Multiple Myeloma: An Occupational Disease
The word “myeloma” means a tumor of the bone marrow. Most people with this disease develop many bone marrow tumors, so the disease is called “multiple myeloma.” Multiple myeloma is cancer of plasma cells. These cells cause large areas of destruction in the bones. Tumors occur most often in the ribs, vertebrae, pelvic bones, and the flat bones of the skull. Complications include intense bone pain, compression, fractures, and kidney damage. Complete remission is rare. With standard therapy the clinical disease phase lasts an average of only 3 years. Virtually all patients with multiple myeloma succumb to their cancer.
About 12,000 new cases of multiple myeloma are diagnosed every year in the United States. About 4 in 100,000 white people get the disease; the incidence is double among blacks. Multiple myeloma is a disease of old age; the median age of diagnosis is 72. Multiple myeloma is uncommon in people under age 50 and rare under age 40, suggesting a potential toxic cause.
Multiple myeloma has been associated with exposure to benzene, fuel exhausts, pesticides, ionizing radiation and other toxic chemicals.
In 2009, the International Agency for Research on Cancer (IARC) concluded that there is “limited evidence” that benzene causes multiple myeloma. According to IARC, the designation “limited evidence” means that “a positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered . . . to be credible, but chance, bias, or confounding could not be ruled out with reasonable confidence.”
In 2010, the President’s Cancer Panel concluded that the evidence between exposure to benzene and multiple myeloma is “strong.”
In 2011, researchers from the National Cancer Institute and the Netherlands published a meta-analysis regarding benzene and lymphoid cancers, concluding that “supportive of an association between benzene exposure with multiple myeloma.” Vlaanderen, J., et al., “Occupational Benzene Exposure and the Risk of Lymphoma Subtypes: A Meta-Analysis of Cohort Studies Incorporating Three Study Quality Dimensions,” Environ Health Perspect. 119(2):159-167 (2011).
Canada and Germany have recognized multiple myeloma as an occupational disease from benzene exposure, and benzene-exposed workers who develop multiple myeloma in Canada and Germany may be compensated under the occupational disease laws of those countries.