Systematic review of the scientific evidence of the pulmonary carcinogenicity of talc

Abstract

We conducted a systematic review to assess the potential pulmonary carcinogenicity of inhaled talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM) and several United States (US) Environmental Protection Agency (EPA) frameworks for systematic reviews. A comprehensive literature search was conducted. Detailed data abstraction and study quality evaluation, adapting the US Toxic Substances Control Act (TSCA) framework, were central to our analysis. The literature search and selection process identified 23 primary studies that assessed exposure to talc and pulmonary cancer risks in humans (n = 19) and animals (n = 3). Integrating all streams of evidence according to the IOM framework yielded classifications of suggestive evidence of no association between inhaled talc and lung cancer and pleural mesothelioma at human-relevant exposure levels.

Systematic review of the association between talc and female reproductive tract cancers

“…However, three of the four studies assessed toxicity related to whole body inhalation of talc, and the relevance to genital routes of exposure is limited for these studies. A detailed discussion of the results for the three sub-chronic and chronic rodent bioassays is included in our previous systematic review; overall, these studies provide limited evidence of lung carcinogenicity except at high, likely non-human relevant doses associated with particle overload conditions ( Lynch et al, 2022 ). A brief discussion of the study findings relevant to perineal and vaginal talc exposure and female reproductive organ outcomes ( Keskin et al, 2009 ) is provided below, followed by the quality evaluation results.…”

“…Another possible MOA stems from immune-related effects, such as via reduction of antibodies that target a transmembrane protein that is overexpressed in ovarian and other tumors ( Cramer et al, 2005 ; Muscat and Huncharek, 2008 ). Talc itself was negative for direct mutagenicity in all available assays and this postulated MOA is not discussed further ( Lynch et al, 2022 ).…”

“…Hazard conclusions were guided by the US Institute of Medicine (IOM, now National Academy of Medicine) framework ( IOM, 2009 ). An overview of our methods is provided below, and a more detailed description can be found in our prior evaluation of pulmonary cancers ( Lynch et al, 2022 ) and in the supplemental Protocol, allowing verification and replication of our review.…”