Mortality in a cohort of asbestos-exposed workers undergoing health surveillance

Occupational asbestos exposure and urinary bladder cancer: a systematic review and meta-analysis

PURPOSE

There is conflicting evidence on the association between asbestos exposure and bladder cancer. We performed a systematic review and meta-analysis to provide evidence on occupational asbestos exposure and the risk of mortality and incidence of bladder cancer.

METHODS

We searched three relevant electronic databases (Pubmed, Scopus, and Embase) from inception to October 2021. The methodological quality of included articles was evaluated using the US National Institutes of Health tool. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) for bladder cancer, as well as respective 95% confidence intervals (CIs), were extracted or calculated for each included cohort. Main and subgroup meta-analyses according to first year of employment, industry, sex, asbestos type, and geographic region were performed.

RESULTS

Fifty-nine publications comprising 60 cohorts were included. Bladder cancer incidence and mortality were not significantly associated with occupational asbestos exposure (pooled SIR: 1.04, 95% CI: 0.95-1.13, P = 0.000; pooled SMR: 1.06, 95% CI: 0.96-1.17, P = 0.031). Bladder cancer incidence was higher among workers employed between 1908 and 1940 (SIR: 1.15, 95% CI: 1.01-1.31). Mortality was elevated in asbestos workers cohorts (SMR: 1.12, 95% CI: 1.06-1.30) and in the subgroup analysis for women (SMR: 1.83, 95% CI: 1.22-2.75). No association was found between asbestos types and bladder cancer incidence or mortality. We observed no difference in the subgroup analysis for countries and no direct publication bias evidence.

CONCLUSION

There is evidence that workers with occupational asbestos exposure have a bladder cancer incidence and mortality similar to the general population.

The association between occupational asbestos exposure with the risk of incidence and mortality from prostate cancer: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence on the association between asbestos exposure and prostate cancer (PCa). Two recent meta-analyses have claimed that exposure is associated with increased PCa incidence and mortality, but they suffer from some methodological flaws. Given the potential importance of this research question, we aimed to perform a methodologically sound systematic review and meta-analysis to investigate the association between occupational asbestos exposure and the incidence of and mortality from PCa.

METHODS

We followed PRISMA guidelines to systematically search for pertinent articles in three relevant electronic databases: Pubmed, Scopus, and Embase, from their inception to July 2020. The methodological quality of included articles was evaluated using the US National Institutes of Health tool. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) for PCa, as well as respective 95% confidence intervals (CIs), were extracted or calculated for each included cohort. Main and subgroup meta-analyses according to first year of employment, industry, asbestos type, and geographic region were performed.

RESULTS

Sixty-five articles comprising 68 cohorts were included. PCa incidence and mortality were not significantly associated with occupational asbestos exposure (pooled SIR: 1.06, 95% CI: 1.00-1.13, P = 0.062; pooled SMR: 1.03, 95% CI: 0.99-1.06, P = 0.115). PCa incidence was higher among workers employed after 1960 (SIR: 1.10, 95% CI: 1.01-1.20). Pooled SIR was elevated in European (SIR: 1.09, 95% CI: 1.01-1.18) and UK cohorts (SIR: 1.05, 95% CI: 1.02-1.09). Mortality was elevated in North American cohorts (SMR: 1.06, 95% CI: 1.02-1.10). Studies of lower methodological quality appeared to yield elevated SIRs or SMRs.

CONCLUSIONS

This systematic review and meta-analysis provides evidence that men with occupational asbestos exposure have a PCa incidence and mortality similar to that of the general population. Temporal and geographical variables seem to be related to higher SMR or SIR.

Prostate Cancer and Asbestos: A Systematic Review and Meta-Analysis

INTRODUCTION

Asbestos-related diseases and cancers represent a major public health concern.

OBJECTIVE

To conduct a systematic review and meta-analysis to demonstrate that asbestos exposure increases the risk of prostate cancer.

METHODS

The PubMed, Cochrane Library, Embase, and ScienceDirect databases were searched using the keywords (prostate cancer OR prostatic neoplasm) AND (asbestos* OR crocidolite* OR chrysotile* OR amphibole* OR amosite*). To be included, articles needed to describe our primary outcome: Risk of prostate cancer after any asbestos exposure.

RESULTS

We included 33 studies with 15,687 cases of prostate cancer among 723,566 individuals. Asbestos exposure increased the risk of prostate cancer (effect size = 1.10, 95% confidence interval [CI] = 1.05-1.15). When we considered mode of absorption, respiratory inhalation increased the risk of prostate cancer (1.10, 95% CI = 1.05-1.14). Both environmental and occupational exposure increased the risk of prostate cancer (1.25, 95% CI = 1.01-1.48; and 1.07, 1.04-1.10, respectively). For type of fibers, the amosite group had an increased risk of prostate cancer (1.12, 95% CI = 1.05-1.19), and there were no significant results for the chrysotile/crocidolite group. The risk was higher in Europe (1.12, 95% CI = 1.05-1.19), without significant results in other continents.

DISCUSSION

Asbestos exposure seems to increase prostate cancer risk. The main mechanism of absorption was respiratory. Both environmental and occupational asbestos exposure were linked to increased risk of prostate cancer.

CONCLUSION

Patients who were exposed to asbestos should possibly be encouraged to complete more frequent prostate cancer screening.

Cancer incidence in a cohort of asbestos-exposed workers undergoing health surveillance

OBJECTIVES

To compare a local cohort of 2488 men occupationally exposed to asbestos and enrolled in a public health surveillance program with the 1995-2009 cancer incidence of the general population of Friuli Venezia Giulia (FVG) region, Northeast Italy, we conducted a historical cohort study.

METHODS

Standardized incidence ratios (SIRs), with 95% confidence interval (95% CI), for specific cancer sites were estimated in the cohort and in subgroups of workers employed in shipbuilding between 1974 and 1994. For internal comparisons, we calculated incidence rate ratios (IRRs) for all cancers, lung cancer and mesothelioma, by level of exposure to asbestos and sector of employment adjusted for smoking habits and age at start of follow-up.

RESULTS

Among cohort members the SIR was 8.82 (95% CI 5.95-12.61) for mesothelioma and 1.61 (95% CI 1.26-2.04) for lung cancer. In subgroup analyses, the SIR for lung cancer in subjects hired in shipbuilding between 1974 and 1984 was 2.09 (95% CI 1.32-3.13). In the overall cohort, a borderline increased incidence was also found for stomach cancer (SIR = 1.53 95% CI 0.96-2.31). Internal comparisons within the cohort show that among men with high asbestos exposure level the relative risk was almost threefold for lung cancer (IRR = 2.94 95% CI 1.01-8.57).

CONCLUSIONS

This cohort experienced an excess in the incidence of both mesothelioma and lung cancer, showing increasing incidence rates at higher level of asbestos exposure. For lung cancer, the relative incidence was highest among workers hired in shipbuilding between 1974 and 1984.