Detection of circulating genetically abnormal cells in peripheral blood for early diagnosis of non-small cell lung cancer.

BACKGROUND: Circulating genetically abnormal cells (CACs) with specific chromosome variations have been confirmed to be present in non-small cell lung cancer (NSCLC). However, the diagnostic performance of CAC detection remains unclear. This study aimed to evaluate the potential clinical application of the CAC test for the early diagnosis of NSCLC. METHODS: In this prospective study, a total of 339 participants (261 lung cancer patients and 78 healthy volunteers) were enrolled. An antigen-independent fluorescence in situ hybridization was used to enumerate the number of CACs in peripheral blood. RESULTS: Patients with early-stage NSCLC were found to have a significantly higher number of CACs than those of healthy participants (1.34 vs. 0.19; P < 0.001). The CAC test displayed an area under the receiver operating characteristic (ROC) curve of 0.76139 for discriminating stage I NSCLC from healthy participants with 67.2% sensitivity and 80.8% specificity, respectively. Compared with serum tumor markers, the sensitivity of CAC assays for distinguishing early-stage NSCLC was higher (67.2% vs. 48.7%, P < 0.001), especially in NSCLC patients with small nodules (65.4% vs. 36.5%, P = 0.003) and ground-glass nodules (pure GGNs: 66.7% vs. 40.9%, P = 0.003; mixed GGNs: 73.0% vs. 43.2%, P < 0.001). CONCLUSIONS: CAC detection in early stage NSCLC was feasible. Our study showed that CACs could be used as a promising noninvasive biomarker for the early diagnosis of NSCLC. KEY POINTS: What this study adds: This study aimed to evaluate the potential clinical application of the CAC test for the early diagnosis of NSCLC. Significant findings of the study: CAC detection in early stage NSCLC was feasible. Our study showed that CACs could be used as a promising noninvasive biomarker for the early diagnosis of NSCLC.

LncRNA H19 downregulation confers erlotinib resistance through upregulation of PKM2 and phosphorylation of AKT in EGFR-mutant lung cancers.

First-generation EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib have significant activity in NSCLC patients with activating EGFR mutations. However, EGFR-TKI resistance inevitably occurs after approximately 12 months of treatment. Acquired mechanisms of resistance, other than secondary mutations in EGFR (T790 M) which account for 50-60%, are less well understood. Here, we identified lncRNA H19 as a significantly downregulated lncRNA in vitro models and clinical specimens with acquired EGFR-TKI resistance, H19 knockdown or overexpression conferred resistance or sensitivity, respectively, both in vitro and in vivo models. H19 downregulation contributed to erlotinib resistance through interaction and upregulation of PKM2, which enhanced the phosphorylation of AKT. AKT inhibitors restored the sensitivity of erlotinib-resistant cells to erlotinib. In EGFR-mutant patients treated with EGFR-TKIs, low H19 levels were associated with a shorter progression-free survival (PFS) (P = 0.021). These findings revealed a novel mechanism of low-level H19 in the regulation of erlotinib resistance in EGFR-mutant lung cancers. Combination of AKT inhibitors and EGFR-TKIs could be a rational therapeutic approach for some subgroups of EGFR-mutant lung cancer patients.