Epigenetic modifications associated with occupational exposure to lung carcinogens: a systematic review

The number of recognized occupational lung carcinogens has grown substantially over time, and, despite regulations and technological progress, exposure levels have gradually increased. This ongoing burden of occupational cancer highlights gaps between regulations and real-world conditions, emphasizing the need for better early risk detection and biological monitoring of exposed workers. MiRNAs and long non-coding RNAs have emerged as promising non-invasive biomarkers reflecting early carcinogenic mechanisms. Thus, this systematic review critically evaluates the available evidence on biomarker’s changes in response to lung carcinogens exposure, assessing their potential role in early detection and prevention within occupational medicine. Applying the PRISMA workflow 29 studies were selected. The main carcinogen investigated was asbestos ( n = 20), followed by chromium VI, diesel exhaust exposure (DEE), polycyclic aromatic hydrocarbons, nickel, titanium, and radon. A total of 45 distinct miRNAs were analyzed. Among those, miR-103a-3p was consistently downregulated across multiple studies and may improve diagnostic performance when combined with established protein markers such as mesothelin. In chromium-exposed workers, downregulation of tumor-suppressive miRNAs such as miR-142-3p and miR-15b-5p was observed. DEE was linked to upregulation of oncogenic miRNAs (miR-106a-3p, miR-92a-3p) and downregulation of tumor suppressors (miR-122-5p, miR-191-5p). Despite the limitations identified in this review, the epigenetic alterations observed in the present study are largely consistent with those previously reported in the literature in association with lung cancer. These findings suggest their potential utility as early biomarkers of disease. However, future research should prioritize well-designed longitudinal studies within occupational cohorts, for identifying robust multi-marker signatures rather than isolated biomarkers.