Objectives Although epidemiological studies have generally shown inconsistent findings for prostate cancer risk and occupation, some associations with firefighting have been observed. Firefighters are exposed to harmful substances that include known carcinogens. This meta-analysis aimed to synthesise the available published evidence on prostate cancer risk in firefighters.

Methods A comprehensive search of PubMed and Web of Science was conducted for all epidemiological studies on firefighting and prostate cancer published in English from 1980–2017. Studies that reported on risk estimates for incidence and/or mortality with corresponding ever/never employment were extracted from included studies. Meta risk estimates (mRE) were determined in a random effects model and between-study heterogeneity was evaluated based on I² values.

Results Of the 101 studies retrieved, 25 firefighter studies were included in this analysis. Ever employment as a firefighter, based on results from all studies, was associated with a 15% increase in prostate cancer risk (95% CI 1.04–1.27, I²=71%). By study design, the mRE was 1.14 (95% CI 1.03–1.26, I²=67%) for 18 cohort studies and 1.22 (95% CI 0.90–1.67, I²=82%) for 5 case-control studies. Incidence studies had an mRE of 1.17 (95% CI 1.07–1.28, I²=74%) and mortality studies had an mRE of 1.12 (95% CI 0.92–1.36, I²=50%). For linkage and registry-based studies, an mRE of 1.19 (95% CI 1.05–1.33, I²=61%) was observed. Estimates showed moderate to substantial heterogeneity.

Conclusions This analysis showed evidence of a small excess risk of prostate cancer in firefighters across study designs. Further evaluation of heterogeneity, potential biases, and quality assessment are currently underway.