[Crizotinib Treatment for Lorlatinib-resistant MET-amplified EML4-ALK-fusion Positive Advanced Lung Adenocarcinoma: A Case Report].

Lung cancer is a major cause of cancer-related mortality worldwide. Among patients with non-small cell lung cancer (NSCLC), approximately 3%-7% harbor anaplastic lymphoma kinase (ALK) gene fusions. In recent years, multiple tyrosine kinase inhibitors (TKIs) have significantly improved the survival of patients with metastatic ALK-positive NSCLC. However, disease progression due to resistance remains a challenge. This article retrospectively analyzes a case of advanced lung adenocarcinoma with the echinoderm microtubule associated protein like 4 (EML4)-ALK fusion variant 3 (V3). The patient developed resistance to Lorlatinib treatment accompanied by mesenchymal-epithelial transition factor (MET) amplification. Effective tumor control was achieved with the combined use of Crizotinib and Lorlatinib, providing a valuable reference for further exploration of treatment strategies following resistance to ALK-TKIs in clinical practice. .