An Anaplastic Lymphoma Kinase-rearranged Squamous Cell Lung Cancer Treated with Sequential ALK-tyrosine Kinase Inhibitor Therapy: a Case Report

━━ Background. Anaplastic lymphoma kinase (ALK) rearrangement is a rare subset of squamous cell lung cancer (SCC). The efficacy of ALK-tyrosine kinase inhibitors (TKIs) in ALK-rearranged SCC patients re-mains unclear. Case. A 49-year-old Japanese woman presented to our hospital with symptoms of cough and supraclavicular fossa lymph node swelling. She was diagnosed with SCC (cT4N3M1c, cStage IVB) by a percutane-ous core needle biopsy from the supraclavicular fossa lymph node. As the patient was a non-smoking woman, and the progression of the disease was rapid, we suspected the presence of an oncogenic driver. Immunostaining and fluorescence in situ hybridization revealed the presence of an ALK fusion gene. Cytotoxic chemotherapy was not feasible because the patient was suffering from idiopathic thrombocytopenic purpura. She was therefore treated with sequential ALK-TKI therapy involving alectinib, brigatinib, and lorlatinib. The tumors decreased in size with these treatments, but the duration of the effect was shorter than expected, and she ultiamtly died 12 months after the diagnosis. Conclusion. ALK-TKIs are treatment options for ALK-rearranged SCC patients; however, their efficacy is limited. Molecular testing for the ALK fusion gene is recommended even in SCC if the patient has a background that suggests the presence of an oncogenic driver.