Myeloma bone disease is cancer that affects certain white blood cells called plasma cells. It represents about 1 percent of all cancers in the United States, and about four to five out of every 100,000 people are diagnosed with it each year.
Plasma cells, and other white blood cells, are part of the immune system. Plasma cells produce antibodies--immune system proteins that assist the body in ridding itself of harmful substances. Each plasma cell responds to one specific substance by producing one kind of antibody. The body has many types of plasma cells, and, therefore, can respond to many types of substances.
When cancer occurs, the body overproduces plasma cells, which are abnormal and alike. These abnormal plasma cells are called myeloma cells.
Myeloma cells collect in the bone marrow and the outer layer of the bone. Because the cells begin in the blood plasma, myeloma is not a bone cancer, but is cancer that affects bones.
The exact cause of myeloma bone disease is not known, but theories and associations have been suggested as risk factors.
Suggested risk factors for myeloma bone disease include the following:
Age (occurs rarely under the age of 40)
Exposure to petroleum and other chemicals
Exposure to high amounts of radiation
Twice as common among African-Americans as Caucasian Americans
The following are the most common symptoms for myeloma bone disease. However, each individual may experience symptoms differently. Myeloma cells and antibodies may cause the following:
Fractures in bones
Problems with urination
Weakness or numbness in legs
The symptoms of myeloma bone disease may resemble other bone disorders or medical problems. Always consult your physician for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for myeloma bone disease may include the following:
X-ray--A diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. Bone scans are used to evaluate for bone involvement with most cancers, but they are unreliable in multiple myeloma.
Blood and urine tests
Bone marrow aspiration and/or biopsy--A procedure that involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size, and maturity of blood cells and/or abnormal cells.
Magnetic resonance imaging (MRI)--A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
Specific treatment for myeloma bone disease will be determined by your physician based on:
Your age, overall health, and medical history
Extent of the disease
Your tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
Treatment may include:
Medications to control pain
Medications to prevent fractures
Radiation therapy to control pain, prevent fractures, and allow bone lesions to heal
Biological or targeted therapies, such as Velcade (bortezomib), Thalomid (thalidomide), and Revlimid (lenalidomide), are revolutionizing the treatment of multiple myeloma
Alpha interferon--A biological response modifier (a substance that stimulates or improves the ability of the body's immune system to fight disease) that interferes with the division of cancer cells, therefore slowing tumor growth. Interferons are substances normally produced by the body but can be produced in the laboratory.
Bone marrow transplantation or stem cell transplantation has been used extensively in multiple myeloma, but newer targeted therapies are making it less appealing due to the high toxicity associated with transplantation