New York City firefighters who were exposed to chemicals released into the environment following the World Trade Center (WTC) attacks on September 11, 2001, had an increased risk of both monoclonal gammopathy of undetermined significance (MGUS) and light-chain MGUS – two myeloma precursor diseases – according to results of a case-series study published in JAMA Oncology.1
“Based on the [large] number of patients being diagnosed and treated at our myeloma service, we felt there [were] possibly more multiple myeloma (MM) cases among people exposed to the WTC disaster, compared with all other patients we see and treat,” lead investigator Ola Landgren, MD, PhD, professor of medicine and chief attending physician in the myeloma service at Memorial Sloan Kettering Cancer Center in New York, told ASH Clinical News. “The prevalence of myeloma precursor disease is twice as high as the general population, and the average age of onset for MM among first responders was 10 to 15 years earlier than the general population.”
Researchers worked collaboratively with the NYC fire department to conduct this large study of MM precursor disease among first responders. First, they obtained patient data from 12,942 firefighters who were exposed to the WTC attack and who received physical and mental health services through the WTC Health Program.
From this cohort, investigators identified 16 male firefighters who received a post-9/11 diagnosis of MM as of July 1, 2017, and had available serum samples. Their median age was 57 years (range = 50-68 years); approximately half of patients presented with light-chain MM, and five patients had CD20-positive disease.
In the screening study, the investigators identified 781 white male WTC site–exposed firefighters between the ages of 50 and 79 years with available serum samples to screen for MGUS or light-chain MGUS. Participants spent an average of 3.17 months at the WTC site, and most (53.6%) arrived at the site on the afternoon of September 11, 2001.
Researchers compared firefighters’ data with an age- and sex-matched cohort from Olmsted County, Minnesota – the only available screening study for both MGUS and light-chain MGUS (n=7,612).2
For both portions of the study, the authors measured:
- case information of MM
- age-adjusted and -specific prevalence rates for overall MGUS and either MGUS alone or light-chain MGUS
Compared with the Olmsted County cohort, the age-standardized prevalence rate of overall MGUS was approximately 1.8-fold higher in the WTC site–exposed firefighters: 4.34 per 100 persons (95% CI 1.34-2.29) versus 7.63 per 100 persons (95% CI 5.45-9.81; p value not reported).
WTC site–exposed firefighters had a 3.1-fold higher risk of having light-chain MGUS, compared with the Olmsted County cohort (relative rate = 3.1; 95% CI 1.99-4.93; p value not reported).
While there are no published guidelines that recommend screening for myeloma precursor disease in the general population, Dr. Landgren noted that, “if a person has been exposed, such as the first responders were to the WTC disaster, and he or she later develops symptoms typical for MM (e.g., fatigue, bone pain, repeated infections), the individual needs to seek medical attention to rule out the disease and/or get appropriate workup and therapy.”
He also stressed that individuals with jobs that entail potential exposure to hazardous material need adequate protection devices. “We have conducted research screening studies of MGUS and light-chain MGUS among agricultural workers spraying pesticides, and we found a doubling of the risk among exposed people,” Dr. Landgren said. Based on these findings, “we would recommend screening for MGUS and light-chain MGUS in individuals exposed to environmental hazards.
A limitation of the analysis included the investigators’ inability to determine whether the onset of precursor disease preceded exposure to WTC environmental hazards. Also, the investigators noted that their study was “underpowered to detect an exposure-response gradient association between WTC exposure and MGUS.” The retrospective design and use of a cohort from Olmstead County may have introduced biases.
To further understand the role of the WTC disaster in myeloma risk, Dr. Landgren and colleagues plan to investigate myeloma and its precursor disease among non-firefighters who were exposed to the WTC disaster, such as residents of lower Manhattan.
“The hypothesis is that there are certain molecular myeloma features that are common in those exposed to the WTC disaster, and [we could] compare these patients with those we see in the general population,” he said. “This could help uncover the link between etiology and pathogenesis.”
The study was funded by the V Foundation for Cancer Research, the Byrne Fund for the benefit of Memorial Sloan Kettering, the Memorial Sloan Kettering Cancer Center Core Grant from the National Cancer Institute, the Albert Einstein Cancer Center, and the National Institute for Occupational Safety and Health.
The corresponding authors report no financial conflicts.
- Landgren O, Zeig-Owens R, Giricz O, et al. Multiple myeloma and its precursor disease among firefighters exposed to the World Trade Center disaster. JAMA Oncol. 2018 April 26. [Epub ahead of print]
- Dispenzieri A, Katzmann JA, Kyle RA, et al. Prevalence and risk of progression of light-chain monoclonal gammopathy of undetermined significance: a retrospective population-based cohort study. Lancet. 2010;375:1721-1728.