Multiple Myeloma Health Center

Most blood cells develop from cells in the bone marrow called stem cells. Bone marrow is the soft material in the center of most bones.

Stem cells mature into different types of blood cells. Each type has a special job:

• White blood cells help fight infection. There are several types of white blood cells.
• Red blood cells carry oxygen to tissues throughout the body.
• Platelets help form blood clots that control bleeding.
• Plasma cells are white blood cells that make antibodies. Antibodies are part of the immune system. They work with other parts of the immune system to help protect the body from germs and other harmful substances. Each type of plasma cell makes a different antibody.

Myeloma, like other cancers, begins in cells. In cancer, new cells form when the body doesn't need them, and old or damaged cells don't die when they should. These extra cells can form a mass of tissue called a growth or tumor.

Myeloma begins when a plasma cell becomes abnormal. The abnormal cell divides to make copies of itself. The new cells divide again and again, making more and more abnormal cells. These abnormal plasma cells are called myeloma cells.

In time, myeloma cells collect in the bone marrow. They may damage the solid part of the bone. When myeloma cells collect in several of your bones, the disease is called "multiple myeloma." This disease may also harm other tissues and organs, such as the kidneys.

Myeloma cells make antibodies called M proteins and other proteins. These proteins can collect in the blood, urine, and organs.

No one knows the exact causes of multiple myeloma. Doctors seldom know why one person develops this disease and another doesn't. However, we do know that multiple myeloma isn't contagious. You cannot catch it from another person.

Research has shown that certain risk factors increase the chance that a person will develop this disease. Studies have found the following risk factors for multiple myeloma:

• Age over 65: Growing older increases the chance of developing multiple myeloma. Most people with myeloma are diagnosed after age 65. This disease is rare in people younger than 35.
• Race: The risk of multiple myeloma is highest among African Americans and lowest among Asian Americans. The reason for the difference between racial groups is not known.
• Men: In 2011, about 11,400 men and 9,100 women will be diagnosed with multiple myeloma in the United States. It is not known why more men are diagnosed with the disease.
• Personal History of Monoclonal Gammopathy of Undetermined Significance (MGUS). MGUS is a benign condition in which abnormal plasma cells make M proteins. Usually, there are no symptoms, and the abnormal level of M protein is found with a blood test. Sometimes, people with MGUS develop certain cancers, such as multiple myeloma. There is no treatment, but people with MGUS get regular lab tests (every 1 or 2 years) to check for a further increase in the level of M protein. They also get regular exams to check for the development of symptoms.
• Family History of Multiple Myeloma. Studies have found that a person's risk of multiple myeloma may be higher if a close relative had the disease.
• Many other suspected risk factors are under study. Researchers have studied whether being exposed to certain chemicals or germs (especially viruses), having alterations in certain genes, eating certain foods, or being obese increases the risk of developing multiple myeloma. Researchers continue to study these and other possible risk factors.

Having one or more risk factors does not mean that a person will develop myeloma. Most people who have risk factors never develop cancer.