Four lines of anaplastic lymphoma kinase inhibitors and brain radiotherapy in a long-surviving non-small-cell lung cancer anaplastic lymphoma kinase-positive patient with leptomeningeal carcinomatosis

Lung cancer is the most common tumor and the leading cause of cancer-related death worldwide. Approximately 6.7% of non-small-cell lung cancers (NSCLCs) show anaplastic lymphoma kinase (ALK) rearrangement and could benefit from ALK-targeted treatment. Various anti-ALK drugs have been developed during the past years, but it is actually controversial which sequence and which ALK inhibitor is recommended for a single patient. Leptomeningeal carcinomatosis (LC) is associated with a poor prognosis, with an overall survival of 2-4 months for treated patients. The data about LC management derive mainly from retrospective studies, being an exclusion criterion for most trials. Intrathecal chemotherapy and whole-brain radiotherapy (WBRT), associated with a systemic treatment, are the most commonly used approach. Here we present a case of NSCLC harboring an ALK translocation treated with four lines of ALK inhibitors and receiving WBRT for LC, showing an overall survival of ∼5 years from the diagnosis of metastatic disease. This case report focuses mainly on several controversial clinical aspects, that is, the sequence of treatment in ALK-positive NSCLC, the ALK inhibitors' efficacy on brain disease and beyond progression, the management of LC, and the role of WBRT despite the risk of cognitive impairment.