Multiple myeloma most commonly affects older adults, men, and Black Americans. The overall incidence rate is 7.3 per 100,000 people per year, but that number rises sharply in specific groups. Understanding where the risk concentrates can help you gauge your own situation or that of someone you care about.
Age Is the Strongest Risk Factor
Multiple myeloma is rare before age 40 and becomes increasingly common with each decade after that. The median age at diagnosis is around 66 to 70 years old, depending on racial background. By the early 2030s, an estimated three out of every four newly diagnosed patients will be between 64 and 84 years old, up from roughly two out of three today. This shift reflects the aging population overall, but the takeaway is straightforward: the older you are, the higher your risk.
Black Americans Face Two to Three Times the Risk
The racial disparity in multiple myeloma is one of the largest of any cancer. The age-adjusted incidence rate for Black Americans is 11.0 per 100,000 person-years, compared to 4.9 for white Americans. That gap is consistent over time and is especially pronounced in younger age groups. Among people under 50, Black individuals are more than three times as likely to be diagnosed. By age 70 and older, the ratio narrows to roughly two to one, but the disparity never disappears.
Black Americans also tend to be diagnosed about four years younger on average, with a mean age at diagnosis of 65.8 compared to 69.8 for white Americans. The reasons behind this disparity likely involve a combination of genetic susceptibility, higher rates of the precursor condition discussed below, and socioeconomic factors that affect when and how the disease is detected.
Men Are Diagnosed More Often Than Women
Multiple myeloma is roughly 30% more common in men. Between 2011 and 2013, about 11,200 men were diagnosed each year in the United States compared to 8,500 women. The reasons aren’t entirely clear, though differences in occupational exposures and hormonal factors have both been proposed as contributors.
Family History and Genetic Predisposition
Having a parent, sibling, or child who was diagnosed with multiple myeloma increases your own risk by two to four times. This elevated risk also extends to related blood cancers and a precursor condition called MGUS (monoclonal gammopathy of undetermined significance). The family history connection is particularly strong among Black Americans, where having a first-degree relative with myeloma is associated with roughly a fivefold increase in risk, compared to a more modest increase in white Americans.
Researchers have identified several inherited genetic variants that contribute to susceptibility, but no single gene drives the disease. The family clustering suggests that shared genetics, and possibly shared environmental exposures, both play a role.
MGUS: The Precursor Condition
Nearly all cases of multiple myeloma are preceded by MGUS, a condition where abnormal proteins appear in the blood but haven’t yet caused damage. MGUS itself is common, especially in older adults and Black Americans. A landmark study published in the New England Journal of Medicine followed over 1,300 people with MGUS and found that the condition progresses to myeloma or a related disorder at a rate of about 1% per year. Over 10 years, 12% had progressed. Over 25 years, 30% had.
Most people with MGUS will never develop myeloma, but the condition is the single clearest biological marker of elevated risk. If you’ve been told you have MGUS, your doctor will typically recommend periodic blood tests to monitor for changes.
Obesity Increases Risk Steadily
Body weight has a well-established connection to multiple myeloma. For every 5-point increase in BMI, the risk of myeloma rises by about 18%. People with severe obesity (a BMI of 40 or higher) face roughly double the risk compared to those at a normal weight. This effect appears strongest in Black men with severe obesity, where the risk increase may be nearly fourfold, though that estimate comes with wider statistical uncertainty due to smaller sample sizes. Excess body fat is thought to promote chronic inflammation and alter the hormonal environment in ways that encourage abnormal plasma cell growth.
Occupational and Chemical Exposures
Certain jobs carry elevated risk because of what workers breathe in or handle. Farmers are at higher risk, likely from chronic pesticide exposure. Petroleum workers face increased exposure to benzene, a known carcinogen. Carpenters and forestry workers encounter wood dust, which has also been linked to myeloma. Industrial exposure to organic solvents like trichloroethane, chloroform, and methylene chloride adds risk as well.
Asbestos exposure has been associated with myeloma, as has contact with certain animal viruses. Farmers who work closely with sheep, for example, may face additional risk from the Orf virus, though this connection is less firmly established than the chemical exposures.
Ionizing Radiation
People exposed to significant levels of ionizing radiation have higher rates of multiple myeloma. Studies of nuclear facility workers at sites like Los Alamos, Hanford, and Sellafield in England have consistently found increasing myeloma death rates with increasing radiation doses. Research on atomic bomb survivors in Japan confirmed the same pattern. The National Research Council has formally recognized that widespread irradiation of bone marrow is associated with elevated myeloma incidence. The greatest risk appears at high cumulative exposure levels, making this primarily a concern for nuclear workers, certain military veterans, and survivors of large-scale radiation events rather than people receiving standard medical imaging.
Autoimmune and Inflammatory Conditions
Several autoimmune diseases are associated with a modestly increased risk of myeloma. Rheumatoid arthritis raises the risk by roughly 18% to 32%, depending on the study. Ankylosing spondylitis, a type of inflammatory spinal arthritis, is linked to a relative risk increase of about 2.3 times. Inflammatory muscle diseases like dermatomyositis and polymyositis carry a similar elevation. Pernicious anemia, an autoimmune condition that impairs vitamin B12 absorption, has been associated with about a 47% increase in myeloma risk. Inflammatory bowel disease also appears on the list, though with less certainty.
The common thread among these conditions is chronic immune system activation. Prolonged stimulation of immune cells, including the plasma cells that become cancerous in myeloma, may create more opportunities for the genetic errors that lead to malignancy. Autoimmune conditions like lupus, scleroderma, and Sjögren’s syndrome have also been linked to myeloma and related plasma cell disorders.
How These Risks Overlap
Risk factors for myeloma don’t exist in isolation. A Black man over 65 with obesity and a family history of the disease sits at a very different point on the risk spectrum than a younger white woman with no family history and a normal BMI. The five-year relative survival rate for myeloma is now 62.4%, a significant improvement over past decades thanks to newer treatments. But outcomes still vary by how early the disease is caught and how aggressively it’s treated. If multiple risk factors apply to you, paying attention to symptoms like unexplained bone pain, fatigue, frequent infections, or unexpected kidney problems becomes especially important.