The impact of smoking status on radiologic tumor progression patterns and response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in lung adenocarcinoma with activating EGFR mutations

Background: The aim of this study was to evaluate the impact of smoking on the treatment outcome of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in patients with EGFR-mutant lung adenocarcinoma, with consideration of other factors including radiologic tumor progression pattern according to patient smoking status. Methods: A total of 224 patients with EGFR mutant lung adenocarcinomas that were treated with EGFRTKIs were retrospectively reviewed. Radiologic tumor progression pattern and treatment outcomes were evaluated according to smoking history. Results: There were no significant differences in radiologic tumor progression pattern based on smoking status. There were no significant differences in survival between never-smokers and smokers or among never-, former-, and current-smokers, but there was a trend of shorter progression free survival (PFS) and poorer overall survival (OS) in smokers compared with never-smokers. In multivariate analysis, long-term smokers had shorter PFS and poorer OS than those who had never smoked. Conclusions: A history of smoking had no significant effect on radiologic tumor progression pattern; however, smoking history is a negative predictive factor of survival in patients with EGFR-mutant lung adenocarcinoma undergoing EGFR-TKI therapy.