C77-23 Prognostic Value of Ros1 Fusion in Lung Adenocarcinoma Stratified by Clinicopathologic and Radiological Features

Abstract Objectives The prognosis of ROS1 fusion remains in lung adenocarcinoma (LUAD) remains controversial, This study systematically explored the clinicopathological characteristics and prognostic value of ROS1 fusion in early and advanced-stage lung adenocarcinoma according to different clinicopathologic and radiological features characteristics. Methods This study retrospectively enrolled complete clinic data and follow-up records of resected LUAD patients with ROS1 examination from 2008 to 2020. Cases were stratified by early and advanced-stage features as follows: “stage I” versus “stage II-III”, “part-solid” versus “solid”, “moderately-differentiated” (including papillary, acinar or invasive mucinous adenocarcinoma) versus “poorly-differentiated” (including micropapillary or solid adenocarcinoma), “passive” versus “aggressive” (defined by the lymphovascular invasion, visceral pleural invasion or spread through air spaces) groups. Prognostic significance for ROS1-postive and ROS1-negative patients were analyzed within each group. Results In total, 3162 patients were collected and 145 (4.5%) were ROS1-postiive. ROS1 positivity was associated with non-smoking status, pure solid nodule, poor differentiation and lymphovascular invasion. ROS1 fusion was correlated with worse recurrence-free survival (RFS) and overall survival (OS) in stage II-III, solid, poorly-differentiated and aggressive cohorts. The RFS and OS of ROS1-positive LUAD was comparable in stage I, part-solid, moderately-differentiated and passive groups. Cox multivariable analysis demonstrated that ROS1 fusion was an independent risk factor for RFS and OS in stage II-III, solid, poorly-differentiated and aggressive cohorts.stage I, but not in stage I, part-solid, moderately-differentiated and passive cohorts. Conclusions ROS1 fusion plays a significant prognostic role in advanced progression of LUAD, however, the generally favorable survival outcomes may obscure its prognostic value. This abstract is funded by: 1·3·5 project for disciplines of excellence from West China Hospital of Sichuan University (ZYGD23010 to LXL)