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.