It has been reported that the animal experiments using rats have revealed the emergence of lung cancer, mainly bronchioalveolar carcinoma and combined carcinoma and adenoma after the exposure to multi-walled carbon nanotubes (MWCNTs). Interestingly enough, male rats were much more susceptible to the carcinogenesis due to MWCNTs as compared with female rats. Males develop tumors with the exposure concentration of 0.2 mg/m3 whereas females exposed to 2mg/m3.

Ref.

* Kasai T, Umeda Y, Ohnishi M, et al. Lung carcinogenicity of inhaled multi-walled carbon nanotube in rats. Part Fibre Toxicol 2016; 13: 53.

* Sargent LM, Porter DW, Staska LM, et al. Promotion of lung adenocarcinoma following inhalation exposure to multi-walled carbon nanotubes. Part Fibre Toxicol 2014; 11: 3.

My major two questions are

What is the major pathohistological subtype of lung cancer due to the exposure to MWCNTs in human?

and

What makes the difference in the susceptibility to the tumor development due to the exposure to MWCNTs depending on sex?

I am appreciated if you would give me helpful comments.

Thank you in advance.

Sincerely

Go J. Yoshida MD, PhD.