Analysis of the relationship between p53 immunohistochemical expression and risk factors for lung cancer, with special emphasis on residential radon exposure

Background: Indoor radon exposure has been postulated as the second risk factor of lung cancer after tobacco. The objective of this work is to analyze if there exists any effect on p53 immunohistochemical expression mainly due to radon exposure and other risk factors for lung cancer. Patients and methods: The tumor samples of a case series of 163 lung cancer cases were analyzed to know the p53 staining. The staining was classified into four categories from no staining to intense staining (> 60%). This staining was correlated with radon exposure, tobacco consumption, having worked in risk occupations for lung cancer and alcohol consumption. Results: Only 72 samples could be analyzed for immunohistochemistry and some of these samples were sequenced from exons 4-8. No association was observed for staining intensity and radon exposure and also for tobacco and occupation. A slight association with a more intense staining was observed for high alcohol intake. In the four samples with a staining > 60% that could be sequenced from exons 4 to 8, no mutation was observed in the p53 gene. Conclusion: There is no association between radon exposure and p53 expression, indicating that maybe the effect of radon is not mediated through p53 alterations.