[Different Gene Mutation Spectrum of the Paired CSF and Plasma Samples in Lung Adenocarcinoma with Leptomeningeal Metastases: the Liquid Biopsy Based on Circulating Tumor DNA].
ABSTRACT: BACKGROUND:Leptomeningeal metastasis (LM) are a severe complication of non-small cell lung cancer (NSCLC), and normally accompanied by poor prognosis. For the patients with targetable mutations, epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are the preferred treatment, but the acquired TKI resistance is inextricable. The aim of this study is to analyze the different gene mutation spectrum and mutation frequency of the cerebrospinal ?uid (CSF) and plasma in NSCLC patients with LM, and screen out the drug-resistant mutations so as to guide the choice of treatment accurately. METHODS:The paired CSF and plasma samples were collected from the NSCLC-LM patients with acquired TKI resistance. Next generation sequencing (NGS) was used to detect the gene variations of circulating tumor DNA (ctDNA). RESULTS:A total of 18 NSCLC patients with LM were collected. Of the basic mutations, 11 cases (61.11%) were EGFR, 6 cases (33.33%) were anaplastic lymphoma kinase (ALK), and 1 case (5.56%) was ROS proto-oncogene 1, receptor tyrosine kinase (ROS1). Tumor protein p53 gene (TP53) and mesenchymal-epithelial transition factor (MET) were the two most frequently accompanying mutated genes in CSF ctDNA. The detected mutation rate of CSF samples was higher than that of plasma samples (100.00% vs 66.67%, P=0.006), and the maximum allelic fractions were all higher in CSF than in plasma (P<0.001). Abundant single-nucleotide variations (SNV) and copy number variants (CNV) were detected in CSF, the amount of both of which were more than in blood. In addition, the CSF and plasma samples of patients treated with several TKIs had more SNV mutations than patients who received only a single TKI treatment. CONCLUSIONS:For the patients of NSCLC, ctDNA in CSF could reveal genomic alterations of LM more exactly and overally than it in plasma, thus could be an optimal source of liquid biopsy for guiding therapy, monitoring therapeutic effect, and predicting prognosis.
Project description:Background: The significance of uncommon epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC) and brain metastasis (BM) remains unclear. Cerebrospinal fluid (CSF) liquid biopsy is a novel tool for assessing EGFR mutations in BM. This study aimed to evaluate the EGFR mutations in patients with NSCLC and newly diagnosed BM and to examine the effect of EGFR tyrosine kinase inhibitors (TKI) on BM harboring CSF-tested uncommon EGFR mutations. Methods: This was a prospective study of 21 patients with NSCLC and BM diagnosed between 04/2018 and 01/2019. CSF was obtained to detect the BM EGFR mutations by next-generation sequencing. BM characteristics at magnetic resonance imaging (MRI) and EGFR-TKI response were examined. Results: Of 21 patients with NSCLC, 10 (47.6%) had leptomeningeal metastasis (LM), while 11 (52.4%) had brain parenchymal metastasis (BPM); 13 (61.9%) had confirmed EGFR mutation-positive primary tumors. The uncommon mutation rate in CSF ctDNA was 33.3% (7/21). Among those with EGFR mutation-positive primary tumors, the rate of uncommon EGFR mutations in CSF was 53.8% (7/13). Uncommon EGFR mutations were more common in patients with LM than in patients with PBM (6/11, 54.5% vs. 1/10, 10%), and included G719A, L861Q, L703P, and G575R. TKI was effective for four patients with BMs harboring uncommon EGFR mutations. Conclusion: In patients with NSCLC and LM, the rate of uncommon EGFR mutation was high. The BMs with uncommon EGFR mutations seem to respond to EGFR-TKI treatment. CSF liquid biopsy could reveal the EGFR genetic profile of the BM and help guide treatment using small-molecule TKI.
Project description:Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are standard treatments for advanced non-small-cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations. Nowadays, tumor tissues acquired by surgery or biopsy are the routine materials for EGFR mutation analysis. However, the accessibility of tumor tissues is not always satisfactory in advanced NSCLC. Moreover, a high proportion of NSCLC patients will eventually develop resistance to EGFR-TKIs. Invasive procedures, such as surgery or biopsy, are impractical to be performed repeatedly to assess the evolution of EGFR-TKI resistance. Thus, exploring some convenient and less invasive techniques to monitor EGFR-TKI treatment is urgently needed. Circulating cell-free tumor DNA (ctDNA) has a high degree of specificity to detect EGFR mutations in NSCLC. Besides, ctDNA is capable of monitoring the disease progression during EGFR-TKI treatment. Certain serum microRNAs that correlate with EGFR signaling pathway, such as miR-21 and miR-10b, have been demonstrated to be helpful in evaluating the efficiency of EGFR-TKI therapeutics. A commercialized serum-based proteomic test, named VeriStrat test, has shown an outstanding ability to predict the clinical outcome of NSCLC patients receiving EGFR-TKIs. Analysis of EGFR mutations in circulating tumor cells (CTCs) is feasible, and CTCs represent a promising material to predict EGFR-TKI-treatment efficacy and resistance. These evidences suggested that non-invasive techniques based on serum or plasma samples had a great potential for monitoring EGFR-TKI treatment in NSCLC. In this review, we summarized these non-invasive approaches and considered their possible applications in EGFR-TKI-treatment monitoring.
Project description:INTRODUCTION:Despite initial effectiveness of ALK receptor tyrosine kinase inhibitors (TKIs) in patients with ALK+ NSCLC, therapeutic resistance will ultimately develop. Serial tracking of genetic alterations detected in circulating tumor DNA (ctDNA) can be an informative strategy to identify response and resistance. This study evaluated the utility of analyzing ctDNA as a function of response to ensartinib, a potent second-generation ALK TKI. METHODS:Pre-treatment plasma was collected from 76 patients with ALK+ NSCLC who were ALK TKI-naive or had received prior ALK TKI, and analyzed for specific genetic alterations. Longitudinal plasma samples were analyzed from a subset (n = 11) of patients. Analysis of pre-treatment tumor biopsy specimens from 22 patients was compared with plasma. RESULTS:Disease-associated genetic alterations were detected in 74% (56 of 76) of patients, the most common being EML4-ALK. Concordance of ALK fusion between plasma and tissue was 91% (20 of 22 blood and tissue samples). Twenty-four ALK kinase domain mutations were detected in 15 patients, all had previously received an ALK TKI; G1269A was the most prevalent (4 of 24). Patients with a detectable EML4-ALK variant 1 (V1) fusion had improved response (9 of 17 patients; 53%) to ensartinib compared to patients with EML4-ALK V3 fusion (one of seven patients; 14%). Serial changes in ALK alterations were observed during therapy. CONCLUSIONS:Clinical utility of ctDNA was shown, both at pre-treatment by identifying a potential subgroup of ALK+ NSCLC patients who may derive more benefit from ensartinib and longitudinally by tracking resistance. Prospective application of this technology may translate to improved outcomes for NSCLC patients treated with ALK TKIs.
Project description:This study was conducted to identify whether the presence of circulating tumor DNA (ctDNA) in plasma before treatment with EGFR-tyrosine kinase inhibitors (TKIs) is associated with clinical outcomes.Fifty-seven pairs of tissues and plasma samples were obtained from patients with NSCLC adenocarcinoma harboring activating EGFR mutations before the administration of EGFR-TKI treatment. ctDNA mutation was identified using the PANAMutyper EGFR mutation kit. Both qualitative and quantitative analyzes of the data were performed.Concordance rates with tissue biopsy were 40.4% and 59.6% for the qualitative and quantitative methods, respectively. Bone metastasis showed a statistically significant correlation with ctDNA detection (odds ratio 3.985, 95% confidence interval [CI] 1.027-15.457; P?=?0.046). Progression-free survival (PFS) was significantly shorter in the group detected with ctDNA than in the undetected ctDNA group (median PFS 9.8 vs. 20.7?months; hazard ratio [HR] 2.30, 95% CI 1.202-4.385; P?=?0.012). Detection of ctDNA before treatment with EGFR-TKIs (HR 2.388, 95% CI 1.138-5.014; P?=?0.021) and extra-thoracic lymph node metastasis (HR 13.533, 95% CI 2.474-68.747; P?=?0.002) were independently associated with PFS. Six of 11 patients (45.5%) monitored by serial sampling showed a dynamic change in ctDNA prior to disease progression.Quantitative testing can increase the sensitivity of the ctDNA detection test. Patients with detectable ctDNA had significantly shorter PFS after receiving EGFR-TKIs than those with undetectable ctDNA. Tumor burden may be associated with plasma ctDNA detection. A shorter PFS was associated with detection of ctDNA and extra-thoracic lymph node metastasis. Dynamic changes in the ctDNA level may help predict clinical outcomes.
Project description:EGFR T790M mutation occurs in half of non-small cell lung cancer (NSCLC) patients with acquired EGFR-TKI (TKI) resistance, based on tumor re-biopsies using an invasive clinical procedure. Here, we dynamically monitored T790M mutation in circulating tumor DNA (ctDNA) using serial plasma samples from NSCLC patients receiving TKI through Droplet Digital PCR (ddPCR) method and the associations between overall survival (OS) starting from initial TKI treatment and the T790M ctDNA status detected in plasma were analyzed. Among 318 patients, 117 who acquired TKI resistance were eligible for the analysis. T790M ctDNA was detected in the plasma of 55/117 (47%) patients. Almost half of the T790M ctDNA positive patients were identified at a median time of 2.2 months prior to clinically progressive disease (PD). Furthermore, within the patients receiving TKI treatment at 2(nd) line or later, the T790M ctDNA positive group had significantly shorter OS than the negative group (median OS: 26.9 months versus NA, P?=?0.0489). Our study demonstrates the feasibility of monitoring EGFR mutation dynamics in serial plasma samples from NSCLC patients receiving TKI therapy. T790M ctDNA can be detected in plasma before and after PD as a poor prognostic factor.
Project description:INTRODUCTION:Plasma circulating tumor DNA (ctDNA) is an ideal approach to detecting the epidermal growth factor receptor (EGFR) T790M mutation, which is a major mechanism of resistance to first-generation EGFR-tyrosine kinase inhibitor (TKI) therapy. The present study aimed to explore the association of ctDNA-identified T790M mutation with disease failure sites and clinical prognosis in non-small cell lung cancer (NSCLC) patients. METHODS:Patients who progressed on first-generation TKIs were categorized into failure site groups of chest limited (CF), brain limited (BF) and other (OF). Amplification refractory mutation system (ARMS) and droplet digital PCR (ddPCR) were used to identify the T790M mutation in ctDNA. Prognosis was analyzed with Kaplan-Meier methods. RESULTS:Overall concordance between the two methods was 78.3%. According to both ARMS and ddPCR, patients in the OF group had a significantly higher rate of T790M mutation than did patients in the BF and CF groups (P?<?0.001), and a significantly higher T790M mutation rate was also observed in OF-group patients than in those in the CF and BF groups (P?<?0.001). AZD9291 was found to be an excellent treatment option and yielded the longest survival for T790M+ patients in all groups who had progressed on EGFR-TKIs; for other treatments, the prognosis of T790M- patient subgroups varied. CONCLUSIONS:The present study demonstrates that T790M mutation in ctDNA is associated with failure sites for NSCLC patients after EGFR-TKI therapy and indicates that both failure site and T790M mutational status greatly influence treatment selection and prognosis.
Project description:BACKGROUND:The demonstration of EGFR T790M gene mutation in plasma is crucial to assess the eligibility of Non Small Cell Lung Cancer (NSCLC) patients, who have acquired resistance to first or second generation Tyrosine Kinase Inhibitors (TKIs), to receive a subsequent treatment with osimertinib. Since circulating tumor DNA (ctDNA) is present in very low amounts in plasma, high sensitive and specific methods are required for molecular analysis. Improving sensitivity of T790M mutation detection in plasma ctDNA enables a larger number of NSCLC patients to receive the appropriate therapy without any further invasive procedure. METHODS:A tag-based next generation sequencing (NGS) platform capable of tagging rare circulating tumor DNA alleles was employed in this study for the identification of T790M mutation in 42 post-TKI NSCLC patients. RESULTS:Compared to Real Time PCR, tag-based NGS improved the T790M detection rate (42.85% versus 21.4%, respectively), especially in those cases with a low median mutation abundance (i.e. 0.24, range 0.07-0.78). Moreover, the tag-based NGS identified EGFR activating mutations more efficiently than Real Time PCR (85.7% versus 61.9% detection rate, respectively), particularly of the L858R variant type (0.06-0.75 mutation abundance range). Patients in whom the T790M mutation was detected in plasma, achieved an objective response to osimertinib (9/14, 64.28%). CONCLUSIONS:Tag-based NGS represents an accurate and sensitive tool in a clinical setting for non-invasive assessment and monitoring of T790M variant in NSCLC patients.
Project description:EGFR (exon 19 and exon 21) mutations in patients with advanced non-small cell lung cancer (NSCLC) treated by EGFR-TKIs are associated with a better survival; while KRAS mutations predict a worse prognosis. However, there are divergent findings regarding the prognostic value of EGFR and KRAS mutations in circulating tumor DNA (ctDNA). We aimed to summarize the evidence for the use of circulating EGFR and KRAS mutations as prognostic factors in advanced NSCLC patients.We searched the network databases for studies reporting progression-free survival (PFS) and overall survival (OS) stratified by EGFR or KRAS mutations in ctDNA in advanced NSCLC patients. Thirteen studies enrolling 2,293 patients were reviewed. Correlation of circulating EGFR or KRAS mutations with patients' prognosis was assessed by meta-analysis.The pooled analyses showed that EGFR mutations in ctDNA significantly prolong PFS (HR=0.64,95% CI 0.51-0.81, I2=0%, p=0.0002), namely, in patients treated by EGFR-TKIs. There is a trend to have a prolonged OS for advanced NSCLC patients with circulating EGFR mutations who were treated by EGFR-TKIs (HR=0.79, 95% CI 0.52-1.21, I2=0, p=0.28). KRAS mutations detected in ctDNA predict a worse PFS (HR=1.83, 95% CI 1.40-2.40, p<0.0001) and OS (HR=2.07, 95% CI 1.54-2.78, p<0.00001) in advanced NSCLC patients treated by chemotherapy. Sensitivity analyses and subgroup analyses demonstrated the stability of our conclusion.Our analysis showed that EGFR mutations in ctDNA predicted a better PFS, in particular in advanced NSCLC patients treated by EGFR-TKIs. KRAS mutations in ctDNA indicated a worse PFS and OS in patients treated by chemotherapy.
Project description:BACKGROUND:Leptomeningeal metastases (LM), associated with poor prognosis, are frequent complications of advanced non-small cell lung cancer (NSCLC) patients, especially in patients with epidermal growth factor receptor (EGFR) mutations. Due to limited access to leptomeningeal lesions, the mutational landscape of LM has not been comprehensively investigated in large cohorts and the underlining biology of LM remains elusive. Some studies have explored the potential of cerebrospinal fluid (CSF) in reflecting the molecular profile of LM but with limited number of patients enrolled. METHODS:In this study, we performed capture-based targeted sequencing using a panel consisting of 168 lung cancer-related genes on matched CSF and plasma samples from 72 advanced NSCLC patients with confirmed LM to interrogate the potential of CSF as a source of liquid biopsy. RESULTS:We revealed a rate of detection of 81.5% and 62.5% for CSF and plasma, respectively (p = 0.008). The maximum allelic fraction (MaxAF) was also significantly higher in CSF (43.6% vs. 4.6%) (p < 0.001). CSF, harboring a unique genomic profile by having a significant number of CSF-specific mutations, primarily copy number variations, is superior to plasma in reflecting the mutational profile of LM. Further pathway enrichment analysis revealed that most of CSF-specific mutations participated in pathways relevant to the tumorigenesis and the development of metastases. Moreover, our data also revealed that TP53 loss of heterozygosity (LOH) predominantly existed in CSF (p < 0.001). CONCLUSIONS:Collectively, we demonstrated that CSF provides a more comprehensive profile of LM than plasma in a large cohort, thus can be used as an alternative source of liquid biopsy for LM patients.
Project description:There are few effective treatment options for leptomeningeal metastasis (LM) in non-small-cell lung cancer (NSCLC). This study assessed the feasibility of high-dose gefitinib in patients with LM from NSCLC harboring EGFR mutations or prior systemic response to EGFR-TKI.This phase I open-label trial of a novel gefitinib dosing schedule employed a 3+3 design. Eligible NSCLC patients with LM had known EGFR mutations and/or prior response to EGFR-TKI. Patients alternated 2 weeks of high-dose daily gefitinib (dose levels: 750 mg, 1000 mg, 1250 mg) with 2 weeks of maintenance therapy (500 mg daily). Primary endpoints were safety and toxicity. Secondary endpoints included overall survival (OS), neurological progression-free survival, radiological response, and cytological response in cerebrospinal fluid (CSF).Seven patients were treated: 3 at 750 mg dose level, 4 at 1000 mg dose level. There were no DLTs at the 750 mg dose level, and one DLT (toxic epidermal necrolysis) at the 1000 mg dose level. The study was closed due to slow accrual. Median neurological PFS was 2.3 months (range 1.6-4.0 months); median OS was 3.5 months (range 1.6-5.1 months). Though there were no radiologically documented remissions of LM disease, four patients had improvement in neurological symptoms. One patient cleared their CSF of NSCLC cells, while 2 others had decrease in malignant cells in CSF.Although the MTD was not defined due to slow accrual, this study provides important information about the tolerability and CSF penetration of high-dose gefitinib as a therapeutic option for modest palliation for NSCLC patients with LM and a known EGFR mutation.