Occupational exposures to cosmetic talc and risk of mesothelioma: an updated pooled cohort and statistical power analysis with consideration of latency period

Abstract

Objectives: We previously published a pooled statistical power analysis of mesothelioma incidence in the Italian, Norwegian, Austrian, and French cosmetic talc miner and miller cohorts. Soon thereafter, updates to the Italian and Norwegian cohorts were published, providing an additional 14,322 person-years of observation. In this study, we provide an updated power analysis using the newly available information.

Methods: We pooled the current results regarding pleural cancer/mesothelioma mortality or incidence in four cosmetic talc miner and miller cohorts in Italy, Norway, Austria, and France. We used the expected numbers of cases as reported by the authors and the power analysis was based on an a priori one-sided significance level of 0.05 and Poisson distribution probabilities.

Results: There was a pooled total of 113,344 person-years in the cohorts. Although 3.0 pleural cancers/mesotheliomas were expected, there were no reported pleural cancer or mesothelioma cases in any cohort. Our pooled analysis was associated with 79 and 62% power to detect a 3.0-fold and 2.5-fold or greater increase in pleural cancer/mesothelioma, respectively. These favorable power characteristics were effectively maintained when restricting the pooled cohort to workers with a latency period of 30 or more years (observation time from first employment).

Conclusions: The epidemiological evidence from the cosmetic talc miner/miller cohort studies does not support the hypothesis that exposure to cosmetic talc is associated with the development of pleural cancer/mesothelioma.

Keywords:

• Mesothelioma
• pleural cancer
• cosmetic talc
• asbestos
• pooled cohort analysis
• statistical power calculation
• cohort study
• mortality
• miners and millers
• latency period

Acknowledgments

The authors would like to acknowledge Drs. Enrico Pira and Paolo Boffetta for providing cause of death data for the censored individuals in the Italian cohort study. We would also like to thank Michael Tyson for his assistance in the creation of the figures presented herein.

Disclosure statement

All of the authors are employed by Cardno ChemRisk, a consulting firm that provides scientific advice to the government, corporations, law firms, and various scientific/professional organizations. GMM is also Professor of Biostatistics and Director and Founder, Center for Occupational Biostatistics and Epidemiology at the University of Pittsburgh, Graduate School of Public Health. This manuscript was prepared and written exclusively by the authors. No organizations other than Cardno ChemRisk were aware of the preparation of this manuscript, and no other organizations other than Cardno ChemRisk reviewed any part of this manuscript prior to its submission for publication. Two of the authors (BLF, GMM) have served as defense experts in cosmetic talc-related litigation.