Multiple myeloma is a cancer of the plasma cells — a type of white blood cell responsible for producing antibodies that fight infections. In myeloma, abnormal plasma cells multiply uncontrollably in the bone marrow, producing dysfunctional antibodies that cannot protect against infections. The term 'multiple' refers to the fact that the disease commonly affects multiple sites in the skeleton.
The overproduction of abnormal antibodies (called M-proteins or paraproteins) can damage the kidneys, while the accumulation of myeloma cells in the bone marrow disrupts normal production of red blood cells, white blood cells, and platelets. Myeloma cells also release substances that activate bone-destroying cells, leading to bone weakening, pain, and fractures.
The classic symptoms of myeloma are summarized by the acronym CRAB: Calcium elevation (hypercalcemia causing confusion, excessive thirst, and constipation), Renal insufficiency (kidney failure from abnormal protein buildup), Anemia (fatigue and weakness from reduced red blood cells), and Bone disease (pain, osteoporosis, and pathological fractures). Other symptoms include frequent infections due to impaired immunity, unexplained weight loss, and high protein levels detected in blood or urine tests.
Myeloma does not always require immediate treatment. Two precursor conditions — Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM) — represent early stages where abnormal plasma cells are present but have not yet caused organ damage. These conditions require regular monitoring because they carry a risk of progressing to active myeloma, though many patients with MGUS never develop cancer.
Diagnosis involves a combination of blood tests, urine tests, bone marrow biopsy, and imaging studies. Blood tests reveal the presence and quantity of M-proteins through serum protein electrophoresis (SPEP) and free light chain assays. A bone marrow biopsy confirms the percentage of plasma cells and provides material for cytogenetic and molecular studies that determine risk category. Imaging with X-rays, CT, MRI, or PET scans identifies bone lesions and disease extent.
Risk factors include male gender, age over 50, African-American descent, obesity, family history of myeloma, radiation exposure, and occupational exposure in the petroleum industry. Patients with a history of MGUS are also at increased risk and should be monitored regularly.
Treatment for active myeloma has improved dramatically over the past two decades. Current options include chemotherapy, immunomodulatory drugs (lenalidomide, pomalidomide), proteasome inhibitors (bortezomib, carfilzomib), monoclonal antibodies (daratumumab), and corticosteroids. Eligible patients may benefit from autologous stem cell transplantation. More recently, CAR T-cell therapy and bispecific antibodies have shown remarkable results in relapsed or resistant myeloma.
Supportive care is equally important — medications to strengthen bones (bisphosphonates or denosumab), erythropoiesis-stimulating agents for anemia, and infection prevention strategies. With modern treatment combinations, many myeloma patients achieve deep remissions and significantly improved quality of life. If you have been diagnosed with myeloma or a precursor condition, understanding your risk category through comprehensive testing is the first step toward the best possible outcome.