Novel NLRC4‐ALK and EML4‐ALK double fusion mutations in a lung adenocarcinoma patient: A case report

Anaplastic lymphoma kinase (ALK) rearrangements have been reported in 5% to 6% of non‐small cell lung cancer (NSCLC) patients. However, the concurrent existence of two ALK fusions within the same patient have rarely previously been reported. Moreover, considering the diversities of ALK mutations, it is necessary to evaluate the response of both double and new types of ALK fusions to ALK‐tyrosine kinase inhibitors (ALK‐TKIs). Here, we report a case of a 64‐year‐old Chinese woman who was diagnosed with lung adenocarcinoma (ADC) who concurrently harbored two types of ALK‐rearrangements, including an unreported NLRC4‐ALK fusion and EML4‐ALK fusion. After surgery, the patient had a progression‐free survival (PFS) of over 10 months with continuous crizotinib treatment after surgery. Our findings provide a better understanding of ALK‐TKI in patients with two novel ALK concomitant fusions. Key points A lung adenocarcinoma patient harboring concurrent NLRC4‐ALK and EML4‐ALK fusion mutations benefited from crizotinib after surgery. Our findings provide important information for future treatment decision‐making in patients with double ALK fusions.