A non-small cell lung carcinoma patient responded to crizotinib therapy after alectinib-induced interstitial lung disease / 浙江大学学报·医学版

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.

Potential unreliability of ALK variant allele frequency in the efficacy prediction of targeted therapy in NSCLC / 医学前沿

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.

Which Tyrosine Kinase Inhibitor Must We Apply Before? A Case Report of Crizotinib-resistant Patient with Concomitant EGFR and EML4-ALK Gene Mutations

ABSTRACT The concomitant epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) translocations in lung adenocancers are very rare scenarios. Until now, 42 cases described in the literature have all been treated by different drugs. There is no overall consensus regarding the treatment for this adenocarcinoma subgroup. We report here a case of lung adenocarcinoma with concomitant EGFR mutation in exon 21 (L858R) and ALK rearrangement in primary tumour, EGFR mutation in exon 21 (L858R) and no ALK rearrangement in its synchronous metastasis. We treated this patient with crizotinib as the second-line therapy (after the first line docetaxel-cisplatin chemotherapy), but no response was obtained. The therapeutic choice for the lung adenocancer patients with concomitant EGFR mutation and ALK rearrangement is unclear. Examination of c-ros oncogene 1 mutation can be used as an indicator in the prediction of the crizotinib treatment success. The ALK mutation may not responsible for the resistance to EGFR-tyrosine kinase inhibitors (TKI), and EGFR-TKI can be initiated to EGFR and ALK dual mutant patients as the first treatment.