10 December 2018
Response to the article entitled:
"Cytotoxic effects of heated tobacco products (HTP) on human bronchial epithelial cell"
by Leigh et al., 20181.
 Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
by Gizelle Baker, Patrick Picavet, Maurice Smith, Patrick Vanscheeuwijck, Emilija Veljkovic and Manuel C. Peitsch2.
Philip Morris International R&D
 Philip Morris Products S.A., PMI Research and Development, Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland. Authors are listed in alphabetical order.
The Department of Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA has recently published a Research Paper in Tobacco Control (Leigh, 2018) claiming that “emissions from heated tobacco products (HTP) damaged bronchial epithelial cells, and their cytotoxic effect was higher compared with e-cigarettes but lower compared with tobacco cigarettes.”
Independent studies, like this one, are important to assess the potential health impacts of smoke-free products. This study presents a valuable contribution to further understand the effects of different smoke-free alternatives to cigarettes. We have reviewed and assessed those conclusions of this study, based on the methodology used and the results presented. The conclusions drawn by the authors are far reaching, and perhaps go beyond what the study results support. Methodological limitations with the conduct of the study should be considered when interpreting the results and drawing conclusions (e.g., the study did not follow the established guidelines for conducting cytotoxicity assays, or performing tests in an acute setting).
We have therefore prepared a point-by-point assessment of the conclusion drawn by the authors, and this detailed analysis can be found below.
Overall, based on an analysis of our in vitro studies performed according to international standards of Good Laboratory Practice (GLP), the Tobacco Heating System (THS, marketed under the brand name IQOS) presents less risk of harm and can reduce the risk of smoking-related diseases compared with continued smoking. This includes a significant reduction in cytotoxicity when compared to effects of cigarette smoke generated by combustion.
Although THS is not risk-free, switching completely to THS presents less risk and can reduced the risk of smoking related diseases for adult smokers than continuing to smoke cigarettes.