What is Multiple Myeloma?
Reviewed by: HU Medical Review Board | Last reviewed: June 2020.
Multiple myeloma is a type of blood cancer that develops from plasma cells, a type of white blood cell. Plasma cells are found in the bone marrow, which is the inner, spongy center of bones. When plasma cells become cancerous, they can form a tumor called a plasmacytoma, which may form in the bone or other places in the body.
If a person has one plasma cell tumor, it is called a solitary or isolated plasmacytoma. If a person has multiple plasmacytomas, it is called multiple myeloma.1
What causes multiple myeloma?
Doctors do not know the exact cause of multiple myeloma. They do know that cancers like multiple myeloma begin with changes (mutations) to the DNA of cells. Mutations to the DNA may be inherited, can occur randomly, or occur after exposure to something in the environment.
Three types of genes that have been identified in multiple myeloma include MYC, RAS, and p53 genes.2
Multiple myeloma cells often have changes in their chromosomes. (DNA is packaged into 46 chromosomes.) Some people with multiple myeloma are missing part of chromosome 13, which can result in a more aggressive type of myeloma that can be hard to treat. About half of all cases of multiple myeloma show a translocation, where part of one chromosome is switched with part of another.2
How does multiple myeloma develop?
Plasma cells form from a type of white blood cell called B lymphocytes. When B lymphocytes are exposed to bacteria or viruses, they can change into plasma cells which help the body fight infection.1
If these plasma cells grow out of control, they become a cancer. These cancerous cells then crowd out healthy cells in the bone marrow, including red blood cells, white blood cells, and platelets.1
Multiple myeloma may require treatment or it may not. Multiple myeloma that is causing symptoms may be called active myeloma and treatment is necessary. If the myeloma is not causing symptoms, it may be called a smoldering or indolent myeloma. Smoldering myeloma may be closely watched and treatment may not be needed until symptoms occur.3
What are the common symptoms of multiple myeloma?
Because it crowds out healthy blood cells, multiple myeloma can create symptoms all over the body. For example, if the body does not have enough red blood cells, it is called anemia. Anemia can cause fatigue, dizziness, cold hands or feet, or pale skin.
When the body does not have enough white blood cells, it is called neutropenia. Neutropenia can cause repeated infections or infections that will not go away.
When there are not enough platelets, thrombocytopenia occurs. Thrombocytopenia can cause the body to bleed more easily, and result in frequent nosebleeds, bruising, or small, pinhead-sized red spots on the skin called petechiae.1
Other symptoms of multiple myeloma may include:1,4,5
- Bone pain
- Bone fractures
- Kidney damage or failure
- High levels of calcium in the blood (hypercalcemia), which can cause frequent urination, constipation, extreme thirst, weakness or drowsiness
- Monoclonal gammopathy, which is having too many copies of the same antibody
- Nerve damage
- Thick blood, which is called hyperviscosity
- Severe back pain or numbness in the legs
In some cases, multiple myeloma can cause amyloidosis, a condition that damages organs like the kidneys and heart. Amyloidosis can cause symptoms such as:4,6
- Congestive heart failure
- Enlarged liver and spleen
- Kidney problems
- Enlarged tongue
- Tingling in the hands or feet (carpal tunnel syndrome)
- Skin changes such as bruising easily, changes to skin texture, or"raccoon eyes"
Who gets it?
Multiple myeloma usually occurs in adults. It is very rare for multiple myeloma to occur before age 35, and most people with multiple myeloma are diagnosed after age 65. Multiple myeloma is more than twice as common in African Americans than in white Americans. Multiple myeloma is also more common in men than women.7
What are the risk factors of multiple myeloma?
Risk factors that have been identified as potentially increasing an individual’s chances of developing multiple myeloma include:5
- Getting older
- Being male
- Being African American
- Exposure to high doses of radiation, benzene, asbestos, pesticides or chemicals from rubber manufacturing
- Having a family history of multiple myeloma
- Being overweight or obese
- Having other plasma cell diseases, like monoclonal gammopathy of undetermined significance (MGUS) or solitary plasmacytoma
How is the disease staged?
The stage of multiple myeloma is determined by the amount of beta 2 microglobulin and albumin proteins found in the blood. Multiple myeloma may be classified as Stage I, II, or III.3
What is the prognosis for multiple myeloma?
Over the past few decades, the survival rate for multiple myeloma has been steadily improving. There is no cure but it is generally a manageable disease.5
Survival rates are based on previous outcomes of people who survive a set amount of time after diagnosis. In cancer estimates, experts use the “5-year survival rate” as a marker. However, it is important to keep in mind that many people live beyond 5 years after diagnosis and the statistics are not necessarily predictive for any one individual.) Based on data from 2010-2016, the 5-year survival rate for multiple myeloma is 53.9 percent.7