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.
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Humans ; Adenocarcinoma/genetics* ; Adenocarcinoma of Lung/genetics* ; Aminopyridines/therapeutic use* ; Crizotinib/therapeutic use* ; Drug Resistance, Neoplasm/drug effects* ; Lactams/therapeutic use* ; Lung Neoplasms/genetics* ; Oncogene Proteins, Fusion/metabolism* ; Protein Kinase Inhibitors/therapeutic use* ; Proto-Oncogene Proteins c-met/metabolism* ; Pyrazoles/therapeutic use*

A 54-year-old, non-smoking woman was diagnosed as stage ⅣB adenocarcinoma with widespread bone metastasis (cT4N2M1c) in the First Affiliated Hospital, Zhejiang University School of Medicine. Immunohistochemistry result showed the presence of anaplastic lymphoma kinase (ALK) gene rearrangement; next-generation sequencing (NGS) indicated EML4-ALK fusion (E6:A20) with concurrent CCDC148-ALK (C1:A20), PKDCC-ALK (Pintergenic:A20)and VIT-ALK (V15:A20) fusions. After 32 weeks of alectinib treatment, the patient complained cough and exertional chest distress but had no sign of infection. Computed tomography (CT) showed bilateral diffuse ground glass opacities, suggesting a diagnosis of alectinib-related interstitial lung disease (ILD). Following corticosteroid treatment and discontinuation of alectinib, clinical presentations and CT scan gradually improved, but the primary lung lesions enlarged during the regular follow-up. The administration of crizotinib was then initiated and the disease was stable for 25 months without recurrence of primary lung lesions and ILD.
Female ; Humans ; Middle Aged ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Crizotinib/therapeutic use* ; Lung Neoplasms/drug therapy* ; Anaplastic Lymphoma Kinase/therapeutic use* ; Lung Diseases, Interstitial/diagnosis*

Anaplastic lymphoma kinase (ALK) is the most common fusion gene involved in non-small cell lung cancer (NSCLC), and remarkable response has been achieved with the use of ALK tyrosine kinase inhibitors (ALK-TKIs). However, the clinical efficacy is highly variable. Pre-existing intratumoral heterogeneity (ITH) has been proven to contribute to the poor treatment response and the resistance to targeted therapies. In this work, we investigated whether the variant allele frequencies (VAFs) of ALK fusions can help assess ITH and predict targeted therapy efficacy. Through the application of next-generation sequencing (NGS), 7.2% (326/4548) of patients were detected to be ALK positive. On the basis of the adjusted VAF (adjVAF, VAF normalization for tumor purity) of four different threshold values (adjVAF < 50%, 40%, 30%, or 20%), the association of ALK subclonality with crizotinib efficacy was assessed. Nonetheless, no statistical association was observed between median progression-free survival (PFS) and ALK subclonality assessed by adjVAF, and a poor correlation of adjVAF with PFS was found among the 85 patients who received first-line crizotinib. Results suggest that the ALK VAF determined by hybrid capture-based NGS is probably unreliable for ITH assessment and targeted therapy efficacy prediction in NSCLC.
Humans ; Carcinoma, Non-Small-Cell Lung/pathology* ; Anaplastic Lymphoma Kinase/therapeutic use* ; Crizotinib/therapeutic use* ; Lung Neoplasms/pathology* ; Protein Kinase Inhibitors/pharmacology* ; Gene Frequency

Acrylamides ; Aniline Compounds ; Carcinoma, Non-Small-Cell Lung/genetics* ; Crizotinib/therapeutic use* ; Drug Resistance, Neoplasm/genetics* ; Erlotinib Hydrochloride/therapeutic use* ; Humans ; Lung Neoplasms/genetics* ; Mutation ; Protein Kinase Inhibitors/therapeutic use* ; Proto-Oncogene Proteins c-met/genetics*