Severity of pulmonary emphysema and lung cancer: Analysis using quantitative lobar emphysema scoring

The aim of this study was to determine the relationship between lobar severity of emphysema and lung cancer using automated lobe segmentation and emphysema quantification methods. This study included 78 patients (74 males and 4 females; mean age of 72 years) with the following conditions: pathologically proven lung cancer, available chest computed tomographic (CT) scans for lobe segmentation, and quantitative scoring of emphysema. The relationship between emphysema and lung cancer was analyzed using quantitative emphysema scoring of each pulmonary lobe. The most common location of cancer was the left upper lobe (LUL) (n=28), followed by the right upper lobe (RUL) (n=27), left lower lobe (LLL) (n=13), right lower lobe (RLL) (n=9), and right middle lobe (RML) (n=1). Emphysema ratio was the highest in LUL, followed by that in RUL, LLL, RML, and RLL. Multivariate logistic regression analysis revealed that upper lobes (odds ratio: 1.77; 95% confidence interval: 1.01-3.11, P=0.048) and lobes with emphysema ratio ranked the 1st or the 2nd (odds ratio: 2.48; 95% confidence interval: 1.48-4.15, P<0.001) 8were significantly and independently associated with lung cancer development. In emphysema patients, lung cancer has a tendency to develop in lobes with more severe emphysema.