Detection of epidermal growth factor receptor (EGFR) mutations from preoperative circulating tumor DNA (ctDNA) as a prognostic predictor for stage I-III non-small cell lung cancer (NSCLC) patients with baseline tissue EGFR mutations

Values of circulating tumor DNA for non-small cell lung cancer patients receiving neoadjuvant therapy, progress and challenges: a narrative review

Background and Objective

The value of circulating tumor DNA (ctDNA) in neoadjuvant therapy (NAT) for lung cancer remains controversial. Therefore, we conducted a review to further investigate the role of ctDNA in non-small cell lung cancer (NSCLC) patients undergoing NAT for individualized management.

Methods

A search of online databases (PubMed, Embase, Web of Science, Science Direct, and Cochrane Library) was conducted to evaluate the value of ctDNA in predicting relapse, risk stratification, and efficacy of NAT in NSCLC. Only articles published in English within the last 25 years, between January 1st, 1998 and November 30th, 2023, were included. Additionally, the application of ctDNA in NSCLC is briefly reviewed.

Key Content and Findings

ctDNA is a non-invasive and dynamic method that plays an important role in future treatment guidance. Additionally, ctDNA successfully predicted the effect of neoadjuvant immunotherapy before surgery, and positive testing was strongly correlated with a lower major pathological response or complete pathological response rate. Sequential testing of ctDNA may serve as a secondary indicator to guide the adjustment of treatment programs. However, the application of this method has been limited by false negative results, a lack of objective indicators, and high costs. These issues must be addressed by researchers.

Conclusions

ctDNA has strong potential in NAT, based on positive preliminary studies. However, its widespread use is limited by the high cost of testing. Further research is needed to explore its value in risk stratification and treatment guidance in the future.

Clinical application of ctDNA in early diagnosis, treatment and prognosis of patients with non-small cell lung cancer

Lung cancer is one of the most common malignancies worldwide, with non-small cell lung cancer (NSCLC) being the most common type. As understanding of precise treatment options for NSCLC deepens, circulating tumor DNA (ctDNA) has emerged as a potential biomarker that has become a research hotspot and may represent a new approach for the individualized diagnosis and treatment of NSCLC. This article reviews the applications of ctDNA for the early screening of patients with NSCLC, guiding targeted therapy and immunotherapy, evaluating chemotherapy and postoperative efficacy, assessing prognosis and monitoring recurrence. With the in-depth study of the pathogenesis of NSCLC, plasma ctDNA may become an indispensable part of the precise treatment of NSCLC, which has great clinical application prospects.

Dual-probe ligation without PCR for fluorescent sandwich assay of EGFR nucleotide variants in magnetic gene capture platform

A simple, rapid, and highly efficient fluorescent detection technique without PCR through dual-probe ligation with the genetic capture of magnetic beads and reported probe was developed for determination of epidermal growth factor receptor (EGFR) gene exon 19 deletions. The EGFR exon 19 deletion mutation makes up 48% of all mutations associated with anti-tyrosine kinase inhibition sensitivity, and thus, the EGFR nucleotide variant is very important in clinical diagnosis. In this approach, the dual-probe ligation was designed to target exon 19 deletion. The magnetic genetic captured system was then applied to capture the successful dual-probe ligation. Thereafter, a reporter probe which is coupled with 6-fluorescein amidite (6-FAM) was introduced to hybridize with dual-probe ligation product on the surface of streptavidin magnetic beads, and finally, the supernatant was taken for fluorescence measurements for distinguishing mutant types from wild types. After optimization (the RSD of the fluorescent intensity was less than 4.5% (n = 3) under the optimal condition), 20 blind DNA samples from the population were analyzed by this technique and further confirmed by direct sequencing. The results of our assay matched to those from direct sequencing data, evidencing that the developed method is accurate and successful. These 20 blind DNA samples were diagnosed as wild and then spiked with different percentages of the mutant gene to quantify the ratio of the wild and mutant genes. This strategy was also successfully applied to quantify the ratio of the wild and mutant genes with good linearity at the λex/λem of 480 nm/520 nm (r = 0.996), and the limit of detection reached 1.0% mutant type. This simple fluorescent detection of nucleotide variants shows its potential to be considered a tool in biological and clinical diagnosis. Importantly, this strategy offers a universal detection capability for any kind of mutation (point, deletion, insertion, or substitution) in a gene of interest.

Clinical implications of ctDNA for EGFR-TKIs as first-line treatment in NSCLC

PURPOSE

This study aimed to explore the clinical implications of ctDNA for epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) as the first-line treatment in EGFR-mutated (EGFRm) non-small cell lung cancer (NSCLC) in real-world settings.

METHODS

A total of 122 patients with NSCLC who underwent tissue and liquid next generation sequencing (NGS) tests were included. 66 patients with detected EGFR mutation in both tumor-tissue and plasma were included into the EGFR^{t+, p+} group, and 56 patients with EGFR mutation detected only in tumor-tissue were included into the EGFR^{t+, p-} group. The differences in clinical characteristics, concomitant mutations and prognosis between the two groups were compared.

RESULTS

The detection rate of the EGFR^{t+, p+} group was 54.1% (66/122). EGFR^{t+, p+} in the NGS test was particularly relevant to the size of tumors, liver metastasis, bone metastasis and TP53 mutation. In patients with TP53 mutation in ctDNA, the detection rate of EGFR mutation in ctDNA was up to 91.3%. EGFR^{t+, p+} could be an independent prognostic factor for first-line EGFR-TKIs treatment. Combination therapy seems to be a promising approach to improve the outcome for EGFR^{t+, p+} (P = 0.017, HR 0.509 [95% CI 0.288-0.897]). Moreover, the combination of TP53 mutated status and EGFRm status in plasma showed a better completion of risk stratification for PFS (Log-rank P < 0.001).

CONCLUSIONS

Co-detection of EGFR mutation in tumor tissue and plasma is an independent prognostic factor for first-line EGFR-TKIs treatment. Moreover, combination therapy could be a promising approach to improve the outcome for these patients.

Can Liquid Biopsy Based on ctDNA/cfDNA Replace Tissue Biopsy for the Precision Treatment of EGFR-Mutated NSCLC?

More and more clinical trials have explored the role of liquid biopsy in the diagnosis and treatment of EGFR-mutated NSCLC. In certain circumstances, liquid biopsy has unique advantages and offers a new way to detect therapeutic targets, analyze drug resistance mechanisms in advanced patients, and monitor MRD in patients with operable NSCLC. Although its potential cannot be ignored, more evidence is needed to support the transition from the research stage to clinical application. We reviewed the latest progress in research on the efficacy and resistance mechanisms of targeted therapy for advanced NSCLC patients with plasma ctDNA EGFR mutation and the evaluation of MRD based on ctDNA detection in perioperative and follow-up monitoring.

Potential clinical utility of liquid biopsy in early-stage non-small cell lung cancer

BACKGROUND

Liquid biopsy has been widely researched for early diagnosis, prognostication and disease monitoring in lung cancer, but there is a need to investigate its clinical utility for early-stage non-small cell lung cancer (NSCLC).

METHODS

We performed a meta-analysis and systematic review to evaluate diagnostic and prognostic values of liquid biopsy for early-stage NSCLC, regarding the common biomarkers, circulating tumor cells, circulating tumor DNA (ctDNA), methylation signatures, and microRNAs. Cochrane Library, PubMed, EMBASE databases, ClinicalTrials.gov, and reference lists were searched for eligible studies since inception to 17 May 2022. Sensitivity, specificity and area under the curve (AUC) were assessed for diagnostic values. Hazard ratio (HR) with a 95% confidence interval (CI) was extracted from the recurrence-free survival (RFS) and overall survival (OS) plots for prognostic analysis. Also, potential predictive values and treatment response evaluation were further investigated.

RESULTS

In this meta-analysis, there were 34 studies eligible for diagnostic assessment and 21 for prognostic analysis. The estimated diagnostic values of biomarkers for early-stage NSCLC with AUCs ranged from 0.84 to 0.87. The factors TNM stage I, T1 stage, N0 stage, adenocarcinoma, young age, and nonsmoking contributed to a lower tumor burden, with a median cell-free DNA concentration of 8.64 ng/ml. For prognostic analysis, the presence of molecular residual disease (MRD) detection was a strong predictor of disease relapse (RFS, HR, 4.95; 95% CI, 3.06-8.02; p < 0.001) and inferior OS (HR, 3.93; 95% CI, 1.97-7.83; p < 0.001), with average lead time of 179 ± 74 days between molecular recurrence and radiographic progression. Predictive values analysis showed adjuvant therapy significantly benefited the RFS of MRD + patients (HR, 0.27; p < 0.001), while an opposite tendency was detected for MRD - patients (HR, 1.51; p = 0.19). For treatment response evaluation, a strong correlation between pathological response and ctDNA clearance was detected, and both were associated with longer survival after neoadjuvant therapy.

CONCLUSIONS

In conclusion, our study indicated liquid biopsy could reliably facilitate more precision and effective management of early-stage NSCLC. Improvement of liquid biopsy techniques and detection approaches and platforms is still needed, and higher-quality trials are required to provide more rigorous evidence prior to their routine clinical application.

Prognostic Value of Circulating Tumor DNA (ctDNA) in Oncogene-Driven NSCLC: Current Knowledge and Future Perspectives

As we enter an unprecedented era of personalized medicine, molecular targeted therapies have the potential to induce improved survival outcome in patients with non-small cell lung cancer (NSCLC). However, a significant percentage of oncogene-driven NSCLC patients will relapse even after definitive treatment, whereas chronic and durable response to targeted therapies is a less common event in advanced-stage lung cancer. This phenomenon could be attributed to minimal residual disease (MRD), defined as a population of disseminated tumor cells that survive during the course or after treatment, eventually leading to recurrence and limiting patient survival. Circulating tumor DNA (ctDNA) is a powerful biomarker for MRD detection and monitoring and is a non-invasive approach of treating cancer, and especially NSCLC, based on a real-time assessment of the tumor genomic landscape. In this review, we present the key findings of studies that have used ctDNA with regard to its prognostic value and in respect to the most common druggable driver mutations of genes in NSCLC, such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), rearranged during transfection (RET), Kirsten rat sarcoma virus (KRAS), B-Raf proto-oncogene (BRAF), and mesenchymal epithelial transition factor receptor (MET).

Prognostic potential of circulating tumor DNA detection at different time periods in resectable non-small cell lung cancer: Evidence from a meta-analysis

This study was undertaken to evaluate the prognostic significance of circulating tumour DNA (ctDNA) detection at different time periods in resectable non-small cell lung cancer (NSCLC). A comprehensive search strategy was conducted through the electronic platforms published up to June 2022. In total, 7 studies with 1138 patients were included. Patients with positive ctDNA have an increased risk of recurrence and mortality. The association between risk of recurrence and detectable ctDNA after surgery 3 days-2 weeks and 1-3 months was stronger than detected at 1 week before surgery. The predictive value of longitudinal detection ctDNA for recurrence and mortality was not stronger than at other time periods. In conclusion, ctDNA is a promising biomarker for predictive recurrence and survival in resectable NSCLC patients. The ctDNA detection after surgery 3 days-2 weeks with more reliably and feasible in identifying resectable NSCLC patients at high risk for recurrence.

Clinicopathologic Features and Molecular Biomarkers as Predictors of Epidermal Growth Factor Receptor Gene Mutation in Non-Small Cell Lung Cancer Patients

Lung cancer ranks first in the incidence and mortality of cancer in the world, of which more than 80% are non-small cell lung cancer (NSCLC). The majority of NSCLC patients are in stage IIIB~IV when they are admitted to hospital and have no opportunity for surgery. Compared with traditional chemotherapy, specific targeted therapy has a higher selectivity and fewer adverse reactions, providing a new treatment direction for advanced NSCLC patients. Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are the widely used targeted therapy for NSCLC patients. Their efficacy and prognosis are closely related to the mutation status of the EGFR gene. Clinically, detecting EGFR gene mutation is often limited by difficulty obtaining tissue specimens, limited detecting technology, and economic conditions, so it is of great clinical significance to find indicators to predict EGFR gene mutation status. Clinicopathological characteristics, tumor markers, liquid biopsy, and other predictors are less invasive, economical, and easier to obtain. They can be monitored in real-time, which is supposed to predict EGFR mutation status and provide guidance for the accurate, individualized diagnosis and therapy of NSCLC patients. This article reviewed the correlation between the clinical indicators and EGFR gene mutation status in NSCLC patients.