ALK and non-small cell lung carcinoma: Furthermore, ALK-rearranged non-small cell lung cancer (NSCLC) is associated with a 50% lifetime incidence of brain metastases (BM), and several studies have shown that patients with NSCLC BM harboring ALK rearrangements have prolonged survival compared with other NSCLC subgroups, with median survival exceeding 4 years and a 2-year survival rate of approximately 70% 3-4.