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Multiple Myeloma

• Definition of Multiple Myeloma
• Description of Multiple Myeloma
• Causes and Risk Factors of Multiple Myeloma
• Symptoms of Multiple Myeloma
• Diagnosis of Multiple Myeloma
• Treatment of Multiple Myeloma
• What Questions To Ask Your Doctor About Multiple Myeloma

Definition of Multiple Myeloma

Article updated and reviewed by Corey Cutler, MD MPH FRCP(C), Instructor in Medicine, Harvard Medical School, Dana-Farber Cancer Institute on June 1, 2005.

Multiple Myeloma is a malignant neoplasm (cancer) of the bone marrow. The tumor, is composed of plasma cells, a component of the immune system. Multiple myeloma destroys osseous (bony) tissue, especially in flat bones, causing pain, fractures, and skeletal deformities.

Plasma cells produce proteins called immunoglobulins (antibodies) which circulate in the blood.. Antibodies are an important part of the body's natural defense against disease since they recognize and can mount the attack against foreign matter such as bacteria or other infectious agents that invade the body.

In multiple myeloma, the plasma cells become malignant (cancerous). The plasma cells grow and multiply without control in the bone marrow - destroying normal bone tissue and causing pain. If sufficient amounts of bone are destroyed, the calcium from this bone may increase the level of calcium in the blood stream. The rapidly growing plasma cells crowd out normal cells. When there is inadequate room in the bone marrow for normal cells to grow, a patient may become anemic (low red cells) or develop a low platelet count, increasing the risk of bleeding. In addition, the number of white blood cells may be decreased and the remaining plasma cells produce insufficient amounts of immunoglobulins, both of which increase the risk of infection.

Description of Multiple Myeloma

Multiple myeloma is a malignant disorder of the plasma cells, a type of white blood cell found in many tissues of the body but mainly in the bone marrow.

Plasma cells produce proteins called immunoglobulins which circulate in the blood and function as antibodies. Antibodies are an important part of the body's natural defense against disease since they recognize and mount the attack against foreign matter such as poisons or disease agents that invade the body.

In multiple myeloma, the plasma cells become malignant and abnormal. They grow and multiply continuously - especially in the bone marrow - destroying normal bone tissue and causing pain. Also, they crowd out the normal cells which can no longer function properly.

Malignant plasma cells produce abnormal immunoglobulins. The abnormal immunoglobulins are ineffective in fighting infection, flood the bloodstream and interfere with normal antibody production. Ultimately, the body loses resistance to infection.

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Causes and Risk Factors of Multiple Myeloma

Multiple myeloma is a disease of older adults. The median age at presentation is 60 years. As with most cancers, the cause is largely unknown.

Symptoms of Multiple Myeloma

Frequently, the first sign of multiple myeloma is bone pain due to bony destruction by plasma cells. The bone pain associated with myeloma can be very intense and may occur with motion or at rest. Often, narcotics, such as morphine, are required to alleviate the discomfort of the bone pain. Any bony region can be involved – often times the destructive bone changes are very advanced before any symptoms begin. The axial skeleton (vertebrae), rib cage, skull, and bones of the extremities are commonly involved in multiple myeloma.

As the malignant plasma cells replace the normal blood forming elements in the marrow, anemia and fatigue may be apparent. The marrow also produces fewer platelets, blood cells which regulate clots and bleeding. As a result, multiple myeloma victims may experience bleeding gums, nosebleeds or easy bruising. Unexplained bone fractures, kidney failure, persistent infections and weight loss are other signs of the disease. Often, the disease can be found incidentally on routine blood testing.

Diagnosis of Multiple Myeloma

In addition to the medical history and physical examination, blood and urine tests are done to document the amount of abnormal protein (immunoglobulin) production. X-rays are important to establish the diagnosis because lytic (punched-out) bone lesions are often seen in skull, spine, long bone, and rib X-rays. A bone marrow biopsy is required to demonstrate an increase in the number of plasma cells.

Treatment of Multiple Myeloma

Treatment varies between individuals. Since myeloma cannot be cured with standard chemotherapy, all therapy is considered palliative. Since all therapy can be associated with side effects, therapy is generally reserved for patients with symptomatic myeloma and not administered to patients with indolent, or non-aggressive disease. The choice of therapy also depends on the age and general health of the patient. Young individuals with very aggressive disease may choose to pursue aggressive chemotherapy options, while elderly patients with more indolent forms of the disorder may choose less intense forms of oral chemotherapy, or no therapy at all.

Chemotherapy. There are numerous forms of oral and intravenous chemotherapy that are used as therapy for myeloma. Standard oral forms of chemotherapy include corticosteroids, thalidomide, and melphalan. Intravenous chemotherapy agents include velcade and other traditional chemotherapy drugs. These agents can either be given alone or in combination.

Radiation therapy. Radiation therapy can be used to treat areas of bony pain caused by plasma cell destruction. Sometimes, plasma cells gather in solid tumors, called plasmacytomas, which may be treated with radiation therapy.

Supportive therapy. This therapy tries to get the body to fight cancer. It uses materials made by your own body or made in a laboratory to boost, direct, or restore your body's natural defenses against disease. Biological therapy is sometimes called biological response modifier (BRM) therapy or immunotherapy.

Bone marrow transplantation. Bone marrow transplantation is commonly used to treat multiple myeloma. The procedure is done when the disease is considered to be in a remission (when the least amount of myeloma cells are present in the bone marrow). First, healthy stem cells are removed from the blood stream or from the marrow itself. These stem cells are frozen and stored in the laboratory. Next, high doses of chemotherapy are given to kill all the remaining myeloma cells in the bone marrow. Unfortunately, 100% of the myeloma cells cannot be killed with chemotherapy. Once the chemotherapy has been given, the healthy, frozen stem cells are readministered to the patient. These cells reconstitute the bone marrow and immune system. This procedure is used to prolong remission, but unfortunately it is not curative.

Occasionally, stem cells from a healthy donor are used rather than a patient’s own stem cells. This procedure, called an allogeneic transplant, is much riskier than the procedure using one’s own stem cells; however, it has the potential to cure the condition.

What Questions To Ask Your Doctor About Multiple Myeloma

What tests need to be done for a diagnosis?

What treatment do you recommend?

Will any medication be prescribed?

What are the side effects?

What can be expected while receiving these medications?

What is the possibility of a bone marrow transplant?

What is the procedure?

How successful is this procedure?

What is the prognosis?

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Editorial review provided by VeriMed Healthcare Network.

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