Overview

Multiple myeloma is a type of blood cancer that affects plasma cells, a type of white blood cell found in the bone marrow. Plasma cells normally produce antibodies that help the body fight infections. In multiple myeloma, these plasma cells become abnormal and multiply uncontrollably, producing excessive amounts of abnormal proteins called monoclonal proteins (M-proteins) or light chains. This abnormal buildup can damage bones, impair kidney function, and weaken the immune system. Multiple myeloma is a chronic but treatable condition, most commonly diagnosed in older adults.

Causes

The exact cause of multiple myeloma is unknown, but several risk factors have been identified:

• Age: Most cases are diagnosed in individuals over the age of 60.
• Gender: Men are slightly more likely to develop multiple myeloma than women.
• Race: African Americans have a higher risk compared to other ethnic groups.
• Family history: Having a close relative with multiple myeloma increases risk.
• Pre-existing plasma cell disorders: Conditions like monoclonal gammopathy of undetermined significance (MGUS) can develop into multiple myeloma.
• Environmental exposure: Prolonged exposure to radiation or certain chemicals, such as benzene, may increase risk.
• Immune system conditions: Some autoimmune diseases are associated with a slightly higher risk.

Symptoms

Multiple myeloma can cause a wide range of symptoms, or in early stages, it may not cause noticeable symptoms at all. Common signs include:

• Bone pain: Especially in the back, ribs, and hips due to bone damage.
• Fatigue: Resulting from anemia caused by reduced red blood cell production.
• Frequent infections: A weakened immune system makes infections more common and severe.
• Hypercalcemia: High calcium levels in the blood can cause nausea, constipation, confusion, and excessive thirst.
• Kidney problems: Accumulation of abnormal proteins can damage the kidneys, leading to renal dysfunction.
• Weight loss: Unintentional weight loss may occur as the disease progresses.
• Weakness or numbness: Spinal fractures or compression of nerves can lead to neurological symptoms.

Diagnosis

Diagnosing multiple myeloma involves a combination of clinical assessments, laboratory tests, and imaging studies:

• Blood tests: Detection of high levels of monoclonal proteins (M-proteins), abnormal calcium, or low blood counts.
• Urine tests: Identification of Bence Jones proteins, a type of light chain protein found in urine.
• Bone marrow biopsy: Examination of bone marrow samples to assess the percentage of abnormal plasma cells.
• Imaging studies: X-rays, MRI, PET scan, or CT scans can reveal bone lesions or fractures typical of myeloma.
• Serum free light chain assay: Measures light chains in the blood to detect abnormal production.
• Cytogenetic testing: Evaluates genetic abnormalities that can influence prognosis and treatment approach.

Treatment

Treatment for multiple myeloma depends on the stage of the disease, symptoms, and overall health of the patient:

• Observation (smoldering myeloma): In cases without symptoms, doctors may monitor the condition without immediate treatment.
• Targeted therapy: Drugs like proteasome inhibitors (bortezomib, carfilzomib) and immunomodulatory agents (lenalidomide, thalidomide) are used to target myeloma cells.
• Chemotherapy: Combines multiple drugs to kill cancerous plasma cells.
• Steroids: Dexamethasone and prednisone are used to control inflammation and kill myeloma cells.
• Stem cell transplant: High-dose chemotherapy followed by stem cell transplantation can help achieve long-term remission in eligible patients.
• Radiation therapy: Used to relieve bone pain or treat localized areas of bone damage.
• Bisphosphonates: Medications to strengthen bones and reduce the risk of fractures.
• Supportive care: Includes antibiotics for infections, erythropoietin for anemia, and dialysis for severe kidney damage.

Prognosis

The prognosis of multiple myeloma varies depending on individual factors, including age, stage of the disease, and response to treatment:

• Chronic condition: Multiple myeloma is generally considered incurable but treatable, with periods of remission and relapse.
• Advancements in therapy: Newer treatments and targeted therapies have significantly improved survival rates and quality of life.
• Survival rate: Median survival varies from 5 to 10 years depending on risk factors and treatment options.
• Early treatment response: Patients who respond well to initial therapy often have better outcomes.
• Regular monitoring: Ongoing follow-up is essential to detect relapses early and adjust treatment as needed.

With modern therapies, many patients with multiple myeloma can lead active and fulfilling lives, though long-term management is typically required.