be proposed to reduce skeletal events 3

The European Society for Medical Oncology recommends that patients with indolent (smoldering) myeloma should not receive immediate treatment 1
For patients with stable response to initial treatment (plateau phase), chemotherapy can be stopped safely 3
Interferon-α (3 million units/m² three times weekly) can significantly prolong remission induced by conventional chemotherapy 4

Regimens similar to those used initially can induce a second remission for relapses after unmaintained remission 5
Thalidomide alone or in combination with high-dose dexamethasone is an option for relapsed/refractory disease 6
Bortezomib-based regimens are also an option for relapsed/refractory disease 6

Assessment of response is based on serum and urine electrophoresis 6
Complete response requires bone marrow aspiration (<5% plasma cells) and immunofixation 6

Multiagent chemotherapy has not proven superior and may be even inferior in elderly patients 1
Spinal cord compression requires immediate intervention with high-dose dexamethasone, surgical decompression if due to bone fragments, and local radiotherapy 7
When monitoring response with free light chain assays, it's crucial to use the same test for serial measurements to ensure accurate relative quantification 8