Esophagus cancer and occupational exposure to asbestos: results from a meta-analysis of epidemiology studies

Abstract

The relationship between occupational asbestos exposure and esophagus cancer (EC) is not fully understood. We performed a meta-analysis to quantitatively assess the association. We systematically searched databases of PubMed, EMBASE, and Web of Science for studies with quantitative estimates of asbestos exposure and EC mortality. Pooled standardized mortality ratios (SMRs) and their corresponding 95% confidence intervals (CIs) were calculated. Twenty cohort studies on EC and asbestos exposure were included in this meta-analysis. Overall, occupational exposure to asbestos was associated with an excess risk of EC (SMR = 1.24, 95% CI: 1.13-1.38, P < 0.001), with little evidence of heterogeneity among studies (I(2) = 0.0%, P = 0.682). Being male, exposure to chrysotile or mixed asbestos, working at textile industry, long study follow-up (≥20 years), Asia, Europe and America cohorts with larger cohort size (>500), and high-exposure group all contribute to significantly higher SMR. Publication bias was not detected (Egger's test P-value = 0.374). This meta-analysis suggested that occupational asbestos exposure might be associated with an increased risk of EC in male. High-exposure level of asbestos could contribute to significantly higher risk of EC mortality.

Cancer mortality in a population exposed to nephrite processing

“…The International Agency for Research on Cancer (IARC) Working Group concluded that asbestos causes mesothelioma and cancer of the lung and larynx 3. Positive associations have been observed between exposure to all forms of asbestos and cancer of the pharynx,30 31 hypopharynx,32 larynx,33 34 oesophagus35 36 and stomach 37 38. In this study, we observed that nephrite processing increases the mortality risk from cancer in the same sites.…”

Meta-Analysis of the Association between Asbestos Exposure and Esophageal Cancer

“…Based on description from Institute of Medicine (US) Committee on Asbestos in 2006, the evidence related to association between asbestos and esophageal cancer was insufficient [ 54 ]. In contrast, Li et al had conducted a meta-analysis through 20 cohort studies and they found positive association between esophageal cancer and asbestos exposure [ 55 ]. However, we made a more comprehensive search from 1963 to 2017, and finally included 34 studies which generated 36 SMR for meta-analysis.…”

Cancer of the esophagus and asbestos exposure

“…A meta‐analysis conducted in 2006 and based on 25 cohort studies and three case‐control studies, showed neither a link nor a dose‐effect relationship between asbestos exposure and esophageal cancer . Nevertheless, a recent meta‐analysis by Li et al based on 20 studies of esophageal cancer mortality among workers exposed to asbestos, published between 1988 and 2014, concluded that high levels of asbestos exposure could contribute to significantly elevated risks of mortality from esophageal cancer. The authors demonstrated an elevated risk in the pooled estimate for esophageal cancer mortality in relation to asbestos exposure (SMR = 1.24 [1.12‐1.37]).…”

“…Indeed, according to the IARC (International Agency for Research on Cancer), this association is uncertain. Nevertheless, a meta‐analysis, conducted in 2016 concluded that high levels of exposure to asbestos may contribute toward a significantly higher risk of mortality from esophageal cancer.…”