What Is Multiple Myeloma?

Multiple myeloma (also referred to as myeloma) is a type of rare, incurable cancer of the blood—also known as hematologic cancer. It affects cells called plasma cells, which are types of white blood cells. Normal plasma cells function to make antibodies, helping the body to fight infection. Myeloma involves malignant plasma cells that build up in the bone marrow or the soft tissue in the center of bones.

The term malignant describes the tendency to progressively worsen, invade, and destroy nearby tissue by spreading (metastasizing) to other parts of the body. Myeloma is considered a devastating disorder of the plasma cells that can result in many complications such as bone fractures, kidney problems, and other blood cell disorders. 

Background

Although multiple myeloma has been said to have been around since ancient times, the very first authenticated case was documented in 1844. The case was that of Thomas Alexander McBean in London. In 1889, the disease became more recognized after a famous case was reported of a subject who survived for 8 years without any type of chemotherapy treatment.

As time progressed, new drug therapies (as well as stem-cell transplant treatment) evolved for the treatment of myeloma. Although the disease is not considered curable, it has evolved into a disease that is considered highly manageable, having had rapid medical advancement—particularly over the past decade. 

In fact, the advancement of new therapies has resulted in as many as 10 new drugs that have been approved in the time it usually takes to get medical clearance for a single drug approval, according to the Multiple Myeloma Research Foundation (MMRF).

Statistics in the United States

Multiple myeloma accounts for just over 10% of all blood cancers. In the United States, over 32,000 people were diagnosed with this disease in 2019. It is believed that approximately 100,000 Americans currently have the disease. In addition, the National Cancer Institute (NCI) estimates that 1.8% of all new cancer cases in the United States involve myeloma.

The NCI claims that 52.2% of those diagnosed with myeloma in the United States survived 5 years or more after diagnosis, while 0.8% of men and women in the United States will be diagnosed with myeloma in their lifetime.

Global Statistics

Multiple myeloma is considered the second most common blood cancer, with close to 160,000 new cases diagnosed globally per year. Regardless of the many new treatment modalities being developed for myeloma, it is still a disease that is accompanied by consistent relapses and according to one source, led to an estimated 117,077 deaths worldwide in 2020.

Overview

Multiple myeloma is an abnormal growth of plasma cells. This cancer starts in the bone marrow. The immune system is the primary bodily system impacted by multiple myeloma.

Bone Marrow

Bone marrow is a spongy, soft tissue with the consistency of gelatin, found in the center of the bones. There are two types of bone marrow: red and yellow. 

Bone marrow’s primary function is to produce new blood cells. In fact, it is known to produce as many as 200 billion red blood cells every day. Bone marrow produces white blood cells and platelets, which are cells that are needed for normal blood clotting.

Plasma Cells

Plasma cells are a type of white blood cell that bone marrow produces. They fight off infection within the body by producing antibodies. Normally, the bone marrow has a small number of plasma cells; however, when there are cancerous cells in the bone marrow as a result of multiple myeloma, the cancerous cells produce abnormal plasma cells. These are called myeloma cells. 

The accumulation of myeloma cells can cause localized tumors in the bones, called plasmacytomas. By contrast, in multiple myeloma, the accumulation of plasma cells involves the bone marrow of multiple bones and can negatively impact other healthy immune cells as it interferes with their ability to adequately fight infection. In turn, this can lead to a shortage of red blood cells (anemia) as well as a shortage of healthy white blood cells (leukopenia). 

Antibodies

An antibody is a protein produced by the plasma cells in response to an antigen. Antibodies circulate in the blood and are present in certain secretions (tears, saliva, and more). Antigens that may be produced by infectious agents, such as bacteria, induce an immune reaction. By attaching to antigens, antibodies destroy the cells that bear the antigens on the surface.

The formation of cancerous cells in the marrow in multiple myeloma may reduce the number of normal producing plasma cells, and in turn, expose the body to infections.

Antigens

An antigen is a molecule that may induce a response from the immune system in the body (the immune system response involves the production of antibodies). Antigens are also present on the surface of normal or cancer cells. The myeloma cells may reduce the number of plasma cells and, as a result, diminish the capacity of the immune system to fight off antigens as the antibody production is inhibited.

M Protein

As the malignant plasma cells begin crowding out the normal plasma cells, they inhibit the body’s ability to fight infection. 

An abnormal antibody called “M protein” (monoclonal protein) is produced by the malignant plasma cells. The hallmark characteristic of having high levels of M protein in the blood, noted in people with multiple myeloma, can cause:

• Tumors
• Kidney damage
• Bone destruction
• Impaired immune function

Multiple myeloma is considered a “clonal plasma cell malignancy.” This is because usually, the myeloma cells come from a single cell that becomes cancerous.

Multiple Myeloma Symptoms

Common symptoms of multiple myeloma include:

• Frequent infections due to a weakened immune system (a person with myeloma is referred to as being immunocompromised)
• Bone pain (often in the back, ribs, and hips)
• Kidney problems
• Weakness due to anemia

Causes

The exact cause of multiple myeloma has not been clearly established. It is thought that there may be a genetic factor involved because of the increased incidence of the disease among close relatives. 

Another possible causative factor may be radiation exposure or contact with chemical solvents such as benzene. 

Diagnosis

The diagnosis of multiple myeloma is suspected by finding an elevated amount of certain antibodies in the blood and urine. A bone marrow biopsy and a bone marrow aspirate (using a needle for biopsy and a syringe to aspirate a small amount of bone marrow blood) are performed to confirm the diagnosis.

Treatment

Multiple myeloma treatment may include:

• Traditional chemotherapy drugs such as melphalan, cyclophosphamide, or bendamustine which work to kill cancer cells.
• Anti-inflammatory drugs which work to reduce inflammation by stopping white blood cells from traveling to areas where myeloma cells are causing damage.
• Proteasome inhibitors such as bortezomib, carfilzomib, or ixazomib which work to kill myeloma cells.
• Immunomodulatory drugs such as lenalidomide, thalidomide, or pomalidomide which possess strong anti-cancer properties.
• Monoclonal antibodies, including daratumumab, elotuzumab, or belantamab mafodotin which treat multiple myeloma by targeting antigens on the surface of myeloma cells, called CD38. (Monoclonal antibodies are often used for people with myeloma who do not respond to initial treatment, those who do not qualify for stem cell therapy, or those who have symptoms that recur after a period of remission from the disease.)
• Stem cell transplant which helps replenish normal cells in bone marrow after high-dose chemotherapy.
• Other treatments such as analgesics and radiation therapy which treat bone pain and more.
• New agents such as panobinostat, venetoclax, and selinexor. Zolendronic acid and denosumab are often used to prevent bone fractures.

Prognosis

According to a report published by the National Cancer Institute, the number of people surviving past 5 years has increased from about 46% in 2006 to almost 54% in 2016. Of course, some people can dramatically beat those statistics, living well beyond five years to 10 or even 20 years after diagnosis. 

The key to longevity, says one person with multiple myeloma who has survived the disease for 11.5 years, is early diagnosis and intervention (before kidney failure occurs), coping effectively with the disease, and seeking out the highest level of care available.

Complications

There are many complications that can occur from multiple myeloma, these may include:

• Bone fractures (due to plasma cell tumors invading the bone)
• Hypercalcemia (high calcium levels)
• Anemia (decreased level of red blood cells)
• Decreased platelet production (inhibits the body’s normal blood clotting ability; symptoms are bleeding or easy bruising)
• A compromised immune system (resulting in various types of infections)
• Myeloma kidney (monoclonal antibodies collect in the kidneys, which can interfere with kidney function)
• Kidney stones (from an increase in uric acid caused by the growth of cancerous cells)
• Kidney failure
• Amyloidosis (the build-up of proteins called amyloid in the kidneys, liver, and other organs)
• Other rare complications (such as hyperviscosity syndrome from a disruption in normal blood flow which makes the blood thicken)

Coping

Having multiple myeloma usually requires making some difficult adjustments in life. Some of these changes may be transitory, while others are long-term. It’s important to seek out a support network and learn to employ methods of dealing with an ongoing life-threatening disease such as multiple myeloma. 

Confronted with advanced incurable disease, some people find it beneficial to explore options for end-of-life decisions. Topics such as pain relief, the use of feeding tubes, and other important medical issues can be proactively managed well in advance of ever needing to employ them.

While it's understandable that most people do not want to focus on the fatality of any disease, taking charge in managing advanced directives, living wills, and other end-of-life care issues can be very empowering.

A Word From Verywell

While researchers are learning more about the causes and risk factors for multiple myeloma, there is still much to be discovered. If you or a loved one is either facing a diagnosis or coping with the disease, be sure to seek out an experienced healthcare team to consult with on your concerns as well as an outside support group to speak with. These things can be reassuring as you face the uncertainty of living with multiple myeloma.