Coexistence of a primary ALK-positive and MET14 exon skipping mutation double-fusion in one patient with NSCLC and response to crizotinib: A case report and literature review.

[RATIONALE] Lung cancer exhibits one of the highest incidence and fatality rates globally. With the advancement of next-generation sequencing testing techniques, double or multiple gene driver mutations have been identified in certain patients.

[PATIENT CONCERNS] A 78-year-old female presented with a chest shadow.

[DIAGNOSES] In this case of lung adenocarcinoma, second-generation sequencing revealed a co-occurrence of echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase and MET exon 14 skipping mutation.

[INTERVENTIONS] Crizotinib was administered orally on August 31, 2022, resulting in a partial response and progression-free survival for a duration of 8 months. After 8 months of treatment, the patient's disease progressed, after which the treatment dose of crizotinib was increased; the patient's condition improved again.

[OUTCOMES] Over 4 months of increased-dose oral crizotinib treatment, the patient achieved durable partial response, with significant reduction in tumor burden and without new metastases.

[LESSONS] This report supports crizotinib can provide potential benefit for anaplastic lymphoma kinase/MET14 co-mutated lung adenocarcinoma patients, but sufficient cases and further research are needed to confirm and explore the possible mechanisms involved.