CT Imaging Features and Distribution of Metastases in ROS1-Rearranged Non-Small Cell Lung Cancer

Abstract Background ROS proto-oncogene 1 (ROS1) rearrangements are a known molecular target in non-small cell lung cancer (NSCLC). Our goal was to determine if ROS1-rearranged NSCLC has imaging features and patterns of metastasis, which differ from those of anaplastic lymphoma kinase (ALK)-rearranged or epidermal growth factor receptor (EGFR)-mutant NSCLC. Methods We retrospectively identified patients with metastatic ROS1-rearranged, ALK-rearranged, or EGFR-mutant NSCLC between January 2014 and June 2018 and included those with pre-treatment imaging. We assessed the imaging features of the primary tumor and the distribution of metastases in these patients. Wilcoxon rank-sum test and Fisher’s exact test were used to compare features. Results We identified 257 patients (167 women and 90 men; median age: 56 years; range: 19-90 years) with metastatic NSCLC (ROS1=53; ALK=87; EGFR=117). Compared to ALK-rearranged or EGFR-mutant NSCLC, ROS1-rearranged NSCLC was less likely to present with extrathoracic metastases (ROS1=49% vs. ALK=75% vs. EGFR=72%, p Conclusion While there is considerable overlap in the imaging features of ROS1-rearranged, ALK-rearranged, and EGFR-mutant NSCLC, ROS1-rearranged NSCLC has certain distinct imaging features and patterns of spread.