A risk factor is something that increases your chances of getting a disease or condition. Most cases of multiple myeloma develop in patients with no risk factors.


The median age patients are diagnosed with myeloma is 65. This disease is rarely found in people younger than 40. The reason is not known. But many cancers are more common in older adults.

Genetic Factors

Multiple myeloma seems to run in some families. However, most patients do not have a family member with the disease.

Environmental Toxins

Exposure to toxins or radiation may increase your risk of multiple myeloma. The cancer is more often found in people who work in the petroleum industry or in agriculture. Working in a nuclear plant or radiology center, where you are exposed to radiation, may also increase the risk.

Medical Conditions

Patients with other plasma cell disease are more likely to develop multiple myeloma. Twenty percent of patients with monoclonal gammopathy of undetermined significance or extramedullary plasmacytoma go on to develop multiple myeloma. ]]>Amyloidosis]]>, another rare disease of the plasma cells, is also associated with myeloma.

Monoclonal gammopathy is a blood disorder. The blood normally contains many different proteins called plasma proteins. One type of protein is called gamma globulin and combines to make antibodies. Normally many different types of gamma globulin are produced to deal with different infections. When most of the protein being produced is one particular form of gamma globulin this is called monoclonal gammopathy.

An extramedullary plasmacytoma is a discrete, solitary mass of plasma cells that grow out of control. In amyloidosis, abnormal proteins accumulate in various organs of the body. These organs, usually heart, muscle, nervous system, and intestines, can malfunction due to the accumulation of proteins.


African Americans are more likely than Caucasians to develop multiple myeloma. The reason is unknown.