Laryngeal cancer and silica dust exposure: A systematic review and meta-analysis

Individual epidemiological studies generally lack the power to examine the association between silica exposure or silicosis and laryngeal cancer. In this study, the authors summarised pertinent evidence from published literature by using meta-anal. A systematic literature search was performed to identify cohort and case-control studies, and the method of meta-analysis was used to combine standardised mortality ratios (SMRs) or standardised incidence ratios (SIRs) from cohort studies and odds ratios (ORs) from case-control studies. A significantly increased risk of laryngeal cancer (pooled OR ) 1.39, 95% confidence interval (95% CI): 1.17-1.67) among workers exposed to silica dust was observed by combining six case-control studies with adjustment for smoking and alcohol consumption. A similarly increased but statistically non-significant risk estimate was observed from cohort studies, with a pooled SMR of 1.38 (95% CI: 0.79-1.96) for silicosis cases; and a pooled SMR of 1.13 (95% CI: 0.82-1.45) and a pooled SIR of 1.50 (95% CI: 0.59-2.42) for workers with silica dust exposure. The authors concluded that this systematic review demonstrated a weak association between silica or silicosis and laryngeal cancer. Owing to the inherent limitations of the original studies, interpretation of the results of this meta-analysis should be cautious.