A recent systematic review and meta-analysis has examined the relationship between occupational asbestos exposure and three gastrointestinal (GI) cancers: esophageal, stomach, and colorectal cancer. This comprehensive study analysed 192 research papers published through March 2024, representing the most thorough assessment of this relationship to date.
Key Findings
The meta-analysis revealed significant elevated risks for all three GI cancers associated with occupational asbestos exposure:
- Esophageal cancer: 17% increased risk (mRR 1.17, 95% CI 1.07-1.29)
- Stomach cancer: 14% increased risk (mRR 1.14, 95% CI 1.05-1.23)
- Colorectal cancer: 16% increased risk (mRR 1.16, 95% CI 1.08-1.24)
Importantly, the risk was substantially higher among workers with greater asbestos exposure:
- For those with the highest exposure levels, the risk increased to 63% for esophageal cancer, 28% for stomach cancer, and 29% for colorectal cancer
- Asbestos insulation workers faced even higher risks, with increases of 68%, 53%, and 59% for esophageal, stomach, and colorectal cancers, respectively
Clinical Significance
These findings have significant implications for occupational health and cancer prevention:
- Screening: Workers with a history of asbestos exposure may benefit from earlier and more frequent GI cancer screenings.
- Risk assessment: Occupational history should be considered when evaluating a patient’s cancer risk profile.
- Prevention: The results underscore the importance of strict asbestos exposure controls in workplaces where it’s still present.
- Workers’ compensation: The study provides strong evidence to support compensation claims for GI cancers among workers with documented asbestos exposure.
Research Context
This study builds upon previous reviews by international organisations, including IARC (2009), IOM (2006), and FIOH (2014), which found suggestive but limited evidence for these associations. The current findings provide additional evidence regarding the potential relationship between occupational asbestos exposure and these GI cancers.
Implications
The research suggests that occupational asbestos exposure may be associated with increased risk of esophageal, stomach, and colorectal cancers. The consistency of findings across different exposure metrics and the presence of exposure-response relationships may have implications for workplace safety practices and health monitoring for asbestos-exposed workers.
These findings contribute to the ongoing scientific understanding of potential health effects associated with occupational asbestos exposure beyond the well-established links to mesothelioma and lung cancer.