Radiologic features of precancerous areas of the lungs in chronic obstructive pulmonary disease

Only a few studies have evaluated the radiologic features of pre-existing structural abnormalities where lung cancer may develop. This study aimed to analyze the computed tomography (CT) images of lung areas where new cancer developed in chronic obstructive pulmonary disease (COPD) patients. We conducted a multicenter, longitudinal cohort study, called the Keio COPD Comorbidity Research, to assess the incidence of lung cancer. Emphysema and interstitial abnormalities were evaluated in 240 COPD patients who had baseline CT scans applicable for further digital analyses. For patients who developed lung cancer during the 3-year follow-up period, the local spherical lung density of the precancerous area was individually quantified. Lung cancer was newly diagnosed in 21 participants (2.3% per year). The percent-age of low attenuation area in patients who developed lung cancer was higher than that of the other patients (20.0% vs 10.4%, =0.014). The presence of emphysema (odds ratio [OR] 4.2, 95% confidence interval [CI] 1.0-29.0, =0.049) or interstitial lung abnormalities (OR 15.6, 95% CI 4.4-65.4,