A Case Report of Acquired ALK Fusion in ALK Wild‐Type Lung Adenocarcinoma Following Chemotherapy and a Literature Review Is Presented

ALK fusion is a key driver mutation in non‐small cell lung cancer, typically present as a primary genetic alteration. This article reports a rare case of a patient who was initially ALK‐negative but subsequently developed an ALK fusion following chemotherapy. A 52‐year‐old female was diagnosed with advanced lung adenocarcinoma. Initial genetic testing showed wild‐type EGFR and ALK. She received first‐line platinum‐based doublet chemotherapy combined with a VEGF inhibitor and a PD‐L1 inhibitor, achieving a partial response. Upon disease progression, repeat genetic testing unexpectedly detected an ALK fusion. Treatment was then switched to the ALK inhibitor alectinib, and the patient again achieved a partial response. This case suggests that chemotherapy may enrich ALK fusion‐positive tumour cell clones through selective pressure. These findings highlight the clinical importance of repeated genetic testing after disease progression and provide new insights for post‐resistance treatment strategies.