Radiologic Characteristics of Surgically Resected Non-Small Cell Lung Cancer With ALK Rearrangement or EGFR Mutations

Background. Radiogenomic features are predictive of anaplastic lymphoma kinase (ALK) rearrangement in surgically resected non-small cell lung cancer (NSCLC). Methods. ALK rearrangement was screened by fluorescent in situ hybridization in 497 patients with resected NSCLC. Of these, 198 patients screened for both ALK and epidermal growth factor receptor (EGFR) mutation were enrolled. Clinicopathologic findings, survival after surgical procedure, computed tomographic (CT) features, and maximum standardized uptake value according to different genotypes were investigated with univariate and multivariate analyses. A receiver operating characteristic (ROC) curve analysis was performed to quantify the predictive value of these factors. Results. The prevalence of ALK positivity in resected NSCLC was 5.0% (25 of 497). Patients with ALK rearrangement showed significant differences in terms of patient's age (p = 0.006 for ALK versus EGFR, and 0.04 for ALK versus wild type [WT]/WT, respectively), solid lesion (p = 0.0074 for ALK versus EGFR), degree of contrast enhancement (p = 0.0006 for ALK versus EGFR), and lesion margin (p = 0.0011 for ALK versus EGFR, and 0.0314 for ALK versus WT/WT, respectively) compared with EGFR mutant and WT/WT cohorts. Multivariate analysis revealed that young age, solid lesion, lobulated margin, and hypoattenuation at contrast-enhanced CT scan were independent predictors of ALK positivity (p = 0.027, 0.046, 0.001, 0.021, respectively). The area under the ROC curve of the predictive model was 0.832, which suggests good discrimination. Conclusions. ALK-rearranged lung cancer has characteristic clinical and imaging features compared with EGFR mutant or WT/WT cohorts. Our findings suggest that young age, lobulated margin, solid lesion, and hypoattenuation at contrast-enhanced CT scan are important predictors of ALK-rearranged lung cancer. (C) 2016 by The Society of Thoracic Surgeons