Absence of mesothelioma risk maintained in an expanded international cohort of cosmetic talc miners and millers

Abstract

Objectives: Based on novel information for the Vermont cosmetic talc miner/miller cohort, including a reported case of mesothelioma, we sought to update our prior pooled statistical power analyses of mesothelioma incidence among European cosmetic talc miners/millers. With the inclusion of the Vermont cohort, we expanded our pooled analysis by 17,170 person-years of observation.

Methods: Cosmetic talc miner/miller cohort studies conducted in Italy, Norway, France, Austria, and Vermont were pooled. The expected numbers of mesothelioma cases for each cohort as reported in these studies were used. Our statistical power analysis was based on an a priori one-sided significance level of 0.05 and Poisson distribution probabilities.

Results: A total of 130,514 person-years of observation was generated across the five cohorts. One case of mesothelioma was observed (in the Vermont cohort), while approximately 3.34 cases (a mid-value estimate) were expected overall. Thus, we found that the pooled cohorts had 59% and 78% power to detect a 2.5-fold or greater and a 3.0-fold or greater increase in mesothelioma, respectively. The work history characteristics of the one mesothelioma case, which included mention of prior asbestos exposure on the case’s death certificate, do not support a causal link with cosmetic talc exposure.

Conclusions: Despite the recent finding of one case of mesothelioma in the Vermont cohort (a case unlikely related to talc exposure), we continue to conclude that the epidemiological evidence from the cosmetic talc miner/miller cohort studies does not support the hypothesis that cosmetic talc exposures are associated with an increased risk of pleural mesothelioma.

Keywords:

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

Acknowledgement

The authors thank and acknowledge Dr. Brent Finley for his helpful comments on the draft manuscript.

Disclosure statement

Both 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, and no external funding was received for this study. 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. Both AMI and GMM have been retained as defense experts in cosmetic talc-related litigation.