What Is Multiple Myeloma?

A relatively rare cancer that affects plasma cells, multiple myeloma can greatly impact the body's immune system. In multiple myeloma, malignant (cancerous) cells grow and multiply uncontrolled in plasma cells, a type of white blood cell. When the body makes too many plasma cells, known as neoplasms, they can turn cancerous and cause tumors, called multiple myeloma.

A key part of the body's disease-fighting immune system, plasma cells form in the bone marrow from B cells and produce antibodies, proteins that attack bacteria and viruses. In multiple myeloma, plasma cells create an abnormal antibody—known as monoclonal immunoglobulin, monoclonal protein, M-protein, M-spike or paraprotein—and the excess number of abnormal cells can become cancerous. When this happens, it can:

  • Build up in the bone marrow
  • Produce proteins (monoclonal protein) that may damage the kidneys
  • Weaken the bone, leading to fractures
  • Cause tumors (abnormal growths) to form in the bone or soft tissue in various parts of the body, also known as plasmacytomas

The following types of plasma cell neoplasms are cancerous:

  • Multiple myeloma occurs when there are two or more plasma cell tumors
  • Plasmacytoma occurs when there is only one plasma cell tumor

Multiple myeloma and other plasma cell neoplasms can also cause amyloidosis. This rare disease occurs when amyloid proteins slowly deposit in normal tissue, affecting the function of the affected organ.

Each year, the American Cancer Society estimates that about 35,000 new cases of multiple myeloma get diagnosed in the United States, causing around 12,000 deaths in the country each year.

What Is the Cause of Multiple Myeloma?

While there's no known cause for the abnormal plasma cell creation in bone marrow that leads to multiple myeloma, often multiple myeloma develops from another plasma cell neoplasm called monoclonal gammopathy of undetermined significance (MGUS). MGUS does not typically start cancerous and if the levels of M proteins remain low, MGUS may not contribute to any symptoms or develop into multiple myeloma.

Multiple Myeloma Risk Factors

The risk factors for multiple myeloma are typically not in a patient's control. Most multiple myeloma risk factors have to do with age, gender and personal and family medical histories. They include:

  • Age over 65
  • Men have a marginally higher risk than women
  • In the U.S., Black patients are twice as likely as white patients to develop multiple myeloma
  • Family history can increase the chances of multiple myeloma
  • Other plasma cell conditions can lead to multiple myeloma
  • Obesity

Is Multiple Myeloma Hereditary?

Only a small number of cases show multiple myeloma genetic predispositions. There may be a correlation of multiple myeloma genetic inheritance. Some families with a sibling or parent with the disease show an increased risk, but that is still a minor connection.

Who Is at Risk for Developing Multiple Myeloma?

One of the most telling risk factors for multiple myeloma is age. Most multiple myeloma cases affect people 65 years or older, with the average age for diagnosis between 66 and 70 years old. Those aged 35 to 64 account for just over one-third of multiple myeloma detections. Less than 1% of multiple myeloma diagnosis are for people younger than 35.

Multiple Myeloma Environmental Causes

While researchers have studied environmental causes for multiple myeloma, including exposure to asbestos, benzene and other agricultural chemicals, there are no clear connections. Some studies have suggested an association between farming, pesticides and multiple myeloma, but the findings have been inconsistent. There have also been studies of firefighters, hairdressers and other occupations to assess chemical exposure and risk of multiple myeloma, but these have been inconclusive.

Multiple Myeloma Symptoms

Multiple myeloma symptoms can appear in the bones but aren't necessarily limited there. Symptoms of multiple myeloma can include a range of medical issues that could look similar to other conditions, so it is important to check with a doctor when early multiple myeloma symptoms appear. Key symptoms of multiple myeloma include:

  • Bone pain, particularly in the back, hips or ribs, that does not go away
  • A tendency to break bones
  • Weakness or numbness, especially in the feet or legs
  • Fatigue or shortness of breath
  • Nausea and vomiting
  • Constipation
  • Weight loss for no clear reason
  • Frequent infections
  • Loss of appetite
  • Mental confusion
  • Itching
  • Swelling in the legs

What Are the Early Symptoms of Multiple Myeloma?

Early multiple myeloma symptoms may not present at all or could look like other medical conditions. Often when caught early, multiple myeloma is noticed through routine blood or urine tests and not because of signs or symptoms of cancer. The first early multiple myeloma symptoms will likely be the same as symptoms found in more advanced stages of multiple myeloma.

How is Multiple Myeloma Diagnosed?

The first step in diagnosing multiple myeloma is to complete a medical history and physical examination. When discussing how to diagnose multiple myeloma, your doctor may also order tests and procedures such as:

  • Blood and urine tests: These tests can detect proteins or other substances (such as monoclonal proteins) that are more likely to be seen in the blood or urine of people with multiple myeloma
  • Bone marrow aspiration and/or biopsy: A small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (biopsy) is taken, usually from the back of the hip bone. A pathologist checks the sample(s) for abnormal cells that may signal multiple myeloma
  • X-rays: Electromagnetic energy beams produce images of tissues, bones and organs. These images can show areas where myeloma cells have caused bone damage
  • Skeletal bone survey: A series of X-rays are taken of all of the major bones in the body to detect where myeloma cells may have caused bone damage
  • Magnetic resonance imaging (MRI): A magnetic field and computer assistance are used to produce detailed pictures of various organs and structures. This test can show areas where myeloma cells are involving the bone
  • Computed tomography (CT) scan: A series of X-ray images are combined to produce cross-sectional views of the body and show where myeloma cells have caused bone damage
  • Positron emission tomography (PET) scan: A radioactive glucose (sugar) tracer is injected to create pictures of inside the body and highlight cancer cells. A computer puts these images together to show where cancer cells are located.  This scan is generally combined with a CT scan

Treating Multiple Myeloma

If you are diagnosed with multiple myeloma, your care team will work with you to develop treatment options for multiple myeloma that are right for you. Some treatment options offer a local treatment plan, targeted at specific locations where multiple myeloma exists. Systemic treatment options focus on attacking cancer cells throughout the body.

Treatment for multiple myeloma may involve one or more of these options:

  • Watchful waiting for patients with smoldering myeloma (myeloma without symptoms) involves careful monitoring of the disease until it progresses or symptoms emerge. You may also hear this called active surveillance
  • Chemotherapy kills myeloma cells using intravenous (IV), subcutaneous, or oral drugs
  • Corticosteroids may be used alone or in combination with other drugs to kill myeloma cells. They may also help treat common multiple myeloma symptoms such as nausea and vomiting
  • Radiation therapy uses high-energy radiation beams to kill or shrink a tumor while saving healthy tissue. The radiation source generally comes from outside the body (external radiation therapy). Radiation therapy can also help control pain, prevent fractures and allow bone lesions to heal in multiple myeloma patients
  • Targeted therapy uses drugs that attack specific parts of cancer cells without damaging normal cells
  • Stem cell transplantation (autologous) or bone marrow transplant involves collecting and storing stem cells from the patient's bone marrow, administering high-dose chemotherapy, and then returning the stem cells to the patient's body through an infusion. This generally occurs in the hospital. The stem cell collection process is similar to donating blood and occurs after a period of time when a patient receives medications to help "mobilize" the stem cells. Stem cell transplantation aims to help the bone marrow recover faster from the effects of the high-dose chemotherapy

Some hospitals also offer clinical trials that may provide access to new and promising therapies for multiple myeloma.

Mass General Cancer Center offers the latest treatments for multiple myeloma, including CAR T-cell therapy, and access to cutting-edge research, clinical trials, and novel targeted therapies.

Multiple Myeloma Prognosis

The earlier that multiple myeloma is detected, the better the patient prognosis. Blood, urine, and bone marrow tests can help establish the stage of the disease. Genetic tests of the cancer cells, along with X-rays and other imaging tests, can identify how aggressive the cancer is. In general, your prognosis will depend on the stage of the disease, how aggressive the form of cancer is, your age and your general health.

What Is the Survival Rate of Multiple Myeloma?

The American Cancer Society groups all patients with multiple myeloma together and gives them a 60% five-year survival rate, meaning they are 60% as likely as people who don't have the cancer to live for at least five years after a diagnosis. For those with an early localized diagnosis—the cancer is contained in one area—the survival rate increases to 78%. If the cancer has spread throughout the body, the survival rate dips below 50%.

The National Cancer Institute has more information on multiple myeloma.

Multiple Myeloma FAQs

Can Multiple Myeloma Be Detected Early?

Multiple myeloma is tricky to diagnose early since it often presents no symptoms until advanced. The best opportunity at detecting multiple myeloma early is through blood or urine tests. Patients with monoclonal gammopathy of unknown significance (MUGS) are at a greater risk of developing multiple myeloma and should have bloodwork checked regularly to watch for multiple myeloma.

What Are Complications of Multiple Myeloma?

Along with the list of multiple myeloma symptoms, additional complications of multiple myeloma can include additional bone problems, including bone pain and more frequent bone breaks. The body's reduced immune system response with multiple myeloma could lead to more frequent infections. Kidney problems and failure is also tied to the disease. As red blood cell counts decrease with multiple myeloma, anemia and additional blood complications are possible.

Is Multiple Myeloma Cancer Curable?

With no known cure for multiple myeloma, treatment options focus on reducing symptoms and improving a patient's quality of life. Even if symptoms are kept in check for a time, multiple myeloma can continue to cause complications.

What Type of Cancer Is Multiple Myeloma?

Multiple myeloma is a cancer of abnormal plasma cells, a type of white blood cell, found in the bone marrow. With multiple myeloma, tumors can form in bones.