Circulating free tumor-derived DNA to detect EGFR mutations in patients with advanced NSCLC: French subset analysis of the ASSESS study

Non-Small Cell Lung Cancer: Targetable Variants in Concurrent Tissue and Liquid Biopsy Testing in a North Indian Cohort

OBJECTIVES

Testing for EGFR, ALK, ROS1 and MET alterations in paired tissue and plasma samples of treatment-naïve patients of NSCLC and correlating their status with overall survival.

MATERIALS AND METHODS

One hundred treatment-naïve patients were recruited after obtaining informed consent. Ten ml of blood was collected within a period of two weeks from histological diagnosis, prior to the start of any treatment. DNA & RNA extraction was done from formalin-fixed paraffin embedded (FFPE) tissue and total cell-free nucleic acid extraction was done from plasma samples. EGFR mutation, ALK, ROS1 and MET rearrangements were tested by ARMS (Amplification Refractory Mutation System) PCR. All statistical analyses were conducted in R version 4.1.1.

RESULTS

A total of 61 cases showed molecular alterations in tissue samples which included EGFR mutations (47), ALK rearrangements (12), ROS1 fusion (2). MET alteration was not detected. Forty-three cases showed EGFR mutations in plasma, 26 of which were concurrently positive in tissue. Concordance observed was 62%. ALK-EML4 rearrangement, ROS1 fusion and MET were not detected in plasma samples. Sensitivity and specificity for detection of EGFR mutation in plasma were 55.3% and 67.9% respectively. Univariate Cox regression analysis showed a positive association between EGFR mutation in tissue and overall survival (HR = 0.4; 95% CI: 0.2-0.7; p = 0.003) and improved overall survival in those who received targeted therapy (HR = 0.29; 95% CI: 0.1-0.8; p = 0.02).

CONCLUSION

Concurrent testing in tissue and liquid biopsy in NSCLC increased the detection of EGFR mutations (47% to 64%). This has substantial implications in deciding treatment and administration targeted therapy and the consequent overall survival.

Dual NGS Comparative Analysis of Liquid Biopsy (LB) and Formalin-Fixed Paraffin-Embedded (FFPE) Samples of Non-Small Cell Lung Carcinoma (NSCLC)

Lung cancer ranks second worldwide after breast cancer and third in Europe after breast and colorectal cancers when both sexes and all ages are considered. In this context, the aim of this study was to emphasize the power of dual analysis of the molecular profile both in tumor tissue and plasma by NGS assay as a liquid biopsy approach with impact on prognosis and therapy modulation in NSCLC patients. NGS analysis was performed both from tissue biopsies and from cfNAs isolated from peripheral blood samples. Out of all 29 different mutations detectable by both NGS panels (plasma and tumor tissue), seven different variants (24.13%; EGFR L858R in two patients, KRAS G13D and Q61H and TP53 G244D, V197M, R213P, and R273H) were detected only in plasma and not in the tumor itself. These mutations were detected in seven different patients, two of them having known distant organ metastasis. Our data show that NGS analysis of cfDNA could identify actionable mutations in advanced NSCLC and, therefore, this analysis could be used to monitor the disease progression and the treatment response and even to modulate the therapy in real time.

Results of a worldwide external quality assessment of cfDNA testing in lung Cancer

BACKGROUND

Circulating cell free DNA (cfDNA) testing of plasma for EGFR somatic variants in lung cancer patients is being widely implemented and with any new service, external quality assessment (EQA) is required to ensure patient safety. An international consortium, International Quality Network for Pathology (IQNPath), has delivered a second round of assessment to measure the accuracy of cfDNA testing for lung cancer and the interpretation of the results.

METHODS

A collaboration of five EQA provider organisations, all members of IQNPath, have delivered the assessment during 2018-19 to a total of 264 laboratories from 45 countries. Bespoke plasma reference material containing a range of EGFR mutations at varying allelic frequencies were supplied to laboratories for testing and reporting according to routine procedures. The genotyping accuracy and clinical reporting was reviewed against standardised criteria and feedback was provided to participants.

RESULTS

The overall genotyping error rate in the EQA was found to be 11.1%. Low allelic frequency samples were the most challenging and were not detected by some testing methods, resulting in critical genotyping errors. This was reflected in higher false negative rates for samples with variant allele frequencies (VAF) rates less than 1.5% compared to higher frequencies. A sample with two different EGFR mutations gave inconsistent detection of both mutations. However, for one sample, where two variants were present at a VAF of less than 1% then both mutations were correctly detected in 145/263 laboratories. Reports often did not address the risk that tumour DNA may have not been tested and limitations of the methodologies provided by participants were insufficient. This was reflected in the average interpretation score for the EQA being 1.49 out of a maximum of 2.

CONCLUSIONS

The variability in the standard of genotyping and reporting highlighted the need for EQA and educational guidance in this field to ensure the delivery of high-quality clinical services where testing of cfDNA is the only option for clinical management.

Clinical Utility of Plasma Cell-Free DNA EGFR Mutation Analysis in Treatment-Naïve Stage IV Non-Small Cell Lung Cancer Patients

Background: Plasma cell-free Deoxyribo nucleic acid epidermal growth factor receptor (EGFR) mutation tests are widely used at initial diagnosis and at progression in stage IV non-small cell lung cancer (NSCLC). We analyzed the factors associated with plasma EGFR mutation detection and the effect of plasma EGFR genotyping on the clinical outcomes of the patients with treatment-naïve stage IV NSCLC. Methods: In this retrospective cohort study, we included subjects with treatment-naïve stage IV NSCLC who underwent plasma EGFR genotyping between 2018 and 2020. The presence of plasma EGFR mutation was determined by real-time polymeric chain reaction. Results: The prevalence of EGFR mutation in this cohort was 52.7% (164/311). Among 164 EGFR mutant subjects, 34 (20.7%) were positive for the plasma EGFR mutation assay only. In multivariable analysis, the detection of plasma EGFR mutation was significantly related to higher serum carcinoembryonic antigen levels, never-smoker status, N3 stage, and brain or intrathoracic metastasis. The time to treatment initiation (TTI) of the plasma EGFR mutation-positive group (14 days) was shorter than that of the plasma EGFR mutation-negative group (21 days, p < 0.001). More patients received the 1st line EGFR-TKI in the plasma positive group compared with the tissue positive group. Conclusion: Smoking status and the factors reflecting tumor burden were associated with the detection of plasma EGFR mutation. The plasma EGFR mutation assay can shorten the TTI, and facilitate the 1st line EGFR-TKI therapy for patients with treatment-naïve stage IV NSCLC, especially in the region of high-prevalence of EGFR mutation.

Detection of epidermal growth factor receptor mutations in peripheral blood circulating tumor DNA in patients with advanced non-small cell lung cancer: A PRISMA-compliant meta-analysis and systematic review

BACKGROUND

The epidermal growth factor receptor (EGFR) mutation status related to the treatment approach for advanced non-small cell lung cancer (NSCLC) patients. This study aimed to evaluate the diagnostic accuracy of peripheral blood circulating tumor DNA (ctDNA) in EGFR mutated advanced NSCLC patients.

METHOD

The related database was systematically searched with keywords until January 19, 2020. Studies contained the histopathological and cytological advanced NSCLC samples were included, and the diagnostic data were recorded for calculating sensitivity and specificity. I statistics were used for detecting heterogeneity across studies, and the meta-regression was performed to seek the source of heterogeneity.

RESULT

A total of 32 studies with 4527 advanced NSCLC patients were included in our meta-analysis. Among them, 87% of the patients were diagnosed as stage IV. The pooled sensitivity of peripheral blood ctDNA was 0.70 (95% CI: 0.63-0.75, I = 81.76) and the pooled specificity was 0.98 (95% CI: 0.96-0.99, I = 88.33). The meta-regression showed that the prospective study design and the ARMS detection method were the main source of heterogeneity for sensitivity (P < .05), and the publication country (Asia or non-Asia) was the main source of heterogeneity for specificity (P < .01).

CONCLUSION

ctDNA biopsy has high specificity and diagnostic accuracy in detection of EGFR mutation in advanced NSCLC patients. When the ctDNA gene test result is negative, we should fully consider the risk of missed diagnosis, and further tissue biopsy is still needed to undertake.

Smoking habit and chemo-radiotherapy and/or surgery affect the sensitivity of EGFR plasma test in non-small cell lung cancer

OBJECTIVE

This study aimed to identify the influential factors for the sensitivity of epidermal growth factor receptor (EGFR) plasma test in non-small cell lung cancer (NSCLC). The mutations were detected in tumor tissue and matched plasma samples from 125 newly diagnosed adenocarcinoma, clinical-stage IIIB-IV patients, and compared the diagnostic values of EGFR plasma test between groups of clinical characteristics. The influential factors for the sensitivity were identified and assessed by logistic regression.

RESULTS

EGFR mutations were detected in 65 (52.0%) tumor tissue and 50 (40.0%) matched plasma samples (P = 0.028). Compared to the tissue method, the concordance rate, sensitivity, and specificity of the EGFR plasma test were 86.4%, 75.4%, and 98.3%, respectively. Notably, we found that sensitivity of the test is higher in non-smokers (84.1%) compared to smokers (57.1%, P = 0.018), and in treatment naïve subjects (85.7%) compared to whom undergone chemo-radiotherapy with/without surgery before testing (56.5%, P = 0.009). Furthermore, the highest sensitivity was attained in patients without these two factors (90.3%), whilst the lowest value was noted in those with both factors (40.0%, P = 0.004). The multivariable analysis confirmed that smoking habit and treatment history have independently negative impacts on sensitivity (OR = 0.24, P = 0.019, and OR = 0.36, P = 0.047, respectively).

The Diagnostic Accuracy of Liquid Biopsy in EGFR-Mutated NSCLC: A Systematic Review and Meta-Analysis of 40 Studies

Epidermal growth factor receptor (EGFR) mutations are the most common carcinogenic driver mutations in non-small-cell lung cancer (NSCLC) patients, while invasive tissue biopsy has certain inherent defects. PubMed, Ovid Medline, Embase, and the Cochrane Library were systematically searched on January 4, 2020, using the keywords "liquid biopsy," "EGFR," and "NSCLC." The pooled sensitivity and specificity of EGFR mutations in paired tissue and blood were calculated. The accuracy was assessed by receiver operating characteristic curve. The meta-regression of the subgroup was performed to analyze the heterogeneity. Hazard ratio (HR) and 95% confidence interval (CI) were combined for evaluating the impact of EGFR mutation in tissue and liquid blood biopsy. A total of 40 studies with 5,995 patients were involved in the study. The pooled sensitivity was 68% (95% CI = 60-75%), and the specificity was 98% (95% CI = 95-99%). The diagnostic odds ratio was 88 (95% CI = 40-195), and the area under the curve was 0.91 (95% CI = 0.88-0.93). In the meta-regression, the sensitivity and specificity remain lower in the Asian studies than non-Asian studies (sensitivity: 66% vs. 73%, P = 0.04; specificity: 96% vs. 97%, P = 0.03, respectively). The EGFR mutation was associated with a better progression-free survival than wild type in both tissue (HR = 0.54, 95% CI = 0.34-0.85, P = 0.007) and blood (HR = 0.81, 95% CI = 0.71-0.92, P = 0.001) detection. Peripheral blood liquid biopsy had a better specificity for detecting EGFR mutation in NSCLC patients, while tissue biopsy still needs to be undertaken for negative blood biopsy patients due to its lower sensitivity.

Safety of EGFR-TKIs for EGFR mutation-positive non-small cell lung cancer

Introduction: Lung cancer is the most prevalent malignant tumors worldwide. Over the past decade, the emergence of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has ushered in a new era of lung cancer treatment. Therefore, clinical trials investigating the efficacy and safety of these drugs are important.Areas covered: This review provides an overview on the safety of three classes of EGFR-TKIs and discusses the adverse events (AEs) and reactions reported in the literature.Expert opinion: EGFR-TKIs significantly improve progression-free survival and overall survival in non-small cell lung cancer (NSCLC) patients with an activating mutation of EGFR. However, EGFR-TKIs also block the EGFR-regulating pathways in the skin and gastrointestinal tract and cause AEs, including diarrhea, liver toxicity, skin disease, stomatitis, interstitial lung disease, and ocular toxicity, which have detrimental effects on quality of life and drug compliance. Clinicians should understand how to prevent and control these adverse reactions, which can often be achieved by dose reduction, discontinuation of treatment, or switching to another drug.

Target-based genomic profiling of ctDNA from Chinese non-small cell lung cancer patients: a result of real-world data

PURPOSE

Approximately 30% of NSCLC patients cannot obtain tissue sample or sufficient tissue sample for molecular subtyping. Cell-free circulating tumor DNA (ctDNA) in plasma is a potential alternative specimen type to assess genomic variants in patients with non-small cell lung cancer (NSCLC). The purpose of this study was to identify the genomic alteration profile of ctDNA in real-world Chinese NSCLC patients.

METHODS

A total of 325 subjects with pathological diagnosis of NSCLC were enrolled. 10 ml Peripheral blood was collected in streck tube, and ctDNA NGS analysis was carried out using an Ampliseq-based 11-gene panel.

RESULTS

295 out of 325 patients (90.8%) had detected ctDNA results. In 62.1% (183/295) of these cases, at least one genomic alterations was detected. Frequency altered genes were EGFR (27.8%), TP53 (22.7%), KRAS (21.36%), and PIK3CA (4.75%). EGFR mutation was associated with female, younger age (< 65 years), and adenocarcinoma. The most common mutations in EGFR were L858R (39.4%), exon19 deletions (31.73%), and T790M (18.3%); G13S was the most common alterations in KRAS. TP53 mutation was most occurred in exon7 and exon8. TP53 mutation was significantly more common in patients with history of radiochemotherapy/chemotherapy therapy, and T790M was mainly found in patients with TKIs treatments. Co-existence EGFR mutation with KRAS and different multiple gene co-mutation panels were detected.

CONCLUSION

In Chinese NSCLC patients, EGFR mutation was significantly associated with female, younger age (< 65 years), and adenocarcinoma. Genomic profiles of NSCLC were associated with the treatment history; TP53 mutation was significantly more frequent in the patients with history of radiochemotherapy/chemotherapy therapy. Various multiple genes co-mutation panels, especially EGFR and KRAS co-mutation, were observed in the ctDNA of Chinese NSCLC patients.

Assessing the Concordance of Genomic Alterations between Circulating-Free DNA and Tumour Tissue in Cancer Patients

Somatic alterations to the genomes of solid tumours, which in some cases represent actionable drivers, provide diagnostic and prognostic insight into these complex diseases. Spatial and longitudinal tracking of somatic genomic alterations (SGAs) in patient tumours has emerged as a new avenue of investigation, not only as a disease monitoring strategy, but also to improve our understanding of heterogeneity and clonal evolution from diagnosis through disease progression. Furthermore, analysis of circulating-free DNA (cfDNA) in the so-called "liquid biopsy" has emerged as a non-invasive method to identify genomic information to inform targeted therapy and may also capture the heterogeneity of the primary and metastatic tumours. Considering the potential of cfDNA analysis as a translational laboratory tool in clinical practice, establishing the extent to which cfDNA represents the SGAs of tumours, particularly actionable driver alterations, becomes a matter of importance, warranting standardisation of methods and practices. Here, we assess the utilisation of cfDNA for molecular profiling of SGAs in tumour tissue across a broad range of solid tumours. Moreover, we examine the underlying factors contributing to discordance of detected SGAs between cfDNA and tumour tissue.