Abstract
BACKGROUND: Lung cancer adjoining bullae (LC-AB) is an uncommon manifestation. The clinical characteristics and prognosis of LC-AB remain unclear. The aim of this study is to investigate the clinical features and overall survival (OS) of patients with LC-AB following lung resection compared to non-LC-AB group. METHODS: We retrospectively investigated 291 consecutive patients with lung cancer who underwent curative resection in a single institution between April 2007 and March 2015. A total of LC-AB was 52 patients. LC-AB was determined using thin slice computed tomography (CT) imaging and pathological findings. Survival analysis was calculated using the Kaplan-Meier method. We used a Cox proportional hazards model for the univariate and multivariate analysis to identify prognostic factors. RESULTS: The LC-AB group showed a higher frequency of younger patients (P=0.017), former or current smokers (P=0.011), men (P=0.021), tumor location in the upper lobe (P=0.031), moderately or poorly differentiated tumor histology (P<0.001), pleural indentation (P=0.007), and non-adenocarcinoma histology (P=0.016) than the non-LC-AB group. The 5-year survival and recurrence-free survival (RFS) rates were significantly higher in the LC-AB group than the non-LC-AB group (88.5% vs. 74.9%, P=0.010, 75.4% vs. 61.3%, P=0.030, respectively). Multivariate analysis using a Cox proportional hazard model of OS showed that LC-AB was an independent prognostic factor [hazard ratio (HR): 0.30, 95% confidence interval (CI): 0.12-0.77, P=0.012]. CONCLUSIONS: Patients with LC-AB had better OS than those with non-LC-AB. Thus, LC-AB may be an independent favorable prognostic factor following curative resection.