Long-term progression-free survival in an advanced lung adenocarcinoma patient harboring EZR-ROS1 rearrangement: a case report

BACKGROUND Crizotinib is recommended as first-line therapy in ROS1-driven lung adenocarcinoma. However, the optimal first-line therapy for this subgroup of lung cancer is controversial according to the available clinical data. CASE PRESENTATION Here, we describe a 57-year-old man who was diagnosed with stage IIIB lung adenocarcinoma and EGFR/KRAS/ALK-negative tumors. The patient received six cycles of pemetrexed plus cisplatin as first-line therapy and then pemetrexed as maintenance treatment, with a progression-free survival (PFS) of 42 months. The patient relapsed and underwent re-biopsy. EZR-ROS1 fusion mutation was detected by next-generation sequencing (NGS). The patient was prescribed crizotinib as second-line therapy and achieved a PFS of 6 months. After disease progression, lorlatinib was administered as third-line therapy, with a favorable response. CONCLUSIONS Prolonged PFS in patients receiving pemetrexed chemotherapy might be related to the EZR-ROS1 fusion mutation. Lorlatinib is an optimal choice in patients showing crizotinib resistance.