Detection Of EGFR Mutations Research Articles

Analytical Validation of a Pan-Cancer Panel for Cell-Free Assay for the Detection of EGFR Mutations.

Liquid biopsies have increasingly shown clinical utility. Although next-generation sequencing has been widely used for the detection of somatic mutations from plasma, performance characteristics vary by platform. Therefore, thorough validation is mandatory for clinical use. This study aimed to evaluate the analytical validity of the Oncomine Pan-Cancer Cell-Free Assay. A massively parallel sequencing for the assay was performed using the Ion S5 XL System with Ion 540 kit. The analytical sensitivity and precision were evaluated using pre-characterized reference materials. The specificity was evaluated using plasma from healthy subjects. A comparison with the Cobas EGFR Mutation Test v2 was performed using reference materials and plasma from lung cancer patients. For SNVs and short indels, the analytical sensitivities at variant allele frequencies (VAFs) of 0.1%, 0.5%, and 1% were 50%, 93.4%, and 100% with 20 ng of input, respectively. The overall precision of the true positive variants was 98% at a VAF of 1% with 20 ng input. The assay showed a similar sensitivity to that of the Cobas EGFR Mutation Test v2 at a VAF of 0.5% with 20 ng of input and 100% concordance on clinical samples. The Pan-Cancer Cell-Free Assay can be applied to detect EGFR mutations in advanced lung cancer patients, although follow-up studies will be needed to evaluate the analytical validity for other types of genes and aberrations using clinical samples.

Detection of EGFR Mutations in Plasma cfDNA and Paired CTCs of NSCLC Patients before and after Osimertinib Therapy Using Crystal Digital PCR.

Simple SummaryLiquid biopsy is a useful tool during longitudinal monitoring of NSCLC patients and requires highly sensitive and reliable technologies for accurate detection of genomic alterations. We evaluated and used crystal digital PCR to detect and quantify EGFR mutations in plasma cfDNA and paired CTCs of NSCLC patients before treatment with osimertinib and at progression of disease.Circulating tumor DNA (ctDNA) analysis has clinical utility in EGFR mutant NSCLC. Circulating tumor cells (CTCs) consist a unique source of information at the cellular level. Digital PCR (dPCR) is a valuable tool for accurate and valid analysis of gene mutations in liquid biopsy analysis. In the present study we detected EGFR mutations in ctDNA and paired CTCs under osimertinib therapy at two time points using crystal dPCR and the naica® system (Stilla Technologies). We quantified mutation allele frequencies (MAF) of EGFR mutations in 91 plasma cfDNA samples of 48 EGFR mutant NSCLC patients and in 64 matched CTC-derived genomic DNA samples, and the FDA-cleared cobas® EGFR mutation test in 80 identical plasma samples. Direct comparison between crystal dPCR and the cobas EGFR assay revealed a high concordance for all EGFR mutations. Our comparison of crystal dPCR results in ctDNA with the corresponding primary tissue has shown a strong correlation. EGFR mutations analysis in paired CTC-derived gDNA revealed a high heterogeneity. Crystal dPCR offers the unique advantages of high analytical sensitivity, precision, and accuracy for detecting and quantifying multiple EGFR mutations in plasma cfDNA and CTCs of NSCLC patients.

51 - Plasma cell-free DNA EGFR mutation detection in patients with non-small cell lung carcinoma using two commercially available platforms the COBAS® and Idylla™

51 - Plasma cell-free DNA EGFR mutation detection in patients with non-small cell lung carcinoma using two commercially available platforms the COBAS® and Idylla™

Evaluation of the Idylla ctEGFR mutation assay to detect EGFR mutations in plasma from patients with non-small cell lung cancers

The assessment of EGFR mutations is recommended for the management of patients with non-small cell lung cancer (NSCLC). Presence of EGFR mutation is associated with response or resistance to EGFR tyrosine kinase inhibitors (EGFR-TKI). Liquid biopsy is nowadays widely used for the detection of resistance to EGFR-TKI. We evaluated here the performance of the Idylla ctEGFR mutation assay for the detection of EGFR mutations in circulating tumour DNA (ctDNA) in plasma from patients with NSCLC. Previously characterized plasma samples from 38 patients with NSCLC were analysed using 2 different analytical conditions (C1 and C2). The limit of detection (LOD) was evaluated using 2 mL of healthy donor plasma spiked with commercial DNA controls. Overall agreement, sensitivity and specificity were 92.1%, 86.7% and 95.7% for C1 condition respectively and 94.7%, 86.7% and 100% for C2 condition respectively. The T790M secondary resistance mutation was detected in two samples out of 3. The Idylla system was able to detect the exon 19 deletion from 6 copies/mL and up to 91 copies/mL for the G719S mutation. These results support that the Idylla ctEGFR mutation assay is a rapid option for the detection of EGFR hotspots mutations in plasma samples, however a particular attention is needed for its interpretation.

Performance comparison of commercial kits for isolating and detecting of circulating tumor DNA

Circulating tumor DNA (ctDNA), a fraction of cell-free DNA (cfDNA) in the circulatory system, is released from tumor cells and thus carries tumor-specific genetic signatures. Using blood-derived ctDNA to detect somatic mutations has shown great value in guiding cancer targeted therapy. Isolation and detection efficiencies are the key factors affecting the performance of ctDNA detection. To optimize and standardize our clinical practice, in this study, we analyzed the isolation efficiency of four commercial cfDNA purification kits: QIAamp circulating nucleic acid kit, AmoyDx® Circulating DNA kits, Microdiag® circulating DNA isolation kit, and MagMAX cell-free DNA isolation kit; and the detection efficiency of two mainstream domestic EGFR gene mutation detection kits: MicroDiag EGFR gene mutation detection kit and Fluorometric real-time PCR Detection Kit for the analysis of EGFR gene mutations. Reference materials and plasma samples collected from lung cancer patients and healthy volunteers were used for the analysis. Our results showed that QIAamp circulating nucleic acid kit and Microdiag® circulating DNA kit had the highest recovery rate (up to 21.25 ng/mL) for short DNA fragments of about 173 bp which is the peak length of ctDNA. For ctDNA detection, the MicroDiag® EGFR gene mutation detection kit showed the highest detection rate and sensitivity for detecting EGFR mutations at a mutant frequency of 0.5%. This work provides a reliable choice of commercial kits for the clinical application of ctDNA.

Detection of EGFR Mutations From Plasma of NSCLC Patients Using an Automatic Cartridge-Based PCR System.

The introduction of liquid biopsies for the detection of EGFR mutations in non-small cell lung cancer patients (NSCLC) has revolutionized the clinical care. However, liquid biopsies are technically challenging and require specifically trained personnel. To facilitate the implementation of liquid biopsies for the detection of EGFR mutations from plasma, we have assessed a fully automated cartridge-based qPCR test that allows the automatic detection of EGFR mutations directly from plasma. We have analyzed 54 NSCLC patients and compared the results of the cartridge-base device to an FDA-approved assay. Detection of EGFR mutations was comparable but slightly lower in the cartridge-based device for L858R mutations (14/15 detected, 93%) and exon 19 deletions (18/20 detected, 90%). Unfortunately, 8/54 (15%) tests failed but increasing the proteinase K volume helped to recover 3/4 (75%) unsuccessful samples. In summary, the fully automated cartridge-based device allowed the detection of EGFR mutations directly from plasma in NSCLC patients with promising accuracy. However, protocol adjustments are necessary to reduce a high test failure rate.

39P Tissue vs. cobas vs. DDPCR for EGFR in NSCLC: Real-world evidence from India

Background: EGFR mutant adenocarcinoma accounts for almost 33% cases of NSCLC in the Asian population. Single gene testing on tissue blocks has been the gold standard since its discovery, however owing to the inherent technical difficulties, invasive nature, difficult accessibility to the lung may limit its use in many patients. Liquid biopsy has evolved as a value added tool for early diagnosis of biomarkers in lung cancer. Various detection methods have been employed for the detection of EGFR mutation like Cobas V2 and ddPCR.

Comparison of Biocartis IDYLLA ™ cartridge assay with Qiagen GeneReader NGS for detection of targetable mutations in EGFR, KRAS/NRAS, and BRAF genes

Lung and colorectal cancers (CRC) have two of the highest mortality rates among all cancer types, and their occurrence and the need for personalized diagnostics and subsequent therapy were not influenced by the COVID-19 pandemics. However, due to the disruption of established delivery chains, standard assays for in vitro diagnostics of those cancers were temporarily not available, forcing us to implement alternative testing methods that enabled at least basic therapy decision making. For this reason, we evaluated rapid testing on the Biocartis Idylla™ platform (Biocartis, Mechelen, Belgium) for four important genes commonly mutated in lung and colorectal cancers, namely EGFR, NRAS, KRAS, and BRAF. Clinical specimens from which the mutation status has previously been determined using Next Generation Sequencing (NGS), were retested to determine whether Idylla™ can offer accurate results. To compare the results, the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) are calculated for each of the mutation types and then combined to determine the values of the Idylla™ system in total, while setting NGS as the gold-standard basis the assays were compared with. Idylla testing thereby displayed acceptable sensitivity and specificity and delivered reliable results for initial therapy decisions.

P76.75 Clinical Outcome and Toxicity Profiles of Patients with EGFR-mutation Positive Non-Small-Cell Lung Cancer

Activating mutations of EGFR in advanced lung adenocarcinoma and its inhibition with specific tyrosine kinase inhibitors has been shown to generate clinically significant tumor responses. Treatment outcomes of advanced EGFR mutant lung carcinoma in Pakistani population are not previously reported. We conducted a study using the Real World Data (RWD) in patients with EGFR mutant advanced lung cancer treated at our institution. We evaluated clinical features, toxicity profile and outcome of these patients and compared it with those who were unable to receive TKI due to resource limitations. We identified 27 patients with advanced lung cancer harboring EGFR mutations that were treated at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan, from January 2013 till April 2020. EGFR mutation detection was achieved by real time PCR. Data were collected through electronic medical record. Five patients were excluded from the analysis as they did not start treatment and were lost to follow-up. Progression free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier curves and log-rank analysis. Of the 22 patients analyzed, 54.5% were males and 45.5% were females. Twenty patients (90.9%) presented with de novo stage IV disease. Age ranged from 34-84 years. Frequency of Exon 19 deletion, Exon 21 L858R mutation, Exon18G7196 mutation and Exon 20 mutation was 50%, 32%, 9% and 4.5% respectively. One patient had compound Exon18G719X and Exon20S7681 mutation. 18.2% of patients had CNS metastasis at initial presentation. We identified 4 groups in our patient population. Group-1 consisted of patients who received first-generation TKI followed by third-generation TKI upon progression. Group-2 consisted of patients who received upfront first-generation TKI followed by chemotherapy upon progression. Group-3 consisted of patients who received upfront chemotherapy followed by a first-generation TKI upon progression and Group-4 consisted of patients who received upfront chemotherapy followed by second-line chemotherapy upon progression. These groups reflect the real world issues of TKI affordability in a Low Middle Income country (LMIC) such as Pakistan. Median PFS on first-line treatment (PFS1) was 10.7 months in the upfront chemotherapy group, versus 14.5 months in the upfront TKI group (p-value = 0.280). Median PFS on second-line treatment (PFS2) was 4.4 months in the chemotherapy group versus 23.7 months in the TKI group (p-value = 0.001). Median OS in Group 2, 3 and 4 was 20.0, 85.6 and 26.0 months respectively and not yet reached in Group 1 (p = 0.271). 27.8% patients developed grade I-II skin rash and diarrhea, 5.6% developed grade III-IV anemia, grade I-II neutropenia, and grade III-IV hyperbilirubinemia Within the constraints of a small sample size our real world data shows that the use of EGFR TKI in advanced EGFR mutant lung cancer is well tolerated in a Pakistani population. Use of EGFR TKI yields a superior PFS in both upfront and subsequent line of therapy which is consistent with the previously reported data. Preliminary overall survival favors superior outcome in the TKI group compared to chemotherapy alone or chemo-TKI combination groups.

P37.20 Diagnostic EGFR Mutations in Non Small Cell Lung Cancer With Specimens of Body Cavity Fluids

Based on the nature of the body fluid samples, there are the presence of suspended DNA fragments that help to make an EGFR mutation diagnosis. From this principle, we conduct research with the following objectives: 1. Investigate the positive rate of EGFR mutations in body fluid samples. 2. Comparison with the same patient result diagnosed with EGFR mutation in paraffine block histological specimens. 3. Partially surveying the diagnostic value of EGFR mutations in body fluid samples. Retrospective, descriptive statistics cross-section: a. Cases of NSCLC are diagnosed with EGFR mutations by paraffine block histological specimens with Cobas Test EGFR Version 1. b. And body fluid samples (pleural fluid, pericardial fluid, peritoneal fluid, cerebrospinal fluid) with Cobas Test EGFR Version 2. a. There are 117 cases in the research: Results of EGFR mutation diagnosis on paraffine block histology: (+) 49 cases # 41.88%, equivalent to statistics in the Vietnam and the World (Asia). The majority are still two types of drug-sensitive mutants TKIs: Exon 19 Deletion and Exon 21 L858R (53% and 23%). b. Results of diagnosis of EGFR mutation in samples of body cavity fluids: Most samples of body cavity performing diagnosis of EGFR mutation were pleural fluid (91 cases # 77.77%). The highest rate of detection of mutations in pleural and cerebrospinal fluid samples (29.67% & 83.33%). Comparing the rate of detection of EGFR mutation in body fluid samples (35/117 cases # 29.91%) with the statistically lower rate of detection in histological samples (29.91% ↔ 41, 88% with P = 0.0125). Compared with other studies in the world, the majority of studies have higher results than those at Pham Ngoc Thach Hospital. Investigation of EGFR mutations in body cavity fluids, a positive result of 29.91% shows that this is a new application step to help diagnose EGFR mutations in cases where histological specimens are difficult to obtain. Especially in cases of NSCLC progresses. The ability to detect EGFR mutations was highest in pleural fluid (29.67%) and cerebrospinal fluid (83.33%). It is necessary to improve the technique of performing EGFR mutant diagnosis in body cavity samples with the more sensitive methods: Droplet Digital PCR, Next Generation Sequencing ect.

P02.06 A Novel Loop-Mediated Isothermal Amplification Method for Robust Detection of EGFR Mutations

P02.06 A Novel Loop-Mediated Isothermal Amplification Method for Robust Detection of EGFR Mutations

Radiomic Detection of EGFR Mutations in NSCLC

Radiomics is defined as the use of automated or semi-automated post-processing and analysis of multiple features derived from imaging exams. Extracted features might generate models able to predict the molecular profile of solid tumors. The aim of this study was to develop a predictive algorithm to define the mutational status of EGFR in treatment-naïve patients with advanced non-small cell lung cancer (NSCLC). CT scans from 109 treatment-naïve patients with NSCLC (21 EGFR-mutant and 88 EGFR-wild type) underwent radiomics analysis to develop a machine learning model able to recognize EGFR-mutant from EGFR-WT patients via CT scans. A "test-retest" approach was used to identify stable radiomics features. The accuracy of the model was tested on an external validation set from another institution and on a dataset from the Cancer Imaging Archive (TCIA). The machine learning model that considered both radiomic and clinical features (gender and smoking status) reached a diagnostic accuracy of 88.1% in our dataset with an AUC at the ROC curve of 0.85, whereas the accuracy values in the datasets from TCIA and the external institution were 76.6% and 83.3%, respectively. Furthermore, 17 distinct radiomics features detected at baseline CT scan were associated with subsequent development of T790M during treatment with an EGFR inhibitor. In conclusion, our machine learning model was able to identify EGFR-mutant patients in multiple validation sets with globally good accuracy, especially after data optimization. More comprehensive training sets might result in further improvement of radiomics-based algorithms. SIGNIFICANCE: These findings demonstrate that data normalization and "test-retest" methods might improve the performance of machine learning models on radiomics images and increase their reliability when used on external validation datasets.

Comparative study of the loop-mediated isothermal amplification method and the QIAGEN therascreen PCR kit for the detection of EGFR mutations in non-small cell lung cancer.

BackgroundEpidermal growth factor receptor (EGFR) mutations are important biomarkers in the treatment of patients with advanced or metastatic diseases. The therascreen EGFR Rotor-Gene Q (RGQ) PCR Kit® (Qiagen, Inc.) is an approved diagnostic test for EGFR mutations in non-small cell lung cancer (NSCLC). This study aims to investigate the diagnostic capability of a loop-mediated isothermal amplification (LAMP) assay as an accurate, efficient, and cost-effective alternative to the therascreen assay.MethodsEGFR mutations were investigated by LAMP and therascreen assays using tissue samples that were surgically resected or biopsied from 117 consecutive patients with NSCLC tumors. The EGFR status from the LAMP assay was compared with that of the therascreen assay. Next-generation sequencing (NGS) was performed to confirm EGFR status of tumors that did not match in both assays. To establish an optimal LAMP AUC value, receiver operating characteristics (ROC) curve analysis was performed within tumors with exon 19 deletion or L858R point mutation.ResultsOf the 117 tumors assayed, 45 tumors with EGFR mutations and 68 tumors with EGFR wild type were matched in both assays, four tumors having mismatched EGFR statuses. NGS further confirmed that two of the four discordant tumors had the same EGFR status that was determined by the LAMP assay. The AUC values were 0.973 (95% CI: 0.929–1.00) in exon 19 deletion, and 0.952 (95% CI: 0.885–1.00) in L858R point mutation. In exon 19 deletion, sensitivity, specificity, and accuracy were 89.3%, 98.9%, and 96.6%, respectively, and 94.7%, 95.9%, and 95.7%, respectively, in L858R using AUC value of 0.222.ConclusionsThe LAMP assay compared favorably with the therascreen assay and has potential as an effective, simple, rapid, and low-cost diagnostic alternative. Based on these results, a liquid biopsy LAMP system should be developed for point-of-care testing of oncogenes in the near future.

EGFR mutation detection of lung circulating tumor cells using a multifunctional microfluidic chip

Microfluidics has become a reliable platform for circulating tumor cells (CTCs) detection because of its high integration, small size, low consumption of reagents and rapid response. Here, we developed a multifunctional microfluidic device consists of three parts, including CTCs capture area, single-layer membrane valves area, and microcavity nucleic acid detection and analysis region based on digital polymerase chain reaction (dPCR), allowing CTCs capture, lysis, and genetic characterization to be performed on a single chip. The CTCs capture chip is coupled to the nucleic acid detection chip via a control valve. CTCs were firstly trapped in the CTC capture area, and then lysed using proteinase K to release nucleic acids. Subsequently CTCs lysate was transferred into nucleic acid detection area consisting of 12800 micro-cavity chambers for nucleic acids detection. To evaluate the performance of this chip, this study detected EGFR-L858R mutation in lung cancer cell lines H1975 and A549 cells, as well as leukocytes from normal donors. The results showed that positive signals were only observed in H1975 cells, and the detected value had a high linear relationship with the expected value (R2 = 0.9897). In conclusion, this multi-functional microfluidic chip that integrates CTCs capture, lysis and nucleic acid detection can successfully detect gene mutations in CTCs, providing reference for tumor-targeted drugs and precise diagnosis and treatment.

Positive Mutation of EGFR Inhibitor Undergo Erlotinib, Gefitinib, Icotinib or Osimertinib Plus Chinese Medicine Versus EGFRTKIs Alone In Patients With NSCLC, A Regional Study East China

Management of non-small cell lung cancer has been changed dramatically since detection of EGFR mutation. The rate of EGFR mutation in East China is unknown. In China, lung cancer is the most frequently diagnosed cancer and the leading cause of cancer-related mortality. The five-year survival rate in patients with lung cancer varies from 3.7–32.9%, depending on stage and regional differences. The majority of the tumors were Stage IIIB or IV Advanced Lung Adenocarcinoma. The two year survival rate of the patients was 70.6%, the overall survival was 58.8%. Methods: We electronically searched CNKI, Pub Med, Cochrane from database inception and manually searched Chinese-language oncology journals to identify A Positive Mutation of EGFR Inhibitor Undergo Erlotinib, Gefitinib, Icotinib Or Osimertinib Plus Chinese Medicine Versus Erlotinib, Gefitinib, Icotinib Or Osimertinib Alone In Patients With NSCLC, A Regional Study East China. The quality of the included trials was assessed using the method of Cochrane. If heterogeneity existed among subgroups, then overall results (OS) were calculated based on a random-effects model; otherwise, a fixed effects model used. Results: Electronic database searches yielded 1450 citations with NSCLC. We identified full text articles retrieved for detailled evaluation 70. Sample size of each trial had calculated by Rev Man 5.3.

Combined assay of Circulating Tumor DNA and Protein Biomarkers for early noninvasive detection and prognosis of Non-Small Cell Lung Cancer.

Purpose: Early diagnosis of lung cancer is critical to curtailing cancer-related deaths. We aimed to develop a highly sensitive assay for the analysis of circulating tumor DNA (ctDNA) to detect non-small cell lung cancer (NSCLC) in the early stages.Materials and Methods: We detected EGFR and KRAS mutations in paired plasma and tumor tissue samples from 147 NSCLC patients. Of these, EGFR/KRAS ctDNA mutations and protein biomarkers were comparatively analyzed in 87 individuals. In addition, tissue samples of 20 patients were subjected to repeat multi-gene detection, and pre- and post-operative paired samples of 28 patients were subjected to multi-gene detection. Clinical information was obtained to complement the prognostic value of the combined assay results and post-operative new ctDNA mutation status.Results: EGFR/KRAS mutations were highly consistent in ctDNA and tumor DNA. Combining the detection of EGFR and KRAS mutations in ctDNA with the detection of protein biomarkers increased cancer detection sensitivity to 74.7% (65/87). None of the healthy controls tested positive using the combined assay (100% specificity). Combined assay results independently associated with recurrence-free survival. Post-operative new ctDNA mutation status independently associated with overall survival and recurrence-free survival.Conclusion: The detection of ctDNA may be exploited for early diagnosis of NSCLC, as highlighted by the developed assay. Further, the combined assay results and post-operative new ctDNA mutation status are promising prognostic indicators in NSCLC patients.

6-Color Crystal Digital PCRTM for the High-Plex Detection of EGFR Mutations in Non-Small Cell Lung Cancer.

The profiling of EGFR mutations, the most common genetic alterations in non-small cell lung cancer (NSCLC) predictive of targeted therapy efficacy, is crucial to anticipate the patient response to EGFR tyrosine kinase inhibitors. Here, we introduce the naica® system for 6-color Crystal Digital PCRTM and describe in detail a standardized workflow for the multiplexed, single-assay detection of the 19 most prevalent sensitizing and resistance EGFR mutations in both tumor and circulating tumor DNA (ctDNA) samples. Two major advantages of the 6-color multiplexing system over current digital PCR systems are the rapid time to results, and the large quantity of mutational information obtained per patient sample, rendering the 6-color system highly cost effective. The 6-color CrystalDigital PCRTM technology enables highly sensitive and efficient therapeutic monitoring through liquid biopsy, resulting in the early detection of treatment resistance. While the assay presented here specifically addresses EGFR mutation status monitoring in NSCLC patients, 6-color Crystal Digital PCRTM assays are flexible and evolutive in design. As such, 6-color detection assays can be optimized to monitor mutations associated with a range of cancers and other genetic diseases, as well as to detect genetic changes beyond the oncology and human health domains.

Detection of EGFR Activating and Resistance Mutations by Droplet Digital PCR in Sputum of EGFR-Mutated NSCLC Patients.

Background:Proof of the T790M resistance mutation is mandatory if patients with EGFR-mutated non-small cell lung cancer (NSCLC) progress under first- or second-generation tyrosine kinase inhibitor therapy. In addition to rebiopsy, analysis of plasma circulating tumor DNA is used to detect T790M resistance mutation. We studied whether sputum is another feasible specimen for detection of EGFR mutations.Methods:Twenty-eight patients with advanced EGFR-mutated NSCLC were included during stable and/or progressive disease. The initial activating EGFR mutations (exon 19 deletions or L858R mutations) at stable disease and at progressive disease (together with T790M) were assessed in simultaneously collected plasma and sputum samples and detected by droplet digital polymerase chain reaction (ddPCR).Results:Activating EGFR mutations were detected in 47% of the plasma samples and 41% of sputum samples during stable disease, and in 57% of plasma samples and 64% of sputum samples during progressive disease. T790M was detected in 44% of the plasma samples and 66% of the sputum samples at progressive disease. In ddPCR T790M-negative results for both specimens (plasma and sputum), negativity was confirmed by rebiopsy in 5 samples. Concordance rate of plasma and sputum for T790M was 0.86, with a positive percent agreement of 1.0 and a negative percent agreement of 0.80.Conclusions:We demonstrated that EGFR mutation analysis with ddPCR is feasible in sputum samples. Combination of plasma and sputum analyses for detection of T790M in NSCLC patients with progressive disease increases the diagnostic yield compared with molecular plasma analysis alone.

Prognostic significance of longitudinal evaluation on egfr mutant ctdna during tki treatment in nsclc

Detection of EGFR mutations in tumor tissue is the gold standard for prescribing tyrosine kinase inhibitor therapy.However even in the same molecularly defined population effect of the treatment, response duration and survival might differ significantly. We did a prospective clinical trial to assess ctDNA-based EGFR mutations as a prognostic marker for patients with lung adenocarcinoma receiving TKI as first-line treatment.

Comparison of the analytical performance between the Oncomine Dx Target Test and a conventional single gene test for epidermal growth factor receptor mutation in non‐small cell lung cancer

BackgroundNext‐generation sequencing (NGS) has been implemented in clinical oncology to analyze multiple genes and to guide targeted therapy; however, little is known about the performance of the Oncomine Dx Target Test compared with conventional single gene tests for detecting EGFR mutations. The objective of this study was to evaluate the performance of the Oncomine Dx Target Test compared with a PNA‐LNA PCR clamp test to detect EGFR mutations.MethodsWe retrospectively reviewed consecutive patients with non‐small cell lung cancer (NSCLC) from whom FFPE samples were simultaneously submitted for the Oncomine Dx Target Test, and a PNA‐LNA PCR clamp test using the same specimen. We subsequently compared the analysis success rates and detection rates between the two tests.ResultsA total of 116 samples were identified. The success rates and detection rates of EGFR mutations in the total number of samples were 90% and 28%, respectively for the Oncomine Dx Target Test, and 100% and 35% for the PNA‐LNA PCR clamp test. The Oncomine Dx Target Test was unable to analyze three samples (2%) due to the samples not passing the nucleic acid concentration threshold, and nine (8%) samples had invalid results. The exon 19 deletion was not detected by the Oncomine Dx Target Test in four cases (4%).ConclusionsThe analytical performance of the Oncomine Dx Target Test analysis for EGFR mutations may not be comparable with conventional single gene tests due to both invalid and false‐negative results.Key pointsSignificant findings of the study The success rate of the Oncomine Dx Target Test was significantly lower than the PNA‐LNA PCR clamp test.Among the samples successfully analyzed, four exon 19 deletions were not detected by the Oncomine Dx Target Test. What this study adds The analytical performance of the Oncomine Dx Target Test may not be comparable with conventional single gene tests.We should revise the sampling procedures, and review the sample quality assessment methods, to improve the analytical performance.