Among a group of firefighters exposed to the World Trade Center (WTC) disaster of September 11, 2001, there was an almost twofold increased rate of monoclonal gammopathy of undetermined significance (MGUS) — a known precursor of multiple myeloma — compared with an age-matched population from another area of the country.1
“When the World Trade Center buildings came down, there was a tremendous amount of particulate matter in the environment,” said Amit Verma, MBBS, director of the Division of Hemato-Oncology at the Montefiore Einstein Center for Cancer Care in the Bronx, New York. “A lot of things like this — inorganic material — have been shown to be harmful to DNA, to cause DNA mutations or DNA breaks, and all of these changes can potentially lead to development of cancer down the road.”
In fact, a 2011 study published in The Lancet showed that first responders to the 9/11 disaster were at an increased risk for a variety of types of cancer, including multiple myeloma.2 In the current study, Dr Varma and colleagues further examined this increased risk of myeloma.
Dr Varma and colleagues evaluated a group of 16 Fire Department of the City of New York (FDNY) firefighters diagnosed with myeloma after September 11, 2001, as well as all WTC-exposed FDNY white, male firefighters older than 50 years with available serum samples (781 people).
Among the 781 WTC-exposed firefighters, the age-standardized prevalence rate of MGUS and a subset of MGUS, light-chain MGUS, was 7.63 per 100 persons, or a 1.8-fold higher rate than that found in a non-exposed comparison group of men living in Olmsted County, Minnesota (4.34 cases per 100).
Dr Verma noted that in addition to the increased frequency, WTC-exposed firefighters were also diagnosed with MGUS or myeloma at a younger age. In the group of 16 WTC-exposed firefighters diagnosed with myeloma after September 11, 2001, the median age of diagnosis was 57 compared with 69 in the general population.
About 50% of these cases of myeloma were, furthermore, light-chain myeloma, which usually occurs at about a 20% frequency. Among the group of 781 WTC-exposed firefighters, the age-standardized prevalence rate of light-chain MGUS was 3.08 per 100 persons compared with 0.98 per 100 persons in the control population.