Remarkable response to crizotinib in a patient with advanced lung adenocarcinoma harboring the MPRIP-ROS1 fusion gene: A case report

For patients with advanced non-small cell lung cancer (NSCLC), genetic testing is crucial to identify alterations in targetable driver genes. ROS1-tyrosine kinase inhibitors have shown efficacy against NSCLC with common <i>ROS1</i> fusion genes, but the impact of rare fusion partners on therapeutic outcomes is not well understood. Here, we describe a 75-year-old female with advanced lung adenocarcinoma who was treated with crizotinib after the identification of the extremely rare <i>MPRIP-ROS1</i> fusion. Despite stepwise dose reductions due to adverse effects, the patient exhibited a significant tumor response to crizotinib. The sustained response, even at reduced doses, highlights the potential for targeted therapies in managing NSCLC with <i>MPRIP-ROS1</i> fusion. This case also underscores the importance of comprehensive genomic profiling using hybrid capture-based next-generation sequencing to identify rare driver gene alterations that may not be detected by conventional target sequencing-based methods.