Multiple Myeloma

Definition

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

Description

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.

Causes and Risk Factors

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

Frequently the first sign of multiple myeloma is bone pain due to the presence of many malignant cells in the bone marrow. This pain can start in the back and ribs, but as more malignant cells grow in the bone marrow, the pain may spread to the pelvic bones, neck and skull, and less frequently to the lower arms or legs.

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.

Diagnosis

In addition to the medical history and physical examination, blood and urine tests are done to document abnormal protein 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 may be suggested.

Once plasma cell neoplasm has been found, more tests will be done to see how far the cancer has spread. This is called staging. Plasma cell neoplasms are grouped together depending on the type of plasma cell cancer that is found.

Treatment

Treatment varies by patient but may include:

Medications. Patients treated with a drug called melphalan (Alderan), usually combined with prednisone, may respond favorably. This approach reduces abnormal protein in the blood, eases bone pain and can lead to a remission. Combination chemotherapy with other medications may also be beneficial. The optimal chemotherapy regimen has not been determined. Medications to help control pain will also be prescribed.

Radiation therapy. This therapy uses x-rays or other high-energy rays to kill cancer cells, shrink tumors, and reduce bone pain. Radiation for plasma cell neoplasms usually come from a machine outside the body (external radiation therapy).

Biological 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. This procedure is used to replace your bone marrow with healthy bone marrow. First, all of the bone marrow in your body is destroyed with high doses of chemotherapy with or without radiation therapy. Healthy marrow is then taken from another person (donor) whose tissue is the same as or almost the same as yours. The healthy marrow from the donor is given to you through a needle in the vein to replace the marrow that was destroyed. Other types of transplants are:

Autologous bone marrow transplant. Bone marrow is taken from the individual and treated with drugs to kill any cancer cells. The marrow is then frozen to save it. Next, the individual is given high-dose chemotherapy with or without radiation therapy to destroy all of their remaining marrow. The frozen marrow that was saved is then thawed and given to person through a needle in the vein or replace the marrow that was destroyed.

Peripheral blood stem cell transplant. The person's blood is passed through a machine that removes the stem cells (immature cells from which all blood cells develop), then returns the individual's blood to them. This procedure is call leukapheresis and usually takes 3 or 4 hours to complete. The stem cells are treated with drugs to kill any cancer cells and then frozen until they are transplanted into the patient. This procedure may be done alone or with an autologous bone marrow transplant.

Questions to Ask Your Doctor

What tests need to be done for a diagnosis?

How much has the disease spread?

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?