[A Case of EGFR-mutant Lung Adenocarcinoma with Secondary SCLC Transformation and ALK Fusion after Osimertinib Treatment].

Epidermal growth factor receptor (EGFR) gene mutations are the most common driver mutations in non-small cell lung cancer (NSCLC). This article reports a case of a patient with EGFR-sensitive mutant lung adenocarcinoma who developed secondary transformation to small cell lung cancer (SCLC) and anaplastic lymphoma kinase (ALK) gene fusion following first-line Osimertinib therapy. This paper reported a case of concurrent SCLC transformation and ALK fusion occurring after Osimertinib treatment, suggesting that the two can coexist as dual drug resistance mechanisms. Re-biopsy combined with genetic testing is essential for identifying drug resistance mechanisms and guiding individualized therapy.
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