Liquid biopsy into the clinics: Current evidence and future perspectives

Comprehensive assessment of the role of spectral data pre-processing in spectroscopy-based liquid biopsy

Spectroscopic data often contain artifacts or noise related to the sample characteristics, instrumental variations, or experimental design flaws. Therefore, classifying the raw data is not recommended and might lead to biased results. Nevertheless, most issues may be addressed through appropriate data pre-processing. Effective pre-processing is particularly crucial in critical applications like liquid biopsy for disease detection, where even minor performance improvements may impact patient outcomes. Unfortunately, there is no consensus regarding optimal pre-processing, complicating cross-study comparisons. This study presents a comprehensive evaluation of various pre-processing methods and their combinations to assess their influence on classification results. The goal was to identify whether some pre-processing methods are associated with higher classification outcomes and find an optimal strategy for the given data. Data from Raman optical activity and infrared and Raman spectroscopy were processed, applying tens of thousands of possible pre-processing pipelines. The resulting data were classified using three algorithms to distinguish between subjects with liver cirrhosis and those who had developed hepatocellular carcinoma. Results highlighted that some specific pre-processing methods often ranked among the best classification results, such as the Rolling Ball for correcting the baseline of Raman spectra or the Doubly Reweighted Penalized Least Squares and Mixture model in the case of Raman optical activity. On the other hand, the selection of filtering and/or normalization approach usually did not have a significant impact. Nonetheless, the pre-processing of top-scoring pipelines also depended on the classifier utilized. The best pipelines yielded an AUROC of 0.775-0.823, varying with the evaluated spectroscopic data and classifier.

Exploring breast cancer-related biochemical changes in circulating extracellular vesicles using Raman spectroscopy

Extracellular vesicles (EVs) are a subgroup of the circulating particles, released by cells in both normal and diseased states, carrying active biomolecules. They have gained significant attention as potential cancer biomarkers, particularly in breast cancer (BC). Previous research showed variations in EVs content and quantity between BC patients and healthy controls (HC). However, studying the biochemical profile of EVs remains challenging due to their low abundance and complex composition. Additionally, EVs may interact with other plasma components, like lipoproteins (LPs), forming a so called "biomolecular corona" that further complicates their analysis. Here, Raman spectroscopy (RS) is proposed as a fast tool to obtain the biochemical profile of circulating EVs in the context of BC. RS was employed to differentiate various extracellular particles (EPs) in blood, including LPs and EVs. The study also evaluated RS's capability to quantify major classes of biomolecules and compared these results with those obtained by traditional biochemical assays. Finally, compositional differences in large EVs (lEVs) and small EVs (sEVs) were assessed between HC and BC patients. RS revealed the existence of distinct biochemical signatures associated with BC, highlighting increased levels of nucleic acids and lipids in the BC group.

The growing field of liquid biopsy and its Snowball effect on reshaping cancer management

Liquid biopsy (LB) has emerged as a transformative tool in oncology, providing a minimally invasive approach for tumor detection, molecular characterization, and real-time treatment monitoring. By analyzing circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), extracellular vesicles (EVs), and microRNA (miRNA), LB enables comprehensive tumor profiling without the need for traditional tissue biopsies. Over the past decade, research in this field has expanded exponentially, leading to the integration of LB into clinical practice for specific cancer types, including lung and breast cancer. In 2024, the Journal of Liquid Biopsy (JLB) published innovative studies exploring the latest advancements in LB technologies, biomarkers, and their applications for cancer detection, minimal residual disease (MRD) monitoring, and therapy response assessment. This review synthesizes recent findings on the role of LB in cancer treatment and monitoring across different biomarkers, with a particular focus on newly published studies and their context within translational research. Additionally, it highlights emerging techniques such as fragmentomics, artificial intelligence, and multiomics, paving the way for more precise, personalized treatment decisions. Despite these advancements, challenges remain in standardizing methodologies, optimizing clinical validation, and integrating LB into routine oncological workflows. This mini-review highlights the evolving landscape of LB research and its potential to revolutionize cancer diagnosis, treatment monitoring, and therapeutic decision-making, ushering in a new era of precision oncology.

Development and implementation of novel liquid biopsy NGS panels via the OncNGS precommercial procurement (PCP) initiative

BACKGROUND

Circulating tumor DNA (ctDNA) analysis is transforming oncology, but challenges such as insufficient analytical sensitivity, difficult variant interpretation, suboptimal turnaround time, limited deployment flexibility, and high costs hinder its broader adoption and raise concerns about reimbursement sustainability across European health care systems.

MATERIALS AND METHODS

To address these challenges, we created the OncNGS consortium, comprising academic, public, and private hospitals (buyers' group) and several supporting entities, to run a European precommercial procurement (PCP) initiative. The consortium defined ctDNA diagnostic testing requirements, conducted an open market consultation, and launched a call for tender. Suppliers were invited to develop an end-to-end, Conformité Européenne In Vitro Diagnostic (CE-IVD)-compliant solution integrating wet laboratory, dry laboratory, and reporting workflow in a single procedure, offering short turnaround time and reasonable cost.

RESULTS

The OncNGS consortium defined criteria for a versatile, modular, cost-effective solution, deployable centrally or on-site, and adaptable to advancements in precision oncology. Launched in July 2022, the tender attracted seven companies, with four selected for phase I-OncNGS solution(s) design. From these, three advanced to phase II-prototyping. Ultimately, two contractors were awarded contracts for phase III to assess the clinical performance of their prototypes.

CONCLUSIONS

By leveraging the PCP approach, OncNGS aims to deliver innovative, affordable solutions to standardize ctDNA testing and reporting across European Union countries, improving diagnostic and therapeutic strategies for oncology patients.

ESR1 testing on FFPE samples from metastatic lesions in HR + /HER2- breast cancer after progression on CDK4/6 inhibitor therapy

Mutations in ESR1 play a critical role in resistance to endocrine therapy (ET) in hormone receptor-positive (HR +)/HER2- metastatic breast cancer (MBC). Testing for ESR1 mutations is essential for guiding treatment with novel oral selective estrogen receptor degraders (SERDs) like elacestrant or camizestrant. While most studies have utilized liquid biopsy (LB) for mutation detection, the role of formalin-fixed paraffin-embedded (FFPE) tissue biopsy in this context remains unclear. In this study, we analyzed a cohort of HR + /HER2- MBC patients who experienced resistance to ET and CDK4/6 inhibitors. Next-generation sequencing (NGS) was performed on FFPE biopsy samples obtained from metastatic sites at the time of disease progression. ESR1 mutations were detected in 24 out of 38 patients (63.2%), with p.D538G identified in 10 patients (45.5%) and p.Y537S in 6 patients (27.2%) as the most frequent alterations. One patient exhibited dual ESR1 mutations, and a recurrent ESR1-CCDC170 gene fusion was identified, underscoring the diversity and potential interplay of genetic alterations driving resistance in HR + /HER2- MBC. Notably, lung metastases were significantly more common in ESR1 mutant cases (8/24, 33.3%) compared to wild-type cases (1/14, 7.1%), while liver metastases showed no difference between mutant (12/24, 50.0%) and wild-type groups (7/14, 50.0%). Co-mutations in actionable pathways, particularly PIK3CA, were observed in n = 10 ESR1 mutant tumors (41.6%), highlighting their contribution to resistance mechanisms and posing significant challenges for treatment selection, as these alterations may necessitate combination therapies to effectively target multiple resistance pathways. This study presents new insights into the prevalence and clinical significance of ESR1 mutations in HR + /HER2- MBC, highlighting the potential utility of FFPE biopsy samples as a viable alternative or complementary approach to LB for mutation detection, particularly in resource-limited settings where access to ctDNA analysis may be constrained.

Extracellular vesicles in uveal melanoma - Biological roles and diagnostic value

Uveal melanoma (UM), which originates from the uveal tract of the eye, is the most common and aggressive intraocular cancer in adults. The detection of genetic markers is crucial for an accurate diagnosis, but this requires tumor biopsies that can be challenging to obtain. Extracellular vesicles (EVs) have emerged as potential biomarkers for UM due to their presence in biological fluids and their ability to carry disease-related biomolecules such as proteins and nucleic acids. Increasing evidence indicates that EVs released from UM cells play crucial roles in UM development, including cancer progression, pre-metastatic niche formation, and metastasis. Moreover, many studies have demonstrated that UM-derived EVs carry proteins and microRNAs that might be used as biomarkers. This review explores the role of EVs in UM, focusing on their biological functions and their potential as diagnostic and prognostic biomarkers of UM. Additionally, current challenges to the use of UM-derived EVs in clinical translation were identified, as well as perspectives and future directions in the field.

Biobanking and gynecologic oncology - Special considerations, challenges and opportunities

Biobanks of gynecological tissues occupy a critical niche in oncologic research. They are essential components of contemporary research strategies on gynecologic malignancy by integrating clinical, molecular and longitudinal biospecimen data. They also implement protocols for quality control, regulate sample and data sharing, provide ethical and regulatory oversight, and establish governance mechanisms to regulate their function. Gynecologic tissue biobanks also face some unique challenges. The broad heterogeneity of disease entities encompassed under this domain include common and rare malignancies, each with unique molecular subtypes that must be integrated into biobank information systems. Specimen acquisition extends beyond conventional tissues to include cervicovaginal microbiomes and ascitic fluid. Thus, gynecologic tissue biobanks should develop tailored collection strategies and the establishment of dedicated gynecologic tissue repositories that enable the aggregation of rare specimens through collaborative networks. This article emphasizes the need for high-quality annotation of biospecimens, the incorporation of multi-omics approaches to enhance the translational approaches, challenges associated with integration of high dimensional datasets, the role of biobank networks, and various ethical and cultural considerations concerning gynecologic biobanks. Emerging technologies that integrate multi omics, spatial biology and liquid biopsies now offer enhanced opportunities that augment classical specimen collection and should be integrated into standardized protocols.

Circulating tumor DNA to monitor treatment response in solid tumors and advance precision oncology

Circulating tumor DNA (ctDNA) has emerged as a dynamic biomarker in cancer, as evidenced by its increasing integration into clinical practice. Carrying tumor specific characteristics, ctDNA can be used to inform treatment selection, monitor response, and identify drug resistance. In this review, we provide a comprehensive, up-to-date summary of ctDNA in monitoring treatment response with a focus on lung, colorectal, and breast cancers, and discuss current challenges and future directions.

Building the Future of Clinical Diagnostics: An Analysis of Potential Benefits and Current Barriers in CRISPR/Cas Diagnostics

Advancements in molecular diagnostics, such as polymerase chain reaction and next-generation sequencing, have revolutionized disease management and prognosis. Despite these advancements in molecular diagnostics, the field faces challenges due to high operational costs and the need for sophisticated equipment and highly trained personnel besides having several technical limitations. The emergent field of CRISPR/Cas sensing technology is showing promise as a new paradigm in clinical diagnostics, although widespread clinical adoption remains limited. This perspective paper discusses specific cases where CRISPR/Cas technology can surmount the challenges of existing diagnostic methods by stressing the significant role that CRISPR/Cas technology can play in revolutionizing clinical diagnostics. It underscores the urgency and importance of addressing the technological and regulatory hurdles that must be overcome to harness this technology effectively in clinical laboratories.

Magnetic-Plasmonic Core-Shell Nanoparticles: Properties, Synthesis and Applications for Cancer Detection and Treatment

Nanoparticles have been widely used in cancer diagnostics and treatment research due to their unique properties. Magnetic nanoparticles are popular in imaging techniques due to their ability to alter the magnetization field around them. Plasmonic nanoparticles are mainly applied in cancer treatments like photothermal therapy due to their ability to convert light into heat. While these nanoparticles are popular among their respective fields, magnetic-plasmonic core-shell nanoparticles (MPNPs) have gained popularity in recent years due to the combined magnetic and optical properties from the core and shell. MPNPs have stood out in cancer theranostics as a multimodal platform capable of serving as a contrast agent for imaging, a guidable drug carrier, and causing cellular ablation through photothermal energy conversion. In this review, we summarize the different properties of MPNPs and the most common synthesis approaches. We particularly discuss applications of MPNPs in cancer diagnosis and treatment based on different mechanisms using the magnetic and optical properties of the particles. Lastly, we look into current challenges they face for clinical applications and future perspectives using MPNPs for cancer detection and therapy.

Liquid biopsies and exosomal ncRNA: Transforming pancreatic cancer diagnostics and therapeutics

Pancreatic cancer is a highly fatal malignancy due to poor early detection rate and resistance to conventional therapies. This review examines the potential for liquid biopsy as a transformative technology to identify diagnostic and therapeutic targets in pancreatic cancer. Specifically, we explore emerging biomarkers such as exosomal non-coding RNAs (ncRNAs), circulating tumor DNA (ctDNA), and circulating tumor cells (CTCs). Tumor-derived exosomes contain nucleic acid and protein that reflect the unique molecular landscape of the malignancy and can serve as an alternative diagnostic approach vs traditional biomarkers like CA19-9. Herein we highlight exosomal miRNAs, lncRNAs, and other ncRNAs alongside ctDNA and CTC-based strategies, evaluating their combined ability to improve early detection, disease monitoring and treatment response. Furthermore, the therapeutic implications of ncRNAs such as lncRNA UCA1 and miR-3960 in chemoresistance and progression are also discussed via suppression of EZH2 and PTEN/AKT pathways. Emerging therapeutic strategies that target the immune response, epithelial-mesenchymal transition (EMT) and drug resistance are explored. This review demonstrates a paradigm shift in pancreatic cancer management toward personalized, less invasive and more effective approaches.

Dual Biomarker Strategies for Liquid Biopsy: Integrating Circulating Tumor Cells and Circulating Tumor DNA for Enhanced Tumor Monitoring

The liquid biopsy has gained significant attention in cancer diagnostics, with circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) being recognized as key biomarkers for tumor detection and monitoring. However, each biomarker possesses inherent limitations that restrict its standalone clinical utility, such as the rarity and heterogeneity of CTCs and the variable sensitivity and specificity of ctDNA assays. This highlights the necessity of integrating both biomarkers to maximize diagnostic and prognostic potential, offering a more comprehensive understanding of the tumor biology and therapeutic response. In this review, we summarize clinical studies that have explored the combined analysis of CTCs and ctDNA as biomarkers, providing insights into their synergistic value in diverse tumor types. Specifically, this paper examines the individual advantages and limitations of CTCs and ctDNA, details the findings of combined biomarker studies across various cancers, highlights the benefits of dual biomarker approaches over single-biomarker strategies, and discusses future prospects for advancing personalized oncology through liquid biopsies. By offering a comprehensive overview of clinical studies combining CTCs and ctDNA, this review serves as a guideline for researchers and clinicians aiming to enhance biomarker-based strategies in oncology and informs biosensor design for improved biomarker detection.

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.

Evaluating Circulating Biomarkers for Diagnosis, Prognosis, and Tumor Monitoring in Pediatric Sarcomas: Recent Advances and Future Directions

Pediatric sarcomas present a significant challenge in oncology. There is an urgent need for improved therapeutic strategies for high-risk patients and better management of long-term side effects for those who survive the disease. Liquid biopsy is emerging as a promising tool to optimize treatment in these patients by offering non-invasive, repeatable assessments of disease status. Circulating biomarkers can provide valuable insights into tumor genetics and treatment response, potentially facilitating early diagnosis and dynamic disease monitoring. This review examines the potential of liquid biopsies, focusing on circulating biomarkers in the most common pediatric sarcomas, i.e., osteosarcoma, Ewing sarcoma, and rhabdomyosarcoma. We also highlight the current research efforts and the necessary advancements required before these technologies can be widely adopted in clinical practice.

The Role of ctDNA and Liquid Biopsy in the Diagnosis and Monitoring of Head and Neck Cancer: Towards Precision Medicine

Recent data have shown a continued rise in the worldwide annual incidence and mortality rates of head and neck cancers. The present standard for diagnosis and monitoring for disease recurrence or progression involves clinical examination, imaging, and invasive biopsy techniques of lesions suspected of being malignant. In addition to limitations relating to cost, time, and patient discomfort, these methodologies have inherent inaccuracies for detecting recurrence. In view of these limitations, the analysis of patient bodily fluid samples via liquid biopsy proposes a cost-effective and convenient alternative, which provides insight on the biogenetic and biomolecular underpinnings of oncologic disease processes. The monitoring of biomarkers for head and neck cancer via liquid biopsy, including circulating tumor DNA, circulating tumor cells, and circulating cell-free RNA, has shown clinical utility in the screening, diagnosis, prognostication, and monitoring of patients with various forms of head and neck cancer. The present review will provide an update on the current literature examining the use of liquid biopsy in head and neck cancer care and the clinical applicability of potential biomarkers, with a focus on viral and non-viral circulating tumor DNA. Possible future avenues for research to address specific shortcomings of liquid biopsy will be discussed.