[A Case of EML4-ALK Fusion V1 Subtype Lung Adenocarcinoma 
Detected by RNA-based NGS].

Lung cancer is the malignant tumor with the highest incidence and mortality rate worldwide. For lung adenocarcinoma, identifying specific gene mutations, fusions, and giving corresponding targeted drugs can greatly improve the survival time of the patients. Among them, anaplastic lymphoma kinase (ALK) fusion occurs in 3%-7% of non-small cell lung cancer (NSCLC). In clinical practice, a variety of detection methods can be used to determine the ALK fusion status, but false negative test results are possible. This paper retrospectively analyzed the diagnosis and treatment of a patient with lung adenocarcinoma, judged the ALK fusion status by various detection methods. Among them, immunohistochemistry (IHC)(Ventana D5F3), RNA based next-generation sequencing (RNA-based NGS) confirmed positive echinoderm microtubule associated protein like 4 (EML4)-ALK fusion, while DNA-based NGS was negative. This paper analyzed the detection methods of ALK fusion, in order to clarify which detection method is the most accurate and simple to choose in different clinical cases and guide the subsequent treatment.
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