Better understanding of carcinogenic exposures may decrease skin cancer incidence among firefighters
A high percentage of young firefighters in Florida developed skin cancer, suggesting the potential for elevated risk in this population, according to a research letter published in JAMA Dermatology.
“The increased skin cancer rates and earlier presentation may be attributable to carcinogenic occupational exposures; however, nonwork-related ultraviolet light exposure may also contribute. Better understanding of these carcinogens is needed to inform best practices for protection,” Alberto J. Caban-Martinez, DO, PhD, MPH, CPH, public health researcher with Sylvester Comprehensive Cancer Institute at University of Miami Health System, and colleagues wrote.
Although previous research has identified traces of carcinogenic chemicals on firefighter skin and gear following fire-incident response, limited data exist on the association of occupational hazards on skin cancer risk in this population.
Caban-Martinez and colleagues examined skin cancer history, skin cancer screening and sun protection habits among 2,399 active Florida firefighters (median age, 41.7 years; median employment as a firefighter, 15.1 years). Firefighters were invited to complete the 127-item comprehensive Annual Cancer Survey using a secure iPad device during regular work shifts.
The researchers analyzed standardized subjective measures that assessed for doctor-diagnosed skin cancer, type of skin cancer, frequency of sunburn, tanning bed use, health insurance status, skin cancer screening behavior, sociodemographic characteristics and job characteristics.
Investigators reported 109 cases of skin cancer during the first 12 months of data collection. Researchers reported a much higher rate of melanoma diagnosis among firefighters (0.7%) than that reported among Florida adults in other epidemiologic studies (0.011%).
Moreover, the median age of melanoma diagnoses was 42 years among the firefighters in the study vs. 64 years among the general U.S. population.
HemOnc Today spoke with Caban-Martinez about the study results, the potential explanations for the increased prevalence of skin cancer among firefighters, and the interventions that should be implemented to reduce skin cancer risk in this population.
Question: What prompted this research?
Answer: This research was very organic, as it came through the request of Florida firefighters themselves. Our senior faculty member at University of Miami, Erin N. Kobetz, PhD, MPH, met with the Florida firefighters and they figured out a strategy to assess how the work environment among first-responder firefighters could be contributing to the increased skin cancer risk. Normally, at the national level, the research interests have been focused on cardiovascular disease among firefighters. In more recent years, interest has shifted to cancer. We are seeing at the national and even international level that the data replicate the same findings in the United States — certain cancer types are slightly more elevated among firefighters compared with the general population.
Q: How did you conduct the research?
A: This particular study was based upon data from the Annual Cancer Survey (ACS), which stemmed from an idea of ours to develop a cohort of firefighters that we could follow so we could document their baseline experience with cancer, cancer screening behaviors, health status and occupational exposures. We follow up with them once per year. The ACS is now in its third year. When we started, we focused primarily on South Florida because it was our local area. During the second year, we branched up further north toward the Florida panhandle, so the ACS slowly but surely is capturing firefighters across the state.
Q: What are the potential explanations for the increased prevalence of skin cancer among firefighters?
A: One idea is that fires produce chemicals when materials burn, and those materials contain known carcinogens. We, therefore, think that exposure to fires is contributing to the increase in melanoma incidence. Another idea is that flame retardants that firefighters use to douse out flames also contain certain chemicals that are known carcinogens. The low-dose, chronic exposure to some of these particulates may contribute to the increased rates of skin cancer among firefighters.
Q: What are the potential explanations for firefighters being diagnosed at younger ages than the general population?
A: Firefighters start their career early in life. They also conduct a lot of training in between shifts, and that is conducted outdoors. There has to be some sort of mechanism contributing to the earlier diagnosis. It could be synergistic with the sun, given we spend a lot of time outdoors in Florida. We have other studies in which we are measuring environmental exposures and are having firefighters wear wristbands so we can try to figure out the types of carcinogens and how much of them they come across. We hope we can physically see the chemicals and know the quantity of them so we can identify more of what is contributing to this increase.
Q: Now that we have this information, should there be interventions developed for this population?
A: There are three major stakeholders. First, health care providers should conduct annual full-body skin examinations of all firefighters. Firefighters are required to have annual physicals; however, every department is different in terms of what they include in those physicals. Second, the families and spouses of firefighters should help by encouraging firefighters to get full-body skin exams. Finally, firefighters themselves should encourage each other to get skin exams.
Q: What should happen next in terms of additional investigations or analyses to further clarify the potential association between firefighters and skin cancer?
A: First, our data have to be followed longer term. Second, we have to dig deeper to understand the physiology of when a carcinogen lands on the skin of a firefighter, how it enters the skin and how it is accelerating the presence of that melanoma or any type of cancer that develops in the skin.
Q: Is there anything else that you would like to mention?
A: I encourage physicians to look at the causes of the work environment and how they contribute to cancer diagnoses, particularly among firefighters. – by Jennifer Southall
For more information:
Alberto J. Caban-Martinez, DO, PhD, MPH, CPH, can be reached at Sylvester Comprehensive Cancer Institute, University of Miami Health System, 1475 N.W. 12th Ave., Miami, FL 33136; email: firstname.lastname@example.org.
Disclosure: Caban-Martinez reports no relevant financial disclosures.