Multiple Myeloma Incidence: Trends, Risk Factors, and Patterns

Multiple myeloma is a blood cancer affecting plasma cells in the bone marrow. Though less common than other malignancies, its incidence has been rising globally. Understanding affected populations and contributing factors is key to improving prevention and treatment.

Examining trends, as well as genetic and environmental influences, helps explain why certain groups are more vulnerable.

Demographic Variation

Multiple myeloma incidence varies across age, sex, and racial or ethnic backgrounds. Age is the strongest risk factor, with the National Cancer Institute’s SEER Program reporting a median diagnosis age of 69. Fewer than 1% of cases occur in individuals under 40, suggesting cumulative genetic mutations and prolonged environmental exposure play roles in disease development.

Men face a higher risk than women, with a Lancet Haematology meta-analysis showing men are 1.5 times more likely to develop the disease. Hormonal differences, occupational exposures, and immune system variations may contribute, with some studies suggesting estrogen offers a protective effect.

Racial disparities are striking. African Americans are diagnosed at twice the rate of White Americans, a trend not solely explained by socioeconomic factors. Research in Blood indicates a genetic predisposition, as African Americans have higher rates of monoclonal gammopathy of undetermined significance (MGUS), which can progress to multiple myeloma. Differences in access to early diagnosis and treatment may also impact outcomes.

Geographic variation adds complexity. The disease is more prevalent in North America, Europe, and Australia, while incidence rates are lower in Asia. A British Journal of Haematology study suggests lifestyle, diet, and environmental exposures may contribute. Higher obesity rates in Western countries have been linked to increased risk, potentially due to chronic inflammation and immune dysregulation.

Environmental And Genetic Factors

Genetic predisposition and environmental exposures shape multiple myeloma risk. Genome-wide association studies (GWAS) have identified inherited genetic variants linked to susceptibility, particularly in genes regulating plasma cells and DNA repair. Variants in loci such as 7p15.3 and 17p11.2 increase disease likelihood, suggesting disruptions in hematopoietic processes contribute to malignancy. Studies in Nature Genetics show individuals with a first-degree relative diagnosed with multiple myeloma or MGUS have a two- to fourfold greater risk.

Environmental exposures can trigger disease progression. Long-term contact with occupational hazards like benzene, pesticides, and organic solvents has been linked to increased risk due to genomic instability. A Occupational and Environmental Medicine systematic review found agricultural and petroleum industry workers had higher incidence rates, implicating carcinogenic exposure. Prolonged ionizing radiation exposure, such as that encountered in the nuclear industry or through repeated high-dose radiation treatments, has also been associated with plasma cell malignancies, according to the International Agency for Research on Cancer (IARC).

Lifestyle factors further influence risk. Obesity has emerged as a significant factor, with American Journal of Clinical Nutrition meta-analyses showing individuals with a BMI over 30 have a 20% to 30% higher likelihood of developing multiple myeloma. Chronic inflammation and altered adipokine signaling may create an environment conducive to plasma cell proliferation. Diets high in processed meats and saturated fats may exacerbate oxidative stress and inflammation, while plant-based or Mediterranean diets rich in antioxidants and polyphenols could offer protection, though further research is needed.

Patterns Observed Over Time

Multiple myeloma incidence has been rising for decades, with global cancer registries documenting increases in both cases and mortality. The Global Burden of Disease (GBD) study reports age-standardized incidence rates have grown by 1% to 2% annually in many high-income countries. Advances in diagnostic techniques, such as serum protein electrophoresis and free light chain assays, have contributed to earlier and more frequent detection, but they do not fully account for the continued rise.

Population health trends play a role. Rising obesity rates have been linked to increased myeloma risk, with adipose-derived inflammatory cytokines potentially fostering plasma cell malignancies. Longer life expectancy has also led to more diagnoses in older adults, amplifying disease burden.

Geographic patterns are shifting. North America and parts of Europe report the highest incidence, but rates are climbing in Asia and Latin America. Changes in lifestyle, environmental exposures, and healthcare infrastructure likely contribute. Improved diagnostic access in historically lower-incidence regions may account for some of the increase, though the extent to which true incidence is rising versus improved reporting remains under investigation.