SOT 2019: Q&A with Dr. Natalie Egnot

Posted on Behalf of  Natalie Egnot

Please read below for more information from Dr. Natalie Egnot on her SOT presentation.

1.         What was the title of your presentation?  

Systematic Review and Meta-Analysis of Epidemiological Literature Evaluating the Association between Exposure to Man-Made Vitreous Fibers and Respiratory System Cancers

2.         What was the scope of your research?

The carcinogenic potential of man-made vitreous fibers (MMVF) has been extensively studied epidemiologically since the 1970’s, and in 2002, the International Agency for Research on Cancer (IARC) classified insulation glass wool, rock (stone) wool, and slag wool as not classifiable as to their carcinogenicity to humans (Group 3). However, since the release of the 2002 IARC Monograph, several studies evaluating the association between MMVF exposure and respiratory system cancers have been published. We therefore conducted a systematic review of studies published since 2002, and performed a meta-analysis of all peer-reviewed epidemiological studies evaluating the association between MMVF exposure (specifically glass, rock, and slag wool) and respiratory system cancers (including cancers of the bronchus, trachea, lung, and larynx) published since the 1970’s. Our meta-analysis if the first pooled-analysis on this topic to separately consider the summary effects of studies which statistically accounted for harmful co-exposures (occupational asbestos and smoking habits) and those which did not take participants’ co-exposures into account.

3.         What did you find?

Overall, we did not identify a statistically significant risk of respiratory system cancers among those with occupational exposure to MMVFs (summary relative risk (RR)=1.09; 95% CI=0.99-1.22). When including only studies which adjusted for participants’ asbestos and/or smoking exposure the RR attenuated yielding a summary RR of 1.01 (95% CI=1.15). When evaluating the potential health effects of specific MMVF types, we did not observe any statistically significant elevations in risk of respiratory system cancer associated with either glass wool or rock/slag wool exposures. Overall, our findings suggest that IARC’s 2002 Group 3 classification of glass, rock, and slag wools remains valid in light of new evidence.

4.       What are the next steps / what other research is needed?

We are presently working on drafting a manuscript based on this systematic review and analysis for publication in a peer-reviewed journal. Due to a limited number of studies evaluating the association between MMVF exposure and cancers beyond those of the respiratory system (bronchus, trachea, lung, and larynx), we were prevented from conducting robust meta-analyses related to other cancer outcomes. Lastly, we have begun work on a similar systematic review and meta-analysis of the association between occupational exposure to MMVFs and non-malignant respiratory diseases.

For more information, please contact Dr. Natalie Egnot at