<scp> <i>KANK1‐ALK</i> </scp> , a rare <scp> <i>ALK</i> </scp> fusion in mucinous lung adenocarcinoma with primary resistance to <scp>ALK</scp> ‐ <scp>TKI</scp> treatment: A case report

Abstract Patients harboring rearrangements of anaplastic lymphoma kinase ( ALK ) fusion may respond differently to ALK tyrosine kinase inhibitors (TKIs) depending on changes in the type of ALK rearrangements. We report the first documented case of KANK1‐ALK fusion in mucinous lung adenocarcinoma, co‐occurring with TP53 mutation. The patient underwent targeted therapy with loratinib and iruplinalkib, followed by alternative chemotherapy. Unfortunately, the KANK1‐ALK fusion in this patient exhibited resistance to all the existing ALK ‐TKIs, and the patient's condition has worsened repeatedly. Uncommon ALK fusion patterns present substantial therapeutic obstacles in clinical practice. Accurate detection of ALK fusion types is of great significance in formulating precise treatment plans. An increasing number of clinical specimens have detected rare fusions, and the treatment of rare fusions may be a research direction in the future.