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Smoldering multiple myeloma

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What is smoldering multiple myeloma (SMM)?

Smoldering multiple myeloma is a precancerous form myeloma. Normally, plasma cells in blood and bone marrow produce antibodies. These antibodies fight infection. In myeloma, the plasma cells produce an abnormal protein.

On its own, SMM often does not present symptoms. Occasionally, patients may experience numbness or tingling in their hands or feet, or difficulty balancing.

SMM may progress to active multiple myeloma, a cancerous blood condition. It is important for patients with SMM to watch out for symptoms which may indicate this progression, including:

  • Bone pain
  • Excessive fatigue
  • Balance issues
  • Extended numbness in the hands and feet
  • Weight loss

It is also important that patients with SMM receive regular monitoring for early detection of progression.

Smoldering multiple myeloma risk factors

The cause for SMM is unknown. SMM is more common among men than women, and is nearly twice as common in African-Americans. While patients with SMM may not experience symptoms, it is an indicator of a greater risk for active multiple myeloma.

Smoldering multiple myeloma diagnosis and treatment

SMM is first detected by the presence of paraproteins or free light chains in the blood or urine. Other blood tests and a bone marrow biopsy are then performed to confirm this diagnosis.

The bone marrow biopsy is also used to determine the risk type of SMM. For patients with low risk SMM, no specific treatment is necessary. Close monitoring is important, though, as SMM may progress to active myeloma.

Treatments are available to help slow the progression from high risk SMM to active myeloma. Physicians and scientists at University of Iowa Health Care are currently investigating treatments using ascorbic acid (vitamin C) and drugs that work with the immune system (known as immunomodulatory and monoclonal antibodies).

Not every patient with SMM will develop active myeloma, but it is important for patients to continue to have blood work completed, and immediately report any new symptoms to their doctor.