Asbestos Exposure and Ovarian Cancer: A Meta-analysis

Our plain-English summary of Asbestos Exposure and Ovarian Cancer: A Meta-analysis, by S.Y. Kim, H.K. Chang, O. Kwon, et al (Safety and Health at Work, 2024).

The study

• Authors: S.Y. Kim, H.K. Chang, O. Kwon, J. Park, J.P. Myong
• Journal: Safety and Health at Work
• Published: 2024;15(1):1-8
• Type of article: Review
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: The International Agency for Research on Cancer (IARC) Monograph conducted a systematic review of the relationship between asbestos and ovarian cancer. However, there may have been information bias due to the undue weight given to few articles. To address this limitation, the present study performed a meta-analysis integrating studies published both before and after the 2012 IARC Monograph on Asbestos, with the aim of investigating the association between asbestos exposure and ovarian cancer.

Methods: A comprehensive search of major journal databases was conducted to identify studies examining the relationship between asbestos exposure and ovarian cancer, including those featured in the 2012 IARC Monograph on Asbestos. A meta-analysis on asbestos exposure and cancer risk was performed.

Results: The meta-analysis of studies published after the 2012 IARC Monograph on Asbestos found a summary Standardized Mortality Ratio (SMR) of 2.04 (95% CI: 1.03-4.05; p = 0.0123; 5 studies), with a significant degree of heterogeneity among the studies (I2 = 72.99%). The combined analysis of 15 studies before and after the 2012 IARC Monograph showed an overall summary SMR of 1.72 (95% CI: 1.43-2.06; p = 0.0349; 15 studies), with a moderate degree of heterogeneity (I2 = 42.99%).

Conclusion: This meta-analysis provides evidence of a significant association between asbestos exposure and ovarian cancer mortality. While the possibility of misdiagnosis in earlier studies cannot be completely ruled out, recent findings suggest a robust correlation between asbestos exposure and ovarian cancer. This highlights the importance of sustained efforts to minimize asbestos exposure and protect public health.

© 2024 Occupational Safety and Health Research Institute. Published by Elsevier B.V. on behalf of Institute, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency.

In plain English

This review article was a meta-analysis, which pooled results from earlier studies. In July 2022 the authors searched PubMed, EMBASE and the Cochrane Library, and added cohort studies listed in the 2012 IARC Monograph on asbestos. They included 17 studies published between 1982 and 2022, covering more than 73,797 participants from nine countries. The main fibers were chrysotile, crocidolite and amosite, and most cohorts were occupational. Pooling 15 studies from before and after the 2012 Monograph, the summary standardized mortality ratio (SMR) for ovarian cancer was 1.72 (95% CI 1.43 to 2.06), with moderate variation between studies. Pooling five studies published after the Monograph gave a summary SMR of 2.04 (95% CI 1.03 to 4.05), with high variation between studies. Leaving out a cohort of wives of asbestos cement factory workers gave 1.74 (95% CI 1.44 to 2.10). Non-occupational and incidence studies were too few to pool. The authors concluded there was a significant association between asbestos exposure and ovarian cancer mortality. They noted that many included studies did not account for other ovarian cancer risk factors, and that the underlying studies lacked pathology findings from the time of diagnosis.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Review article: systematic literature search and meta-analysis of cohort studies (fixed-effect and random-effects models)
• Who was studied: 17 cohort studies published 1982 to 2022, reporting data from 1941 to 2015, with more than 73,797 participants from nine countries
• Exposure: Asbestos exposure, mainly chrysotile, crocidolite and amosite, in occupational cohorts and a few non-occupational cohorts
• Main results:
  • Fixed-effect analysis of 15 studies from before and after the 2012 IARC report: summary SMR for ovarian cancer 1.72 (95% CI 1.43 to 2.06)
  • Heterogeneity in the 15-study analysis: I2 42.99%. The p-value of 0.0349 belongs to this heterogeneity test.
  • Random-effects analysis of 5 more recent studies: summary SMR for ovarian cancer in asbestos-exposed cohorts 2.04 (95% CI 1.03 to 4.05), with high heterogeneity. The p-value of 0.0123 belongs to the heterogeneity test.
  • Excluding Ferrante et al (2007), which included nonoccupational exposures, the summary SMR was 1.74 (95% CI 1.44 to 2.10)
  • Egger's test for publication bias in the 15-study analysis: p = 0.1830
• The authors' conclusion: The authors concluded that the meta-analysis provides evidence of a significant association between asbestos exposure and ovarian cancer mortality, while misdiagnosis in earlier studies cannot be completely ruled out.
• Limitations the authors state:
  • Most included studies were occupational SMR cohorts, so subgroup analyses of non-occupational and SIR (incidence) cohorts were not feasible
  • Most studies relied on retrospective analyses of occupational cohorts, making it difficult to address confounding factors and independent ovarian cancer risk factors
  • Exposure-response relationships could not be well investigated because of the small number of ovarian cancer cases
  • The included studies were mainly retrospective cohorts without contemporaneous pathology, so misdiagnosis (for example, of peritoneal mesothelioma) remains possible
  • Too few studies to investigate the cause of the high heterogeneity in the post-2012 analysis

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Ovarian Cancer, Meta-Analysis, IARC, Systematic Review, standardized mortality ratio (SMR), Misdiagnosis.

Related studies

• Occupational exposure to asbestos and ovarian cancer: a meta-analysis — M.C. Camargo, L.T. Stayner, et al. (2011)
• Does exposure to asbestos cause ovarian cancer? A systematic literature review and meta-analysis — A. Reid, N. de Klerk, et al. (2011)
• Occupational Burden of Asbestos-Related Diseases in Korea, 1998-2013: Asbestosis, Mesothelioma, Lung Cancer, Laryngeal Cancer, and Ovarian Cancer — D.M. Kang, J.E. Kim, et al. (2018)
• Ovarian cancer in a former asbestos textile factory worker: a case report — S. Park, J. Park, et al. (2018)
• A systematic review and meta-analysis of surgical treatments for malignant pleural mesothelioma — C. Cao, D. Tian, et al. (2014)
• Epidemiology of ovarian cancer: a review — B.M. Reid, J.B. Permuth, et al. (2017)

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