Characteristics of Smoking Patients with Lung Cancer with Emphysematous Bullae

IntroductionEmphysema is thought to be a risk factor for lung cancer in smokers, with emphysematous bullae (EBs), which are believed to have the potential to give rise to lung cancer. The clinical characteristics of patients with lung cancer with EBs have remained incompletely defined, however.MethodsA total of 488 patients with primary lung cancer with or without EBs as detected by computed tomography were studied retrospectively, and the regional relationship between EBs and the primary cancer was evaluated.ResultsEBs were detected in 45 of the 488 patients with lung cancer (9.2%) (in 45 of 339 smokers [13.3%] versus in 0 of 149 never-smokers [0%]). The frequency of lung cancer in an upper lobe was significantly higher in smokers with EBs than in those without EBs (71.1% versus 47.3%, p = 0.0107). The lobar site of primary lung cancer in smokers with EBs was significantly associated with that of the EBs (p < 0.0001). Most primary lung cancers (86.7%) in such patients were found in the area adjoining EBs. Smoking patients with lung cancer with EBs were significantly younger (63.6 versus 67.7 years, p = 0.0179) and had tumors with a lower frequency of epidermal growth factor gene (EGFR) mutations (3.8% versus 24.2%, p = 0.0184) compared with those without EBs.ConclusionsThe clinical characteristics of smoking patients with lung cancer differ according to the absence or presence of EBs, with patients with EBs being potentially more susceptible to the carcinogenic effects of cigarette smoke. Further analysis of genetic alterations is warranted to elucidate the mechanism of carcinogenesis for lung cancer associated with EBs.