On September 11, 2001, terrorists hijacked four airplanes on United States soil — two hit the World Trade Center, one the Pentagon and another crashed in a field in Pennsylvania after passengers fought back. The terror attack left nearly 3,000 Americans dead and thousands more injured.
That day, police officers, firefighters, EMTs, construction workers and volunteers jumped into action trying to rescue and help as many people as they could. In the months after the attack, the cleanup of Ground Zero continued for many rescue and recovery workers.
Since then, years of research have linked environmental exposures from the World Trade Center disaster site to health risks, such as cancer — the World Trade Center Health Program
lists more than 80 — and lung diseases, as well as mental health concerns like depression and post-traumatic stress disorder.
Now shedding even more light on cancer risk is a study recently published in the Journal of the American Medical Association Oncology
, which shows that these
exposures may increase the risk that firefighters who responded on 9/11 will develop early-onset multiple myeloma or monoclonal gammopathy of undetermined significance (MGUS), a precursor disease that can lead to the blood cancer.
"MGUS is a premalignant condition that typically does not cause symptoms," lead author Ola Landgren, M.D., Ph.D., chief of the myeloma service at Memorial Sloan Kettering Cancer Center (MSK) in New York City, said in an interview with CURE
. "Therefore, individuals affected will not know they have it, unless they check the blood. Depending on several factors, the individual’s risk of progressing to multiple myeloma varies a lot. The lower end of the spectrum is 1 percent risk per year, while individuals with more developed precursor disease, also referred to as 'smoldering myeloma,' can have 75 percent risk of progressing within less than five years. Some of the most advanced cases have a median time to progression of one to two years."
The study included two parts: a case series that examined firefighters who received a diagnosis of multiple myeloma after September 11 and a screening study that included blood samples collected from World Trade Center-exposed firefighters during routine monitoring examinations.
In the cases series, the researchers reviewed the medical records of 16 white male firefighters who were diagnosed with multiple myeloma after 9/11. They determined that the median age at diagnosis was 57 years, which is roughly 12 years younger than that in the national population, noted researchers.
In the screening study, blood samples of 781 white male firefighters older than 50 who were exposed to debris from the World Trade Center were analyzed for MGUS or light-chain MGUS in 2016. Researchers compared them with a population of men in Olmsted County, Minnesota, where the population is predominantly white, who had patterns of myeloma precursor disease and were demographically similar. The researchers found a two-fold significantly higher risk of MGUS among the firefighters.
"For someone diagnosed with myeloma precursor disease, the current guidelines are that, at the initial visit, additional workup is typically done to rule out multiple myeloma," Landgren said. "This depends on one or several of these: blood and urine tests, imaging and bone marrow biopsy. If negative for multiple myeloma, annual blood tests and clinical monitoring is recommended."
Landgren explained that team members were prompted to study this topic further after they learned that several World Trade Center-exposed firefighters and rescue workers had received new diagnoses of multiple myeloma at MSK.
"Our study shows that there is a doubling in the prevalence of myeloma precursor disease among World Trade Center-exposed firefighters compared with the general population," he said. "When we characterize all World Trade Center-exposed firefighters with newly diagnosed multiple myeloma, compared with the general population, we found 10 to 15 years earlier age of onset for multiple myeloma. Also, we found markers of more aggressive myeloma biology to be more common in these patients."
However, Otis Brawley, M.D., chief medical and scientific officer for the American Cancer Society, noted some limitations to the study. "These trials, because of the size of cohort, cannot identify a small increase in cancer risk due to WTC exposure, and correlation does not mean causation," Brawley wrote in commentary simultaneously published with the study.
"In noting the differences, one must appreciate that the firefighting profession is documented to be associated with a higher risk of MGUS and multiple myeloma compared with that of the general population," he continued. "This study comparing firefighters with people from a general population tends to show a higher than true relative risk. It would be preferable to compare the World Trade Center-exposed firefighters with an intensively screened age-matched cohort of firefighters from another big city."
To further their research in this area, investigators plan to include more firefighters, expand the age window below 50 years and use a control study of firefighters not exposed to World Trade Center debris, Landgren explained. In addition, he would like to investigate the risk in people who lived or worked near Ground Zero.
The World Trade Center Health Program, which was established following the passage of the James Zadroga Act
in 2010, works to help monitor and treat those who were directly affected by the 9/11 disaster for related health problems. The services come at no cost.