CASE REPORT Rapid response of brain metastasis to crizotinib in a patient with KLC1-ALK fusion and MET gene amplification positive non-small cell lung cancer: a case report

Non-small cell lung cancer (NSCLC) ranks as the leading cause of cancer-related death in the world. Brain metastasis (BM) is a common complication of NSCLC, with 25%–40% of patients developing BM during the course of the disease. A significant strategy of local disease control in the central nervous system is radiation therapy. With the development of precision medicine, the concept of treating lung cancer BM has gradually changed. In this case, we performed a surgical procedure to obtain enough tumor tissue for the detection of the target gene and other related experiments after the patient was informed. Finally, we found that the patient had both hepatocyte growth factor receptor (MET) gene amplification and kinesin light chain 1-anaplastic lymphoma kinase fusion (KLC1-ALK) through next-generation sequencing and showed sensitivity to the targeted therapy of crizotinib. The patient exhibited good response. Our case was successful and underwent targeted therapy with the guidance of precise diagnosis.