Multiple myeloma risk factors: who is more likely to get it

What multiple myeloma is

Multiple myeloma is a cancer that begins in plasma cells, a type of white blood cell that is part of the immune system (MedlinePlus). Plasma cells develop from B cells and make antibodies that fight infection (NCI PDQ). In multiple myeloma, abnormal plasma cells (myeloma cells) build up in the bone marrow and form tumors in many bones. As they increase, the marrow makes fewer red blood cells, white blood cells and platelets, and the myeloma cells damage and weaken the bone (NCI PDQ).

NCI groups multiple myeloma with other plasma cell neoplasms: MGUS, plasmacytoma and lymphoplasmacytic lymphoma (Waldenström macroglobulinemia) (NCI PDQ).

Who is more likely to get multiple myeloma

No one knows the exact causes of multiple myeloma (MedlinePlus). Plasma cell neoplasms are most common in people who are middle aged or older (NCI PDQ). For multiple myeloma and plasmacytoma, NCI lists these other risk factors (NCI PDQ):

• being Black
• being male
• a personal history of MGUS or plasmacytoma
• being exposed to radiation or certain chemicals

MedlinePlus adds that it is more common in older people and African Americans, and that it can run in families (MedlinePlus). NCI notes that studies of how racial, social and financial factors affect access to treatment and rates of these diseases are ongoing (NCI PDQ).

Not every person with a risk factor gets myeloma, and it can develop in people with no known risk factor (NCI PDQ).

MGUS: the condition that can come first

Monoclonal gammopathy of undetermined significance (MGUS) is not cancer, but it can become cancer, such as multiple myeloma (NCI PDQ). The abnormal plasma cells make a protein called M protein, which is sometimes found during a routine blood or urine test. In most people with MGUS, the amount of M protein stays the same and there are no signs, symptoms or health problems (NCI PDQ). Plasmacytoma of the bone, a single plasma cell tumor, often becomes multiple myeloma (NCI PDQ).

Smoking, genes and work exposures

• Smoking. The NCI and MedlinePlus myeloma pages we use do not list smoking as a risk factor (NCI PDQ) (MedlinePlus), so we do not add one. If you smoke and want help quitting, see the quit smoking check.
• Genes and family. MedlinePlus says multiple myeloma can run in families (MedlinePlus). Neither source names a specific gene.
• Work exposures. NCI lists exposure to radiation or certain chemicals but does not name the chemicals or jobs (NCI PDQ).

Symptoms to check with a doctor

Sometimes multiple myeloma causes no symptoms; this is called smoldering multiple myeloma and may be found when a blood or urine test is done for another reason (NCI PDQ). MedlinePlus lists these common symptoms (MedlinePlus):

• bone pain, often in the back or ribs
• broken bones
• weakness or fatigue
• weight loss
• frequent infections and fevers
• feeling very thirsty
• frequent urination

NCI adds easy bruising or bleeding, trouble breathing and weakness of the arms or legs. Myeloma can damage bone and raise blood calcium, which may cause loss of appetite, nausea, thirst, constipation, muscle weakness and confusion (NCI PDQ). These symptoms can have other causes, so see a doctor rather than guess.

How multiple myeloma is found

Doctors diagnose multiple myeloma using lab tests, imaging tests and a bone marrow biopsy (MedlinePlus). NCI lists blood and urine tests for M protein and other proteins, a complete blood count, a 24-hour urine test, bone x-rays and other scans (NCI PDQ). Our cancer screening hub covers the cancers that have screening checks for people without symptoms.

Common questions

Is multiple myeloma a type of leukemia or lymphoma?

MedlinePlus describes it as a cancer that begins in plasma cells (MedlinePlus). NCI groups it with the other plasma cell neoplasms; one of them, lymphoplasmacytic lymphoma, is covered in NCI's non-Hodgkin lymphoma summary (NCI PDQ). See leukemia risk factors and lymphoma risk factors.

Does MGUS always turn into myeloma?

No. In most people with MGUS the M protein level stays the same with no health problems; in some it later becomes a more serious condition or cancer (NCI PDQ).

At what age is multiple myeloma most common?

Plasma cell neoplasms are most common in people who are middle aged or older (NCI PDQ).