Prognostic significance of CT-determined emphysema in patients with small cell lung cancer

Abstract

Background: Although emphysema and small cell lung cancer (SCLC) are prevalent in smokers, no previous study has investigated the prognostic impact of computed tomography (CT)-determined emphysema in SCLC. This study was undertaken to analyze the prognostic value of emphysema scores as determined by baseline CT scans in patients with SCLC. Methods: The data of 149 consecutive patients with SCLC were analyzed. Emphysema severity was semi-quantitatively scored on baseline chest CT images using the Goddard scoring system (possible scores for individual patients ranged from 0 to 24). Data on clinical characteristics and survival were retrospectively collected. Survivals were estimated using the Kaplan-Meier method and compared using the log-rank test. A multivariable Cox proportional hazard model was used to identify prognostic factors. Results: Most of the 149 patients were male (85.2%) and current/ex-smokers (87.2%). The median CT emphysema score was 4 (range, 0 to 23). Univariable analysis, patients with a higher CT emphysema score (>= 8) had significantly poorer overall survivals (OS) than those with lower scores (5.0 vs. 12.3 months, P<0.001). Multivariable analysis showed a higher CT emphysema score (treated as a continuous variable) was a significant independent prognostic factor of poor survival [hazard ratio (HR), 1.85; 95% confidence interval (CI), 1.14 to 3.00; P=0.012], along with extensive stage (HR, 2.27; 95% CI, 1.45-3.53; P<0.001), elevated lactate dehydrogenase (LDH) (HR, 1.52; 95% CI, 1.03-2.23; P=0.034), and supportive care only (HR, 6.46; 95% CI, 3.64-11.48; P<0.001). Conclusions: Emphysema severity, as determined by baseline CT, is significantly associated with poor prognosis in SCLC.