Ever since the September 11 attack on the World Trade Center (WTC), there have been mounting concerns that rescue and recovery workers at the site were exposed to hazardous materials that could cause long-term damage to their health. Now research led by Memorial Sloan Kettering shows that firefighters present at Ground Zero in the immediate aftermath may be at an increased risk for developing a blood cancer called multiple myeloma.
The study, published today in JAMA Oncology, reveals that firefighters at the scene were nearly twice as likely to have a multiple myeloma precursor condition called monoclonal gammopathy of undetermined significance (MGUS). This is the first comprehensive study showing that WTC first responders are at higher risk for MGUS. In addition, the researchers found that they may be at a higher risk for developing multiple myeloma at an earlier age, as well as a more lethal form of the disease.
“Although MGUS will not necessarily lead to multiple myeloma, it is always present as a preliminary stage before someone develops the disease,” says Ola Landgren, Chief of MSK’s Myeloma Service, who led the study. “It can serve as an early warning.”
In 2015, Dr. Landgren published research showing that exposure to Agent Orange, an herbicide that was widely used during the Vietnam War, also increases the risk of having MGUS and multiple myeloma. The new study provides more evidence supporting the idea that multiple myeloma can be triggered by environmental factors.
Rescue and recovery workers may have been exposed to known carcinogens in the dust from the collapsed buildings and from diesel smoke emitted by heavy equipment used in the search. The findings suggest that these first responders should consider being checked for MGUS. The condition, which is marked by elevated levels of a protein called M protein, can be detected with a simple blood test.
“The clinical guidelines for multiple myeloma don’t currently address being tested for MGUS,” Dr. Landgren says. “But for people who spent significant amounts of time around the recovery site, it is reasonable for them to speak with their primary care physician about being checked for this precursor condition. This could apply even to people who didn’t work at the site but lived or worked nearby at the time.”
Most people with MGUS remain well for many years without developing multiple myeloma. But Dr. Landgren says that anyone who learns they have MGUS should have their protein levels monitored going forward through annual blood tests to watch for multiple myeloma. This monitoring can typically be done by a primary care doctor. If multiple myeloma is suspected, further diagnostic tests, including imaging, blood, urine, and bone marrow tests, would be recommended.
Multiple Myeloma: A Slow-Moving But Incurable Cancer
Multiple myeloma, the second most common blood cancer among adults, arises from a type of white blood cell called a plasma cell. The disease usually is treated with chemotherapy, immune-modifying drugs or other medications, or stem cell transplantation. It can be held at bay for many years but there is no cure. When it relapses, it becomes resistant to further treatment.
Although there are currently no drugs approved to treat MGUS, close monitoring could still benefit someone who eventually develops multiple myeloma. A 2015 study led by Dr. Landgren showed that people with MGUS who develop multiple myeloma during clinical monitoring have better overall survival and fewer complications than those who never received an MGUS diagnosis. This is likely because treatment of multiple myeloma begins sooner, which makes it more effective.
Increased Risk and Earlier Onset
In the study, the researchers screened blood samples from 781 WTC-exposed male firefighters. As a comparison population, they used published data on MGUS from a group of 7,612 men in Minnesota.
The firefighters had enrolled in the WTC Health Program to receive physical and mental health services and consented to have blood samples analyzed for research. The samples were tested at MSK.
The researchers found that the prevalence of MGUS in this group was approximately twice as high as in the comparison group. The rate in the study group was 7.73 per 100 people compared with 4.34 in the comparison group.
A second part of the study looked at all firefighters at the WTC site who had developed multiple myeloma between September 11, 2001, and July 1, 2017. The median age of onset for the disease was 57 years — about 15 years earlier than the general population. The firefighters also were more likely to have aggressive types of the disease compared with the overall myeloma population.
“It’s possible that specific environmental factors can cause specific subtypes of myeloma — including those that are more or less aggressive,” Dr. Landgren says.