P53 protein overexpression in lung adenocarcinomas in non-smokers.

Greater than 55% of all lung cancers contain mutations in the p53 tumor suppressor gene, and the frequency of p53 mutations has been directly correlated with the use of tobacco and the smoking of cigarettes. To determine if environmental tobacco smoke (ETS) is associated with changes in p53 expression in human lung cancer in never-smokers, we determined the degree of p53 protein expression in ten lung tumors from never-smokers exposed to ETS. We show that 5 of 8 (62.5%) adenocarcinomas contained significant levels of p53 protein overexpression as detected by immunohistochemical staining. While these findings suggest that ETS is a possible inducer of altered p53 expression in lung adenocarcinoma in non-smokers, larger studies are needed to confirm this relationship.