Long-lasting response to crizotinib in brain metastases due to EML4-ALK-rearranged non-small-cell lung cancer

Anaplastic lymphoma kinase (ALK) rearranged non-small-cell lung cancer (NSCLC) is highly responsive to crizotinib, an oral ATP-competitive selective inhibitor of ALK. However, crizotinib exhibits extremely poor blood–brain barrier penetration; therefore, it is considered to play a limited role in the treatment of brain metastases. We present a case of a 50-year-old man with a diagnosis of ALK-rearranged NSCLC with brain metastasis and malignant pleural effusion. Despite the several systemic chemotherapy regimens and whole brain radiotherapy, brain metastasis was refractory; therefore, crizotinib was initiated. A CT scan showed a slight reduction in the brain metastasis and no change in intrathoracic disease 17 weeks after initiating crizotinib. Moreover, CT obtained 12 months after crizotinib treatment revealed brain metastasis without progression. To our knowledge, the present case is the second report of crizotinib-responsive brain metastases due to echinoderm microtubule-associated protein-like 4-ALK (EML4-ALK)-rearranged NSCLC