Navigating the liquid biopsy Minimal Residual Disease (MRD) in non-small cell lung cancer: Making the invisible visible

Recent advances in the use of liquid biopsy for the diagnosis and treatment of lung cancer

INTRODUCTION

In the era of precision medicine, liquid biopsy rapidly emerges as an integrative diagnostic tool to successfully stratify solid tumor patients in accordance with molecular fingerprinting. As the matter of fact, a plethora of analytes may be isolated from liquid biosources supporting the potential application of liquid biopsy in several clinical scenarios. Despite this promising role, liquid biopsy is drastically affected by low abundance of analytes in biological matrix requiring highly sensitive technologies, trained personnel, and optimized diagnostic procedures to successfully administrate this revolutionary diagnostic tool in clinical practice.

AREAS COVERED

This review aims to investigate the recent advancements in technical approaches available to manage liquid biopsy samples, particularly focusing on their application in LC diagnosis and treatment.

EXPERT OPINION

The rapidly evolving scenario of liquid biopsy-based approaches is revolutionizing clinical administration of lung cancer patients. Of note, the integration of genomic, epigenomic, and transcriptomic markers lays the basis for 'comprehensive' molecular fingerprinting of lung cancer patients. Here, the next-generation technologies are fundamental in molecular profiling in diagnostic routine biofluids.

Exploring the potential of multiomics liquid biopsy testing in the clinical setting of lung cancer

The transformative role of artificial intelligence (AI) and multiomics could enhance the diagnostic and prognostic capabilities of liquid biopsy (LB) for lung cancer (LC). Despite advances, the transition from tissue biopsies to more sophisticated, non-invasive methods like LB has been impeded by challenges such as the heterogeneity of biomarkers and the low concentration of tumour-related analytes. The advent of multiomics - enabled by deep learning algorithms - offers a solution by allowing the simultaneous analysis of various analytes across multiple biological fluids, presenting a paradigm shift in cancer diagnostics. Through multi-marker, multi-analyte and multi-source approaches, this review showcases how AI and multiomics are identifying clinically valuable biomarker combinations that correlate with patients' health statuses. However, the path towards clinical implementation is fraught with challenges, including study reproducibility and lack of methodological standardization, thus necessitating urgent solutions to solve these common issues.

Liquid and Tissue Biopsies for Lung Cancer: Algorithms and Perspectives

The targeted therapies and immunotherapies in thoracic oncology, particularly for NS-NSCLC, are associated with an increase in the number of predictive biomarkers to be assessed in routine clinical practice. These treatments are administered thanks to marketing authorization for use in daily practice or are evaluated during clinical trials. Since the molecular targets to be identified are more and more complex and numerous, it is now mandatory to use NGS. NGS can be developed from both tissue and fluid (mainly blood). The blood tests in oncology, so-called "liquid biopsies" (LB), are performed with plasmatic circulating free DNA (cf-DNA) and are complementary to the molecular testing performed with a TB. LB use in lung cancer is associated with international guidelines, but additional algorithms could be set up. However, even if useful for better care of patients, notably with advanced and metastatic NS-NSCLC, until now LB are not often integrated into daily practice, at least in Europe and notably in France. The purpose of this review is to describe the different opportunities and algorithms leading to the identification of the molecular signature of NS-NSCLC, using both tissue and liquid biopsies, and to introduce the principle limitations but also some perspectives in this field.

Clinical utility of ctDNA by amplicon based next generation sequencing in first line non small cell lung cancer patients

The assessment of ctDNA has emerged as a minimally invasive avenue for molecular diagnosis and real-time tracking of tumor progression in NSCLC. However, the evaluation of ctDNA by amplicon-based NGS has been not endorsed by all the healthcare systems and remains to be fully integrated into clinical routine practice. To compare tissue single-gene with plasma multiplexed testing, we retrospectively evaluated 120 plasma samples from 12 consecutive patients with advanced non-squamous NSCLC who were part of a prospective study enrolling treatment-naïve patients and in which tissue samples were evaluated using a single-gene testing approach. While the plasma ctDNA detection of EGFR and BRAF mutations had an acceptable level of concordance with the archival tissue (85%), discordance was seen in all the patients in whom ALK alterations were only detected in tissue samples. Among six responders and six non-responders, early ctDNA mutant allelic frequency (MAF) reduction seemed to predict radiologic responses and longer survival, whereas increasing MAF values with the emergence of co-mutations like BRAFV600E, KRASG12V or TP53M237I seemed to be an early indicator of molecular and radiologic progression. This report using an amplicon-based NGS assay on ctDNA underscores the real-life need for plasma and tissue genotyping as complementary tools in the diagnostic and therapeutic decision-making process.

Latest Research Progress of Liquid Biopsy in Tumor-A Narrative Review

Human life expectancy is significantly impacted by cancer, with liquid biopsy emerging as an advantageous method for cancer detection because of its noninvasive nature, high accuracy, ease of sampling, and cost-effectiveness compared with conventional tissue biopsy techniques. Liquid biopsy shows promise in early cancer detection, real-time monitoring, and personalized treatment for various cancers, including lung, cervical, and prostate cancers, and offers innovative approaches for cancer diagnosis and management. By utilizing circulating tumor DNA, circulating tumor cells, and exosomes as biomarkers, liquid biopsy enables the tracking of cancer progression. Various techniques commonly used in life sciences research, such as polymerase chain reaction (PCR), next-generation sequencing (NGS), and droplet digital PCR, are employed to assess cancer progression on the basis of different indicators. This review examines the latest advancements in liquid biopsy markers-circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and exosomes-for cancer diagnosis over the past three years, with a focus on their detection methodologies and clinical applications. It encapsulates the pivotal aims of liquid biopsy, including early detection, therapy response prediction, treatment monitoring, prognostication, and its relevance in minimal residual disease, while also addressing the challenges facing routine clinical adoption. By combining the latest research advancements and practical clinical experiences, this work focuses on discussing the clinical significance of DNA methylation biomarkers and their applications in tumor screening, auxiliary diagnosis, companion diagnosis, and recurrence monitoring. These discussions may help enhance the application of liquid biopsy throughout the entire process of tumor diagnosis and treatment, thereby providing patients with more precise and effective treatment plans.

Extracellular Vesicles in Liquid Biopsies as Biomarkers for Solid Tumors

Extracellular vesicles (EVs) are secreted by all living cells and are ubiquitous in every human body fluid. They are quite heterogeneous with regard to biogenesis, size, and composition, yet always reflect their parental cells with their cell-of-origin specific cargo loading. Since numerous studies have demonstrated that EV-associated proteins, nucleic acids, lipids, and metabolites can represent malignant phenotypes in cancer patients, EVs are increasingly being discussed as valuable carriers of cancer biomarkers in liquid biopsy samples. However, the lack of standardized and clinically feasible protocols for EV purification and characterization still limits the applicability of EV-based cancer biomarker analysis. This review first provides an overview of current EV isolation and characterization techniques that can be used to exploit patient-derived body fluids for biomarker quantification assays. Secondly, it outlines promising tumor-specific EV biomarkers relevant for cancer diagnosis, disease monitoring, and the prediction of cancer progression and therapy resistance. Finally, we summarize the advantages and current limitations of using EVs in liquid biopsy with a prospective view on strategies for the ongoing clinical implementation of EV-based biomarker screenings.