The American Cancer Society estimated that in 2009, 20,580 people in the United States will be diagnosed with multiple myeloma. The lifetime risk for developing multiple myeloma is 1 in 161, or 0.62 percent.

Although scientists and doctors do not know the exact causes of multiple myeloma, doctors do know some risk factors that make people more likely to develop multiple myeloma. However, many people who have more than one of these identified risk factors do not get the disease, and many people who get the disease do not display all these risk factors.

Instead, according to the University of Virginia Health System, it is advised for people to know the risk factors for any disease to help them guide their choices about getting monitored and tested.

• Age: Risk for multiple myeloma increases with age. Less than one percent of newly-diagnosed people are younger than 35, and the average age of newly-diagnosed people is about 65.
• Gender: Men are at higher risk than women. The American Cancer Society estimated that in 2009, 11,680 men and 8,900 women will be diagnosed with multiple myeloma.
• Race: Multiple myeloma occurs almost twice as often in African-Americans than in Caucasian-Americans. The reason for this difference is not known.
• Other Plasma Cell Conditions: People who have one myeloma lesion, called a solitary plasmacytoma, or who have monoclonal gammopathy of undetermined significance (MGUS), have higher risk for multiple myeloma. According to the Mayo Clinic, one percent of people in the U.S. with MGUS develop multiple myeloma every year.
• Occupational Exposure: Some studies show that exposure to certain chemicals and substances on the job can increase risks for multiple myeloma. Some of these occupations include workers in petroleum industries and agriculture.
• Radiation Exposure: Exposure to radiation may increase the risk of developing multiple myeloma. However, only a small number of cases are linked to radiation.
• Family History: A person with a brother, sister, or parent with multiple myeloma is more likely to develop the disease. According to the American Cancer Society, the risk for a patient with a family history of myeloma is four times greater than someone without a family history of myeloma. However, most people with multiple myeloma do not have any affected relatives.
• Weight: People who are overweight or obese are more likely to develop multiple myeloma. According to the National Cancer Institute, this risk factor is still being studied.

For more information about some of these risk factors, please see the recent related Beacon articles on racial disparities ^[1], MGUS ^[2], and chemical exposure ^[3] in multiple myeloma.

Signs and Symptoms » ^[4]