Circulating Tumor Biomarkers Research Articles

The role of GD2 as a diagnostic and prognostic tumor marker in neuroblastoma (literature review)

Neuroblastoma (NB) is a rare malignant tumor characterized by highly variable biological behavior, including spontaneous and induced regression, maturation, and progression. To assess the prognosis and response to therapy in NB, the determination of a number of oncological markers is used, such as neuron-specific enolase, lactate dehydrogenase, ferritin. Nevertheless, the models for assessing the prognosis developed so far do not fully predict the specificity of the course of the disease. In this regard, the creation of methods for monitoring tumor status in real time, based on the analysis of circulating tumor biomarkers, seems to be extremely urgent. A characteristic feature of NB is the expression of various gangliosides on the surface of tumor cells. In particular, the content of disialoganglioside GD2 reaches up to 30 % of all gangliosides. At the same time, the level of GD2 expression depends on the differentiation of neurogenic tumors: the highest concentrations are determined on NB cells, the lowest – on ganglioneuroblastoma and ganglioneuroma. The phenomenon of “shedding”, the so-called flushing, of GD2 from the NB cell membrane made it possible to estimate its concentration in the peripheral bloodstream. The article discusses the evolutionary path of the methodology for detecting GD2 in blood serum, with an emphasis on the recently introduced liquid chromatography/ tandem mass spectrometry technique, which can be used as a starting point for the emergence of GD2 as a soluble biomarker of the tumor process, which is undoubtedly a powerful application in the clinical practice that offers hope for improved diagnosis, prognosis and riskadapted therapy strategies based on well-defined, measurable determinants in accordance with the concept of evidence-based medicine.

Appropriateness and Economic Analysis of Conventional Circulating Biomarkers Assessment in Early Breast Cancer: A Real-World Experience from the E.Pic.A Study.

The risk of relapse for early breast cancer (BC) patients persists even after decades and to date, no specific and sensitive effective circulating biomarker for recurrence prediction has been identified yet. The international guidelines do not recommend the assessment of the serum tumor markers CEA and CA15-3 in the follow-up of asymptomatic early BC patients. In our institute, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, as part of the E.Pic.A study, which was designed to assess the economic appropriateness of integrated care pathways in early BC, the use of CEA and CA15-3 as circulating tumor biomarkers in early BC patients was evaluated in 1502 patients one year after surgery, from 2015 to 2018, with an overall expense of EUR 51,764. A total of EUR 47,780 (92%) was used for execution of circulating tumor markers in early BC patients with stage 0, I and II tumors, neglecting the current guidelines and considered inappropriate by our professional board. We found that no patients with stage I BC experienced relapse in the 365 days after surgery, and in any case examination of the circulating markers CEA and CA15-3 was considered crucial for diagnosis of relapse. Our findings suggest that this inadequacy is a low-value area, supporting the reallocation of economic resources for interventions of a higher value for patients.

Precise Molecular Profiling of Circulating Exosomes Using a Metal-Organic Framework-Based Sensing Interface and an Enzyme-Based Electrochemical Logic Platform.

Exosomes have emerged as a promising circulating tumor biomarker; however, it is a big challenge for convenient, multiparametric, and accurate profiling of tumorous exosomes due to their unique structure and heterogeneity. To address these problems, we develop a highly integrated electrochemical platform for molecular profiling of tumor exosomes. A metal-organic framework-functionalized sensing interface is fabricated through a simple self-growth process, which collects exosomes from biofluids without additional separation steps. Meanwhile, a sensing strategy is designed to analyze both exosomal protein and RNA markers on a single chip based on the unique sensor architecture, allowing detection of low-abundance targets (∼250 vesicles in a 10 μL sample) using an integrated microfluidic electrochemical device. Furthermore, a multiple-input, protein enzyme-based logic gate is introduced into the system to accurately identify breast cancer patients with 100% sensitivity and specificity, thus revealing the advantageous role of logical profiling of exosomes in early diagnostics of tumor.

Age-dependent reference intervals in children for the disialoganglioside, GD2, a circulating tumor biomarker for the childhood cancer, neuroblastoma

BackgroundThe disialoganglioside GD2 is a circulating tumor biomarker for the childhood cancer, neuroblastoma. This study establishes reference intervals for GD2 concentration in children within the age range where neuroblastoma commonly occurs. MethodsLeftover plasma samples taken for routine clinical laboratory tests from children without cancer were collected and assayed for the 18-carbon fatty acid chain length lipoform of GD2 using a validated high-pressure liquid chromatography tandem mass spectrometry method with a lower limit of quantification of 3 nM. Samples were stratified into 5 age cohorts (0–6 months, 6–12 months, 12–36 months, 3–10 years and > 10 years). Non-parametric statistical methods were used to define the upper bound of the reference interval for each age cohort. ResultsGD2 was measurable in 90% of samples from children < 10 years of age and GD2 concentration was age-dependent, peaking at 9 months followed by a gradual decline. GD2 was below the lower limit of quantification in 55% of samples in the > 10 years cohort. Upper bounds of reference intervals were 15.5 nM in 0–6 month cohort, 35.1 nM in 6–12 month cohort, 24.9 nM in 12–36 month cohort, 18.4 in 3–10 year cohort and 10.4 nM in > 10 year cohort. ConclusionsAge-dependent reference intervals were defined for circulating GD2 in children. GD2 concentration was highest in the 6–12 month age cohort, which is below the age of most children with high-risk neuroblastoma. The peak GD2 concentration at 9 months may reflect neurodevelopmental events in the brain.

Pharmacokinetics of the disialoganglioside, GD2, a circulating tumor biomarker for neuroblastoma, in nonhuman primates.

Background: The ganglioside GD2 is a potential circulating tumor biomarker for the childhood cancer, neuroblastoma. Interpreting the levels of a circulating tumor biomarker depends in part on a knowledge of the biomarker’s clinical pharmacology. Background: The ganglioside GD2 is a potential circulating tumor biomarker for the childhood cancer neuroblastoma. Interpreting the levels of a circulating tumor biomarker depends in part on a knowledge of the biomarker’s clinical pharmacology. Methods: We studied the plasma and cerebrospinal fluid (CSF) pharmacokinetics of the C18 lipoform of GD2 in two nonhuman primates with indwelling subcutaneous CSF lateral ventricular reservoir systems. GD2 was quantified with a validated high-performance liquid chromatography (HPLC)/tandem mass spectrometry assay. GD2 was administered as a short intravenous infusion and frequent plasma and CSF samples were drawn over 72 hours. Results: GD2 plasma concentration declined monoexponentially with a half-life of 16 hours. Clearance was 0.0136 and 0.0131 L/h and volume of distribution (Vd) was 0.035 and 0.038 L/kg in the two animals. Vd was equivalent to plasma volume. Greater than 98% of GD2 in plasma is in a bound form consistent with its known association with lipoproteins and accounting for its limited volume of distribution. GD2 did not cross over from plasma into the CSF. Conclusions: The pharmacokinetic profile of GD2 is favorable for a circulating tumor biomarker. This study demonstrates the value of characterizing the clinical pharmacology of circulating biomarkers to better understand their clinical behavior.

Unique Features of Hepatitis B Virus-Related Hepatocellular Carcinoma in Pathogenesis and Clinical Significance.

Simple SummaryHepatitis B virus (HBV) infection is the major risk factor for hepatocellular carcinoma (HCC). Understanding the unique features for HBV-induced HCC can shed new light on the unmet needs in its early diagnosis and effective therapy. During decades of chronic hepatitis B, hepatocytes undergoing repeated damage and regeneration accumulate genetic changes predisposing to HCC development. In addition to traditional mutations in viral and cellular oncogenes, HBV integration into the cell chromosomes is an alternative genetic change contributing to hepatocarcinogenesis. A striking male dominance in HBV-related HCC further highlights an interaction between androgen sex hormone and viral factors, which contributes to the gender difference via stimulating viral replication and activation of oncogenes preferentially in male patients. Meanwhile, a novel circulating tumor biomarker generated by HBV integration shows great potential for the early diagnosis of HCC. These unique HBV-induced hepatocarcinogenic mechanisms provide new insights for the future development of superior diagnosis and treatment strategies.Hepatitis B virus (HBV) infection is one of the important risk factors for hepatocellular carcinoma (HCC) worldwide, accounting for around 50% of cases. Chronic hepatitis B infection generates an inflammatory microenvironment, in which hepatocytes undergoing repeated cycles of damage and regeneration accumulate genetic mutations predisposing them to cancer. A striking male dominance in HBV-related HCC highlights the influence of sex hormones which interact with viral factors to influence carcinogenesis. HBV is also considered an oncogenic virus since its X and surface mutant proteins showed tumorigenic activity in mouse models. The other unique mechanism is the insertional mutagenesis by integration of HBV genome into hepatocyte chromosomes to activate oncogenes. HCC survival largely depends on tumor stages at diagnosis and effective treatment. However, early diagnosis by the conventional protein biomarkers achieves limited success. A new biomarker, the circulating virus–host chimera DNA from HBV integration sites in HCC, provides a liquid biopsy approach for monitoring the tumor load in the majority of HBV–HCC patients. To maximize the efficacy of new immunotherapies or molecular target therapies, it requires better classification of HCC based on the tumor microenvironment and specific carcinogenic pathways. An in-depth study may benefit both the diagnosis and treatment of HBV-related HCC.

Evaluation of Monocarboxylate Transporter 4 (MCT4) Expression and Its Prognostic Significance in Circulating Tumor Cells From Patients With Early Stage Non-Small-Cell Lung Cancer.

Purpose: Monocarboxylate transporter 4 (MCT4) can influence the amount of lactate in the tumor microenvironment and further control cancer cell proliferation, migration, and angiogenesis. We investigated for the first time the expression of MCT4 in circulating tumor cells (CTCs) derived from early stage Non-Small Cell Lung Cancer patients (NSCLC) and whether this is associated with clinical outcome.Experimental Design: A highly sensitive RT-qPCR assay for quantification of MCT4 transcripts was developed and validated and applied to study MCT4 expression in CTC isolated through the Parsortix size-dependent microfluidic device from 53 and 9 peripheral blood (PB) samples of NSCLC patients at baseline (pre-surgery) and at relapse, respectively, as well as the “background noise” was evaluated using peripheral blood samples from 10 healthy donors (HD) in exactly the same way as patients.Results: MCT4 was differentially expressed between HD and NSCLC patients. Overexpression of MCT4 was detected in 14/53 (26.4%) and 3/9 (33.3%) patients at baseline and at progression disease (PD), respectively. The expression levels of MCT4 was found to increase in CTCs at the time of relapse. Kaplan-Meier analysis showed that the overexpression of MCT4 was significantly (P = 0.045) associated with progression-free survival (median: 12.5 months, range 5–31 months).Conclusion: MCT4 overexpression was observed at a high frequency in CTCs from early NSCLC patients supporting its role in metastatic process. MCT4 investigated as clinically relevant tumor biomarker characterizing tumor aggressiveness and its potential value as target for cancer therapy. We are totally convinced that MCT4 overexpression in CTCs merits further evaluation as a non-invasive circulating tumor biomarker in a large and well-defined cohort of patients with NSCLC.

Photonic technologies for liquid biopsies: recent advances and open research challenges.

The recent development of sophisticated techniques capable of detecting extremely low concentrations of circulating tumor biomarkers in accessible body fluids, such as blood or urine, could contribute to a paradigm shift in cancer diagnosis and treatment. By applying such techniques, clinicians can carry out liquid biopsies, providing information on tumor presence, evolution, and response to therapy. The implementation of biosensing platforms for liquid biopsies is particularly complex because this application domain demands high selectivity/specificity and challenging limit-of-detection (LoD) values. The interest in photonics as an enabling technology for liquid biopsies is growing owing to the well-known advantages of photonic biosensors over competing technologies in terms of compactness, immunity to external disturbance, and ultra-high spatial resolution. Some encouraging experimental results in the field of photonic devices and systems for liquid biopsy have already been achieved by using fluorescent labels and label-free techniques and by exploiting super-resolution microscopy, surface plasmon resonance, surface-enhanced Raman scattering, and whispering gallery mode resonators. This paper critically reviews the current state-of-the-art, starting from the requirements imposed by the detection of the most common circulating biomarkers. Open research challenges are considered together with competing technologies, and the most promising paths of improvement are discussed for future applications.

Abstract 5371: Real-time serial monitoring of liquid biopsies allows earlier detection of treatment responses and relapse for metastatic esophageal squamous cell carcinoma

Abstract Purpose: Esophageal squamous cell carcinoma (ESCC) is a deadly cancer, frequently diagnosed at advanced stages, when it has already metastasized, making treatment difficult and survival low. We utilized liquid biopsies from ESCC patients for real-time monitoring of treatment responses and detection of relapse and metastasis. We aimed to determine the usefulness of circulating tumor biomarkers for monitoring disease burden and provide real-time assessment of the evolving tumor under treatment pressure. Experimental methods: Blood was collected from metastatic ESCC patients before, during, and at the end of treatment. It was processed to lyse red blood cells and enrich for circulating tumor cells (CTCs). Spiral microfluidics chips for size separation enriched for larger CTCs and removed smaller white blood cells. CTC enumeration was performed by immunofluorescence staining using antibody cocktails [pan-cytokeratin (CK), epithelial cell adhesion molecule (EpCAM), and clusters of differentiation 45 (CD-45)]. We performed next-generation sequencing (NGS) target capture analysis for a customized 300-gene panel of selected cancer-relevant and druggable genes. cfDNAs extracted from plasma were utilized to determine mutation profiles for circulating tumor DNA (ctDNA) with the Roche AVENIO ctDNA 77-gene pan-cancer kit. Mutations or amplifications detected were validated by Sanger sequencing or digital PCR. Summary: The sensitivity and specificity of the cfDNA platform was determined using in-house controls with known mutations, which were validated by digital PCR. At the baseline timepoint, genetic alterations were detected in 90.3% of 31 ESCC patients. TP53 gene was the most frequently mutated with point mutations detected in 77% of ESCC patients and EGFR gains in 19% of patients. Longitudinal cfDNA analysis showed good concordance between mutant allele frequency and tumor mutation burden, suggesting the usefulness of real-time non-invasive monitoring to detect minimal residual disease. Analysis of cfDNAs also provides the opportunity to determine the extent of inter-tumoral heterogeneity between primary and metastatic tumors. Our preliminary data show CTC enumeration at ~6 weeks pre-cycle III for patients treated with palliative CT and at end of chemo-radiation therapy (CRT) for locally advanced ESCC patients, may be useful prognostic and predictive biomarkers for treatment efficacy and to gauge risk relapse and survival. Ongoing studies will increase sample sizes. The clinical relevance of serial CTC enumeration data and the cfDNA and CTC mutational load detected will be correlated with disease progression to determine their usefulness for prognostication. Conclusions: Serial analysis of CTCs and ctDNAs of metastatic ESCC patients indicates the usefulness of real-time monitoring using liquid biopsies to assess tumor mutation burden and to predict treatment efficacy, disease relapse, and patient survival. Acknowledgements: TBRS grant T12-701/17R and HMRF grant 05160926 to MLL Citation Format: Josephine M. KO, Bianca H. NG, Maria L. Lung. Real-time serial monitoring of liquid biopsies allows earlier detection of treatment responses and relapse for metastatic esophageal squamous cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5371.

Aneuploid Circulating Tumor-Derived Endothelial Cell (CTEC): A Novel Versatile Player in Tumor Neovascularization and Cancer Metastasis.

Hematogenous and lymphogenous cancer metastases are significantly impacted by tumor neovascularization, which predominantly consists of blood vessel-relevant angiogenesis, vasculogenesis, vasculogenic mimicry, and lymphatic vessel-related lymphangiogenesis. Among the endothelial cells that make up the lining of tumor vasculature, a majority of them are tumor-derived endothelial cells (TECs), exhibiting cytogenetic abnormalities of aneuploid chromosomes. Aneuploid TECs are generated from “cancerization of stromal endothelial cells” and “endothelialization of carcinoma cells” in the hypoxic tumor microenvironment. Both processes crucially engage the hypoxia-triggered epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition (EndoMT). Compared to the cancerization process, endothelialization of cancer cells, which comprises the fusion of tumor cells with endothelial cells and transdifferentiation of cancer cells into TECs, is the dominant pathway. Tumor-derived endothelial cells, possessing the dual properties of cancerous malignancy and endothelial vascularization ability, are thus the endothelialized cancer cells. Circulating tumor-derived endothelial cells (CTECs) are TECs shed into the peripheral circulation. Aneuploid CD31+ CTECs, together with their counterpart CD31- circulating tumor cells (CTCs), constitute a unique pair of cellular circulating tumor biomarkers. This review discusses a proposed cascaded framework that focuses on the origins of TECs and CTECs in the hypoxic tumor microenvironment and their clinical implications for tumorigenesis, neovascularization, disease progression, and cancer metastasis. Aneuploid CTECs, harboring hybridized properties of malignancy, vascularization and motility, may serve as a unique target for developing a novel metastasis blockade cancer therapy.

Abstract B17: An mRNA signature that accurately discerns gliomas from healthy individuals

Abstract Diagnosis of suspected cases of gliomas such as intracranial space-occupying lesions (ICSOLs) is based on histopathologic analysis of tumor tissue obtained by invasive biopsies, which are, however, associated with risk of serious complication, high rates of mortality, procedural expenses, sequelae, and other risks. Liquid biopsy (LB)-based noninvasive approaches for diagnosis of gliomas based on circulating tumor biomarkers in peripheral blood have hence gained considerable interest. We describe the discovery of a unique 20 exosomal mRNA signature that can discern gliomas from healthy individuals. We obtained 15 mL of peripheral blood by venous draw from 222 individuals, among whom 47 had confirmed diagnosis of gliomas and 175 were asymptomatic. Exosomes were enriched from peripheral blood and were used for isolation of mRNAs. Exosomal mRNAs were used for expression analysis of 20,802 gene transcripts, including 18,574 coding genes and 2,228 noncoding genes based on University of California Santa Cruz (UCSC) hg19 annotation. Differentially expressed mRNAs were analyzed using a machine learning algorithm to identify transcripts that were unique to or uniquely absent in known cases of gliomas and in healthy individuals. The machine learning algorithm identified a 20-mRNA signature that discerned gliomas from healthy individuals with high sensitivity (87%) and specificity (95%) with an overall accuracy of 94%. The differentially expressed transcripts included MST4, RARRES3, TARP, IL32, PPP3CC, RSL1D1, RSL24D1, EIF4B, ARHGEF3, DENND2D, EVL, SEC11A, RPL22L1, HIST1H1C, IRF8, SOS2, GLTSCR2, GIMAP7, HIST1H4D, and CDK11. These differentially expressed transcripts are potentially involved in various functions such as tumor suppression, protein phosphorylation-dephosphorylation, signal transduction (ligand binding), and cell cycle regulation. Our data indicate that exosomal mRNA profiling is a viable approach for discerning suspected cases of gliomas from healthy individuals. The noninvasive nature of this approach coupled with high sensitivity and specificity favor potential clinical application. Citation Format: Sachin Apurwa, Pooja Fulmali, Dadasaheb Akolkar, Darshana Patil, Sushant Pawar, Sneha Puranik, Vipul Todarwal, Akshay Ainwale, Pradip Devhare, Vineet Datta, Cynthe Sims, Ajay Srinivasan, Rajan Datar. An mRNA signature that accurately discerns gliomas from healthy individuals [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B17.

PIM-1 Is Overexpressed at a High Frequency in Circulating Tumor Cells from Metastatic Castration-Resistant Prostate Cancer Patients.

PIM-1 is an oncogene involved in cell cycle progression, cell growth, cell survival and therapy resistance, activated in many types of cancer, and is now considered as a very promising target for cancer therapy. We report for the first time that PIM-1 is overexpressed in circulating tumor cells (CTCs) from metastatic castration-resistant prostate cancer patients (mCRPC). We first developed and validated a highly sensitive RT-qPCR assay for quantification of PIM-1 transcripts. We further applied this assay to study PIM-1 expression in EpCAM(+) CTC fraction isolated from 64 peripheral blood samples of 50 mCRPC patients. CTC enumeration in all samples was performed using the FDA-cleared CellSearch® system. PIM-1 overexpression was detected in 24/64 (37.5%) cases, while in 20/24 (83.3%) cases that were positive for PIM-1 expression, at least one CTC/7.5 mL PB was detected in the CellSearch®. Our data indicate that PIM-1 overexpression is observed at high frequency in CTCs from mCRPC patients and this finding, in combination with androgen receptor splice variant 7 (AR-V7) expression in CTCs, suggest its potential role as a very promising target for cancer therapy. We strongly believe that PIM-1 overexpression in EpCAM(+) CTC fraction merits to be further evaluated and validated as a non-invasive circulating tumor biomarker in a large and well-defined patient cohort with mCRPC.

O-glycan recognition and function in mice and human cancers.

Protein glycosylation represents a nearly ubiquitous post-translational modification, and altered glycosylation can result in clinically significant pathological consequences. Here we focus on O-glycosylation in tumor cells of mice and humans. O-glycans are those linked to serine and threonine (Ser/Thr) residues via N-acetylgalactosamine (GalNAc), which are oligosaccharides that occur widely in glycoproteins, such as those expressed on the surfaces and in secretions of all cell types. The structure and expression of O-glycans are dependent on the cell type and disease state of the cells. There is a great interest in O-glycosylation of tumor cells, as they typically express many altered types of O-glycans compared with untransformed cells. Such altered expression of glycans, quantitatively and/or qualitatively on different glycoproteins, is used as circulating tumor biomarkers, such as CA19-9 and CA-125. Other tumor-associated carbohydrate antigens (TACAs), such as the Tn antigen and sialyl-Tn antigen (STn), are truncated O-glycans commonly expressed by carcinomas on multiple glycoproteins; they contribute to tumor development and serve as potential biomarkers for tumor presence and stage, both in immunohistochemistry and in serum diagnostics. Here we discuss O-glycosylation in murine and human cells with a focus on colorectal, breast, and pancreatic cancers, centering on the structure, function and recognition of O-glycans. There are enormous opportunities to exploit our knowledge of O-glycosylation in tumor cells to develop new diagnostics and therapeutics.

Tumor circulome in the liquid biopsies for cancer diagnosis and prognosis.

Liquid biopsy is a convenient, fast, non-invasive and reproducible sampling method that can dynamically reflect the changes in tumor gene expression profile, and provide a robust basis for individualized therapy and early diagnosis of cancer. Circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) are the currently approved diagnostic biomarkers for screening cancer patients. In addition, tumor-derived extracellular vesicles (tdEVs), circulating tumor-derived proteins, circulating tumor RNA (ctRNA) and tumor-bearing platelets (TEPs) are other components of liquid biopsies with diagnostic potential. In this review, we have discussed the clinical applications of these biomarkers, and the factors that limit their implementation in routine clinical practice. In addition, the most recent developments in the isolation and analysis of circulating tumor biomarkers have been summarized, and the potential of non-blood liquid biopsies in tumor diagnostics has also been discussed.

The ganglioside GD2 as a circulating tumor biomarker for neuroblastoma.

GD2 is a ganglioside that is ubiquitously expressed in the plasma membrane of neuroblastoma and is shed into the circulation. GD2 was measured with a high-pressure liquid chromatography/tandem mass spectrometry assay in serum or plasma from 40 children without cancer (controls) and in biobanked samples from 128 (73 high-risk) children with neuroblastic tumors at diagnosis, 56 children with relapsed neuroblastoma, 14 children with high-risk neuroblastoma after treatment, and 8 to 12 children each with 10 other common childhood cancers at diagnosis. The C18 (18 carbon fatty acid) lipoform was the predominant circulating form of GD2 in controls and in patients with neuroblastoma. The median concentration of GD2 in children with high-risk neuroblastoma at diagnosis was 167nM (range, 16.1-1060nM), which was 30-fold higher than the median concentration (5.6nM) in controls. GD2 was not elevated in serum from children with the differentiated neuroblastic tumors, ganglioneuroma (n=10) and ganglioneuroblastoma-intermixed subtype (n=12), and in children with 10 other childhood cancers. GD2 concentrations were significantly higher in serum from children with MYCN-amplified tumors (P=0.0088), high-risk tumors (P<0.00001), International Neuroblastoma Staging System (INSS) stage 4 tumors (P<0.00001), and in children who died (P=0.034). Circulating GD2 appears to be a specific and sensitive tumor biomarker for high-risk/high-stage neuroblastoma and may prove to be clinically useful as a diagnostic or prognostic circulating tumor biomarker. GD2 will be measured prospectively and longitudinally in children enrolled on a high-risk neuroblastoma treatment trial to assess its ability to measure response to treatment and predict survival.

Engineering State-of-the-Art Plasmonic Nanomaterials for SERS-Based Clinical Liquid Biopsy Applications.

Precision oncology, defined as the use of the molecular understanding of cancer to implement personalized patient treatment, is currently at the heart of revolutionizing oncology practice. Due to the need for repeated molecular tumor analyses in facilitating precision oncology, liquid biopsies, which involve the detection of noninvasive cancer biomarkers in circulation, may be a critical key. Yet, existing liquid biopsy analysis technologies are still undergoing an evolution to address the challenges of analyzing trace quantities of circulating tumor biomarkers reliably and cost effectively. Consequently, the recent emergence of cutting‐edge plasmonic nanomaterials represents a paradigm shift in harnessing the unique merits of surface‐enhanced Raman scattering (SERS) biosensing platforms for clinical liquid biopsy applications. Herein, an expansive review on the design/synthesis of a new generation of diverse plasmonic nanomaterials, and an updated evaluation of their demonstrated SERS‐based uses in liquid biopsies, such as circulating tumor cells, tumor‐derived extracellular vesicles, as well as circulating cancer proteins, and tumor nucleic acids is presented. Existing challenges impeding the clinical translation of plasmonic nanomaterials for SERS‐based liquid biopsy applications are also identified, and outlooks and insights into advancing this rapidly growing field for practical patient use are provided.

Magnetic nanotechnology for circulating tumor biomarkers screening: Rational design, microfluidics integration and applications

Magnetic nanotechnology represents a major and promising frontier with great potential to significantly advance the field of liquid biopsies. The last decade has witnessed considerable progress in the research and development of magnetic nanosystems for circulating tumor biomarkers screening. With the emergence of microfluidics, both rational design of magnetic nanomaterials from microfluidic reactors and efficient magnetic screening of circulating tumor biomarkers from microfluidic chips become available. This review focuses on recent advances of magnetic nanoparticles for the screening of circulating tumor biomarkers including circulating tumor cells, exosomes, and nucleic acids. We summarize the established conventional magnetic nanosystems for circulating tumor biomarkers screening, highlight microfluidic reactors-enabled magnetic nanoparticles synthesis, and discuss the emerging roles of microfluidic chips in magnetic screening of circulating tumor biomarkers. In addition, the current challenges and opportunities are provided for guiding future studies.

Abstract 444: Continuous, high throughput microfluidic device to monitor circulating tumor cells in cancer patients

Abstract Analysis of circulating tumor biomarkers, designated “liquid biopsies” are less invasive and lower risk to the patient and might replace or complement standard tissue biopsies to determine prognosis, predict benefit from specific therapies, or monitor patients with cancer. Circulating tumor cells (CTCs) are extremely rare, with only 1-10 CTCs per mL of blood. Current technologies typically process 1-10 mL of blood ex vivo. We report an in vivo, indwelling CTC-capture device that is analogous to a Holter monitor used to interrogate cardiac rhythm abnormalities over long periods of time. The system incorporates a dual lumen intravenous catheter that directs blood from the vein into a small (~ the size of a wristwatch) capture carriage by virtue of a peristaltic pump. The carriage contains a CTC capture chip which separates CTCs from whole blood based on flow differences and solid phase anti-EpCAM capture, while the remaining whole blood is returned to the venous system via the dual lumen catheter. The chip is then removed from the carriage for further enumeration and characterization of the CTCs. In a proof of principle set of experiments, the system was placed into investigational canines into which fluorescently labeled human breast cancer cells were injected intravenously. Although the vast majority of these xeno-cancer cells were rapidly removed from circulation, the system captured “CTCs” over a 2 hour time period more successfully than was seen in simultaneous blood draws for ex vivo enumeration over the same time. No adverse effects were observed in the subjects at the time of the experiments or over the succeeding 48 hours after removal of the IV system.Our system permits interrogation of a much larger volume of blood than can be processed with standard blood draws. The larger processed volume will drastically increase the number of cells isolated which in turn increases the number of downstream assays that can be performed. This study is focused on developing a high throughput microfluidic device that can detect CTCs and implementing it in a canine model. Citation Format: Kaylee Smith, Tae Hyun Kim, Costanza Paoletti, Douglas H. Thamm, Daniel F. Hayes, Sunitha Nagrath. Continuous, high throughput microfluidic device to monitor circulating tumor cells in cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 444.

Liquid Biopsies for Ovarian Carcinoma: How Blood Tests May Improve the Clinical Management of a Deadly Disease.

Ovarian cancers (OvC) are frequent, with more than 22,000 new cases each year for 14,000 deaths in the United States. Except for patients with BRCA1 or BRCA2 mutations, diagnostic methods, prognostic tools, and therapeutic strategies have not much improved in the last two decades. High throughput tumor molecular analyses have identified important alterations involved in ovarian carcinoma growth and spreading. However, these data have not modified the clinical management of most of patients. Moreover, tumor sample collection requires invasive procedures not adapted to objectives, such as the screening, prediction, or assessment of treatment efficacy, monitoring of residual disease, and early diagnosis of relapse. In recent years, circulating tumor biomarkers (also known as “liquid biopsies”) such as circulating tumor cells, circulating nucleotides (DNA or miRNA), or extracellular vesicles, have been massively explored through various indications, platforms, and goals, but their use has not yet been validated in routine practice. This review describes the methods of analysis and results related to liquid biopsies for ovarian epithelial cancer. The different settings that a patient can go through during her journey with OvC are explored: screening and early diagnosis, prognosis, prediction of response to systemic therapies for advanced stages, and monitoring of residual subclinical disease.

Metronomic Capecitabine With Cyclophosphamide Regimen in Unresectable or Relapsed Pseudomyxoma Peritonei

BackgroundNo standard treatment for advanced unresectable pseudomyxoma peritonei (PMP) has been defined so far. PMP is traditionally considered chemoresistant but nonrandomized series showed promising results with regimens for gastrointestinal tumors. Patients and MethodsWe conducted a single-center prospective single-arm trial. Inclusion criteria were histologically confirmed PMP, unresectable or progressive to surgery/previous treatments. Patients received a continuous metronomic regimen with capecitabine (625 mg/m2 twice per day) with cyclophosphamide (50 mg/d) until progression, unacceptable toxicity, or consent withdrawal. The primary end point was progression-free survival (PFS); secondary end points were disease control rate (DCR), overall survival (OS), and safety. Exploratory analyses were the variation of circulating tumor biomarkers and neutrophil to lymphocyte ratio (NLR). ResultsTwenty-three consecutive patients were enrolled from April 2015 to October 2017. At a median follow up of 22.4 months, median PFS was 9.5 months and 1-year OS rate was 73.7%. Overall, DCR was 87% and 6 (27%) patients achieved disease control ≥12 months. The safety profile was manageable: 26% of patients reported Grade 3 drug-related adverse events and none Grade 4/5. NLR baseline < 3 versus ≥ 3 was associated with prolonged PFS (12.6 vs. 3.4 months; P = .0001). ConclusionMetronomic capecitabine with cyclophosphamide is a well tolerated regimen in unresectable/recurrent PMP, and its safety profile favorably compares with previously investigated regimens.