February 2025: Asbestos is classified as carcinogenic to humans by the WHO’s International Agency for Research on Cancer (IARC) and identified as a specific cause of pleural and peritoneal mesothelioma and cancers of the lung, larynx and ovary, primarily among occupationally exposed workers. Epidemiological evidence for occupational asbestos exposure as a cause of gastrointestinal cancers among workers has been suggestive, limited or inadequate. The objective of this work was to conduct a systematic review and meta-analyses of occupational asbestos exposure and esophageal, stomach and colorectal cancer risk, including a critical exposure assessment approach.
Key findings:
- A total of 82 (esophageal), 153 (stomach), and 144 (colorectal) papers met the inclusion criteria for the systematic review.
- Elevated meta-relative risk (mRR) estimates were observed for any occupational asbestos exposure for esophageal (1.17 (95% CI 1.07 to 1.29)), stomach (1.14 (95% CI 1.05 to 1.23)), and colorectal cancer (1.16 (95% CI 1.08 to 1.24)).
- There was consistency of mRR estimates and higher mRRs in meta-analyses where there was increased confidence in the categorization of highly exposed workers, including among the highest exposed workers in exposure-response studies, among asbestos insulation workers, and among workers in cohorts with a twofold or greater risk of asbestos-related lung cancer.
- The meta-analyses support a causal link between occupational asbestos exposure and the risk of esophageal, stomach, and colorectal cancer.
Read more in Occupational and Environmental Medicine.
