# Assessment of cancer biomarkers in the Grenfell firefighter cohort study

## TL;DR

This study examines DNA damage in UK firefighters, particularly those who responded to the Grenfell Tower fire, to identify potential cancer biomarkers.

## Contribution

The study is the first to investigate molecular markers of DNA damage in UK firefighters, focusing on cell-free DNA and cancer-related genetic variants.

## Key findings

- Eleven firefighters were found to carry pathogenic DNA variants linked to cancer.
- No association was found between fire smoke exposure and the presence of cancer-related DNA variants.
- The study highlights the potential of cell-free DNA as a biomarker for DNA damage in firefighters.

## Abstract

Firefighters are exposed to a diverse range of harmful substances, including polycyclic aromatic hydrocarbons, benzene, and other carcinogens. These toxic compounds induce DNA damage, often causing the formation of DNA adducts and other lesions that can contribute to the development of various diseases, including cancer. Recent advancements in molecular diagnostics have shown that circulating cell-free DNA (cfDNA) in plasma is a valuable biomarker for detecting DNA damage and disease states. In this study, we explored whether changes in the quantity and quality of plasma cfDNA might reveal DNA lesions or serve as early markers for diseases such as cancer in UK firefighters. Whilst there are few published epidemiological studies of risk of cancer in UK firefighters, there are none on molecular markers in this population. All the 685 firefighters who participated in the study were employed by the London Fire Brigade in 2017; many of them also attended the Grenfell Tower fire, the most devastating fire to occur in the UK in modern history. In this exploratory analysis, we sought to gain insights into the potential long-term health impacts of toxic smoke exposure on these first responders by analysing both the concentration of cfDNA present and specific genetic alterations in cfDNA. Using next-generation sequencing and a panel that detects pathogenic DNA variants linked to various cancers, we analysed a subset of 261 firefighters. Our findings revealed that 11 firefighters carried pathogenic DNA variants associated with cancer, but we found no association between fire smoke exposure and the presence of these variants.