Multiple Myeloma vs. Leukemia: What Are the Differences?

Multiple myeloma and leukemia are cancers that both start in blood cells, but they are two very different forms of cancer. Myeloma is a cancer of the bone marrow, specifically the plasma cells. Leukemia also is a cancer of bone marrow and stems from one of the two main groups of young white blood cell types, lymphocytes or myelocytes precursors. There are different types of leukemia, depending on which cells are affected.

Different cancers are treated in different ways, even those affecting the same elements within the body. It's helpful to know the subtle distinctions so you can be prepared for what lies ahead. A diagnosis will ensure the proper treatment is given.

This article will review the differences between multiple myeloma and leukemia.

Symptoms

While symptoms of multiple myeloma and leukemia do have some overlap, there are differences as well.

Causes

Even though there are many similarities between the blood cancers multiple myeloma and leukemia, the underlying causes are different.

Multiple Myeloma

It is not known exactly what causes multiple myeloma. The symptoms develop because of the abnormal replication (copying and reproduction) of plasma cells in the bone marrow.

Researchers hypothesize that multiple myeloma may be a combination of:

• Environmental factors
• Genetic factors

Exposure to dioxins (organic pollutants) has been associated with an increased risk of myeloma, as have abnormalities in chromosome 13.

Before myeloma develops, there usually is an occurrence of a condition called monoclonal gammopathy of undetermined significance (MGUS)—when an abnormal protein called monoclonal protein (M protein) is in the blood. It’s not known what causes MGUS.

Leukemia

Like myeloma, the exact causes of leukemia are unknown.

It’s believed that a combination of genetic and environmental factors cause mutations in blood cells. Risk factors include the genetic condition Down syndrome (trisomy 21), tobacco use, human immunodeficiency virus (HIV), and exposure to certain chemicals.

Diagnosis

Diagnosing multiple myeloma and leukemia are very similar. There may be other tests that are done, depending on the results or the person’s symptoms, but the general diagnostic tests are similar. In addition to a physical exam, they can include:

• Blood work
• Biopsies (removing tissue to be analyzed in a lab)
• Imaging tests

Blood work for multiple myeloma and leukemia can include a complete blood count (CBC). If other tests are needed, your healthcare provider may order blood chemistry tests for levels of specific elements, particularly for multiple myeloma.

Bone marrow biopsies or lumbar punctures (spinal tap), which involves removing cerebrospinal fluid from the lower spine, may also be performed to diagnose either cancer and to reveal the following:

• In leukemia, a bone marrow biopsy can show the number of immature cells in the bone marrow and highlight other characteristics of leukemia cells for the healthcare provider.
• In multiple myeloma, a bone marrow biopsy can show too many plasma cells in the bone marrow.

Imaging tests like X-rays, CT (computed tomography) scans, MRI (magnetic resonance imaging), and PET (positron-emission tomography) scans can show any tumors or cancer in areas of the bones, brain, or spinal cord. These tests can provide more information about any symptoms the person might be having.

Treatment

Treatment varies depending on the type of cancer and any subtype, so it’s especially important to get an accurate diagnosis. Treatments for cancer typically also depend on:

• Your age
• Your general health
• Your stage
• Severity of the cancer
  

Multiple Myeloma

Treatments for multiple myeloma can include:

Drug therapy, including:

• Chemotherapy: This is a treatment that uses powerful drugs to kill fast-growing cells in the body.
• Corticosteroids: These are used to reduce inflammation.
• Immunomtherapy: This treatment uses a person's own immune system to fight cancer.
• Proteasome inhibitors: These stop cells from breaking down proteins involved in controlling cell division.
• Monoclonal antibodies: These are human-made antibodies that can attack certain proteins on the surface of cancer cells.
• Monoclonal antibody and chemotherapy: Along with chemotherapy, monoclonal antibodies can locate and attack specific proteins on cancer cells.
• Nuclear export inhibitor: These block proteins from being transferred and the cell dies.
• Bisphosphonates: These slow bone growth.

Other treatments include:

• Radiation therapy (using high doses of radiation to kill and shrink cancer cells)
• Surgery (rarely used)
• Stem cell (bone marrow) transplant
• CAR T-cell therapy (chimeric antigen receptor T-cell therapy, a form of immunotherapy)

Supportive treatment includes:

• Blood transfusions
• Drugs that improve low red blood cell count
• Plasmapheresis to get rid of myeloma protein from the blood

Leukemia

Treatment options for leukemia can include one or more of these treatments:

• Chemotherapy
• Targeted therapy
• Immunotherapy
• Radiation therapy
• Stem cell transplants
  

Prevention

There is no known way to prevent multiple myeloma or leukemia. Multiple myeloma is rarely associated with risk factors that can be avoided.

There are general health-promoting behaviors you can take to reduce your risk of leukemia like quitting smoking, eating a healthy diet, maintaining a healthy weight, and avoiding known exposures to chemicals, but there is no definitive way to prevent cancer.

Summary

While multiple myeloma and leukemia are both blood cancers and have similarities in some diagnostic tests and treatment options, they are two distinct diseases and should be approached as such.

They arise from different kinds of cells and can have different effects on the body. An appropriate diagnosis is necessary for the proper treatment.

A Word From Verywell

Getting a cancer diagnosis is extremely difficult, but it can help to know how your type of cancer may affect you. Even those diseases that are similar in how they impact the body may have many distinctions. If you have any questions, talk to members of your treatment team. They are there to help.