Multiple Myeloma

Multiple myeloma is cancer that affects white blood cells called plasma cells. Plasma cells and other white blood cells are part of the immune system. They produce antibodies that assist your 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 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 a cancer that affects bones.

Types & Stages

There are two main types of multiple myeloma:

• Active or symptomatic. Active multiple myeloma has signs and symptoms of multiple myeloma. As the myeloma cells and M-proteins — abnormal antibodies that don't work properly — continue to be produced out of control and start to build up in the body, they can eventually cause symptoms related to organ damage, such as kidney damage. 
   
• Smouldering or asymptomatic myeloma. It doesn’t cause any symptoms, but most people with this type will eventually develop multiple myeloma with symptoms (active multiple myeloma).

There are also less common types of multiple myeloma. These include:

• Myeloma by immunoglobulin type. Multiple myeloma can be classified by which immunoglobulin (Ig) the myeloma cells make. The most common types of immunoglobulins the myeloma cells make are IgG (called IgG multiple myeloma) and IgA (called IgA multiple myeloma). The least common types of immunoglobulins the myeloma cells make are IgM (called IgM multiple myeloma); IgD (called IgD multiple myeloma); and IgE (called IgE multiple myeloma). 
   
• Light chain myeloma. The myeloma cells of some types of multiple myeloma don’t make a complete immunoglobulin. Light chain myeloma only makes the light chain part of the immunoglobulin and not the heavy chain. 
   
• Non-secretory myeloma. The myeloma cells of some types of multiple myeloma don't release (secrete) enough M-proteins or light chains into the blood or urine to be detected by protein electrophoresis, a method that separates proteins in the blood or urine.

Signs & Symptoms

Symptoms of multiple myeloma include: 

• bone pain (usually in your back, head, chest, pelvis or upper leg) is often the first symptom people notice
• fatigue and weakness (signs of anemia or low red blood cells)
• getting sick easily (signs of low white blood cells)
• numbness or tingling in your arms or legs
• unexplained weight loss
• nausea and vomiting

Diagnosis

Tests and procedures to diagnose a multiple myeloma include:

• Blood tests. Your doctor will check for low blood cell counts and enzymes that signal problems with an organ. They’ll also check for abnormal antibodies (like M proteins) and signs of tumors.
   
• Urine tests. Checks for high levels of protein in a urine sample that may be a sign of multiple myeloma.
   
• Imaging tests. These may include:  
   
  • X-rays. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
     
  • Computerized tomography scan (CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. It can show bone damage related to multiple myeloma. 
     
  • 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. 
     
  • Positron emission tomography scan (PET scan). An imaging test that uses a radioactive drug called a tracer—most often injected into a vein in your hand or arm—to show both typical and atypical metabolic activity. The PET images are typically combined with CT or MRI and are called PET-CT or PET-MRI scans. 
     
• Biopsy. A bone marrow biopsy tests tissue from your bone marrow for abnormal plasma cells. Or you may need a bone marrow aspiration, which tests the fluid part of bone marrow.
   
• Genetic testing. Your doctor may do a DNA test on the biopsy sample. This test finds gene changes that drive cancer growth.

Treatment

Treatments for multiple myeloma include:

• Stem cell transplant. Stem cells are specialized cells in your bone marrow or blood that can help produce healthy new plasma cells. This treatment replaces damaged or unhealthy stem cells with healthy stem cells from your own body.
   
• Chemotherapy. Chemotherapy drugs reduce the number of abnormal plasma cells. If you get a stem cell transplant, you’ll need chemotherapy first.
   
• Targeted therapy. This treatment “targets” weaknesses in the plasma cells so they die. People with multiple myeloma are living longer than ever because of new targeted therapies.
   
• Immunotherapy. This treatment helps your immune system develop more cancer-fighting cells. CAR T-cell therapy is a specific type that has delivered excellent results during clinical trials to test new treatments.
   
• Steroids. High doses of steroids can kill cancer cells and reduce inflammation.
   
• Radiation therapy. Radiation can reduce bone tumors causing symptoms.

Causes & Risk Factors

Risk factors for multiple myeloma include:

• Gender. Multiple myeloma affects more males than females.
   
• Race. It affects twice as many people who are Black as it does people of other races.
   
• Age. Most people with multiple myeloma are diagnosed between 40 and 70. The median age of diagnosis is 69. 
   
• Family history. Rarely, more than one family member has multiple myeloma. But experts don’t know why there’s a link. This condition isn’t hereditary.
   
• Environmental factors. There may be connections between multiple myeloma and exposure to pesticides, fertilizer or Agent Orange.
   
• Obesity. Having obesity is a known risk factor for the development of multiple myeloma.

Screening

There is no routine screening test for multiple myeloma.