Objective To detect the expression of ROS1 protein and its potential clinical significance in patients with pulmonary adenocarcinoma. Methods Formalin-fixed,paraffin-embedded tissue microarrays prepared from 332 patients with pulmonary adenocarcinoma and 55 samples of adjacent normal lung tissue were analyzed for ROS1 expression using immunohistochemistry. Possible relationships were analyzed between ROS1 expression and clinicopathologic features or EGFR/ALK protein expression, as well as between protein expression and postoperative recurrence. Results The rate of ROS1 expression was 6% in pulmonary adenocarcinoma tissues and 0 in adjacent normal lung tissue(P<0.05). ROS1 expression did not correlate with age or gender, but it did correlate significantly with smoking history and clinical stage(P<0.05). Disease-free survival was 42 months in ROS1-negative patients and 19 months in ROS1-positive patients(P<0.05). Rate of recurrence at 1 year was 30% in ROS1-negative patients and 13.5% in ROS1-positive patients(P<0.05). Conclusion Expression of ROS1 protein is low in pulmonary adenocarcinoma. ROS1 may be a prognostic factor that predicts risk of recurrence and metastasis of lung adenocarcinoma. Screening for ROS1 expression may help guide clinical treatment.

 

Lung neoplasms, ROS1;Immunohistochemistry, Epidermal growth factor receptor, Anaplastic lymphoma kinase, Prognosis