The causes of myeloma are not known or well understood, and there are currently no known ways to prevent it. There are also no strong risk factors for myeloma. Mutations (changes) in plasma cells are acquired, not inherited, so having a relative with the disease usually does not mean another family member is at higher risk for developing it. There appears to be a very slight increase in the incidence of the disease in first-degree relatives (parents or siblings) of people with multiple myeloma, but this link has not been shown to be genetic at this time.
Some factors that may increase your risk of multiple myeloma include:
Age
The risk of multiple myeloma goes up with age. The majority of those diagnosed are over 65 years old. Only 2% of cases occur in people under 40.
Family history
Multiple myeloma seems to run in some families. Having a sibling or a parent who's had multiple myeloma may increase the likelihood of developing the disease as much as four times when compared to people who have no family history of multiple myeloma. However, this has only been found in a small number of cases.
Gender
Men are slightly more likely to develop multiple myeloma than women.
Obesity
Your risk of multiple myeloma is increased if you're overweight or obese.
Other plasma cell diseases
Some people who have a condition known as monoclonal gammopathy of undetermined significance (MGUS) may be at increased risk for multiple myeloma. In MGUS, an abnormal line of antibody-producing plasma cells will begin to produce monoclonal antibody proteins (M-proteins). Over time, the proliferation of the “M-protein” may crowd out the normal plasma cells that are capable of producing functional antibodies. The American Cancer Society has reported that every year approximately 1 percent of all people with MGUS develop a more severe disease, including multiple myeloma. It is not known why some people with MGUS develop multiple myeloma and others do not.
Race
For unknown reasons, the incidence of multiple myeloma is twice as high in African Americans as compared to white Americans.
Radiation
People who were exposed to radiation from an atomic bomb blast had a higher risk of multiple myeloma. Exposure to lower levels of radiation may also increase the risk of multiple myeloma. At most, this accounts for a very small number of cases.
Workplace exposures
A small number of cases may be linked to exposure to high doses of radiation. Studies looking at workplace exposures and multiple myeloma risk have found no clear links.