Multiple myeloma

Although the exact underlying cause of multiple myeloma is poorly understood, the specific symptoms of the condition result from abnormal and excessive growth of plasma cells in the bone marrow. Plasma cells help the body fight infection by producing proteins called antibodies. In people with multiple myeloma, excess plasma cells form tumors in the bone, causing bones to become weak and easily broken. The abnormal growth of plasma cells also makes it more difficult for the bone marrow to make healthy blood cells and platelets. The plasma cells produced in multiple myeloma produce abnormal antibodies that the immune system is unable to use. These abnormal antibodies build up in the body and cause a variety of problems.

Factors that are associated with an increased risk of developing multiple myeloma include increasing age, male sex, African American race, radiation exposure, a family history of the condition, obesity, and/or a personal history of monoclonal gammopathy of undetermined significance (MGUS).

A diagnosis of multiple myeloma may be suspected based on the presence of characteristic signs and symptoms. Additional testing can then be ordered to confirm the diagnosis. This may include:

• Specialized blood tests including immunoglobulin studies, complete blood count with differential, and blood chemistry studies
• Urine tests such as immunoglobulin studies and a twenty-four-hour urine test
• Bone marrow aspiration and biopsy
• Imaging studies such as an X-ray of the bones (skeletal bone survey), MRI, CT scan, and/or PET scan

The American Cancer Society offers more information regarding the diagnosis of multiple myeloma, including a summary of the many tests that may be recommended. Please click on the link to access this resource.

Some affected people may have no suspicious signs or symptoms of multiple myeloma, especially in the early stages of the condition. In these cases, multiple myeloma is sometimes diagnosed by chance when a blood test or urine test is ordered to investigate another condition.

Multiple myeloma is a form of cancer that occurs due to abnormal and uncontrolled growth of plasma cells in the bone marrow. Some people with multiple myeloma, especially those with early stages of the condition, have no concerning signs or symptoms. When present, the most common symptom is anemia, which can be associated with fatigue and shortness of breath. Other features of the condition may include multiple infections; abnormal bleeding; bone pain; weak and/or easily broken bones; and numbness and/or weakness of the arms and legs. The exact underlying cause of multiple myeloma is currently unknown. Factors that are associated with an increased risk of developing multiple myeloma include increasing age, male sex, African American race, radiation exposure, a family history of the condition, obesity, and/or a personal history of monoclonal gammopathy of undetermined significance (MGUS). Treatment varies based on many factors, but may include one or more of the following interventions: chemotherapy, corticosteroid medications, targeted therapy, stem cell transplant, biological therapy, radiation therapy, surgery and/or watchful waiting.

Multiple myeloma usually occurs sporadically within a family and very little is known about familial and/or hereditary forms. Several families have been reported with multiple cases of multiple myeloma. The existence of hereditary multiple myeloma is, therefore, suggested, but no single gene known to cause the condition have been identified. Studies have found that a person's risk of multiple myeloma may be higher if a close relative had the disease. For example, first-degree relatives (i.e. parents, children) of people with multiple myeloma are reported to be two-to four-times more likely to develop the condition; it is presumed the risks are higher for relatives in the case of familial ;multiple myeloma (where multiple people have already been diagnosed). Multiple myeloma among married couples and "community clusters" of multiple myeloma have also been described, suggesting the potential importance of environmental factors, as well.

The long-term outlook (prognosis) for people with multiple myeloma can be difficult to predict as some cases progress rapidly despite treatment, while others remain stable without therapy for a number of years. However, some general patterns have been observed. For example, prognosis appears to vary based on the affected person's age and the stage of the condition at the time of diagnosis. In general, survival is higher in younger people and lower in the elderly. Other factors that can be associated with a poor prognosis include a high tumor burden and kidney damage.

Infections are an important cause of early death among people with multiple myeloma. In fact, studies show that the risk of both bacterial infections and viral infections is approximately seven times higher in people affected by the condition.

The treatment of multiple myeloma varies based on many factors including the age and general health of the affected person; the associated signs and symptoms; and the severity of the condition. In general, one or more of the following interventions may be used to treat multiple myeloma:

• Chemotherapy
• Corticosteroid medications
• Targeted therapy
• Stem cell transplant
• Biological therapy
• Radiation therapy
• Surgery
• Watchful waiting

The National Cancer Institute offers information regarding the management of multiple myeloma, including more specific information regarding the treatments outlined above. Please click on the link to access this resource.

Sonneveld P et al., Treatment of multiple myeloma with high-risk cytogenetics: a consensus of the International Myeloma Working Group. Blood. 2016 Jun 16;127(24):2955-62.