Cancer risks of firefighters: a systematic review and meta-analysis of secular trends and region-specific differences

Abstract

Purpose The objective of this study was to conduct a systematic review and meta-analysis to evaluate the cancer risks among firefighters in the time course and from different geographical areas. Method A PubMed search was performed to identify cohort studies about cancer risk and firefighting presented with standardized incidence ratios (SIRs) or standardized mortality ratios (SMRs). Using random-effect models, meta-relative risk estimates (mSIRs, mSMRs) and 95% confidence intervals (CI) were assessed. Cohort studies with employment starting before 1950 were classified as "old", studies starting between 1950 and 1970 as "medium", and later studies as "new". Results The general cancer risk of firefighters was similar to the general population, but mSMR decreased over time (new studies: mSMR = 0.81, 95% CI 0.70-0.92). We observed an increase of mSIR for melanoma of the skin and prostate cancer as well as a decrease of mSIR for stomach cancer with later employment onset. For those cancer sites, we did not observe a secular trend of mSMRs. Regional differences between relative cancer risks were particularly observed for bladder cancer. Conclusions Among other things, innovative firefighting techniques and better personal protective equipment have provided a safer and healthier working environment for firefighters over time leading to a reduction of overall cancer incidence and mortality ratios. Increased general preventive medical checkups and possible additional screenings for firefighters might have led to more findings of malignant melanoma of the skin and prostate cancer in the recent past.

Temporal Aspects of the Association between Exposure to the World Trade Center Disaster and Risk of Skin Melanoma

“…The WTC combined Rescue/Recovery cohort includes firefighters, law enforcement and construction workers. An increased risk of melanoma has consistently been reported in previous studies of firefighters (Casjens et al, 2020) and police officers (Finkelstein, 1998, Forastiere et al, 1994, Harris et al, 2018, while results of studies of construction workers are mainly negative (Alicandro et al, 2020, Gallagher et al, 1987, Hakansson et al, 2001, Robinson et al, 1995. Workplace exposure to UV radiation has been suggested to explain these findings, since other occupational groups with opportunity of UV exposure, such as offshore workers (Stenehjem et al, 2017), airline pilots and cabin crews (Sanlorenzo et al, 2015), and agricultural workers (Kachuri et al, 2017) also experience an increased incidence of melanoma.…”

A Systematic Review of the Antimony Content of the Normal Human Prostate Gland

“…As mentioned above, an ingestion of Sb by humans can cause a variety of disorders, such as irritation of the eyes, severe vomiting, diarrhea, skin lesions, lung diseases, heart problems, stomach ulcers [67,70] and different types of cancers, including PCa [31][32][33][34]. In spite of a significant correlations between Sb exposure and the risk of PCa have been There are some limitations in our study, which need to be taken into consideration when interpreting the results of this review.…”

“…Furthermore, experimental and epidemiological data identified that Sb compounds should be considered as genotoxic carcinogens [30][31][32][33][34]. Consequently, the International Agency for Research on Cancer (IARC) has evaluated Sb as possibly carcinogenic to humans (Group 2B) [35].…”

“…Recorded observations range from a deficiency state, through normal function as biologically essential components, to an imbalance, when excess of one element interferes with the function of another, to pharmacologically active concentrations, and finally to toxic and even life-threatening concentrations [36][37][38]. In this context, for example, low dose of Sb has some useful effects on health, but significant exposure to this metalloid may result in adverse health effects in different organs or tissues, including malignancy such as Non-Hodgkin's lymphoma and melanoma, cancer of the lung, colon, rectum, bladder, thyroid, pleura, testis and PCa [31][32][33][34].…”

“…Pg. no.-24 reported[31][32][33][34], precise molecular mechanisms by which this metalloid causes healthy cells to transform to malignant states have yet to be fully defined. Possibly, production of active oxygen species and/or DNA repair inhibition are mechanisms involved[30].…”