Prognostic significance of CT-emphysema score in patients with advanced squamous cell lung cancer

Background: Although emphysema is a known independent risk factor of lung cancer, no study has addressed the prognostic impact of computed tomography (CT)-emphysema score in advanced stage lung cancer. Methods: For 84 consecutive patients with stage IIIB and IV squamous cell lung cancer that underwent palliative chemotherapy, severity of emphysema was semi-quantitatively scored using baseline chest CT images according to the Goddard scoring system (possible scores range, 0-24). The cutoff of high CT-emphysema score was determined using the maximum chi-squared test and the prognostic significance of the high CT-emphysema score was evaluated using Kaplan-Meier analysis and Cox proportional hazards analysis. Results: The median CT-emphysema score was 5 (range, 0-22). Patients with a high CT-emphysema score (>= 4) tended to have poorer overall survival (OS) (median: 6.3 vs. 13.7 months) than those with a score of <4 (P=0.071). Multivariable analysis revealed that a higher CT-emphysema score was a significant independent prognostic factor for poor OS [hazard ratio (HR) =2.06; 95% confidence interval (CI), 1.24-3.41; P=0.005), along with no response to first-line therapy (P=0.009) and no second-line therapy (P<0.001). Conclusions: CT-emphysema score is significantly associated with poor prognosis in patients with advanced squamous cell lung cancer.