Meta-Analysis of Incidence and Mortality of Firefighter Cancer: An Update on Emerging Science.

backgroundFirefighters are faced with a broad range of toxic exposures during their work, including known and suspected carcinogens. The current study is an update to the previously published meta-analysis of cancer risk among firefighters by Soteriades and colleagues, and focuses on studies published from 2008 to 2020.

methodsA comprehensive search of the literature was conducted, including electronic databases and bibliographies of recently published papers. Analyses include stratification of studies conducted in the United States (US) versus other countries. Cancer incidence and mortality rates were compared to the relevant general population. Random effects models were used to calculate summary risk estimates and their 95% confidence intervals.

resultsA total of 24 studies were included in the meta-analysis. Among the 42 cancer types covered, incidence was associated with firefighting in US samples for colon, kidney, large intestine, pleura, and prostate cancer, as well as malignant melanoma. There was an increased incidence of Hodgkin's Disease and malignant melanoma and a significantly lower risk of kidney cancer for non-US samples. Significant cancer mortality estimates for US samples included oral/buccal/mouth, other parts of the buccal cavity, pharynx, colon, esophagus, large intestine, lung, Non-Hodgkin's Lymphoma, pancreas, pleura, rectum, and soft tissue sarcoma. No cancer had a significantly higher rate of mortality among non-US samples.

conclusionsThe findings underscore the global cancer burden among firefighters, and indicate that geographically stratifying studies afford a more nuanced risk perspective. Further research should investigate why US firefighters exhibit higher cancer mortality rates compared to international counterparts.