Association Between Plasma Genotyping and Outcomes of Treatment With Osimertinib (AZD9291) in Advanced Non-Small-Cell Lung Cancer

Early Metabolic Response by PET Predicts Sensitivity to Next-Line Targeted Therapy in EGFR-Mutated Lung Cancer with Unknown Mechanism of Acquired Resistance

Targeted therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has established the precision oncology paradigm in lung cancer. Most patients with EGFR-mutated lung cancer respond but eventually acquire resistance. Methods: Patients exhibiting the EGFR p.T790M resistance biomarker benefit from sequenced targeted therapy with osimertinib. We hypothesized that metabolic response as detected by 18F-FDG PET after short-course osimertinib identifies additional patients susceptible to sequenced therapy. Results: Fourteen patients with EGFR-mutated lung cancer and resistance to first- or second-generation EGFR TKI testing negatively for EGFR p.T790M were enrolled in a phase II study. Five patients (36%) achieved a metabolic 18F-FDG PET response and continued osimertinib. In those, the median duration of treatment was not reached (95% CI, 24 mo to not estimable), median progression-free survival was 18.7 mo (95% CI, 14.6 mo to not estimable), and median overall survival was 41.5 mo. Conclusion: Connecting theranostic osimertinib treatment with early metabolic response assessment by PET enables early identification of patients with unknown mechanisms of TKI resistance who derive dramatic clinical benefit from sequenced osimertinib. This defines a novel paradigm for personalization of targeted therapies in patients with lung cancer dependent on a tractable driver oncogene.

Unlocking the future of cancer diagnosis - promises and challenges of ctDNA-based liquid biopsies in non-small cell lung cancer

The advent of liquid biopsies has brought significant changes to the diagnosis and monitoring of non-small cell lung cancer (NSCLC), presenting both promise and challenges. Molecularly targeted drugs, capable of enhancing survival rates, are now available to around a quarter of NSCLC patients. However, to ensure their effectiveness, precision diagnosis is essential. Circulating tumor DNA (ctDNA) analysis as the most advanced liquid biopsy modality to date offers a non-invasive method for tracking genomic changes in NSCLC. The potential of ctDNA is particularly rooted in its ability to furnish comprehensive (epi-)genetic insights into the tumor, thereby aiding personalized treatment strategies. One of the key advantages of ctDNA-based liquid biopsies in NSCLC is their ability to capture tumor heterogeneity. This capability ensures a more precise depiction of the tumor's (epi-)genomic landscape compared to conventional tissue biopsies. Consequently, it facilitates the identification of (epi-)genetic alterations, enabling informed treatment decisions, disease progression monitoring, and early detection of resistance-causing mutations for timely therapeutic interventions. Here we review the current state-of-the-art in ctDNA-based liquid biopsy technologies for NSCLC, exploring their potential to revolutionize clinical practice. Key advancements in ctDNA detection methods, including PCR-based assays, next-generation sequencing (NGS), and digital PCR (dPCR), are discussed, along with their respective strengths and limitations. Additionally, the clinical utility of ctDNA analysis in guiding treatment decisions, monitoring treatment response, detecting minimal residual disease, and identifying emerging resistance mechanisms is examined. Liquid biopsy analysis bears the potential of transforming NSCLC management by enabling non-invasive monitoring of Minimal Residual Disease and providing early indicators for response to targeted treatments including immunotherapy. Furthermore, considerations regarding sample collection, processing, and data interpretation are highlighted as crucial factors influencing the reliability and reproducibility of ctDNA-based assays. Addressing these challenges will be essential for the widespread adoption of ctDNA-based liquid biopsies in routine clinical practice, ultimately paving the way toward personalized medicine and improved outcomes for patients with NSCLC.

Technical Advances in Circulating Cell-Free DNA Detection and Analysis for Personalized Medicine in Patients' Care

Circulating cell-free DNA (cfDNA) refers to small fragments of DNA molecules released after programmed cell death and necrosis in several body fluids such as blood, saliva, urine, and cerebrospinal fluid. The discovery of cfDNA has revolutionized the field of non-invasive diagnostics in the oncologic field, in prenatal testing, and in organ transplantation. Despite the potential of cfDNA and the solid results published in the recent literature, several challenges remain, represented by a low abundance, a need for highly sensitive assays, and analytical issues. In this review, the main technical advances in cfDNA analysis are presented and discussed, with a comprehensive examination of the current available methodologies applied in each field. Considering the potential advantages of cfDNA, this biomarker is increasing its consensus among clinicians, as it allows us to monitor patients' conditions in an easy and non-invasive way, offering a more personalized care. Nevertheless, cfDNA analysis is still considered a diagnostic marker to be further validated, and very few centers are implementing its analysis in routine diagnostics. As technical improvements are enhancing the performances of cfDNA analysis, its application will transversally improve patients' quality of life.

Nicotinamide in Combination with EGFR-TKIs for the Treatment of Stage IV Lung Adenocarcinoma with EGFR Mutations: A Randomized Double-Blind (Phase IIb) Trial

PURPOSE

RUNX3 is a tumor suppressor gene, which is inactivated in approximately 70% of lung adenocarcinomas. Nicotinamide, a sirtuin inhibitor, has demonstrated potential in re-activating epigenetically silenced RUNX3 in cancer cells. This study assessed the therapeutic benefits of combining nicotinamide with first-generation EGFR-tyrosine kinase inhibitors (TKI) for patients with stage IV lung cancer carrying EGFR mutations.

PATIENTS AND METHODS

We assessed the impact of nicotinamide on carcinogen-induced lung adenocarcinomas in mice and observed that nicotinamide increased RUNX3 levels and inhibited lung cancer growth. Subsequently, 110 consecutive patients with stage IV lung cancer who had EGFR mutations were recruited: 70 females (63.6%) and 84 never-smokers (76.4%). The patients were randomly assigned to receive either nicotinamide (1 g/day, n = 55) or placebo (n = 55). The primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS), respectively.

RESULTS

After a median follow-up of 54.3 months, the nicotinamide group exhibited a median PFS of 12.7 months [95% confidence interval (CI), 10.4-18.3], while the placebo group had a PFS of 10.9 months (9.0-13.2; P = 0.2). The median OS was similar in the two groups (31.0 months with nicotinamide vs. 29.4 months with placebo; P = 0.2). Notably, subgroup analyses revealed a significant reduction in mortality risk for females (P = 0.01) and never-smokers (P = 0.03) treated with nicotinamide.

CONCLUSIONS

The addition of nicotinamide with EGFR-TKIs demonstrated potential improvements in PFS and OS, with notable survival benefits for female patients and those who had never smoked (ClinicalTrials.gov Identifier: NCT02416739).

A Phase II trial of alternating osimertinib and gefitinib therapy in advanced EGFR-T790M positive non-small cell lung cancer: OSCILLATE

In this phase II, single arm trial (ACTRN12617000720314), we investigate if alternating osimertinib and gefitinib would delay the development of resistance to osimertinib in advanced, non-small cell lung cancer (NSCLC) with the epidermal growth factor receptor (EGFR) T790M mutation (n = 47) by modulating selective pressure on resistant clones. The primary endpoint is progression free-survival (PFS) rate at 12 months, and secondary endpoints include: feasibility of alternating therapy, overall response rate (ORR), overall survival (OS), and safety. The 12-month PFS rate is 38% (95% CI 27.5-55), not meeting the pre-specified primary endpoint. Serial circulating tumor DNA (ctDNA) analysis reveals decrease and clearance of the original activating EGFR and EGFR-T790M mutations which are prognostic of clinical outcomes. In 73% of participants, loss of T790M ctDNA is observed at progression and no participants have evidence of the EGFR C797S resistance mutation following the alternating regimen. These findings highlight the challenges of treatment strategies designed to modulate clonal evolution and the clinical importance of resistance mechanisms beyond suppression of selected genetic mutations in driving therapeutic escape to highly potent targeted therapies.

Preoperative cell-free DNA concentration in plasma as a diagnostic and prognostic biomarker of clear cell renal cell carcinoma

Introduction

Assessment of renal tumour masses is based on conventional imaging studies (computer tomography or magnetic resonance), which does not allow characterisation of the histopathological type. Moreover, the prediction of prognosis in localised and metastatic renal cell carcinoma requires improvement as well. Analysis of circulating free DNA (cfDNA) in blood is one of the variants of liquid biopsy that may improve diagnostics and prognosis issues of patients with renal tumour masses suspected to be renal cell carcinoma. The aim of the study was to assess the diagnostic and prognostic role of preoperative cfDNA concentration in the plasma samples of clear cell renal cell carcinoma (ccRCC) patients.

Material and methods

The preoperative plasma cfDNA concentration was assessed in ccRCC patients (n = 46) and healthy individuals (control group) (n = 17). The circulating free DNA concentration was reflected by the 90 bp DNA fragments determined by real-time polymerase chain reaction.

Results

The median cfDNA concentration was significantly higher in ccRCC patients (n = 46) compared to the control g roup (n = 17) (2588 ±2554 copies/ml vs. 960 ±490 copies/ml, p < 0.01). In multivariate analysis, the preoperative plasma cfDNA concentration was the significant factor increasing the probability of ccRCC detection (OR: 1.003; 95% CI: 1.001-1.005). The median cfDNA concentration depended on the stage of ccRCC; it was higher in metastatic ccRCC patients (n = 11) compared to non-metastatic ccRCC patients (n = 35) (3619 ±4059 copies/ml vs. 2473 ±1378 copies/ml, p < 0.03). Kaplan-Meier survival analysis demon-strated that patients with high cfDNA values (above 2913 copies/ml) had significantly worse cancer-specific survival (HR: 4.5; 95% CI: 1.3-16.9, log-rank Mantel-Cox test p = 0.015).

Conclusions

Preoperative plasma cfDNA concentration has diagnostic and prognostic potential in ccRCC pa-tients.

Liquid biopsy for the management of NSCLC patients under osimertinib treatment

Therapeutic management of NSCLC patients is quite challenging as they are mainly diagnosed at a late stage of disease, and they present a high heterogeneous molecular profile. Osimertinib changed the paradigm shift in treatment of EGFR mutant NSCLC patients achieving significantly better clinical outcomes. To date, osimertinib is successfully administered not only as first- or second-line treatment, but also as adjuvant treatment while its efficacy is currently investigated during neoadjuvant treatment or in stage III, unresectable EGFR mutant NSCLC patients. However, resistance to osimertinib may occur due to clonal evolution, under the pressure of the targeted therapy. The utilization of liquid biopsy as a minimally invasive tool provides insight into molecular heterogeneity of tumor clonal evolution and potent resistance mechanisms which may help to develop more suitable therapeutic approaches. Longitudinal monitoring of NSCLC patients through ctDNA or CTC analysis could reveal valuable information about clinical outcomes during osimertinib treatment. Therefore, several guidelines suggest that liquid biopsy in addition to tissue biopsy should be considered as a standard of care in the advanced NSCLC setting. This practice could significantly increase the number of NSCLC patients that will eventually benefit from targeted therapies, such as EGFR TKIs.

Longitudinal Circulating Tumor DNA Modeling to Predict Disease Progression in First-Line Mutant Epidermal Growth Factor Receptor Non-Small Cell Lung Cancer

This exploratory, post hoc analysis aimed to model circulating tumor DNA (ctDNA) dynamics and predict disease progression in patients with treatment-naïve locally advanced/metastatic epidermal growth factor receptor mutation (EGFRm)-positive non-small cell lung cancer, from the FLAURA trial (NCT02296125). Patients were randomized 1:1 and received osimertinib 80 mg once daily (q.d.) or comparator EGFR-TKIs (gefitinib 250 mg q.d. or erlotinib 150 mg q.d.). Plasma was collected at baseline and multiple timepoints until treatment discontinuation. Patients with Response Evaluation Criteria in Solid Tumors (RECIST) imaging data and detectable EGFR mutations (Ex19del/L858R) at baseline and ≥ 3 additional timepoints were evaluable. Joint modeling was conducted to characterize the relationship between longitudinal changes in ctDNA and probability of progression-free survival (PFS). A Bayesian joint model of ctDNA and PFS was developed solving differential equations with the ctDNA dynamics and the PFS time-to-event probability. Of 556 patients, 353 had detectable ctDNA at baseline. Evaluable patients (with available imaging and ≥ 3 additional timepoints, n = 320; ctDNA set) were divided into training (n = 259) and validation (n = 61) sets. In the validation set, the model predicted a median PFS of 17.7 months (95% confidence interval (CI): 11.9-28.3) for osimertinib (n = 23) and 9.1 months (95% CI: 6.3-14.8) for comparator (n = 38), consistent with observed RECIST PFS (16.4 months and 9.7, respectively). The model demonstrates that EGFRm ctDNA dynamics can predict the risk of disease progression in this patient population and could be used to predict RECIST-defined disease progression.

Circulating Tumor DNA Dynamics Fail to Predict Efficacy of Poly(ADP-ribose) Polymerase/VEGFR Inhibition in Patients With Heavily Pretreated Advanced Solid Tumors

PURPOSE

Cell-free circulating tumor DNA (ctDNA) has shown its potential as a quantitative biomarker for longitudinal monitoring of response to anticancer therapies. However, ctDNA dynamics have not been studied in patients with heavily pretreated, advanced solid tumors, for whom therapeutic responses can be weak. We investigated whether changes in ctDNA could predict clinical outcomes in such a cohort treated with combined poly(ADP-ribose) polymerase/vascular endothelial growth factor receptor inhibitor therapy.

MATERIALS AND METHODS

Patients with metastatic pancreatic ductal adenocarcinoma (PDAC), triple-negative breast cancer (TNBC), small-cell lung cancer (SCLC), or non-small-cell lung cancer (NSCLC) received up to 7 days of cediranib 30 mg orally once daily monotherapy lead-in followed by addition of olaparib 200 mg orally twice daily. Patients had progressed on a median of three previous lines of therapy. Plasma samples were collected before and after cediranib monotherapy lead-in and on combination therapy at 7 days, 28 days, and every 28 days thereafter. ctDNA was quantified from plasma samples using a multigene mutation-based assay. Radiographic assessment was performed every 8 weeks.

RESULTS

ctDNA measurements were evaluable in 63 patients. The median baseline ctDNA variant allele fractions (VAFs) were 20%, 28%, 27%, and 34% for PDAC, TNBC, SCLC, and NSCLC, respectively. No association was observed between baseline VAF and radiographic response, progression-free survival, or overall survival (OS). Similarly, no association was found between ctDNA decline and radiographic response or survival. However, an increase in ctDNA at 56 days of combination therapy was associated with disease progression and inferior OS in a landmark analysis.

CONCLUSION

ctDNA levels or dynamics did not correlate with radiographic response or survival outcomes in patients with advanced metastatic malignancies treated with olaparib and cediranib.

Differential prognostic value of tumor and plasma T790M mutations in EGFR TKI-treated advanced NSCLC

Background

Substitution of methionine for threonine at codon 790 (T790M) of epidermal growth factor receptor (EGFR) represents the major mechanism of resistance to EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small-cell lung cancer. We determined the prognostic impact and association of secondary T790M mutations with the outcomes of osimertinib and chemotherapy.

Methods

Patients (n = 460) progressing from first-line EGFR-TKI treatment were assessed. Tissue and/or liquid biopsies were used to determine T790M status; post-progression overall survival (OS) was analyzed.

Results

Overall, 143 (31.1%) patients were T790M positive, 95 (20.7%) were T790M negative, and 222 (48.2%) had unknown T790M status. T790M status [T790M positive versus T790M negative: hazard ratio (HR) 0.48 (95% confidence interval (CI), 0.32-0.70); p < 0.001, T790M unknown versus T790M negative: HR 1.97 (95% CI, 1.47-2.64); p < 0.001] was significantly associated with post-progression OS. T790M positivity rates were similar for tissue (90/168, 53.6%) and liquid (53/90, 58.9%) biopsies (Fisher's exact test, p = 0.433). Tumor T790M-positive patients had significantly longer post-progression OS than tumor T790M-negative patients (34.1 versus 17.1 months; log-rank test, p = 8 × 10-5). Post-progression OS was similar between plasma T790M-positive and -negative patients (17.4 versus not reached; log-rank test, p = 0.600). In tumor T790M-positive patients, post-progression OS was similar after osimertinib and chemotherapy [34.1 versus 29.1 months; log-rank test, p = 0.900; HR 1.06 (95% CI, 0.44-2.57); p = 0.897].

Conclusion

T790M positivity predicts better post-progression OS than T790M negativity; tumor T790M positivity has a stronger prognostic impact than plasma T790M positivity. Osimertinib and chemotherapy provide similar OS benefits in patients with T790M-positive tumors.

Pitfalls and Considerations in Determining the Potency and Mutant Selectivity of Covalent Epidermal Growth Factor Receptor Inhibitors

Enzyme inhibitors that form covalent bonds with their targets are being increasingly pursued in drug development. Assessing their biochemical activity relies on time-dependent assays, which are distinct and more complex compared with methods commonly employed for reversible-binding inhibitors. To provide general guidance to the covalent inhibitor development community, we explored methods and reported kinetic values and experimental factors in determining the biochemical activity of various covalent epidermal growth factor receptor (EGFR) inhibitors. We showcase how liquid handling and assay reagents impact kinetic parameters and potency interpretations, which are critical for structure-kinetic relationships and covalent drug design. Additionally, we include benchmark kinetic values with reference inhibitors, which are imperative, as covalent EGFR inhibitor kinetic values are infrequently consistent in the literature. This overview seeks to inform best practices for developing new covalent inhibitors and highlight appropriate steps to address gaps in knowledge presently limiting assay reliability and reproducibility.

Machine learning-based radiomics strategy for prediction of acquired EGFR T790M mutation following treatment with EGFR-TKI in NSCLC

The epidermal growth factor receptor (EGFR) Thr790 Met (T790M) mutation is responsible for approximately half of the acquired resistance to EGFR-tyrosine kinase inhibitor (TKI) in non-small-cell lung cancer (NSCLC) patients. Identifying patients at diagnosis who are likely to develop this mutation after first- or second-generation EGFR-TKI treatment is crucial for better treatment outcomes. This study aims to develop and validate a radiomics-based machine learning (ML) approach to predict the T790M mutation in NSCLC patients at diagnosis. We collected retrospective data from 210 positive EGFR mutation NSCLC patients, extracting 1316 radiomics features from CT images. Using the LASSO algorithm, we selected 10 radiomics features and 2 clinical features most relevant to the mutations. We built models with 7 ML approaches and assessed their performance through the receiver operating characteristic (ROC) curve. The radiomics model and combined model, which integrated radiomics features and relevant clinical factors, achieved an area under the curve (AUC) of 0.80 (95% confidence interval [CI] 0.79-0.81) and 0.86 (0.87-0.88), respectively, in predicting the T790M mutation. Our study presents a convenient and noninvasive radiomics-based ML model for predicting this mutation at the time of diagnosis, aiding in targeted treatment planning for NSCLC patients with EGFR mutations.

The Perceived Value of Liquid Biopsy: Results From a Canadian Validation Study of Circulating Tumor DNA T790M Testing-Patient's Willingness-to-Pay: A Brief Report

Introduction

Liquid biopsy is recommended to diagnose molecular resistance to targeted therapy in patients with lung cancer. Nevertheless, not all jurisdictions provide funding and patient access. We report patients' perceived value of liquid biopsy in targeted therapy resistance.

Methods

Canadian patients participating in a national EGFR T790M liquid biopsy validation study completed structured interviews measuring perceived value and willingness-to-pay for plasma circulating tumor DNA testing as an alternative to tumor biopsy using open-ended and iterative bidding approaches.

Results

A total of 60 patients with advanced lung cancer participated with a median age of 64 years (range: 31-87 y); 69% were Asian and 45% female. All had received prior EGFR tyrosine kinase inhibitor; 17% also received chemotherapy. All patients preferred to have plasma testing over repeat tumor biopsy. In the context of the Canadian publicly funded system, patients estimated that a median of 300 (interquartile range: 150-800) Canadian dollars was a reasonable price to pay for liquid biopsy. Patients were personally willing to pay a median 100 (interquartile range: 33-350) Canadian dollars.

Conclusions

In a system that covers the cost of standard diagnostic tests, patients with lung cancer indicated high willingness-to-pay out-of-pocket for liquid biopsy in the setting of acquired targeted therapy resistance. Patients have high perceived value of plasma genotyping and prefer it to repeat tumor biopsy.

Pan-Tumor Analytical Validation and Osimertinib Clinical Validation in EGFR Mutant Non-Small-Cell Lung Cancer, Supporting the First Next-Generation Sequencing Liquid Biopsy in Vitro Diagnostic

Comprehensive genotyping is necessary to identify therapy options for patients with advanced cancer; however, many cancers are not tested, partly because of tissue limitations. Next-generation sequencing (NGS) liquid biopsies overcome some limitations, but clinical validity is not established and adoption is limited. Herein, clinical bridging studies used pretreatment plasma samples and data from FLAURA (NCT02296125; n = 441) and AURA3 (NCT02151981; n = 450) pivotal studies to demonstrate clinical validity of Guardant360 CDx (NGS LBx) to identify patients with advanced EGFR mutant non-small-cell lung cancer who may benefit from osimertinib. The primary end point was progression-free survival (PFS). Patients with EGFR mutation as identified by NGS LBx had significant PFS benefit with first-line osimertinib over standard of care (15.2 versus 9.6 months; hazard ratio, 0.41; P < 0.0001) and with later-line osimertinib over chemotherapy (8.3 versus 4.2 months; hazard ratio, 0.34; P < 0.0001). PFS benefits were similar to the original trial cohorts selected by tissue-based EGFR testing. Analytical validation included accuracy, precision, limit of detection, and specificity. Analytical validity was established for EGFR mutation detection and pan-tumor profiling. Panel-wide limit of detection was 0.1% to 0.5%, with 98% to 100% per-sample specificity. Patients with EGFR mutant non-small-cell lung cancer by NGS LBx had improved PFS with osimertinib, confirming clinical validity. Analytical validity was established for guideline-recommended therapeutic targets across solid tumors. The resulting US Food and Drug Administration approval of NGS LBx demonstrated safety and effectiveness for its intended use and is expected to improve adherence to guideline-recommended targeted therapy use.

Plasma ctDNA liquid biopsy of IDH1, TERTp, and EGFRvIII mutations in glioma

Background

Circulating tumor DNA has emerging clinical applications in several cancers; however, previous studies have shown low sensitivity in glioma. We investigated if 3 key glioma gene mutations IDH1, TERTp, and EGFRvIII could be reliably detected in plasma by droplet digital polymerase chain reaction (ddPCR) thereby demonstrating the potential of this technique for glioma liquid biopsy.

Methods

We analyzed 110 glioma patients from our biobank with a total of 359 plasma samples (median 4 samples per patient). DNA was isolated from plasma and analyzed for IDH1, TERTp, and EGFRvIII mutations using ddPCR.

Results

Total cfDNA was significantly associated with tumor grade, tumor volume, and both overall and progression-free survival for all gliomas as well as the grade 4 glioblastoma subgroup, but was not reliably associated with changes in tumor volume/progression during the patients' postoperative time course. IDH1 mutation was detected with 84% overall sensitivity across all plasma samples and 77% in the preoperative samples alone; however, IDH1 mutation plasma levels were not associated with tumor progression or survival. IDH1m plasma levels were not associated with pre- or postsurgery progression or survival. The TERTp C228T mutation was detected in the plasma ctDNA in 88% but the C250T variant in only 49% of samples. The EGFRvIII mutation was detected in plasma in 5 out of 7 patients (71%) with tissue EGFRvIII mutations in tumor tissue.

Conclusions

Plasma ctDNA mutations detected with ddPCR provide excellent diagnostic sensitivity for IDH1, TERTp-C228T, and EGFRvIII mutations in glioma patients. Total cfDNA may also assist with prognostic information. Further studies are needed to validate these findings and the clinical role of ctDNA in glioma.

Tissue or liquid rebiopsy? A prospective study for simultaneous tissue and liquid NGS after first-line EGFR inhibitor resistance in lung cancer

INTRODUCTION

According to current International Association for the Study of Lung Cancer guideline, physicians may first use plasma cell-free DNA (cfDNA) methods to identify epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant mechanisms (liquid rebiopsy) for lung cancer. Tissue rebiopsy is recommended if the plasma result is negative. However, this approach has not been evaluated prospectively using next-generation sequencing (NGS).

METHODS

We prospectively enrolled patients with lung cancer with first-line EGFR-TKI resistance who underwent tissue rebiopsy. The rebiopsied tissues and cfDNA were sequenced using targeted NGS, ACTDrug®+, and ACTMonitor®Lung simultaneously. The clinicopathological characteristics and treatment outcomes were analyzed.

RESULTS

Totally, 86 patients were enrolled. Twenty-six (30%) underwent tissue biopsy but the specimens were inadequate for NGS. Among the 60 patients with paired tissue and liquid rebiopsies, two-thirds (40/60) may still be targetable. T790M mutations were found in 29, including 14 (48%) only from tissue and 5 (17%) only from cfDNA. Twenty-four of them were treated with osimertinib, and progression-free survival was longer in patients without detectable T790M in cfDNA than in patients with detectable T790M in cfDNA (p = 0.02). For the 31 T790M-negative patients, there were six with mesenchymal-epithelial transition factor (MET) amplifications, four with ERBB2 amplifications, and one with CCDC6-RET fusion. One with MET amplification and one with ERBB2 amplification responded to subsequent MET and ERBB2 targeting agents respectively.

CONCLUSIONS

NGS after EGFR-TKI resistance may detect targetable drivers besides T790M. To do either liquid or tissue NGS only could miss patients with T790M. To do tissue and liquid NGS in parallel after EGFR-TKI resistance may find more patients with targetable cancers.

Recommendations for Cell-Free DNA Assay Validations: A Joint Consensus Recommendation of the Association for Molecular Pathology and College of American Pathologists

Diagnosing, selecting therapy for, and monitoring cancer in patients using a minimally invasive blood test represents a significant advance in precision medicine. Wide variability exists in how circulating tumor DNA (ctDNA) assays are developed, validated, and reported in the literature, which hinders clinical adoption and may negatively impact patient care. Standardization is needed for factors affecting ctDNA assay performance and reporting, including pre-analytical variables, analytical considerations, and elements of laboratory assay reporting. The Association for Molecular Pathology Clinical Practice Committee's Liquid Biopsy Working Group (LBxWG), including organizational representation from the American Society of Clinical Oncology and the College of American Pathologists, has undertaken a full-text data extraction of 1228 ctDNA publications that describe assays performed in patients with lymphoma and solid tumor malignancies. With an emphasis on clinical assay validation, the LBxWG has developed a set of 13 best practice consensus recommendations for validating, reporting, and publishing clinical ctDNA assays. Recommendations include reporting key pre-analytical considerations and assay performance metrics; this analysis demonstrates these elements are inconsistently included in publications. The LBxWG recommendations are intended to assist clinical laboratories with validating and reporting ctDNA assays and to ensure high-quality data are included in publications. It is expected that these recommendations will need to be updated as the body of literature continues to mature.

Liquid biopsy in clinical outcomes and detection of T790M mutation in metastatic non-small cell lung cancer after progression to EGFR-TKI

BACKGROUND

Liquid biopsy (LB) is used to detect epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) and has been demonstrated to have prognostic and predictive value.

OBJECTIVE

To associate the rates of EGFR and T790M mutations detected by LB during disease progression after first- or second-generation EGFR-TKIs with clinical characteristics and survival outcomes.

METHODS

From January 2018 to December 2021, 295 patients with advanced EGFR mutant (EGFRm) NSCLC treated with first- or second-generation EGFR-TKIs were retrospectively analyzed. LB was collected at the time of progression. The frequency of EGFRT790M mutations, overall survival (OS), and the clinical characteristics associated with LB positivity were determined.

RESULTS

The prevalence of EGFRT790M mutation detected using LB was 44%. In patients with negative vs. positive LB, the median OS was 45.0 months vs. 25.0 months (p= 0.0001), respectively. Patients with a T790M mutation receiving osimertinib had a median OS of 44 months (95% CI [33.05-54.99]). Clinical characteristics associated with positive LB at progression extra-thoracic involvement, > 3 metastatic sites, and bone metastases.

CONCLUSIONS

Our findings showed that LB positivity was associated with worse survival outcomes and specific clinical characteristics. This study also confirmed the feasibility and detection rate of T790M mutation in a Latin American population.

Molecular modeling, dynamic simulation, and metabolic reactivity studies of quinazoline derivatives to investigate their anti-angiogenic potential by targeting wild EGFRwt and mutant EGFRT790M receptor tyrosine kinases

Non-small cell lung cancer, head and neck cancer, glioblastoma, and various other cancer types often demonstrate persistent elevation in EGFR tyrosine kinase activity due to acquired mutations in its kinase domain. Any alteration in the EGFR is responsible for triggering the upregulation of tumor angiogenic pathways, such as the PI3k-AKT-mTOR pathway, MAPK-ERK pathway and PLC-Ƴ pathway, which are critically involved in promoting tumor angiogenesis in cancer cells. The emergence of frequently occurring EGFR kinase domain mutations (L858R/T790M/C797S) that confer resistance to approved therapeutic agents has presented a significant challenge for researchers aiming to develop effective and well-tolerated treatments against tumor angiogenesis. In this study, we directed our efforts towards the rational design and development of novel quinazoline derivatives with the potential to act as antagonists against both wild-type and mutant EGFR. Our approach encompasing the application of advanced drug design strategies, including structure-based virtual screening, molecular docking, molecular dynamics, metabolic reactivity and cardiotoxicity prediction studies led to the identification of two prominent lead compounds: QU648, for EGFRwt inhibition and QU351, for EGFRmt antagonism. The computed binding energies of selected leads and their molecular dynamics simulations exhibited enhanced conformational stability of QU648 and QU351 when compared to standard drugs Erlotinib and Afatinib. Notably, the lead compounds also demonstrated promising pharmacokinetic properties, metabolic reactivity, and cardiotoxicity profiles. Collectively, the outcomes of our study provide compelling evidence supporting the potential of QU648 and QU351 as prominent anti-angiogenic agents, effectively inhibiting EGFR activity across various cancer types harboring diverse EGFR mutations.Communicated by Ramaswamy H. Sarma.

BRAF V600E-mutated large cell neuroendocrine carcinoma responding to targeted therapy: a case report and review of the literature

Large cell neuroendocrine carcinoma (LCNEC) is a rare and aggressive high-grade neuroendocrine tumor, commonly arising in the lung or in the gastrointestinal tract, with a frequent proportion of unknown primary origin (20%). In the metastatic setting, platinum-based or fluoropyrimidine-based chemotherapeutic regimens are as considered the first-line treatment, despite the limited duration of response. To date, the prognosis of advanced high-grade neuroendocrine carcinoma remains poor, suggesting the need to explore new treatment strategies in this orphan tumor. The evolving molecular landscape of LCNEC, not yet been completely defined, could explain the heterogeneous response to different chemotherapeutic regimens and suggest that treatment strategy could be driven by molecular features. v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutations, well described in melanoma, thyroid cancer, colon cancer and lung adenocarcinoma, account for approximately 2% of cases in lung LCNEC. Here, we describe the case of a patient with a BRAF V600E-mutated LCNEC of unknown primary origin who partially responded to BRAF/mitogen-activated protein kinase kinase inhibitors after standard treatment. Additionally, BRAF V600E circulating tumor DNA was used to monitor disease response. Thereafter, we reviewed the available literature about the role of targeted therapy in high-grade neuroendocrine neoplasms to provide insight for future research to identify patients with driver oncogenic mutations, who can potentially benefit from target therapy.

Afatinib overcoming resistance to icotinib and osimertinib in NSCLC with leptomeningeal metastasis in patients with acquired EGFR L858R/T790M or L858R/S768I mutations: Two case reports

Background

Advanced non-small cell lung cancer (NSCLC) is often complicated by leptomeningeal metastases (LMs), especially in patients carrying EGFR mutations. EGFR tyrosine kinase inhibitors (TKIs) are the first-line drug for patients with specific gene mutations, such as EGFR exon 19 deletion or exon 21 L858R mutation. However, after long-term TKI use, patients eventually develop drug resistance and acquire new mutations. Acquiring the EGFR T790 M mutation during TKI treatment is a marker for first/second generation TKI resistance. Osimertinib (a third-generation TKI) could overcome this resistance, especially for patients who have already developed NSCLC-LM. Treating NSCLC patients with osimertinib resistance is challenging. Our aim was to investigate whether afatinib is effective in NSCLC-LM patient who showed resistance to osimertinib. Herein, we report two patients with resistance to first- and third-generation TKIs who benefited from second-generation TKI.

Case summary

Case one: A 43-year-old man was diagnosed with stage 3A NSCLC with EGFR exon 19 deletion. He underwent surgery and received 4 rounds of chemotherapy (oxaliplatin combined with liposomal paclitaxel), after which the disease was controlled by icotinib (a first-generation TKI) for 4 years. Then, he showed poor drug response and bone metastasis. A liquid biopsy was carried out, and the EGFR L858R/T790 M compound mutation was found. The patient was given osimertinib (a third-generation TKI). The patient was in a stable condition for 2 years and then he developed bilateral peripheral facial palsy. Brain MRI showed enhancement in the left temporal lobe and meninges, and cerebrospinal fluid (CSF) cytology detected tumour cells in the CSF. NSCLC-LM was diagnosed. His performance status (PS) score was 3-4. Liquid biopsy and next-generation sequencing were performed again. Different gene mutations and copy number alterations were found this time, including EGFR L858R, but without the EGFR T790 M mutation. His disease was controlled with intrathecal methotrexate and oral afatinib (a second generation TKI). The patient has shown clinical remission (PS score: 1-2) until now, which is longer than 10 months.

Case two

A 50-year-old man was diagnosed with NSCLC in May 2020. He underwent one round of chemotherapy before thoracoscopic partial lobectomy of the right upper lung. Histological study of the lung tissue showed lung adenocarcinoma with the EGFR L858R mutation. Then, the disease was controlled with icotinib. One year later, he was diagnosed with NSCLC-LM. Liquid biopsy and sequencing showed an EGFR L858R/S768I compound mutation. The patient was treated with osimertinib. His condition was stable for 5 months before his central nervous system (CNS) symptoms were exacerbated. Liquid biopsy and sequencing were carried out again, and his gene mutation profile had not changed much. Then, the patient was given afatinib, and his condition has remained stable for 11 months.

Conclusion

Afatinib might be suitable for NSCLC-LM patients with EGFR compound mutations who show resistance to icotinib and osimertinib, since it might help overcome first- and third-generation TKI resistance.

Real-world clinical evidence of lazertinib use in acquired EGFR T790M mutated non-small cell lung cancer

Background

Lazertinib is a third generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) designed to overcome EGFR T790M mutation. Currently, lazertinib is approved for usage in the acquired EGFR T790M mutation population based on promising clinical and safety profiles. In this study, we evaluated the clinical outcomes of lazertinib in acquired EGFR T790M mutated non-small cell lung cancer (NSCLC) patients in a real-world clinical setting.

Methods

Clinical outcomes of 103 patients treated with lazertinib, from July 2021 to August 2022, for NSCLC with acquired EGFR T790M mutation were retrospectively analyzed. EGFR T790M mutation was confirmed using either a cell-free EGFR test (48.5%) or a tissue-based test (51.5%).

Results

The median follow-up duration was 11.4 months [95% confidence interval (CI): 10.4-13.1], and 58.3% of patients remained on treatment at the time point of data analysis. The objective response rate was 72.8%. The median progression-free survival (PFS) was not reached, and the PFS rates at 6 and 12 months were 81.7% and 65.1%, respectively. The median PFS in a subgroup treated with lazertinib based on T790M-positive tissue was significantly longer than that in a subgroup treated based on T790M-positive plasma (not reached vs. 14.5 months) (hazard ratio, 0.43; 95% CI: 0.21-0.87). Related to adverse events, there was no treatment-related mortality. However, the lazertinib dose was adjusted in 39 patients (37.9%), including 10 patients (9.7%) with permanent discontinuation. Peripheral sensory-motor related adverse events were observed in 65 patients (63.1%) (paresthesia: n=58; muscle cramping: n=24), leading to dose reduction and permanent discontinuation in 17 (16.5%) and 5 (4.9%) patients, respectively. There was no difference in PFS between the groups with and without dose-adjustment (P=0.40).

Conclusions

Our result demonstrates the real-world clinical efficacy of lazertinib in acquired EGFR T790M mutation. Although dose reduction due to adverse events was not uncommon, it did not impair clinical efficacy of lazertinib.

The Clinical Significance of Circulating Tumor DNA for Minimal Residual Disease Identification in Early-Stage Non-Small Cell Lung Cancer

Lung cancer (LC) is the deadliest malignancy worldwide. In an operable stage I-III patient setting, the detection of minimal residual disease (MRD) after curative treatment could identify patients at higher risk of relapse. In this context, the study of circulating tumor DNA (ctDNA) is emerging as a useful tool to identify patients who could benefit from an adjuvant treatment, and patients who could avoid adverse events related to a more aggressive clinical management. On the other hand, ctDNA profiling presents technical, biological and standardization challenges before entering clinical practice as a decisional tool. In this paper, we review the latest advances regarding the role of ctDNA in identifying MRD and in predicting patients' prognosis, with a particular focus on clinical trials investigating the potential of ctDNA, the technical challenges to address and the biological parameters that influence the MRD detection.

STAT3 expression in patients with fragility fractures and its effect on the biological function of osteoblasts

To determine the expression of signal transducer and activator of transcription 3 (STAT3) in patients with fragility fractures (FFs) and its effect on the biological function of osteoblasts. The study included 32 patients with FFs who were diagnosed and treated in the research group and 30 concurrent healthy individuals in the control group. We observed STAT3 mRNA expression in the patients with FFs and controls and altered STAT3 mRNA to detect changes in the proliferation, invasion, and apoptosis of osteoblasts. The patients with FFs presented higher serum STAT3 mRNA expression than the controls (P < 0.05). We plotted receiver operating characteristic curves based on the STAT3 mRNA expression and found that the area under the curve for STAT3 mRNA was 0.856 (P < 0.05). Transfection of STAT3 mRNA mimics resulted in increased STAT3 mRNA expression, inhibited cell proliferation as detected by an MTT assay, and increased apoptosis rate, which was determined using flow cytometry with human fetal osteoblastic cell line 1.19 cells. STAT3 mRNA expression was elevated in the serum of patients with FFs and can be used as a biomarker for the diagnosis of the disease. Regulating STAT3 mRNA can inhibit the proliferation and induce the osteoblasts apoptosis.

Clinical significance of circulating tumor DNA in localized non-small cell lung cancer: a systematic review and meta-analysis

Circulating tumor DNA (ctDNA) detection holds promise for genetic analyses and quantitative assessment of tumor burden. A systematic review and meta-analysis were conducted to investigate the clinical relevance of ctDNA among patients with localized non-small cell lung cancer (NSCLC). PubMed, EMBASE, and the Cochrane Library were searched for eligible studies published from January 2001 to April 2022. After quality assessments and data extraction, diagnostic accuracy variables and prognostic data were calculated and analyzed by Meta-Disc 1.4, Review Manager 5.4.1, and STATA 17.0. Eight prospective studies and one retrospective study including 784 patients with localized NSCLC were used in our meta-analysis. The pooled sensitivity and specificity of ctDNA for minimal residual disease (MRD) detection were 0.58 and 0.93, respectively. The pooled positive and negative likelihood ratios were 7.57 (95% confidence interval (CI) 2.84-20.20) and 0.45 (95% CI 0.37-0.55), respectively. The area under the summary receiver operating characteristic curve was 0.8967, and the diagnostic odds ratio was 32.26 (95% CI 14.63-71.12). In addition, both precurative-treatment and postcurative-treatment ctDNA positivity was associated with worse recurrence-free survival (hazard ratio (HR), 3.82 and 8.32, respectively) and worse overall survival (HR, 3.82 and 4.73, respectively). The findings suggested that ctDNA detection has beneficial utility regarding MRD detection specificity; moreover, positive ctDNA was associated with poor prognosis in patients with localized NSCLC.

Monitoring of Plasma EGFR Mutations during Osimertinib Treatment for NSCLC Patients with Acquired T790M Mutation

BACKGROUND

Osimertinib was first approved for the treatment of non-small cell lung cancer (NSCLC) in patients who have developed the epidermal growth factor receptor (EGFR) T790M mutation after treatment with EGFR tyrosine kinase inhibitors (TKIs). We routinely evaluated the plasma of NSCLC patients with the T790M mutation to more rapidly detect an increase in disease activity and resistance to treatment.

METHODS

Eligible patients received osimertinib after resistance to the first- or second-generation of EGFR-TKIs in NSCLC harboring T790M mutation detectable in tumor tissue or plasma. Plasma samples were collected every 8 weeks during osimertinib treatment. The plasma analysis was performed using an improved PNA-LNA PCR clamp method. We tested samples for a resistance mechanism, including EGFR-activating, T790M, and C797S mutations, and assessed the association between the mutations and osimertinib treatment.

RESULTS

Of the 60 patients enrolled in the study, 58 were eligible for this analysis. In plasma collected before osimertinib treatment, activating mutations were detected in 47 of 58 patients (81.0%) and T790M was detected in 44 patients (75.9%). Activating mutations were cleared in 60.9% (28/46) and T790M was cleared in 93.0% (40/43). Of these, 71.4% (20/28) of activating mutations and 87.5% (35/40) of T790M mutation were cleared within 8 weeks of treatment. The total response rate (RR) was 53.4% (31/58). The median duration of treatment was 259 days, with a trend toward longer treatment duration in patients who experienced the clearance of activating mutations with osimertinib. At the time of disease progression during osimertinib treatment, C797S was detected in 3 of 37 patients (8.1%).

CONCLUSION

Plasma EGFR mutation analysis was effective in predicting the effect of osimertinib treatment.

The Emerging Role of Liquid Biopsies in Revolutionising Cancer Diagnosis and Therapy

A potential non-invasive technique for identifying and tracking cancer is a liquid biopsy. This review article provides a comprehensive overview of the principles, applications, and challenges associated with liquid biopsies. The circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), exosomes, and microRNAs are just a few of the biomarkers we cover in this article that are discovered in liquid biopsies. The clinical application of liquid biopsies in many stages of cancer management, including early cancer identification, therapy selection and response monitoring, and minimum residual illness, is also investigated. The technical advancements in liquid biopsy techniques, including digital polymerase chain reaction (dPCR) and next-generation sequencing (NGS), have improved the sensitivity and specificity of biomarker identification. Liquid biopsies require assistance with cost-effectiveness, sensitivity, and standardisation despite the potential benefits. We talk about these restrictions and potential solutions. In conclusion, liquid biopsies revolutionise personalised therapies and cancer diagnostics by providing a real-time, non-invasive tool for characterising and monitoring tumours. It will be possible to expand the use of liquid biopsies in clinical practises by having a better understanding of their current state and predicted future developments.

Liquid Biopsy in NSCLC: An Investigation with Multiple Clinical Implications

Tissue biopsy is essential for NSCLC diagnosis and treatment management. Over the past decades, liquid biopsy has proven to be a powerful tool in clinical oncology, isolating tumor-derived entities from the blood. Liquid biopsy permits several advantages over tissue biopsy: it is non-invasive, and it should provide a better view of tumor heterogeneity, gene alterations, and clonal evolution. Consequentially, liquid biopsy has gained attention as a cancer biomarker tool, with growing clinical applications in NSCLC. In the era of precision medicine based on molecular typing, non-invasive genotyping methods became increasingly important due to the great number of oncogene drivers and the small tissue specimen often available. In our work, we comprehensively reviewed established and emerging applications of liquid biopsy in NSCLC. We made an excursus on laboratory analysis methods and the applications of liquid biopsy either in early or metastatic NSCLC disease settings. We deeply reviewed current data and future perspectives regarding screening, minimal residual disease, micrometastasis detection, and their implication in adjuvant and neoadjuvant therapy management. Moreover, we reviewed liquid biopsy diagnostic utility in the absence of tissue biopsy and its role in monitoring treatment response and emerging resistance in metastatic NSCLC treated with target therapy and immuno-therapy.

Liquid biopsy in the management of advanced lung cancer: Implementation and practical aspects

Non-small-cell lung cancer (NSCLC) is a major cause of cancer-related death worldwide. In recent years, the discovery of actionable molecular alterations has changed the treatment paradigm of the disease. Tissue biopsies have been the gold standard for the identification of targetable alterations but present several limitations, calling for alternatives to detect driver and acquired resistance alterations. Liquid biopsies reveal great potential in this setting and also in the evaluation and monitoring of treatment response. However, several challenges currently hamper its widespread adoption in clinical practice. This perspective article evaluates the potential and challenges associated with liquid biopsy testing, considering a Portuguese expert panel dedicated to thoracic oncology point of view, and providing practical insights for its implementation based on the experience and applicability in the Portuguese context.

The Resistance to EGFR-TKIs in Non-Small Cell Lung Cancer: From Molecular Mechanisms to Clinical Application of New Therapeutic Strategies

Almost 17% of Western patients affected by non-small cell lung cancer (NSCLC) have an activating epidermal growth factor receptor (EGFR) gene mutation. Del19 and L858R are the most-common ones; they are positive predictive factors for EGFR tyrosine kinase inhibitors (TKIs). Currently, osimertinib, a third-generation TKI, is the standard first-line therapy for advanced NSCLC patients with common EGFR mutations. This drug is also administered as a second-line treatment for those patients with the T790M EGFR mutation and previously treated with first- (erlotinib, gefitinib) or second- (afatinib) generation TKIs. However, despite the high clinical efficacy, the prognosis remains severe due to intrinsic or acquired resistance to EGRF-TKIs. Various mechanisms of resistance have been reported including the activation of other signalling pathways, the development of secondary mutations, the alteration of the downstream pathways, and phenotypic transformation. However, further data are needed to achieve the goal of overcoming resistance to EGFR-TKIs, hence the necessity of discovering novel genetic targets and developing new-generation drugs. This review aimed to deepen the knowledge of intrinsic and acquired molecular mechanisms of resistance to EGFR-TKIs and the development of new therapeutic strategies to overcome TKIs' resistance.

Circulating Tumor DNA Is Prognostic in Intermediate-Risk Rhabdomyosarcoma: A Report From the Children's Oncology Group

PURPOSE

Novel biomarkers are needed to differentiate outcomes in intermediate-risk rhabdomyosarcoma (IR RMS). We sought to evaluate strategies for identifying circulating tumor DNA (ctDNA) in IR RMS and to determine whether ctDNA detection before therapy is associated with outcome.

PATIENTS AND METHODS

Pretreatment serum and tumor samples were available from 124 patients with newly diagnosed IR RMS from the Children's Oncology Group biorepository, including 75 patients with fusion-negative rhabdomyosarcoma (FN-RMS) and 49 with fusion-positive rhabdomyosarcoma (FP-RMS) disease. We used ultralow passage whole-genome sequencing to detect copy number alterations and a new custom sequencing assay, Rhabdo-Seq, to detect rearrangements and single-nucleotide variants.

RESULTS

We found that ultralow passage whole-genome sequencing was a method applicable to ctDNA detection in all patients with FN-RMS and that ctDNA was detectable in 13 of 75 serum samples (17%). However, the use of Rhabdo-Seq in FN-RMS samples also identified single-nucleotide variants, such as MYOD1L122R, previously associated with prognosis. Identification of pathognomonic translocations between PAX3 or PAX7 and FOXO1 by Rhabdo-Seq was the best method for measuring ctDNA in FP-RMS and detected ctDNA in 27 of 49 cases (55%). Patients with FN-RMS with detectable ctDNA at diagnosis had significantly worse outcomes than patients without detectable ctDNA (event-free survival, 33.3% v 68.9%; P = .0028; overall survival, 33.3% v 83.2%; P < .0001) as did patients with FP-RMS (event-free survival, 37% v 70%; P = .045; overall survival, 39.2% v 75%; P = .023). In multivariable analysis, ctDNA was independently associated with worse prognosis in FN-RMS but not in the smaller FP-RMS cohort.

CONCLUSION

Our study demonstrates that baseline ctDNA detection is feasible and is prognostic in IR RMS.

Structural elements that enable specificity for mutant EGFR kinase domains with next-generation small-molecule inhibitors

Specificity for a desired enzyme target is an essential property of small-molecule inhibitors. Molecules targeting oncogenic driver mutations in the epidermal growth factor receptor (EGFR) kinase domain have had a considerable clinical impact due to their selective binding to cancer-causing mutants compared to wild type. Despite the availability of clinically approved drugs for cancers driven by EGFR mutants, persistent challenges in drug resistance in the past decades have led to newer generations of drugs with divergent chemical structures. The current clinical challenges are mainly due to acquired resistance to third-generation inhibitors, including by the acquisition of the C797S mutation. Several diverse fourth-generation candidates and tool compounds that inhibit the C797S mutant have emerged, and their structural characterization has revealed molecular factors that allow for EGFR mutant selective binding. Here, we have reviewed all known structurally-characterized EGFR TKIs targeting clinically-relevant mutations to identify specific features that enable C797S inhibition. Newer generation EGFR inhibitors exhibit consistent and previously underutilized hydrogen bonding interactions with the conserved K745 and D855 residue side chains. We also consider binding modes and hydrogen bonding interactions of inhibitors targeting the classical ATP and the more unique allosteric sites.

Role of circulating-tumor DNA in the early-stage non-small cell lung carcinoma as a predictive biomarker

Lung cancer is one of the most common solid malignancies. Tissue biopsy is the standard method for accurately diagnosing lung and many other malignancies over decades. However, molecular profiling of tumors leads to establishing a new horizon in the field of precision medicine, which has now entered the mainstream in clinical practice. In this context, a minimally invasive complementary method has been proposed as a liquid biopsy (LB) which is a blood-based test that is gaining popularity as it provides the opportunity to test genotypes in a unique, less invasive manner. Circulating tumor cells (CTC) captivating the Circulating-tumor DNA (Ct-DNA) are often present in the blood of lung cancer patients and are the fundamental concept behind LB. There are multiple clinical uses of Ct-DNA, including its role in prognostic and therapeutic purposes. The treatment of lung cancer has drastically evolved over time. Therefore, this review article mainly focuses on the current literature on circulating tumor DNA and its clinical implications and future goals in non-small cell lung cancer.

Convergence of Precision Oncology and Liquid Biopsy in Non-Small Cell Lung Cancer

This review article illuminates the role of liquid biopsy in the continuum of care for non-small cell lung cancer (NSCLC). We discuss its current application in advanced-stage NSCLC at the time of diagnosis and at progression. We highlight research showing that concurrent testing of blood and tissue yields faster, more informative, and cheaper answers than the standard stepwise approach. We also describe future applications for liquid biopsy including treatment response monitoring and testing for minimal residual disease. Lastly, we discuss the emerging role of liquid biopsy for screening and early detection.

Allele frequency and proportion defined by circulating tumor DNA profiling predict tyrosine kinase inhibitors' therapeutic outcomes for non-small cell lung cancer

PURPOSE

Circulating tumor DNA is more and more accessible for patients who cannot undergo biopsy. No consistent conclusion has been reached on whether frequency and proportion of mutations defined by ctDNA profiling can predict therapeutic outcomes.

METHODS

One hundred patients with non-small cell lung cancer harboring activating EGFR mutations (exon 19 deletion, L858R and T790M mutation) were collected in West China hospital from December 18, 2017 to December 31, 2019. We retrospectively analyzed the frequency and proportion distribution of ctDNA mutations and its relationship with tyrosine kinase inhibitors therapeutic outcomes.

RESULTS

Patients with lower frequency of sensitizing EGFR mutations (< 3%) had a longer progression-free survival (PFS) time than those with higher frequency (15 months vs. 10 months, p = 0.028). Moreover, patients with the lower ratio of T790M mutation frequency and the maximum-somatic-allele-frequency (T790M/MSAF < 30%) had a less prolonged PFS than those with higher T790M/MSAF (7 months vs. 15 months, p = 0.013).

CONCLUSION

The frequency and proportion of ctDNA mutations are worth clinical attention in the prediction of therapeutic outcomes.

Tumor cell plasticity in targeted therapy-induced resistance: mechanisms and new strategies

Despite the success of targeted therapies in cancer treatment, therapy-induced resistance remains a major obstacle to a complete cure. Tumor cells evade treatments and relapse via phenotypic switching driven by intrinsic or induced cell plasticity. Several reversible mechanisms have been proposed to circumvent tumor cell plasticity, including epigenetic modifications, regulation of transcription factors, activation or suppression of key signaling pathways, as well as modification of the tumor environment. Epithelial-to-mesenchymal transition, tumor cell and cancer stem cell formation also serve as roads towards tumor cell plasticity. Corresponding treatment strategies have recently been developed that either target plasticity-related mechanisms or employ combination treatments. In this review, we delineate the formation of tumor cell plasticity and its manipulation of tumor evasion from targeted therapy. We discuss the non-genetic mechanisms of targeted drug-induced tumor cell plasticity in various types of tumors and provide insights into the contribution of tumor cell plasticity to acquired drug resistance. New therapeutic strategies such as inhibition or reversal of tumor cell plasticity are also presented. We also discuss the multitude of clinical trials that are ongoing worldwide with the intention of improving clinical outcomes. These advances provide a direction for developing novel therapeutic strategies and combination therapy regimens that target tumor cell plasticity.

A phase II study (WJOG12819L) to assess the efficacy of osimertinib in patients with EGFR mutation-positive NSCLC in whom systemic disease (T790M-negative) progressed after treatment with first- or second-generation EGFR TKIs and platinum-based chemotherapy

BACKGROUND

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that is an established standard treatment option for chemotherapy-naive patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). However, of such patients who have received prior treatment with a first- or second-generation EGFR TKI, only approximately half are eligible for osimertinib therapy because its indication as second-line treatment and beyond is limited to metastatic NSCLC that is positive for the T790M resistance mutation of the EGFR gene. This study was initiated at the request of a dedicated network for patients with lung cancer in Japan.

METHODS

We conducted a phase II study to assess the efficacy of osimertinib in patients with EGFR mutation-positive NSCLC in whom systemic disease (T790M-negative) progressed after treatment with first- or second-generation EGFR TKIs and platinum-based chemotherapy. The primary end point was response rate (assessed by a central imaging reviewer).

RESULTS

From August 2020 to February 2021, 55 patients from 15 institutions were enrolled in the study. The overall response for primary analysis was achieved in 16 patients (29.1 %; 95 % CI, 17.6-42.9), which exceeded the threshold response rate necessary for analysis. Stable disease was found in 16 patients (29.1 %), and progressive disease, in 18 (32.7 %). The median length of progression-free survival (PFS) was 4.07 months (95 % CI 2.10-4.30), and the rate of 12-month PFS was 17.3 %.

CONCLUSIONS

Osimertinib demonstrated modest antitumor activity against progressive EGFR T790M-negative disease.

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.

Investigation of somatic mutation profiles and tumor evolution of primary oropharyngeal cancer and sequential lymph node metastases using multiregional whole-exome sequencing

Lymph node (LN) metastasis is an important factor in determining the treatment and prognosis of oropharyngeal squamous cell carcinoma (OPSCC). Here, we compared the somatic mutational profiles and clonal evolution of primary and metastatic LNs using multiregion sequencing of human papilloma virus (HPV)-positive OPSCC and HPV-negative OPSCC. We performed high-depth whole-exome sequencing (200×) of 76 samples from 18 patients with OPSCC (10 HPV-positive and 8 HPV-negative), including 18 primary tumor samples, 40 metastatic LN samples, and 18 normal tissue samples. Among 40 metastatic LNs, 22 showed extranodal extension (ENE). Mutation profiles of HPV-positive OPSCC and HPV-negative OPSCC were similar to those reported previously. Somatic mutations in CDKN2A and TP53 were frequently detected in HPV-negative OPSCC. Somatic mutations in HPV-positive OPSCC samples showed APOBEC-related signatures. Somatic mutations from metastatic LNs showed a different pattern than the primary tumor. Somatic mutations acquired in the WNT pathway during metastasis showed a significant relationship with ENE. Clonal evolution analysis of primary and metastatic LNs showed that, in some cases, each metastatic LN originated from a different primary tumor sub-clone.

Osimertinib treatment based on plasma T790M monitoring in patients with EGFR-mutant non-small cell lung cancer (NSCLC): EORTC Lung Cancer Group 1613 APPLE phase II randomized clinical trial

BACKGROUND

The APPLE trial aimed to evaluate the feasibility of longitudinal plasma EGFR T790M monitoring for the best sequencing strategy of gefitinib and osimertinib.

METHODS

APPLE is a randomized, non-comparative, phase II study in patients with common EGFR-mutant, treatment-naïve NSCLC including 3-arms: Arm A (osimertinib upfront until RECIST progression, PD), Arm B (gefitinib until emergence of circulating tumor DNA EGFR T790M mutation by cobas EGFR Test v2 or RECIST PD) and Arm C (gefitinib until RECIST PD), and then switch to osimertinib in both arms. The primary endpoint is the progression-free survival rate "on osimertinib" at 18 months (PFSR-OSI-18) after randomization in Arm B (H₀: PFSR-OSI-18 of ≤40%). Secondary endpoints include response rate, overall survival (OS) and brain PFS (BPFS). We report the results of Arms B and C.

RESULTS

From November 2017 to February 2020, 52 and 51 patients were randomized into Arms B and C. Most patients were females (70%) and had EGFR Del19 (65%); one-third had baseline brain metastases. In Arm B, 17% of patients (8/47) switched to osimertinib based on the emergence of ct-DNA T790M mutation before RECIST PD, with a median time to molecular PD of 266 days. The study met its primary endpoint of PFSR-OSI-18 by 67.2% (84% CI: 56.4-75.9%) in Arm B vs. 53.5% (84% CI 42.3-63.5%) in Arm C, with a median PFS of 22.0 months vs. 20.2 months, respectively. The median OS was not reached in Arm B vs. 42.8 months in Arm C. Median BPFS in Arms B and C were 24.4 months and 21.4 months, respectively.

CONCLUSIONS

The serial monitoring of ct-DNA T790M-status in advanced EGFR-mutant NSCLC during treatment with first-generation EGFR inhibitors was feasible, and a molecular progression before RECIST PD led to an earlier switch to osimertinib in 17% of patients with satisfactory PFS and OS outcomes.

Liquid Biopsies in Lung Cancer

As lung cancer has the highest cancer-specific mortality rates worldwide, there is an urgent need for new therapeutic and diagnostic approaches to detect early-stage tumors and to monitor their response to the therapy. In addition to the well-established tissue biopsy analysis, liquid-biopsy-based assays may evolve as an important diagnostic tool. The analysis of circulating tumor DNA (ctDNA) is the most established method, followed by other methods such as the analysis of circulating tumor cells (CTCs), microRNAs (miRNAs), and extracellular vesicles (EVs). Both PCR- and NGS-based assays are used for the mutational assessment of lung cancer, including the most frequent driver mutations. However, ctDNA analysis might also play a role in monitoring the efficacy of immunotherapy and its recent accomplishments in the landscape of state-of-the-art lung cancer therapy. Despite the promising aspects of liquid-biopsy-based assays, there are some limitations regarding their sensitivity (risk of false-negative results) and specificity (interpretation of false-positive results). Hence, further studies are needed to evaluate the usefulness of liquid biopsies for lung cancer. Liquid-biopsy-based assays might be integrated into the diagnostic guidelines for lung cancer as a tool to complement conventional tissue sampling.

Afatinib in Untreated Stage IIIB/IV Lung Adenocarcinoma with Major Uncommon Epidermal Growth Factor Receptor (EGFR) Mutations (G719X/L861Q/S768I): A Multicenter Observational Study in Taiwan

BACKGROUND

Real-world clinical experience with afatinib as a treatment for advanced lung adenocarcinoma harboring uncommon epidermal growth factor receptor (EGFR) mutations (G719X, L861Q and S768I) has rarely been reported.

OBJECTIVE

We aimed to perform a retrospective multicenter study to analyze afatinib therapy in untreated advanced lung adenocarcinoma harboring uncommon EGFR mutations.

PATIENTS AND METHODS

Between May 2014 and June 2021, the data of 90 stage IIIB/IV lung adenocarcinoma patients with uncommon EGFR mutations (G719X/L861Q/S768I) treated with first-line afatinib from the cancer center database of Linkou, Tucheng, and Kaohsiung Chang Gung Memorial Hospitals were retrospectively retrieved and analyzed.

RESULTS

Afatinib had an objective response rate (ORR) of 63.3% and a disease control rate (DCR) of 86.7%. The median progression-free survival (PFS) with first-line afatinib therapy was 17.3 months (95% confidence interval (CI), 12.07-22.53), and the median overall survival (OS) was 28.5 months (95% CI, 20.22-36.77) in all study patients. In the multivariate analysis, poor performance (Eastern Cooperative Oncology Group performance status (ECOG PS) ≥ 2) and brain and liver metastases were independent predictors of unfavorable PFS. The G719X mutation (alone+compound) was an independent predictor of favorable PFS (hazard ratio (HR) = 0.578; 95% CI, 0.355-0.941; P = 0.027). Most afatinib-related adverse events (AEs) were limited to grades 1 and 2 and were manageable.

CONCLUSIONS

First-line afatinib therapy is effective and safe for advanced lung adenocarcinoma harboring uncommon EGFR mutations. The G719X mutation was an independent factor associated with a favorable outcome. Poor performance (ECOG PS ≥ 2), brain metastasis, and liver metastasis were predictive factors of shorter PFS with first-line afatinib therapy.

Clinical Utility and Application of Liquid Biopsy Genotyping in Lung Cancer: A Comprehensive Review

Precision medicine has revolutionized the therapeutic management of cancer patients with a major impact on non-small cell lung cancer (NSCLC), particularly lung adenocarcinoma, where advances have been remarkable. Tissue biopsy, required for tumor molecular testing, has significant limitations due to the difficulty of the biopsy site or the inadequacy of the histological specimen. In this context, liquid biopsy, consisting of the analysis of tumor-released materials circulating in body fluids, such as blood, is increasingly emerging as a valuable and non-invasive biomarker for detecting circulating tumor DNA (ctDNA) carrying molecular tumor signatures. In advanced/metastatic NSCLC, liquid biopsy drives target therapy by monitoring response to treatment and identifying eventual genomic mechanisms of resistance. In addition, recent data have shown a significant ability to detect minimal residual disease in early-stage lung cancer, underlying the potential application of liquid biopsy in the adjuvant setting, in early detection of recurrence, and also in the screening field. In this article, we present a review of the currently available data about the utility and application of liquid biopsy in lung cancer, with a particular focus on the approach to different techniques of analysis for liquid biopsy and a comparison with tissue samples as well as the potential practical uses in early and advanced/metastatic NSCLC.

Interpretation of Lung Cancer Plasma EGFR Mutation Tests in the Clinical Setting

OBJECTIVES

Comprehensive data synthesis of the clinical parameters that affect plasma EGFR mutation test results in non-small cell lung carcinoma is lacking. Although individual studies have suggested a variety of patient characteristics that can affect diagnostic accuracy, no unified conclusion has been reached.

METHODS

We analyzed 170 plasma EGFR mutation tests performed between 2015 and 2021 at our institution and carried out a systematic review and meta-analysis to identify clinical and imaging features that correlate with plasma EGFR mutation test sensitivity.

RESULTS

Data synthesis from 14 studies of 2,576 patients revealed that patients with stage IV disease had a significantly lower false-negative rate than those with stage I through III disease. For our institutional cohort, which consisted of 75 paired plasma and tissue tests that were assessable for diagnostic accuracy, the overall sensitivity was 70.59% (95% confidence interval, 56.17%-82.51%). Patients who had distant metastases and more suspicious lymph nodes on imaging findings correlated with a low false-negative rate.

CONCLUSIONS

While interpreting plasma EGFR mutation results, extra caution should be exercised for patients with early-stage, localized disease to accommodate the possibility of false-negative results. These meta-analyses and clinical data may enable clinicians to make evidence-based judgments for individual patients.

Application of ddPCR in detection of the status and abundance of EGFR T790M mutation in the plasma samples of non-small cell lung cancer patients

Background/Objective

The third-generation epidermal growth factor receptor (EGFR) -tyrosine kinase inhibitor (TKIs), such as osimertinib, designed for targeting the acquired drug-resistant mutation of EGFR T790M, was approved as the first-line therapy for advanced EGFR-mutated non-small cell lung cancer (NSCLC). Thus, detection of the EGFR T790M mutation for NSCLC is crucial. However, tissue samples are often difficult to obtain, especially in patients at advanced stages. This study assessed the performances of droplet digital polymerase chain reaction (ddPCR) and next-generation sequencing (NGS) in detecting EGFR T790M status and abundance in the plasma ctDNA samples of patients with NSCLC. We also explored the association between T790M status and abundance and the response to third-generation EGFR-TKIs.

Methods

A total of 201 plasma samples with matched tissues, 821 plasma samples, and 56 patients who received third-generation EGFR-TKIs with response evaluation were included in this study. ddPCR and NGS were used to detect the mutation status and abundance of T790M in the tissues and/or blood samples.

Results

The results showed that the sensitivity and the specificity of EGFR T790M mutation status detected by ddPCR in plasma samples were 81.82% and 91.85%, respectively, compared with the tissue samples, with a consistency coefficient of 0.740. Among the 821 plasma samples, the positive rates of EGFR T790M detected by ddPCR and NGS were 34.2% (281/821) and 22.5% (185/821), respectively. With NGS results as the reference, the sensitivity and the specificity of ddPCR were 100% and 84.91%, respectively, and the consistency coefficient of the two methods was 0.717. In addition, we found that a higher EGFR T790M abundance was linked to a higher treatment response rate to the third-generation EGFR-TKIs regardless of the classification of the median value of 0.43% (P = 0.016) or average value of 3.16% (P = 0.010).

Conclusion

Taking these data together, this study reveals that ddPCR is an alternatively potent method for the detection of EGFR T790M in the plasma samples of NSCLC patients.

Tumor Growth Suppression of Pancreatic Cancer Orthotopic Xenograft Model by CEA-Targeting CAR-T Cells

Chimeric antigen receptor engineered T cell (CAR-T) therapy has high therapeutic efficacy against blood cancers, but it has not shown satisfactory results in solid tumors. Therefore, we examined the therapeutic effect of CAR-T therapy targeting carcinoembryonic antigen (CEA) in pancreatic adenocarcinoma (PDAC). CEA expression levels on the cell membranes of various PDAC cell lines were evaluated using flow cytometry and the cells were divided into high, medium, and low expression groups. The relationship between CEA expression level and the antitumor effect of anti-CEA-CAR-T was evaluated using a functional assay for various PDAC cell lines; a significant correlation was observed between CEA expression level and the antitumor effect. We created orthotopic PDAC xenograft mouse models and injected with anti-CEA-CAR-T; only the cell line with high CEA expression exhibited a significant therapeutic effect. Thus, the therapeutic effect of CAR-T therapy was related to the target antigen expression level, and the further retrospective analysis of pathological findings from PDAC patients showed a correlation between the intensity of CEA immunostaining and tumor heterogeneity. Therefore, CEA expression levels in biopsies or surgical specimens can be clinically used as biomarkers to select PDAC patients for anti-CAR-T therapy.

Updated Views in Targeted Therapy in the Patient with Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most frequent form of lung cancer and represents a set of histological entities that have an ominous long-term prognosis, for example, adenocarcinoma, squamous carcinoma and large cell carcinoma. Both small cell and non-small cell lung cancer are the main causes of oncological death and the oncological diseases with the highest incidence worldwide. With regard to clinical approaches for NSCLC, several advances have been achieved in diagnosis and treatment; the analysis of different molecular markers has led to the development of new targeted therapies that have improved the prognosis for selected patients. Despite this, most patients are diagnosed in an advanced stage, presenting a limited life expectancy with an ominous short-term prognosis. Numerous molecular alterations have been described in recent years, allowing for the development of therapies directed against specific therapeutic targets. The correct identification of the expression of different molecular markers has allowed for the individualization of treatment throughout the disease course, expanding the available therapeutic arsenal. The purpose of this article is to summarize the main characteristics of NSCLC and the advances that have occurred in the use of targeted therapies, thus explaining the limitations that have been observed in the management of this disease.

The Implication of Liquid Biopsy in the Non-small Cell Lung Cancer: Potential and Expectation

Nowadays, lung cancer has remained the most lethal cancer, despite great advances in diagnosis and treatment. However, a large proportion of patients were diagnosed with locally advanced or metastatic disease and have poor prognosis. Immunotherapy and targeted drugs have greatly improved the survival and prognosis of patients with advanced lung cancer. However, how to identify the optimal patients to accept those therapies and how to monitor therapeutic efficacy are still in dispute. In the past few decades, tissue biopsy, including percutaneous fine needle biopsy and surgical excision, has still been the gold standard for examining the gene mutation such as EGFR, ALK, ROS, and PD-1/PD/L1, which can indicate the follow-up treatment. Nevertheless, the biopsy techniques mentioned above were invasive and unrepeatable, which were not suitable for advanced patients. Liquid biopsy, accounting for heterogeneity compared with tissue biopsy, is an alternative technique for monitoring the mutation, and a large quantity of research has demonstrated its feasibility to detect the circulating tumor cell, cell-free DNA, circulating tumor DNA, and extracellular vesicles from peripheral venous blood. The proposal of the concept of precision medicine brings a novel medical model developed with the rapid progress of genome sequencing technology and the cross-application of bioinformation, which was based on personalized medicine. The emerging method of liquid biopsy might contribute to promoting the development of precision medicine. In this review, we intend to describe the liquid biopsy in non-small cell lung cancer in detail in the aspect of screening, diagnosis, monitoring, treatment, and drug resistance.