Multiple myeloma

Causes

Plasma cells help your body fight infection by producing proteins called antibodies. In multiple myeloma, plasma cells grow out of control in the bone marrow and form tumors in the areas of solid bone.

The growth of these bone tumors makes it harder for the bone marrow to make healthy blood cells and platelets.

Multiple myeloma mainly affects older adults. Past treatment with radiation therapy raises your risk for this type of cancer.

Symptoms

Multiple myeloma causes a low red blood cell count (anemia). This makes you more likely to get infections and have abnormal bleeding.

As the cancer cells grow in the bone marrow, bone or back pain, most often in the ribs or back.

If the bones in the spine are affected, it can put pressure on the nerves, resulting in numbness or weakness of the arms or legs.

Other symptoms include:

• Bleeding problems
• Brittle bones that are more likely to break
• Fatigue due to anemia
• Fevers without any other cause
• Shortness of breath due to anemia

Exams and Tests

Blood tests can help diagnose this disease. Some are:

• Albumin level
• Calcium level
• Total protein level
• Kidney function blood tests
• Complete blood count (CBC)
• Blood and urine tests to check to identify proteins, or antibodies (immunofixation)
• Blood tests to quickly and accurately measure the specific level of certain proteins called immunoglobulins (nephelometry)

This list is not all-inclusive.

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

Bone density testing may show bone loss.

Treatment

People who have mild disease or where the diagnosis is not certain are often closely watched without treatment. Some people have a slow-developing form of multiple myeloma that takes years to cause symptoms.

Medications for the treatment of multiple myeloma include:

• Dexamethasone, melphalan, cyclophosphamide, doxorubicin, thalidomide, lenalidomide (Revlimid), and bortezomib (Velcade) can be used alone or combined together.
• Bisphosphonates (pamidronate or zoledronic acid) to reduce bone pain and prevent fractures.

Radiation therapy may be done to relieve bone pain or treat a bone tumor.

Two types of bone marrow transplantation may be tried:

• Autologous bone marrow or stem cell transplantation makes use of one’s own stem cells.
• Allogeneic transplant makes use of someone else’s stem cells. This treatment carries serious risks but offers the chance of improved survival.

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.

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

Outlook (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.

Chemotherapy and transplants rarely lead to a permanent cure.

Possible Complications

Kidney failure is a frequent complication. Others may include:

• Bone fractures
• High levels of calcium in the blood, which can be very dangerous
• Increased chances for infection, especially in the lungs
• Weakness or loss of movement due to tumor pressing on spinal cord 

When to Contact a Medical Professional

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

Alternative Names

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

References

National Comprehensive Cancer Network. National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Multiple Myeloma. 2012. Version 1.2012.

Rajkumar SV, Dispenzieri A. Multiple myeloma and related disorders. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG, eds. Abeloff’s Clinical Oncology. 4th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 110.

Rajkumar SV. Plasma cell disorders. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011: chap 193.

Update Date: 3/4/2012

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.