Survival rates in non-small cell lung cancer (NSCLC) are low. Detection of circulating tumor DNA in liquid biopsy (plasma) is increasingly used to identify targeted therapies for clinically actionable mutations, including EGFR mutations in NSCLC. The cobas® EGFR Mutation Test v2 (cobas EGFR test) is FDA-approved for EGFR mutation detection in tissue or liquid biopsy from NSCLC. Standard K2EDTA tubes require plasma separation from blood within 4 to 8 hours; however, Roche Cell-Free DNA (cfDNA) Collection Tubes (Roche cfDNA tube) enable whole blood stability for up to 7 days prior to plasma separation. This analysis assessed performance of Roche cfDNA tubes with the cobas EGFR test for the detection of EGFR mutations in plasma from healthy donors or patients with NSCLC. Overall, test performance was equally robust with either blood collection tube, eg, regarding limit of detection, linearity, and reproducibility, making Roche cfDNA tubes suitable for routine clinical laboratory use in this setting. Importantly, the Roche cfDNA tubes provided more flexibility for specimen handling versus K2EDTA tubes, eg, in terms of tube mixing, plasma separation, and sample stability, and do not require processing of blood within 8 hours thereby increasing the reach of plasma biopsies in NSCLC.

Background and aims Studies suggest that mutations in the CTNNB1 gene are predictive of response to immunotherapy, an emerging therapy for advanced hepatocellular carcinoma (HCC). Analysis of circulating tumor DNA (ctDNA) offers the possibility of serial non-invasive mutational profiling of tumors. Combining tumor tissue and ctDNA analysis may increase the detection rate of mutations. This study aimed to evaluate the frequency of the CTNNB1 p.T41A mutation in ctDNA and tumor samples from HCC patients and to evaluate the concordance rates between plasma and tissue. We further evaluated changes in ctDNA after various HCC treatment modalities and the impact of the CTNNB1 p.T41A mutation on the clinical course of HCC. Methods We used droplet digital PCR to analyze plasma from 95 patients and the corresponding tumor samples from 37 patients during 3 years follow up. Results In tumor tissue samples, the mutation rate was 8.1% (3/37). In ctDNA from HCC patients, the CTNNB1 mutation rate was 9.5% (9/95) in the pre-treatment samples. Adding results from plasma analysis to the subgroup of patients with available tissue samples, the mutation detection rate increased to 13.5% (5/37). There was no difference in overall survival according to CTNNB1 mutational status. Serial testing of ctDNA suggested a possible clonal evolution of HCC or arising multicentric tumors with separate genetic profiles in individual patients. Conclusion Combining analysis of ctDNA and tumor tissue increased the detection rate of CTNNB1 mutation in HCC patients. A liquid biopsy approach may be useful in a tailored therapy of HCC.

BACKGROUND:Intrinsic resistance is a major obstacle in treatment of non-small cell lung cancer (NSCLC) patients with an activating mutation in the epidermal growth factor receptor (EGFR). We investigated co-occurring genetic alterations in circulating tumor DNA (ctDNA) as predictive markers of clinical response to first-line erlotinib.METHODS:Pretreatment plasma samples were collected from 76 patients with EGFR-mutated, advanced-stage NSCLC treated with first-line erlotinib. We isolated ctDNA from plasma for next-generation sequencing.RESULTS:Co-occurring oncogenic drivers were detected in 21% of pretreatment samples and correlated with decreased progression-free survival (PFS) (6.9 months vs 14.4 months; hazard ratio [HR], 2.088; 95% confidence interval [CI], 0.8119-5.370; P = .0355). Concurrent MET amplification was identified in 9 samples (12%), predicting inferior PFS (5.5 months vs 14.4 months; HR, 4.750; 95% CI, 0.5923-38.10; P = .0007) and overall survival (7.6 months vs 28.3 months; HR, 3.952; 95% CI, 0.8441-18.50; P = .0005). Co-occurring non-MET-amplification oncogenic alterations showed a tendency for shorter PFS (9.9 months vs 14.4 months; HR, 1.199; 95% CI, 0.3373-4.265; P = .7586). Clearing EGFR-mutated ctDNA during erlotinib treatment is a positive predictor of clinical outcomes. Among patients who cleared the EGFR mutation, 12% had a co-occurring oncogenic driver, with a tendency toward inferior PFS (8.7 months vs 16.1 months; HR, 1.703; 95% CI, 0.5347-5.424; P = .2508).CONCLUSION:Co-occurring MET amplification in pretreatment ctDNA samples predict inferior clinical response to first-line erlotinib in advanced-stage, EGFR-mutated NSCLC patients. Co-occurring oncogenic alterations were associated with inferior response and may be potential predictors of clinical outcome.

Background: Tyrosine kinase inhibitor (TKI) resistance is a major obstacle in treatment of non-small cell lung cancer (NSCLC). MET amplification drives resistance to EGFR-TKIs in 5-20% of initially sensitive EGFR-mutated NSCLC patients, and combined treatment with EGFR-TKIs and MET-TKIs can overcome this resistance. Yet, inevitably MET-TKI resistance will also occur. Hence, knowledge on development of this sequential resistance is important for identifying the proper next step in treatment. Methods: To investigate sequential resistance to MET-TKI treatment, we established a two-step TKI resistance model in EGFR-mutated HCC827 cells with MET amplification-mediated erlotinib resistance. These cells were subsequently treated with increasing doses of the MET-TKIs capmatinib or crizotinib in combination with erlotinib to establish resistance. Results: In all the MET-TKI resistant cell lines, we systematically observed epithelial-to-mesenchymal transition (EMT) evident by decreased expression of E-cadherin and increased expression of vimentin and ZEB1. Furthermore, FGFR1 expression was increased in all MET-TKI resistant cell lines and four out of the six resistant cell lines had increased sensitivity to FGFR inhibition, indicating FGFR1-mediated bypass signaling. Conclusions: EMT is common in the development of sequential EGFR-TKI and MET-TKI resistance in NSCLC cells. Our findings contribute to the evidence of EMT as a common TKI resistance mechanism.

Currently there are five EGFR tyrosine kinase inhibitors (TKIs) available for the treatment of EGFR-mutated non-small cell lung cancer (NSCLC). However drug resistance is inevitable for virtually all patients and disease progression occurs within 1 to 2 years of starting a TKI. Third-generation agents, such as osimertinib, show improved response rates and extended median overall survival (OS), with potential to overcome previously untreatable resistance mechanisms. However acquired resistance mutations and activation of bypass RTK signalling mechanisms can mediate primary and secondary resistance to all EGFR TKIs. We have identfied activated STAT3 pathway signalling in an erlotinib resistant cell line model HCC827ER compared to the erlotinib sensitive parent cells HCC827P. pSTAT3 and PIM-1 kinase expression is activated in the total resistant cell population (HCC827ER) as well as the EMT-like HCC827ER subclone 10 cells compared to HCC827P cells. MET amplified HCC827ER subclone 3 cells show elevated PIM-1 expression. Exposure to pan-PIM inhibitor (AZD1208) alone and in combination with erlotinib resulted in a decrease in protein kinase phosphorylation in Clone 3 but had little effect on Clone 10 cells. Here, we examine the efficacy of STAT3 pathway inhibitor BBI608 alone and in combination with erlotinib in the erlotinib sensitive and resistant cells. BBI608 is a small molecule STAT3 inhibitor known to suppress cancer relapse, progression and metastasis. We hypothesise that co-targeting STAT3 and EGFR may provide a more durable response to treatment and overcome EGFR TKI resistance.

Abstract Background and aims Plasma circulating tumor DNA (ctDNA) with tumor-specific mutations is an attractive biomarker. The telomerase reverse transcriptase (TERT) C228T promoter mutation is the most prevalent tumor-associated mutation in hepatocellular carcinoma (HCC). We evaluated the presence and prognostic value of the TERT C228T mutation in plasma and tissue in a Danish HCC cohort. Methods We analyzed ctDNA from 95 HCC patients and 45 liver cirrhotic patients without HCC for the TERT mutation using droplet digital polymerase chain reaction. We also analyzed DNA from the corresponding primary tumor tissues in 34 HCC patients. Results The plasma TERT C228T mutation was detected in 42/95 HCC patients (44%) but in none of the non-HCC patients. The TERT mutation was detected in 23/34 tumor samples (68%). The TERT mutation was associated with increased mortality when detected in plasma (adjusted HR 2.16 (1.20–3.88), p = .010) but not in tumor tissue (adjusted HR 1.11 (0.35–3.56), p = .860). There was a positive correlation between the presence of the TERT mutation in plasma and an advanced TNM stage (p < .0001) and vascular invasion (p = .005). Analysis of the TERT mutation in plasma and tumor DNA from the same patient was concordant in 21/34 samples (62%; kappa value 0.31, p = .014). Non-concordance was associated with an early TNM stage. Conclusion The plasma TERT mutation was detected in 44% of HCC patients and in none of non-HCC cirrhotic patients; and was associated with increased mortality. We propose the TERT C228T mutation in ctDNA as a promising HCC biomarker for prognosis.

Objectives: MiR-30b, miR-30c, miR-221 and miR-222 are known to induce gefitinib resistance in lung cancer cell lines with activation of mutations in the epidermal growth factor receptor (EGFR). However, the role of these four microRNAs in tyrosine kinase inhibitor (TKI)-resistance in non-small cell lung cancer (NSCLC) patients is unknown. Thus, the aim of this study was to investigate the predictive value of miR-30b, miR-30c, miR-221 and miR-222 in plasma from EGFR-mutated lung cancer patients receiving erlotinib. Materials and methods: The cohort consisted of 29 EGFR-mutated lung cancer patients receiving erlotinib. Plasma levels of miR-30b, miR-30c, miR-221 and miR-222 were analyzed by qPCR from blood samples collected before treatment start. Plasma concentration of each microRNA was correlated to clinical outcome. Results: Plasma concentrations of miR-30b and miR-30c could be determined in all 29 patients. Low plasma concentrations of miR-30b and miR-30c showed significant correlation with superior progression-free survival (PFS) (miR-30b: HR = 0.303 [0.123-0.747], p < 0.05; miR-30c: HR = 0.264 [0.103-0.674], p < 0.05). Low plasma concentrations of miR-30c were also significantly correlated with superior overall survival (OS) (HR = 0.30 [0.094-0.954], p < 0.041). Conclusion: High plasma concentrations of miR-30b and miR-30c predicted shorter PFS and OS. This implies that miR-30b and miR-30c could have clinical potential as biomarkers in EGFR-mutated lung cancer patients.

Non-small cell lung carcinoma patients with epidermal growth factor receptor (EGFR) mutations are offered EGFR tyrosine kinase inhibitors (TKI) as first line treatment, but 20–40% of these patients do not respond. High expression of alternative receptor tyrosine kinases, such as Fibroblast growth factor receptor 1 (FGFR1), potentially mediates intrinsic EGFR TKI resistance. To study this in molecular detail, we used CRISPR-dCas9 Synergistic Activation Mediator (SAM) for up-regulation of FGFR1 in physiological relevant levels in the EGFR mutated NSCLC cell lines HCC827 and PC9 thereby generating HCC827gFGFR1 and PC9gFGFR1. The sensitivity to the TKI erlotinib was investigated in vitro and in a BALBc nu/nu mouse xenograft model. FGFR1 up-regulation decreased TKI-sensitivity in both NSCLC cell lines in the presence of the ligand fibroblast growth factor 2 (FGF2). Xenografts were established with PC9gFGFR1 cells and it was demonstrated that there was no significant difference in tumor size between TKI- and vehicle-treated PC9gFGFR1 tumors. This supports decreased TKI-sensitivity in NSCLC cells with FGFR1 up-regulation. Our study points to FGFR1 signaling being an intrinsic resistance mechanism abolishing TKI response in EGFR mutated NSCLC.