Liquid biopsy and non-small cell lung cancer: are we looking at the tip of the iceberg?

Longitudinal tracking of circulating rare events in the liquid biopsy of stage III-IV non-small cell lung cancer patients

In the United States, lung cancer is the second most common type of cancer with non-small cell lung cancer (NSCLC) encompassing around 85% of total lung cancer cases. Late-stage patients with metastatic disease have worsening prognosis, highlighting the importance of longitudinal disease monitoring. Liquid biopsy (LBx) represents a way for physicians to non-invasively track tumor analytes, such as circulating tumor cells (CTCs), and understand tumor progression in real-time through analyzing longitudinal blood samples. CTCs have been shown to be effective predictive biomarkers in measuring treatment efficacy and survival outcomes. We used the third-generation High-Definition Single Cell Assay (HDSCA3.0) workflow to analyze circulating rare events longitudinally during treatment in a cohort of 10 late-stage NSCLC patients, identifying rare events including circulating cancer cells (i.e., CTCs), and oncosomes. Here, we show (1) that there is a cancer specific LBx profile, (2) there is considerable heterogeneity of rare cells and oncosomes, and (3) that LBx data elements correlated with patient survival outcomes. Additional studies are warranted to understand the biological significance of the rare events detected, and the clinical potential of the LBx to monitor and predict response to treatment in NSCLC patient care.

Circulating biomarkers as predictors of response to immune checkpoint inhibitors in NSCLC: Are we on the right path?

Immune checkpoints inhibitors (ICIs) have markedly improved the therapeutic management of advanced NSCLC and, more recently, they have demonstrated efficacy also in the early-stage disease. Despite better survival outcomes with ICIs compared to standard chemotherapy, a large proportion of patients can derive limited clinical benefit from these agents. So far, few predictive biomarkers, including the programmed death-ligand 1 (PD-L1), have been introduced in clinical practice. Therefore, there is an urgent need to identify novel biomarkers to select patients for immunotherapy, to improve efficacy and avoid unnecessary toxicity. A deeper understanding of the mechanisms involved in antitumor immunity and advances in the field of liquid biopsy have led to the identification of a wide range of circulating biomarkers that could potentially predict response to immunotherapy. Herein, we provide an updated overview of these circulating biomarkers, focusing on emerging data from clinical studies and describing modern technologies used for their detection.

The cost-effectiveness of including liquid biopsy into molecular profiling strategies for newly diagnosed advanced non-squamous non-small cell lung cancer in an Asian population

OBJECTIVES

Liquid biopsy is complementary to tissue biopsy for lung cancer profiling, yet evidence of the cost-effectiveness is limited. This could retard implementation and reimbursement in clinical practice. The aim of this study is to estimate the cost-effectiveness of profiling strategies that include liquid biopsy and to identify the optimal profiling approach for newly diagnosed advanced non-squamous non-small cell lung cancer (NSCLC) in an Asian population using Singapore as an example.

MATERIALS AND METHODS

A decision tree and partitioned-survival model was developed from the Singapore healthcare system's perspective to evaluate the cost-effectiveness of five molecular profiling strategies: either tissue or plasma next-generation sequencing (NGS) alone, a concurrent, and two sequential approaches. Model inputs were informed by local data or published literature. Sensitivity analyses and scenario analyses were undertaken to understand the robustness of the conclusions for decision making. The optimal strategy at different willingness-to-pay (WTP) thresholds was presented by cost-effectiveness acceptability frontier and the expected loss curve.

RESULTS

The sequential tissue-plasma NGS approach revealed an additional 0.0981 quality adjusted life years (QALYs) for an extra cost of S$3,074 over a 20-year time horizon compared to tissue NGS alone, resulting in an incremental cost-effectiveness ratio (ICER) of S$31,318/QALY and an incremental net monetary benefit of S$1,343 per patient. The findings were sensitive to the costs of pembrolizumab and osimertinib and the probabilities of re-biopsy after tissue NGS. Sequential plasma-tissue NGS and plasma NGS alone were more costly and less effective than alternatives.

CONCLUSION

The sequential tissue-plasma NGS approach generated the highest net monetary benefit and was the optimal testing strategy when WTP was S$45,000/QALY. It retained superiority but understandably with a higher ICER when expensive, non-first line treatments were included. Overall, its routine clinical practice should be proactively considered for newly diagnosed advanced non-squamous NSCLC in an Asian population.

The study of primary and acquired resistance to first-line osimertinib to improve the outcome of EGFR-mutated advanced Non-small cell lung cancer patients: the challenge is open for new therapeutic strategies

The development of targeted therapy in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients has radically changed their clinical perspectives. Current first-line standard treatment for advanced disease is commonly considered third-generation tyrosine kinase inhibitors (TKI), osimertinib. The study of primary and acquired resistance to front-line osimertinib is one of the main burning issues to further improve patients' outcome. Great heterogeneity has been depicted in terms of duration of clinical benefit and pattern of progression and this might be related to molecular factors including subtypes of EGFR mutations and concomitant genetic alterations. Acquired resistance can be categorized into two main classes: EGFR-dependent and EGFR-independent mechanisms and specific pattern of progression to first-line osimertinib have been demonstrated. The purpose of the manuscript is to provide a comprehensive overview of literature about molecular resistance mechanisms to first-line osimertinib, from a clinical perspective and therefore in relationship to emerging therapeutic approaches.

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.

Circulating tumor DNA (ctDNA) as a biomarker for lung cancer: Early detection, monitoring and therapy prediction

Circulating tumor DNA (ctDNA), i.e., DNA shed from tumor cells into the bloodstream, is emerging as one of the most useful plasma biomarkers in patients with multiple types of cancer, including patients with non-small cell lung cancer (NSCLC). Indeed, NSCLC was the first malignancy in which measurement of ctDNA was approved for clinical use, i.e., mutational testing of EGFR for predicting response to EGFR tyrosine kinase inhibitors in patients with advanced disease. Although historically the gold standard method for EGFR mutational analysis required tumor tissue, the use of ctDNA is more convenient and safer for patients, results in a faster turn-around-time for return of results, provides a more complete representation of genetic alteration in heterogeneous tumors and is less costly to perform. Emerging uses of ctDNA in patients with lung or suspected lung cancer include screening for early disease, surveillance following initial treatment and monitoring response to therapy in metastatic disease. For evaluating therapy response, ctDNA appears to be especially useful in patients receiving targeted therapies against driver oncogenes or immunotherapy. Further work should not only validate these emerging findings but also aim to optimize and standardize ctDNA assays.

Resistance to osimertinib in advanced EGFR-mutated NSCLC: a prospective study of molecular genotyping on tissue and liquid biopsies

BACKGROUND

Resistance to osimertinib in advanced EGFR-mutated non-small cell lung cancer (NSCLC) constitutes a significant challenge for clinicians either in terms of molecular diagnosis and subsequent therapeutic implications.

METHODS

This is a prospective single-centre study with the primary objective of characterising resistance mechanisms to osimertinib in advanced EGFR-mutated NSCLC patients treated both in first- and in second-line. Next-Generation Sequencing analysis was conducted on paired tissue biopsies and plasma samples. A concordance analysis between tissue and plasma was performed.

RESULTS

Sixty-five advanced EGFR-mutated NSCLC patients treated with osimertinib in first- (n = 56) or in second-line (n = 9) were included. We managed to perform tissue and liquid biopsies in 65.5% and 89.7% of patients who experienced osimertinib progression, respectively. Acquired resistance mechanisms were identified in 80% of 25 patients with post-progression samples, with MET amplification (n = 8), EGFR C797S (n = 3), and SCLC transformation (n = 2) the most frequently identified. The mean concordance rates between tissue and plasma for the EGFR activating mutation and for the molecular resistance mechanisms were 87.5% and 22.7%, respectively.

CONCLUSIONS

Resistance to osimertinib demonstrated to be highly heterogeneous, with MET amplification the main mechanism. Plasma genotyping is a relevant complementary tool which might integrate tissue analysis for the study of resistance mechanisms.

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.

Liquid biopsy in non-small cell lung cancer: a meta-analysis of state-of-the-art and future perspectives

Introduction: To date, tissue biopsy represents the gold standard for characterizing non-small-cell lung cancer (NSCLC), however, the complex architecture of the disease has introduced the need for new investigative approaches, such as liquid biopsy. Indeed, DNA analyzed in liquid biopsy is much more representative of tumour heterogeneity. Materials and methods: We performed a meta-analysis of 17 selected papers, to attest to the diagnostic performance of liquid biopsy in identifying EGFR mutations in NSCLC. Results: In the overall studies, we found a sensitivity of 0.59, specificity of 0.96 and diagnostic odds ratio of 24,69. Since we noticed a high heterogeneity among different papers, we also performed the meta-analysis in separate subsets of papers, divided by 1) stage of disease, 2) experimental design and 3) method of mutation detection. Liquid biopsy has the highest sensitivity/specificity in high-stage tumours, and prospective studies are more reliable than retrospective ones in terms of sensitivity and specificity, both NGS and PCR-based techniques can be used to detect tumour DNA in liquid biopsy. Discussion: Overall, liquid biopsy has the potential to help the management of NSCLC, but at present the non-homogeneous literature data, lack of optimal detection methods, together with relatively high costs make its applicability in routine diagnostics still challenging.

Economic Evaluations of Imaging Biomarker-Driven Companion Diagnostics for Cancer: A Systematic Review

INTRODUCTION

There is a boom in imaging biomarker-driven companion and complementary diagnostics (CDx) for cancer, which brings opportunity for personalized medicine. Whether adoption of these technologies is likely to be cost-effective is a relevant question, and studies on this topic are emerging. Despite the growing number of economic evaluations, no review of the methods used, quality of reporting, and potential risk of bias has been done. We report a systematic review to identify, summarize, and critique the cost-effectiveness evidence for the use of biomarker-driven and imaging-based CDx to inform cancer treatments.

METHODS

The Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Systematic literature searches until 30 December 2022 were performed in PubMed, Web of Science, Medline, Embase, and Scopus for economic evaluations of imaging biomarker-based CDx for cancer. The inclusion and exclusion of studies were determined by pre-specified eligibility criteria informed by the 'Patient, Intervention, Comparison, Outcome' (PICO) framework. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) was used to assess the quality of reporting, and the Bias in Economic Evaluation (ECOBIAS) was used to examine the potential risk of bias of included studies.

RESULTS

A total of 12 papers were included, with eight model-based and four trial-based studies. Implementing biomarker-driven, imaging-based CDx was reported to be cost-effective, cost saving, or dominant (cost saving and more effective) in ten papers. Inconsistent methods were found in the studies, and the quality of reporting was lacking against the CHEERS reporting guideline. Several potential sources of 'risk of bias' were identified. These should be acknowledged and carefully considered by researchers planning future health economic evaluations.

CONCLUSION

Despite favorable results towards the implementation of imaging biomarker-based CDx for cancer, there is room for improvement regarding the quantity and quality of economic evaluations, and that is expected as the awareness of current study limitations increases and more clinical data become available in the future.

The Comparison of Serum Exosome Protein Profile in Diagnosis of NSCLC Patients

A thorough study of the exosomal proteomic cargo may enable the identification of proteins that play an important role in cancer development. The aim of this study was to compare the protein profiles of the serum exosomes derived from non-small lung cancer (NSCLC) patients and healthy volunteers (control) using the high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) method to identify potentially new diagnostic and/or prognostic protein biomarkers. Proteins exclusively identified in NSCLC and control groups were analyzed using several bioinformatic tools and platforms (FunRich, Vesiclepedia, STRING, and TIMER2.0) to find key protein hubs involved in NSCLC progression and the acquisition of metastatic potential. This analysis revealed 150 NSCLC proteins, which are significantly involved in osmoregulation, cell-cell adhesion, cell motility, and differentiation. Among them, 3 proteins: Interleukin-34 (IL-34), HLA class II histocompatibility antigen, DM alpha chain (HLA-DMA), and HLA class II histocompatibility antigen, DO beta chain (HLA-DOB) were shown to be significantly involved in the cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) infiltration processes. Additionally, detected proteins were analyzed according to the presence of lymph node metastasis, showing that differences in frequency of detection of protein FAM166B, killer cell immunoglobulin-like receptor 2DL1, and olfactory receptor 52R1 correlate with the N feature according to the TNM Classification of Malignant Tumors. These results prove their involvement in NSCLC lymph node spread and metastasis. However, this study requires further investigation.

Ramucirumab plus erlotinib versus placebo plus erlotinib in previously untreated EGFR-mutated metastatic non-small-cell lung cancer (RELAY): exploratory analysis of next-generation sequencing results

BACKGROUND

Ramucirumab plus erlotinib (RAM + ERL) demonstrated superior progression-free survival (PFS) over placebo + ERL (PBO + ERL) in the phase III RELAY study of patients with epidermal growth factor receptor (EGFR)-mutated metastatic non-small-cell lung cancer (EGFR+ mNSCLC; NCT02411448). Next-generation sequencing (NGS) was used to identify clinically relevant alterations in circulating tumor DNA (ctDNA) and explore their impact on treatment outcomes.

PATIENTS AND METHODS

Eligible patients with EGFR+ mNSCLC were randomized 1 : 1 to ERL (150 mg/day) plus RAM (10 mg/kg)/PBO every 2 weeks. Liquid biopsies were to be prospectively collected at baseline, cycle 4 (C4), and postdiscontinuation follow-up. EGFR and co-occurring/treatment-emergent (TE) genomic alterations in ctDNA were analyzed using Guardant360 NGS platform.

RESULTS

In those with valid baseline samples, detectable activating EGFR alterations in ctDNA (aEGFR+) were associated with shorter PFS [aEGFR+: 12.7 months (n = 255) versus aEGFR-: 22.0 months (n = 131); hazard ratio (HR) = 1.87, 95% confidence interval (CI) 1.42-2.51]. Irrespective of detectable/undetectable baseline aEGFR, RAM + ERL was associated with longer PFS versus PBO + ERL [aEGFR+: median PFS (mPFS) = 15.2 versus 11.1 months, HR = 0.63, 95% CI 0.46-0.85; aEGFR-: mPFS = 22.1 versus 19.2 months, HR = 0.80, 95% CI 0.49-1.30]. Baseline alterations co-occurring with aEGFR were identified in 69 genes, most commonly TP53 (43%), EGFR (other than aEGFR; 25%), and PIK3CA (10%). PFS was longer in RAM + ERL, irrespective of baseline co-occurring alterations. Clearance of baseline aEGFR by C4 was associated with longer PFS (mPFS = 14.1 versus 7.0 months, HR = 0.481, 95% CI 0.33-0.71). RAM + ERL improved PFS outcomes, irrespective of aEGFR mutation clearance. TE gene alterations were most commonly in EGFR [T790M (29%), other (19%)] and TP53 (16%).

CONCLUSIONS

Baseline aEGFR alterations in ctDNA were associated with shorter mPFS. RAM + ERL was associated with improved PFS outcomes, irrespective of detectable/undetectable aEGFR, co-occurring baseline alterations, or aEGFR+ clearance by C4. aEGFR+ clearance by C4 was associated with improved PFS outcomes. Monitoring co-occurring alterations and aEGFR+ clearance may provide insights into mechanisms of EGFR tyrosine kinase inhibitor resistance and the patients who may benefit from intensified treatment schedules.

The Impact of Liquid Biopsies Positive for EGFR Mutations on Overall Survival in Non-Small Cell Lung Cancer Patients

In recent years, non-small cell lung cancer treatment has been revolutionized. EGFR tyrosine kinase inhibitors and our improved understanding of its alterations have driven new diagnostic strategies. Liquid biopsies have emerged as a useful tool in these contexts, showing potential utility in early diagnosis combined with low-dose CT scans, as well as potential in monitoring treatment response and predicting the development of patients. We studied the circulating tumor DNA (ctDNA) of 38 EGFR-mutated non-small cell lung cancer patients at diagnosis in different moments of their disease by liquid biopsy techniques. Our results show that mean overall survival was significantly lower when a liquid biopsy was positive for the detection of EGFR mutations compared with wild-type patients in their liquid biopsy in both univariate (29 ± 4 vs. 104 ± 19 months; p = 0.004) and multivariate analysis (p = 0.008). Taking this into consideration, liquid biopsies could be key to improving the control of this disease.

Consensus Recommendations for the Diagnosis, Biomarker Testing, and Clinical Management of Advanced or Metastatic Non-small Cell Lung Cancer With Mesenchymal-Epithelial Transition Exon 14 Skipping Mutations in the Middle East, Africa, and Russia

Mesenchymal-epithelial transition exon 14 (METex14) skipping mutations occur in about 3%-4% of patients with non-small cell lung cancer (NSCLC). This is an aggressive subtype associated with poor prognosis. METex14 skipping is a potentially targetable mutation. Targeted therapy is a promising treatment modality for patients with advanced/metastatic METex14-mutant NSCLC. Performing systematic molecular testing to detect the driver mutation is essential for initiating targeted therapy. However, there is a lack of guidelines on molecular testing for assessing the eligibility of patients for targeted therapy. Therefore, a multidisciplinary panel consisting of experts from the Middle East, Africa, and Russia convened via a virtual advisory board meeting to provide their insights on various molecular testing techniques for the diagnosis of METex14 skipping mutation, management of patients with targeted therapies, and developing consensus recommendations for improving the processes. The expert panel emphasized performing molecular testing and liquid biopsy before treatment initiation and tissue re-biopsy for patients with failed molecular testing. Liquid biopsy was recommended as complementary to tissue biopsy for disease monitoring and prognosis. Selective MET inhibitors were recommended as the first and subsequent lines of therapy. These consensus recommendations will facilitate the management of METex14 skipping NSCLC in routine practice and warrant optimum outcomes for these patients.

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.

Predicting response and toxicity to immune checkpoint inhibitors in lung cancer using antibodies to frameshift neoantigens

PURPOSE

To evaluate a new class of blood-based biomarkers, anti-frameshift peptide antibodies, for predicting both tumor responses and adverse immune events to immune checkpoint inhibitor (ICI) therapies in advanced lung cancer patients.

EXPERIMENTAL DESIGN

Serum samples were obtained from 74 lung cancer patients prior to palliative PD-(L)1 therapies with subsequently recorded tumor responses and immune adverse events (irAEs). Pretreatment samples were assayed on microarrays of frameshift peptides (FSPs), representing ~ 375,000 variant peptides that tumor cells can be informatically predicted to produce from translated mRNA processing errors. Serum-antibodies specifically recognizing these ligands were measured. Binding activities preferentially associated with best-response and adverse-event outcomes were determined. These antibody bound FSPs were used in iterative resampling analyses to develop predictive models of tumor response and immune toxicity.

RESULTS

Lung cancer serum samples were classified based on predictive models of ICI treatment outcomes. Disease progression was predicted pretreatment with ~ 98% accuracy in the full cohort of all response categories, though ~ 30% of the samples were indeterminate. This model was built with a heterogeneous sample cohort from patients that (i) would show either clear response or stable outcomes, (ii) would be administered either single or combination therapies and (iii) were diagnosed with different lung cancer subtypes. Removing the stable disease, combination therapy or SCLC groups from model building increased the proportion of samples classified while performance remained high. Informatic analyses showed that several of the FSPs in the all-response model mapped to translations of variant mRNAs from the same genes. In the predictive model for treatment toxicities, binding to irAE-associated FSPs provided 90% accuracy pretreatment, with no indeterminates. Several of the classifying FSPs displayed sequence similarity to self-proteins.

CONCLUSIONS

Anti-FSP antibodies may serve as biomarkers for predicting ICI outcomes when tested against ligands corresponding to mRNA-error derived FSPs. Model performances suggest this approach might provide a single test to predict treatment response to ICI and identify patients at high risk for immunotherapy toxicities.

Soluble biomarkers to predict clinical outcomes in non-small cell lung cancer treated by immune checkpoints inhibitors

Lung cancer remains the first cause of cancer-related death despite many therapeutic innovations, including immune checkpoint inhibitors (ICI). ICI are now well used in daily practice at late metastatic stages and locally advanced stages after a chemo-radiation. ICI are also emerging in the peri-operative context. However, all patients do not benefit from ICI and even suffer from additional immune side effects. A current challenge remains to identify patients eligible for ICI and benefiting from these drugs. Currently, the prediction of ICI response is only supported by Programmed death-ligand 1 (PD-L1) tumor expression with perfectible results and limitations inherent to tumor-biopsy specimen analysis. Here, we reviewed alternative markers based on liquid biopsy and focused on the most promising biomarkers to modify clinical practice, including non-tumoral blood cell count such as absolute neutrophil counts, platelet to lymphocyte ratio, neutrophil to lymphocyte ratio, and derived neutrophil to lymphocyte ratio. We also discussed soluble-derived immune checkpoint-related products such as sPD-L1, circulating tumor cells (detection, count, and marker expression), and circulating tumor DNA-related products. Finally, we explored perspectives for liquid biopsies in the immune landscape and discussed how they could be implemented into lung cancer management with a potential biological-driven decision.

Liquid Biopsy in Lung Cancer: Biomarkers for the Management of Recurrence and Metastasis

Liquid biopsies have emerged as a promising tool for the detection of metastases as well as local and regional recurrence in lung cancer. Liquid biopsy tests involve analyzing a patient's blood, urine, or other body fluids for the detection of biomarkers, including circulating tumor cells or tumor-derived DNA/RNA that have been shed into the bloodstream. Studies have shown that liquid biopsies can detect lung cancer metastases with high accuracy and sensitivity, even before they are visible on imaging scans. Such tests are valuable for early intervention and personalized treatment, aiming to improve patient outcomes. Liquid biopsies are also minimally invasive compared to traditional tissue biopsies, which require the removal of a sample of the tumor for further analysis. This makes liquid biopsies a more convenient and less risky option for patients, particularly those who are not good candidates for invasive procedures due to other medical conditions. While liquid biopsies for lung cancer metastases and relapse are still being developed and validated, they hold great promise for improving the detection and treatment of this deadly disease. Herein, we summarize available and novel approaches to liquid biopsy tests for lung cancer metastases and recurrence detection and describe their applications in clinical practice.

Circulating Tumour DNA (ctDNA) as a Predictor of Clinical Outcome in Non-Small Cell Lung Cancer Undergoing Targeted Therapies: A Systematic Review and Meta-Analysis

BACKGROUND

Liquid biopsy (LB) analysis using (ctDNA)/cell-free DNA (cfDNA) is an emerging alternative to tissue profiling in (NSCLC). LB is used to guide treatment decisions, detect resistance mechanisms, and predicts responses, and, therefore, outcomes. This systematic review and meta-analysis evaluated the impact of LB quantification on clinical outcomes in molecularly altered advanced NSCLC undergoing targeted therapies.

METHODS

We searched Embase, MEDLINE, PubMed, and Cochrane Database, between 1 January 2020 and 31 August 2022. The primary outcome was progression-free survival (PFS). Secondary outcomes included overall survival (OS), objective response rate (ORR), sensitivity, and specificity. Age stratification was performed based on the mean age of the individual study population. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

A total of 27 studies (3419 patients) were included in the analysis. Association of baseline ctDNA with PFS was reported in 11 studies (1359 patients), while that of dynamic changes with PFS was reported in 16 studies (1659 patients). Baseline ctDNA-negative patients had a trend towards improved PFS (pooled hazard ratio [pHR] = 1.35; 95%CI: 0.83-1.87; p < 0.001; I² = 96%) than ctDNA-positive patients. Early reduction/clearance of ctDNA levels after treatment was related to improved PFS (pHR = 2.71; 95%CI: 1.85-3.65; I² = 89.4%) compared to those with no reduction/persistence in ctDNA levels. The sensitivity analysis based on study quality (NOS) demonstrated improved PFS only for good [pHR = 1.95; 95%CI: 1.52-2.38] and fair [pHR = 1.99; 95%CI: 1.09-2.89] quality studies, but not for poor quality studies. There was, however, a high level of heterogeneity (I² = 89.4%) along with significant publication bias in our analysis.

CONCLUSIONS

This large systematic review, despite heterogeneity, found that baseline negative ctDNA levels and early reduction in ctDNA following treatment could be strong prognostic markers for PFS and OS in patients undergoing targeted therapies for advanced NSCLC. Future randomised clinical trials should incorporate serial ctDNA monitoring to further establish the clinical utility in advanced NSCLC management.

The application of pancreatic cancer organoids for novel drug discovery

INTRODUCTION

Pancreatic ductal adenocarcinoma presents with a dismal prognosis. Personalized therapy is urgently warranted to overcome the treatment limitations of the "one-size-fits-all" scheme. Organoids have emerged as fundamental novel tools to study tumor biology and heterogeneity, hence overcoming limitations of other model systems by better-reflecting tissue heterogeneity and recapitulating in-vivo processes. Besides their crucial role in basic research, they have evolved as tools for translational drug discovery and patient stratification.

AREAS COVERED

This review highlights the achievements of an organoid-based drug investigation and discovery. The authors present an overview of studies using organoids for drug testing. Further, they pinpoint studies correlating the in vitro prediction of organoids to the actual patient`s response. Furthermore, the authors describe novel model systems and take a thorough overlook of microfluidic chips, synthetic matrices, multicellular systems, bioprinting, and stem cell-derived pancreatic organoid systems.

EXPERT OPINION

Organoid systems promise great potential for future clinical applications. Indeed, they may be implemented into informed decision-making for guiding therapies. However, validation by randomized trials is mandatory. Additionally, organoids in combination with other cellular compartments may be exploited for drug discovery by studying niche-tumor interaction. Yet, several precautions must be kept in mind, such as standardization and reproducibility.

Precision Surgery in NSCLC

Non-small cell lung cancer (NSCLC) is still one of the leading causes of death worldwide. This is mostly because the majority of lung cancers are discovered in advanced stages. In the era of conventional chemotherapy, the prognosis of advanced NSCLC was grim. Important results have been reported in thoracic oncology since the discovery of new molecular alterations and of the role of the immune system. The advent of new therapies has radically changed the approach to lung cancer for a subset of patients with advanced NSCLC, and the concept of incurable disease is still changing. In this setting, surgery seems to have developed a role of rescue therapy for some patients. In precision surgery, the decision to perform surgical procedures is tailored to the individual patient; taking into consideration not only clinical stage, but also clinical and molecular features. Multimodality treatments incorporating surgery, immune checkpoint inhibitors, or targeted agents are feasible in high volume centers with good results in terms of pathologic response and patient morbidity. Thanks to a better understanding of tumor biology, precision thoracic surgery will facilitate optimal and individualized patient selection and treatment, with the goal of improving the outcomes of patients affected by NSCLC.

RNA profile of immuno-magnetically enriched lung cancer associated exosomes isolated from clinical samples

Exosomal cargo secreted from cancer cells has been associated with the development and progression of the tumour. Enriching clinically relevant tissue-specific exosomes may assist in the focused analysis of RNA molecules packaged during cancer. Therefore, this study utilized a rapid immunomagnetic enrichment approach for targeted isolation of lung cancer cell-derived exosomes from human plasma, followed by analysing their cargo RNA using high throughput sequencing. The total RNA purified from these immunomagnetically enriched exosomes provided adequate RNA quality for characterization through the Illumina platform. Differential expression analysis was performed between patients and healthy controls to study the altered exosomal RNA profile during lung cancer. Further, functional enrichment analysis was performed with the list of identified differentially expressed genes (DEGs). In total, 1383 mRNAs and 64 lncRNA were identified as differentially expressed between patient plasma exosomes than healthy controls (fold change > 2, P < 0.05). Kyoto encyclopaedia of Genes and Genomes (KEGG) pathway analysis revealed that the DEGs were mainly associated with cancer-related pathways, purine metabolism, calcium, and cGMP-PKG signalling pathways. In conclusion, the presented approach successfully demonstrated a novel strategy for focused disease-specific transcriptome analysis, which provides a feasible option for identifying disease-specific exosome biomarkers for detecting non-small lung cancer.

MET alterations in advanced non-small cell lung cancer

Targeting the MET pathway in advanced NSCLC has been of particular interest due to its role as both a primary oncogenic driver and secondary oncogenic driver of acquired resistance. Activation of the MET pathway can occur through several mechanisms, which can complicate the diagnostic and treatment approach. Recently, several MET-directed therapies have been developed with promising results. In this narrative review, we summarize the biology and mechanism of MET as a clinically relevant driver mutation, distinct MET alterations including diagnostic challenges, significance in the setting of acquired resistance, and novel treatment strategies in advanced NSCLC.

Extracapsular extension of pN2 lymph node metastases is not prognostically significant in surgically resected patients with non-small cell lung cancer

Objectives

In patients with non-small cell lung cancer (NSCLC) the pathologic lymph node status N2 is a heterogeneous entity, with different degrees of lymph node involvement representing different prognoses. It is speculated whether extra capsular nodal extension may help to define a subgroup with implications on long-term survival.

Methods

We retrospectively identified 118 patients with non-small cell lung cancer (65 men, 53 women), who were treated between 2013 and 2018 and found to have pathologic N2 lymph node involvement. In all patients lung resection with systematic mediastinal and hilar lymph node dissection was performed with curative intent. In N2 lymph node metastases capsules of affected lymph nodes were examined microscopically as to whether extracapsular extension was present.

Results

51 patients (43 %) had extracapsular extension (ENE). Most of these patients (n=35) only had ENE in a single lymph node (69 %). The overall 5-year survival rate was 24.6 % and progression-free survival rate 17.8 %. In the multivariate analysis OS was worse for patients with multiple affected pN2 stations, concurrent N1 metastases, increasing age, and larger tumor size. For the percentage of lymph nodes affected with ENE (of total examined) only a non-significant trend towards worse OS could be observed (p=0.06).

Conclusions

Although we could not demonstrate significant prognostic differences between N2 extra capsular nodal involvement within our patient population, other analyses may yield different results. However, clinicians should continue performing thorough lymph nodes dissections in order to achieve local complete resection even in patients with extra capsular tumor spread.

Extrahepatic Distal Cholangiocarcinoma vs. Pancreatic Ductal Adenocarcinoma: Histology and Molecular Profiling for Differential Diagnosis and Treatment

Pancreatic ductal adenocarcinoma (PDAC) and distal cholangiocarcinoma (dCCA) are very aggressive tumors with a high mortality rate. Pancreas and distal bile ducts share a common embryonic development. Hence, PDAC and dCCA exhibit similar histological features that make a differential diagnosis during routine diagnostic practice challenging. However, there are also significant differences, with potential clinical implications. Even if PDAC and dCCA are generally associated with poor survival, patients with dCCA seem to present a better prognosis. Moreover, although precision oncology-based approaches are still limited in both entities, their most important targets are different and include alterations affecting BRCA1/2 and related genes in PDAC, as well as HER2 amplification in dCCA. Along this line, microsatellite instability represents a potential contact point in terms of tailored treatments, but its prevalence is very low in both tumor types. This review aims at defining the most important similarities and differences in terms of clinicopathological and molecular features between these two entities, also discussing the main theranostic implications derived from this challenging differential diagnosis.

A Case of Epidermal Growth Factor Receptor-Mutated Non-Small-Cell Lung Cancer: Multi-Line Treatment and Resistance Mechanisms

In the non-small-cell lung cancer (NSCLC) subtype, adenocarcinoma is the most common histology. The choice of first-line treatment depends on the mutational status. We present a case of a 54-year-old non-smoker woman with lung adenocarcinoma and extensive metastatic disease at diagnosis. The genetic analysis demonstrated a sensitizing epidermal growth factor receptor (EGFR) exon 19 mutation and she began treatment with a first-generation EGFR tyrosine kinase inhibitor (TKI), erlotinib. Due to successively acquired resistances and disease progression, six treatment lines were pursued, including third-generation EGFR TKI and chemotherapy. The patient accomplished an overall survival of 47 months. This case emphasized the importance of monitoring tumor mutational alterations, allowing us to implement a multi-line treatment. Targeted therapy in advanced NSCLC largely improved the overall survival of these patients.

A method for early diagnosis of lung cancer from tumor originated DNA fragments using plasma cfDNA methylome and fragmentome profiles

Early detection is critical for minimizing mortality from cancer. Plasma cell-free DNA (cfDNA) contains the signatures of tumor DNA, allowing us to quantify the signature and diagnose early-stage tumors. Here, we report a novel tumor fragment quantification method, TOF (Tumor Originated Fragment) for the diagnosis of lung cancer by quantifying and analyzing both the plasma cfDNA methylation patterns and fragmentomic signatures. TOF utilizes the amount of ctDNA predicted from the methylation density information of each cfDNA read mapped on 6243 lung-tumor-specific CpG markers. The 6243 tumor-specific markers were derived from lung tumor tissues by comparing them with corresponding normal tissues and healthy blood from public methylation data. TOF also utilizes two cfDNA fragmentomic signatures: 1) the short fragment ratio, and 2) the 5' end-motif profile. We used 298 plasma samples to analyze cfDNA signatures using enzymatic methyl-sequencing data from 201 lung cancer patients and 97 healthy controls. The TOF score showed 0.98 of the area under the curve in correctly classifying lung cancer from normal samples. The TOF score resolution was high enough to clearly differentiate even the early-stage non-small cell lung cancer patients from the healthy controls. The same was true for small cell lung cancer patients.

The Overview of Perspectives of Clinical Application of Liquid Biopsy in Non-Small-Cell Lung Cancer

The standard diagnostics procedure for non-small-cell lung cancer (NSCLC) requires a pathological evaluation of tissue samples obtained by surgery or biopsy, which are considered invasive sampling procedures. Due to this fact, re-sampling of the primary tumor at the moment of progression is limited and depends on the patient’s condition, even if it could reveal a mechanism of resistance to applied therapy. Recently, many studies have indicated that liquid biopsy could be provided for the noninvasive management of NSCLC patients who receive molecularly targeted therapies or immunotherapy. The liquid biopsy of neoplastic patients harbors small fragments of circulating-free DNA (cfDNA) and cell-free RNA (cfRNA) secreted to the circulation from normal cells, as well as a subset of tumor-derived circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA). In NSCLC patients, a longitudinal assessment of genetic alterations in “druggable” genes in liquid biopsy might improve the follow-up of treatment efficacy and allow for the detection of an early progression before it is detectable in computed tomography or a clinical image. However, a liquid biopsy may be used to determine a variety of relevant molecular or genetic information for understanding tumor biology and its evolutionary trajectories. Thus, liquid biopsy is currently associated with greater hope for common diagnostic and clinical applications. In this review, we would like to highlight diagnostic challenges in the application of liquid biopsy into the clinical routine and indicate its implications on the metastatic spread of NSCLC or monitoring of personalized treatment regimens.

Molecular Profiling in Non-Squamous Non-Small Cell Lung Carcinoma: Towards a Switch to Next-Generation Sequencing Reflex Testing

Molecular diagnosis of lung cancer is a constantly evolving field thanks to major advances in precision oncology. The wide range of actionable molecular alterations in non-squamous non-small cell lung carcinoma (NS-NSCLC) and the multiplicity of mechanisms of resistance to treatment resulted in the need for repeated testing to establish an accurate molecular diagnosis, as well as to track disease evolution over time. While assessing the increasing complexity of the molecular composition of tumors at baseline, as well as over time, has become increasingly challenging, the emergence and implementation of next-generation sequencing (NGS) testing has extensively facilitated molecular profiling in NS-NSCLC. In this review, we discuss recent developments in the molecular profiling of NS-NSCLC and how NGS addresses current needs, as well as how it can be implemented to address future challenges in the management of NS-NSCLC.

The evolving role of liquid biopsy in lung cancer

Liquid biopsy has revolutionized the management of cancer patients. In particular, liquid biopsy-based testing has proven to be highly beneficial for identifying actionable cancer markers, especially when solid tissue biopsies are insufficient or unattainable. Beyond the predictive role, liquid biopsy may be a useful tool for comprehensive tumor genotyping, identification of emergent resistance mechanisms, monitoring of minimal residual disease, early detection, and cancer interception. The application of next generation sequencing to liquid biopsy has led to the "quantum leap" of predictive molecular pathology. Here, we review the evolving role of liquid biopsy in lung cancer.

Liquid Biopsy Analysis as a Tool for TKI-Based Treatment in Non-Small Cell Lung Cancer

The treatment of non-small cell lung cancer (NSCLC) has recently evolved with the introduction of targeted therapy based on the use of tyrosine kinase inhibitors (TKIs) in patients with certain gene alterations, including EGFR, ALK, ROS1, BRAF, and MET genes. Molecular targeted therapy based on TKIs has improved clinical outcomes in a large number of NSCLC patients with advanced disease, enabling significantly longer progression-free survival (PFS). Liquid biopsy is an increasingly popular diagnostic tool for treating TKI-based NSCLC. The studies presented in this article show that detection and analysis based on liquid biopsy elements such as circulating tumor cells (CTCs), cell-free DNA (cfDNA), exosomes, and/or tumor-educated platelets (TEPs) can contribute to the appropriate selection and monitoring of targeted therapy in NSCLC patients as complementary to invasive tissue biopsy. The detection of these elements, combined with their molecular analysis (using, e.g., digital PCR (dPCR), next generation sequencing (NGS), shallow whole genome sequencing (sWGS)), enables the detection of mutations, which are required for the TKI treatment. Despite such promising results obtained by many research teams, it is still necessary to carry out prospective studies on a larger group of patients in order to validate these methods before their application in clinical practice.