EML4-ALK rearrangement in squamous cell carcinoma shows significant response to anti-ALK inhibitor drugs crizotinib and alectinib.

EML4-ALK alterations are more common in adenocarcinomas and are rarely found in squamous cell histology. In documented cases, the majority of EML4-ALK translocations are identified in squamous cell histology and occur in patients with no or light smoking history. We report an EML4-ALK4 translocation in a 50-year-old patient with squamous cell carcinoma and an 18 pack-year smoking history. The patient had a near complete response in the CNS to alectinib treatment. Our observation suggests that EML4-ALK genomic testing may be clinically useful in patients with heavy smoking history.