What Is Multiple Myeloma?
Multiple myeloma is cancer that begins in plasma cells (a type of white blood cell). Each year, about 15,000 Americans learn that they have multiple myeloma.
Understanding Normal Blood Cells
In order to better understand multiple myeloma, it may be helpful to know how normal blood cells function. 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, which include:
- White blood cells -- which help fight infection (there are several types of white blood cells)
- Red blood cells -- which carry oxygen to tissues throughout the body
- Platelets -- which help form blood clots that control bleeding.
Plasma cells are white blood cells that make antibodies, which are part of the immune system. Antibodies 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.
Understanding Myeloma Cells
Myeloma, like other cancers, begins in cells. Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place. In cancer, this orderly process goes wrong -- new cells form when the body does not need them, and old cells do not 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 by dividing again and again, making more and more abnormal cells. The abnormal plasma cells are myeloma cells. Myeloma cells:
- Make antibodies called M proteins
- Collect in the bone marrow
- May crowd out normal blood cells
- Collect in the solid part of the bone.
The disease is called "multiple myeloma" because it affects many bones. If myeloma cells collect in only one bone, the single mass is called a plasmacytoma. Multiple myeloma is the most common type of plasma cell tumor.
(Click Plasmacytoma for more information about this type of plasma cell tumor.)
Multiple myeloma is not
bone cancer. Although it affects the bones, it begins in blood cells, not bone cells.
Bone cancer is diagnosed and treated differently than multiple myeloma.
What Causes Multiple Myeloma?
No one knows the exact causes of this condition, and doctors can seldom explain why one person will get it and another person will not. However, research has shown that people with certain risk factors are more likely than others to develop multiple myeloma. A risk factor is anything that increases a person's chances of developing a disease.
Specific multiple myeloma risk factors include:
- Growing older (risk increases with age)
- Being African American
- Having a personal history of monoclonal gammopathy of undetermined significance (MGUS).
In some cases, multiple myeloma does not cause any symptoms. However, if symptoms are present they can include:
- Bone pain, often in the back or ribs
- Bones that break easily
- Fever for no known reason (or frequent infections)
- Easy bruising or bleeding
- Trouble breathing
- Weakness of the arms or legs
- Feeling very tired
- Loss of appetite
- Nausea or vomiting
- Feeling thirsty
- Frequent urination
- Constipation
- Muscle weakness
- Restlessness
- Mental confusion or trouble thinking.
These symptoms are not sure signs of multiple myeloma. Other, less serious health problems can also cause these symptoms. People with possible symptoms of multiple myeloma should see a doctor as soon as possible -- only a doctor can diagnose and treat the problem.
(Click Symptoms of Multiple Myeloma for more information.)
In some cases, multiple myeloma will be diagnosed based on a routine blood test after an x-ray for a broken bone. However, in most cases, it will be diagnosed after a patient goes to his or her healthcare provider for relief of other symptoms of the disease. If a person has possible multiple myeloma symptoms, the healthcare provider will likely need to perform a physical exam and ask about the patient's personal and family medical history. In order to make a diagnosis, the healthcare provider will usually also recommend additional tests and procedures.
Exams and tests that are used to make a diagnosis of multiple myeloma may include:
- Blood tests
- Urine tests
- X-rays
- Biopsy.
Staging of Multiple Myeloma
If a
multiple myeloma diagnosis is made, the doctor will need to determine the stage, or extent, of the disease in order to plan the best treatment. Staging is an attempt to find out the size of the tumor, whether the disease has spread, and if so, to what parts of the body.
Specific stages of multiple myeloma include:
- Stage I
- Stage II
- Stage III.
The multiple myeloma stage also takes into account whether the cancer is causing problems with the patient's bones or kidneys.
(Click Multiple Myeloma Stage for more information.)
In general, treatment can include:
Patients with multiple myeloma who do not have symptoms may not need treatment. However, doctors will need to monitor their patient's health closely so that treatment can begin when symptoms appear. Patients should work with their healthcare providers to develop a treatment plan that meets their medical needs and personal values. Choosing the most appropriate treatment is a decision that ideally involves the patient, the family, and the healthcare team.
(Click Multiple Myeloma Treatment for more information about the different treatment options for multiple myeloma.)
