Rescue and recovery workers exposed to debris at the World Trade Center after the Sept. 11 terror attacks may have higher rates of some cancers, though there appears to be no increase in the disease overall, a study found.
The workers were more likely than the general population to have multiple myeloma, a cancer of the bone marrow, and tumors of the prostate and thyroid, according to a study Tuesday in the Journal of the American Medical Association. The research, though, didn't find an increase in the total number of cancers.
While the finding doesn't prove a definitive link between the cancers and toxins, the dust, smoke and particles released contained known and suspected carcinogens such as asbestos, silica and benzene, raising public health concerns. The data, which looked at cases between 2007 and the end of 2008, are based on a short follow-up time, considering malignancies can take decades to develop, said Steven Stellman, a study author.
"We can't find any specific link to cancer in our study and World Trade Center exposure, we can only discuss the plausibility in carcinogenic exposures," said Stellman, an epidemiology professor at Columbia University in New York, in a telephone interview. "As time goes on, people get older and rates of cancer will naturally increase. With time, we will have more technical statistical power to see if anything is there."
$1.5 BILLION FUND
After months of debate in Washington earlier this year, cancer was added to the list of illnesses covered by the World Trade Center Health Program. The $1.5 billion federal fund created in 2011 provides medical care for specific symptoms and illnesses related to exposure at the Sept. 11 disaster sites. Only one other study has looked at cancer rates in first responders. That research, published last year in the journal Lancet, found a 19 percent higher risk for cancer among 10,000 New York City firefighters who worked at the World Trade Center site following the attack.
The cancer treatment costs may total $181 million by 2016, based on an assumption that members of the fund are 21 percent more likely to have the disease than the general population, according to a September report by the National Institute for Occupational Safety and Health.
The study released Tuesday found 1,187 incidents of cancer among a database of almost 22,000 rescue and recovery workers and 34,000 others exposed to the wreckage that were enrolled in the World Trade Center Health Registry. Among those cancer cases, 439 were workers.
While some cancers were more common among the rescue and response workers, others were less frequent. There was a lower incidence rate of lung tumors than seen in the general population, a finding that surprised researchers even when accounting for the fact that firefighters typically have lower rates of tobacco use, Stellman said.
"Given the relatively short follow-up time and lack of data on medical screening and other risk factors, the increase in prostate and thyroid cancers and multiple myeloma should be interpreted with caution," researchers said in the study. "The etiological role of WTC exposures in these 3 cancers is unclear. Longer follow-up of rescue/recovery workers and participants not involved in rescue/recovery is needed with attention to selected cancer sites and to examine risk for cancers with typically long latency periods."