Multiple Myeloma

What is multiple myeloma?

Multiple myeloma is cancer of the bone marrow caused by the uncontrolled growth of plasma cells. These cells are one type of white blood cells. Normally, they make antibodies called immunoglobulins to fight infections.

In multiple myeloma, cancerous plasma cells multiply rapidly in the bone marrow and invade the outer layers of the bones. This can weaken bones so much that minimal trauma can cause a bone fracture at the cancer site.

The myeloma plasma cells also make too much of one specific type of immunoglobulin (an antibody protein). Large amounts of immunoglobulins in the bloodstream may cause the blood to become thick and sticky. This can lead to blood clots. These abnormally high immunoglobulin levels can also cause kidney damage.

In multiple myeloma, the blood levels of other antibodies drop, leaving the person open to infections.

Other problems that occur in people with multiple myeloma include:

high blood calcium levels, which can lead to dehydration, constipation, and confusion
impaired kidney function
low red blood cell counts (anemia).

A variant of multiple myeloma is called plasmacytoma. A plasmacytoma is a single collection of abnormal plasma cells, typically located in only one bone (although some plasmacytomas can occur in soft tissues of the body such as the head, neck, digestive tract, lungs, or extremities). Plasmacytomas cause bone pain but usually don't cause the problems associated with multiple myeloma. Without treatment, plasmacytoma can turn into multiple myeloma.

Multiple myeloma is an uncommon cancer. It tends to occur in older people, developing around age 60. Other risk factors include exposure to

radiation
a toxic chemical called benzene
pesticides.

Symptoms of multiple myeloma

Early on, multiple myeloma may not cause any symptoms. But as it progresses, symptoms can include:

bone pain, often in the back and ribs
fractures, sometimes from a minor stress or injury
marked fatigue
easy bruising
loss of appetite
nausea and vomiting
confusion.

Diagnosing multiple myeloma

Your doctor will order blood tests to check for anemia, which is a low level of red blood cells. The disease causes anemia when plasma cells crowd the bone marrow. This prevents the bone marrow from making red blood cells as usual.

Blood tests also can check for high levels of protein, a sign that large amounts of immunoglobulin are being made by plasma cells. You may be asked to collect your urine to see if it contains protein created by multiple myeloma cells.

Your doctor may order x-rays of the long bones in your body, your skull, and your chest to confirm the diagnosis and check for weak bones. Other imaging tests, including magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET), may also be used when diagnosing multiple myeloma. A bone marrow biopsy also will be done to confirm an abnormally high level of plasma cells. The bone marrow is where red and white blood cells and platelets are made. Normally these cells will mature and get released into the bloodstream.

During the procedure, your doctor removes a small amount of bone marrow with a long needle. The bone marrow is then looked at using a microscope. Normally, plasma cells account for a very small percentage of the cells in the bone marrow. Multiple myeloma is diagnosed if the biopsy shows an excessive number of plasma cells. But a person can have multiple myeloma with a much lower percentage of plasma cells if other criteria are met.

After diagnosis, laboratory tests will determine the extent of the cancer, which is described in "stages." The stage is assigned based on protein and calcium levels, kidney function, and the presence of cancer in the bone:

Stage I: Few cancer cells have spread through the body. There may not be any symptoms of the disease.
Stage II: A moderate number of cancer cells have spread through the body.
Stage III: A large number of cancer cells have spread through the body. At this stage, patients may also have anemia, high levels of protein and calcium in the blood, and more than three bone tumors.

Expected duration of multiple myeloma

In most cases, the illness progresses slowly for two to five years. Symptoms may then worsen rapidly.

Preventing multiple myeloma

Multiple myeloma cannot be prevented. It may be possible to reduce your risk by avoiding

radiation
the toxic chemical benzene
pesticides.

Treating multiple myeloma

If you do not have any symptoms, treatment may not start immediately. The primary decision after diagnosis is whether stem cell transplant is the best option.

Initial therapy consists of a combination of drugs. Some of the drugs used include:

an immunomodulatory drug, such as lenalidomide (Revlimid) or pomalidomide (Pomalyst)
a proteasome inhibitor, such as bortezomib (Velcade), carfilzomib (Kyprolis), or ixazomib (Ninlaro)
a corticosteroid, usually dexamethasone (Decadron).

This is called induction therapy and is usually given in three to four rounds, each round repeated every three to four weeks.

Additional therapies may include:

infusions of bisphosphonates: this class of drug, often injected into a vein once a month, can decrease the risk of broken bones and prolong survival
infusions of immunoglobulins into a vein to prevent serious infections
radiation therapy to treat painful tumors in bones
monoclonal antibodies designed to attack specific sites on myeloma cells.

Stem cell transplant

Before this procedure, you receive high doses of chemotherapy to kill the cancer cells. Then you receive a transfusion of stem cells taken from the blood. These might have been taken from you before the chemotherapy started. This is called an autologous stem cell transplant. Sometimes the stem cells come from a donor. Stem cells can also be taken from bone marrow. The transplanted stem cells develop into healthy new blood cells.

Once induction therapy and a stem cell transplant are complete, the patient enters a maintenance phase of treatment. Maintenance therapy is drug therapy that helps prevent multiple myeloma from returning.

There is no cure for multiple myeloma, but treatment options such as these may control the disease or delay its return for years.

When to call a professional

Call your doctor if you have persistent or recurrent

bone pain
nosebleeds
prolonged bleeding after minor cuts
bruising or fracture without any trauma
marked fatigue.

Most often these symptoms are caused by some other medical problem, not multiple myeloma.

Prognosis

Overall, about two-thirds of multiple myeloma patients live more than five years. Patients who are diagnosed when the disease is at an early stage may live longer.