Efficacy of Neoadjuvant Therapy for ROS1-Positive Locally-Advanced Lung Adenocarcinoma: A Case Report

BACKGROUND ROS1 fusion-positive locally-advanced lung adenocarcinoma is a rare malignant tumor with no clear neoadjuvant therapy guidelines and a poor prognosis. This report describes a 49-year-old man with a ROS1 fusion-positive locally-advanced lung adenocarcinoma with a pathological complete response (pCR) to the tyrosine kinase inhibitor crizotinib combined with chemotherapy. CASE REPORT A 49-year-old Chinese man visited the hospital with a cough and phlegm that began over 20 days ago. Computed tomography (CT) revealed a 4.5-cm diameter mass in the lower lobe of the left lung with enlarged lymph nodes fused together in the left hilum, staging stage IIIA (cT2bN2aM0). Given the pathological diagnosis of adenocarcinoma of lung from the transbronchial lung biopsy (TBLB), the patient subsequently underwent chemotherapy with the lobaplatin and paclitaxel regimen. Subsequently, genetic tests using fluorescence quantitative polymerase chain reaction (PCR) assay for biopsy pathology showed ROS1 fusion-positivity. Based on this, after completing 1 cycle of chemotherapy, the patient continued with daily oral treatment with 500 mg of crizotinib. A follow-up CT after 30 days of crizotinib therapy showed the tumor had vanished. Radical surgery confirmed pCR, and the patient continues crizotinib maintenance therapy with no signs of recurrence on subsequent chest CTs. CONCLUSIONS This case serves to underscore the excellent efficacy of neoadjuvant therapy in a patient with ROS1 fusion-positive locally-advanced lung adenocarcinoma. Neoadjuvant lobaplatin/paclitaxel combined with crizotinib can be considered for such patients, but attention should be paid to the difficulty of surgery, timing selection, and formulation of management guidelines.