Multiple myeloma

Definition

Multiple myeloma is cancer of the plasma cells in bone marrow.

Alternative Names

Plasma cell dyscrasia; Plasma cell myeloma; Malignant plasmacytoma; Plasmacytoma of bone; Myeloma - multiple

Causes, incidence, and risk factors

Plasma cells help the body's immune system fight disease by producing substances called antibodies. In multiple myeloma, plasma cells grow out of control and form tumors in the bone marrow.

The excess growth of plasma cells interferes with the body's ability to make red blood cells, white blood cells, and platelets. This causes anemia, which makes a person more likely to get infections and have abnormal bleeding.

As the cancer cells grow in the bone marrow, they can cause pain and destruction of the bones. If the bones in the spine are affected, it can put pressure on the nerves, resulting in numbness or paralysis.

Multiple myeloma mainly affects older adults. A history of radiation therapy raises your risk for this type of cancer.

Symptoms

• Bleeding problems
• Bone or back pain
• Increased susceptibility to infection
• Symptoms of anemia (such as tiredness, shortness of breath, and fatigue)
• Unexplained fractures

Signs and tests

Blood tests can help diagnose this disease. They may include:

• Blood chemistry (CHEM 20) may show increased levels of calcium, total protein, and abnormal kidney function
• Complete blood count (CBC) reveals low numbers of red and white blood cells and platelets
• Serum protein electropheresis (SPEP)
• Urine protein electrophoresis (UPEP) or Bence-Jones protein analysis
• Quantitative immunoglobulins (nephelometry)

Bone x-rays show fractures or hollowed out areas of bone. If your doctor suspects this type of cancer, a bone marrow biopsy will be performed.

Treatment

The goal of treatment is to relieve symptoms.

People who have mild disease or a questionable diagnosis are usually carefully monitored without treatment. Some people have a slow-developing form of multiple myeloma that takes years to cause symptoms.

Treatment begins when the disease becomes worse or causes symptoms.

Chemotherapy and radiation therapy may be performed to relieve bone pain or treat a bone tumor.

Bone marrow transplantation in younger patients has been shown to increase disease-free and overall survival, but it has significant risks.

Medications for multiple myeloma include decadron, melophalan, thalidomide, lenalidomide (Revlimid), and bortezomib (Velcade). Bisphosphonates are used to prevent fractures.

People with multiple myeloma should drink plenty of fluids to prevent dehydration and help maintain proper kidney function. They should also be cautious when having x-ray tests that use contrast dye.

Chemotherapy and transplants rarely lead to a permanent cure.

Support Groups

The stress of illness may be eased by joining a support group whose members share common experiences and problems. See: Cancer - support group

Expectations (prognosis)

Survival of people with multiple myeloma depends on the patient's age and the stage of disease. Some cases are very aggressive, while others take years to get worse.

Complications

Kidney failure is a frequent complication. Other complications may include:

• Bone fractures
• Increased chances for infection (especially pneumonia)
• Paralysis from tumor or spinal cord compression

Calling your health care provider

Call your health care provider if you experience decreased urine output.

Call your provider if you have multiple myeloma and infection develops, or numbness, loss of movement, or loss of sensation develops.

References

National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Multiple Myeloma. National Comprehensive Cancer Network; 2009. Version 2.2009.

Rajkumar S, Kyle R. Plasma cell disorders. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 198.