Clinical utility of serial analysis of circulating tumour cells for detection of minimal residual disease of metastatic nasopharyngeal carcinoma

Application of circulating tumor DNA liquid biopsy in nasopharyngeal carcinoma: A case report and review of literature

BACKGROUND

Circulating tumor DNA (ctDNA)-based liquid biopsy has been found to be effective for the detection of minimal residual disease and the evaluation of prognostic risk in various solid tumors, with good sensitivity and specificity for identifying patients at high risk of recurrence. However, use of its results as a biomarker for guiding the treatment and predicting the prognosis of nasopharyngeal carcinoma (NPC) has not been reported.

CASE SUMMARY

In this case study of a patient with stage IVb NPC, we utilized ctDNA as an independent biomarker to guide treatment. Chemotherapy was administered in the early stages of the disease, and local intensity-modulated radiation therapy was added when the patient tested positive for ctDNA, while radiation therapy was stopped and the patient was observed when the ctDNA test was negative. During the follow-up period, ctDNA signals became positive before tumor progression and became negative again at the end of treatment. We also explored the potential of ctDNA in combination with Epstein–Barr virus (EBV) DNA status to predict the prognosis of NPC patients, as well as the criteria for selecting genetic mutations and the testing cycle for ctDNA analysis.

CONCLUSION

The results of ctDNA-based liquid biopsy can serve as an independent biomarker, either independently or in conjunction with EBV DNA status, to guide the treatment and predict the prognosis of NPC.

Circulating Tumor Cells Culture: Methods, Challenges, and Clinical Applications

Circulating tumor cells (CTCs) play a pivotal role in cancer metastasis and hold considerable potential for clinical diagnosis, therapeutic monitoring, and prognostic evaluation. Nevertheless, the limited quantity of CTCs in liquid biopsy samples poses challenges for comprehensive downstream analysis. In vitro culture of CTCs can effectively address the issue of insufficient CTC numbers. Furthermore, research based on CTC cell lines serves as a valuable complement to traditional cancer cell line-based research. While numerous reports exist on CTC in vitro culture and even the establishment of CTC cell lines, the methods used vary, leading to disparate culture outcomes. This review presents the developmental history and current status of CTC in vitro culture research. Additionally, the culture strategies applied in different methods and analyzed the impact of various steps on culture outcomes are compared. Overall, the review indicates that while the short-term culture of CTCs is relatively straightforward, long-term culture success has been achieved for various specific cancer types but still faces challenges. Further optimization of efficient and widely applicable culture strategies is needed. Additionally, ongoing applications of CTC in vitro culture are summarized, highlighting the potential of expanded CTCs for drug susceptibility testing and as therapeutic tools in personalized treatment.

Improving the Prognostic and Predictive Value of Circulating Tumor Cell Enumeration: Is Longitudinal Monitoring the Answer?

Circulating tumor cell (CTC) numbers in the blood of cancer patients can indicate the progression and invasiveness of tumors, and their prognostic and predictive value has been repeatedly demonstrated. However, the standard baseline CTC count at the beginning of treatment, while informative, is not completely reliable and may not adequately reflect the state of the disease. A growing number of studies indicate that the long-term monitoring of CTC numbers in the same patient provides more comprehensive prognostic data and should be incorporated into clinical practice, as a factor that contributes to therapeutic decisions. This review describes the current status of CTC enumeration as a prognostic and predictive factor, highlights the shortcomings of current solutions, and advocates for longitudinal CTC analysis as a more effective method of the evaluation of developing disease, treatment efficacy, and the long term-monitoring of the minimal residual disease. As evidenced by the described reports, the longitudinal monitoring of CTCs should provide a better and more sensitive prediction of the course of the disease, and its incorporation in clinical practice should be beneficial.

Metronomic S-1 Adjuvant Chemotherapy Improves Survival in Patients with Locoregionally Advanced Nasopharyngeal Carcinoma

PURPOSE

This study aimed to investigate the efficacy and safety of using metronomic S-1 adjuvant chemotherapy in locoregionally advanced nasopharyngeal carcinoma (LANPC).

MATERIALS AND METHODS

We retrospectively collected data on patients diagnosed with LANPC between January 2016 and December 2021. All patients were treated with induction chemotherapy and concurrent chemoradiotherapy with or without metronomic chemotherapy (MC). Toxicities during MC were recorded. The chi-square test, Kaplan-Meier methods, propensity score matching (PSM), and Cox proportional hazards model were used for statistical analyses.

RESULTS

A total of 474 patients were identified, including 64 (13.5%) and 410 (83.5%) patients with or without receiving MC, respectively. Patients who received metronomic S-1 had significantly better 3-year locoregional recurrence-free survival (LRFS) (100% vs. 90.9%, p=0.038), distant metastasis-free survival (DMFS) (98.5% vs. 84.1%, p=0.002), disease-free survival (DFS) (98.4% vs. 77.5%, p < 0.001), and overall survival (OS) (98.0% vs. 87.7%, p=0.008) compared to those without metronomic S-1. The multivariate prognostic analysis revealed that metronomic S-1 was identified as an independent prognostic factor associated with better DMFS (hazard ratio [HR], 0.074; p=0.010), DFS (HR, 0.103; p=0.002) and OS (HR, 0.127; p=0.042), but not in LRFS (p=0.071). Similar results were found using PSM. Common adverse events observed in the metronomic S-1 group included leukopenia, neutropenia, increased total bilirubin, anorexia, rash/desquamation, and hyperpigmentation. All patients with adverse events were grade 1-2.

CONCLUSION

It is worth conducting a randomized controlled trial to assess the effect of metronomic S-1 on survival outcomes and toxicities of LANPC.

Significance of Pre-Treatment CALLY Score Combined with EBV-DNA Levels for Prognostication in Non-Metastatic Nasopharyngeal Cancer Patients: A Clinical Perspective

Background

The C-reactive protein-albumin-lymphocyte (CALLY) score is a novel indicator associated with inflammation, immunity, and nutrition, utilized for cancer prognostic stratification. This study aimed to evaluate the integrated prognostic significance of the pre-treatment CALLY score and Epstein-Barr virus (EBV) DNA levels in nasopharyngeal carcinoma (NPC) patients and to develop prognostic models.

Patients and Methods

A total of 1707 NPC patients from September 2015 to December 2017 were retrospectively enrolled. The cut-off point for the CALLY score, determined by maximum selected rank statistics, integrates with the published cut-off point for pre-EBV DNA to develop a comprehensive index. Subsequently, patients were randomly allocated in a 1:1 ratio into training and validation cohorts. Survival analysis was conducted using the Kaplan-Meier method with Log rank tests, and the Cox proportional hazards model was applied to identify independent prognostic factors for constructing predictive nomograms. The predictive ability of the nomograms were assessed through the concordance index (C-index), calibration curves, and decision curve analysis.

Results

By integrating CALLY scores and EBV-DNA levels, patients were categorized into three risk clusters. Kaplan-Meier curves reveal significant differences in overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) outcomes among different risk groups (all P values < 0.05). Multivariate analysis revealed that CALLY-EBV DNA index serves as an independent prognostic factor for the OS, DMFS, and LRRFS. The prognostic nomograms based on the CALLY-EBV DNA index provided accurate predictions for 1-year, 3-year, and 5-year OS, DMFS, and LRRFS. Additionally, compared to the traditional TNM staging system, the nomograms exhibited enhanced discriminatory power, calibration capability, and clinical applicability. All results were in agreement with the validation cohort.

Conclusion

The CALLY-EBV DNA index is an independent prognostic biomarker. The nomogram prediction models, constructed based on the CALLY-EBV DNA index, demonstrates superior predictive performance compared to the traditional TNM staging.

Drug-tolerant persister cells in cancer: the cutting edges and future directions

Drug-tolerant persister (DTP) cell populations were originally discovered in antibiotic-resistant bacterial biofilms. Similar populations with comparable features have since been identified among cancer cells and have been linked with treatment resistance that lacks an underlying genomic alteration. Research over the past decade has improved our understanding of the biological roles of DTP cells in cancer, although clinical knowledge of the role of these cells in treatment resistance remains limited. Nonetheless, targeting this population is anticipated to provide new treatment opportunities. In this Perspective, we aim to provide a clear definition of the DTP phenotype, discuss the underlying characteristics of these cells, their biomarkers and vulnerabilities, and encourage further research on DTP cells that might improve our understanding and enable the development of more effective anticancer therapies.

Combining Nimotuzumab With Chemotherapy for Patients With Locally Advanced and Intermediate-Stage Nasopharyngeal Cancer: A Retrospective Comparison Study Using Five-Year, Real-World Survival Data

BACKGROUND

Nasopharyngeal carcinoma (NPC) is the most prevalent geographically-specific head and neck cancer. Its incidence was high in the Asian population, especially in certain parts such as Southern China and South East Asia. Most patients with NPC are presented with intermediate-stage or locally advanced disease requiring chemoradiation as the primary treatment of choice. Epidermal Growth Factor Receptor (EGFR) was found overexpressed in most patients with NPC associated with poor prognosis making its inhibitor one of the most plausible treatment options in addition to chemoradiation. In EGFR-positive NPC patients, nimotuzumab, a humanized anti-EGFR monoclonal antibody will bind the extracellular domain of EGFR leading to tumor growth suppressions. This study's objective was to assess the real-world clinical efficacy of nimotuzumab for patients with intermediate-stage and locally advanced NPC when in combination with concurrent chemoradiation.

METHODS

This retrospective real-world study examined a sample of intermediate-stage and locally advanced NPC patients who were treated with or without adding nimotuzumab to concurrent chemoradiation at Dr. Cipto Mangunkusumo General Hospital in Indonesia from January 2009 to December 2017. The outcomes were patients' real-world five-year overall survival (rwOS) and progression-free survival (rwPFS) compared using Kaplan-Meier analysis and Cox proportional hazard models adjusting for age, gender, comorbidities, clinical staging, staging based on Tumor status (T), staging based on Nodes status (N), and types of radiotherapy.  Results: A total of 407 patients were included in the analysis, 61 patients receiving concurrent nimotuzumab and chemoradiation and 346 patients receiving chemoradiation alone. Patients receiving concurrent nimotuzumab and chemoradiation tended to have less aggressive NPC than patients receiving chemoradiation alone. Multivariate-adjusted Cox models revealed that combining nimotuzumab with chemoradiation was associated with a statistically significant longer rwOS gain (hazard ratio (HR)=0.46 (95% CI: 0.26-0.82, p=0.008)) and a trend of longer rwPFS (hazard ratio (HR)=0.67 (95% CI: 0.41-1.09, p=0.109)) in comparison to chemoradiation alone.  Conclusion: In this retrospective real-world study, concurrent nimotuzumab and chemoradiation usage was associated with a significant overall survival benefit than chemoradiation alone for intermediate-stage and locally advanced NPC patients. Hence, adding nimotuzumab to patients' chemoradiation should be considered in patients with intermediate-stage and locally advanced NPC.

Prognostic significance of the novel nutrition-inflammation marker of lymphocyte-C-reactive protein ratio in patients with nasopharyngeal carcinoma receiving concurrent chemoradiotherapy

BACKGROUND

Recent studies indicate that the novel lymphocyte-C-reactive protein ratio (LCR) is strongly associated with the survival of various tumors, but its prognostic value in nasopharyngeal carcinoma (NPC) is understudied. This study aimed to explore the relationship between LCR and overall survival (OS) in NPC and develop a predictive model.

METHODS

A total of 841 NPC patients who received concurrent chemoradiotherapy (CCRT) between January 2010 and December 2014 were retrospectively enrolled and randomly divided into a training cohort (n = 589) and a validation cohort (n = 252), and 122 patients between January 2015 and March 2015 were included as an additional validation cohort. Univariate and multivariate Cox analyses were performed to identify variables associated with OS and construct a predictive nomogram. The predictive accuracy of the nomogram was evaluated and independently validated.

RESULTS

The LCR score differentiated NPC patients into two groups with distinct prognoses (HR = 0.53; 95% CI: 0.32-0.89, P = 0.014). Multivariate analysis showed that age, T stage, N stage, EBV-DNA status, and LCR score were independently associated with OS, and a predictive nomogram was developed. The nomogram had a good performance for the prediction of OS [C-index = 0.770 (95% CI: 0.675-0.864)]. and outperformed the traditional staging system [C-index = 0.589 (95% CI: 0.385-0.792)]. The results were internally and additionally validated using independent cohorts.

CONCLUSION

The pretreatment LCR could independently predict the overall survival in NPC patients. A novel LCR-based prognostic model of an easy-to-use nomogram was established, and it outperformed the conventional staging system in terms of predictive power. Further external verification remains necessary.

Nasopharyngeal carcinoma ecology theory: cancer as multidimensional spatiotemporal "unity of ecology and evolution" pathological ecosystem

Nasopharyngeal carcinoma (NPC) is a particular entity of head neck cancer that is generally regarded as a genetic disease with diverse intertumor and intratumor heterogeneity. This perspective review mainly outlines the up-to-date knowledge of cancer ecology and NPC progression, and presents a number of conceptual stepping-stones. At the beginning, I explicitly advocate that the nature of NPC (cancer) is not a genetic disease but an ecological disease: a multidimensional spatiotemporal "unity of ecology and evolution" pathological ecosystem. The hallmarks of cancer is proposed to act as ecological factors of population fitness. Subsequently, NPC cells are described as invasive species and its metastasis as a multidirectional ecological dispersal. The foundational ecological principles include intraspecific relationship (e.g. communication) and interspecific relationship (e.g. competition, predation, parasitism and mutualism) are interpreted to understand NPC progression. "Mulberry-fish-ponds" model can well illustrate the dynamic reciprocity of cancer ecosystem. Tumor-host interface is the ecological transition zone of cancer, and tumor buddings should be recognized as ecological islands separated from the mainland. It should be noted that tumor-host interface has a significantly molecular and functional edge effect because of its curvature and irregularity. Selection driving factors and ecological therapy including hyperthermia for NPC patients, and future perspectives in such field as "ecological pathology", "multidimensional tumoriecology" are also discussed. I advance that "nothing in cancer evolution or ecology makes sense except in the light of the other". The cancer ecology tree is constructed to comprehensively point out the future research direction. Taken together, the establishment of NPC ecology theory and cancer ecology tree might provide a novel conceptual framework and paradigm for our understanding of cancer complex causal process and potential preventive and therapeutic applications for patients.

Circulating Tumor Cell Enumeration for Serial Monitoring of Treatment Outcomes for Locally Advanced Esophageal Squamous Cell Carcinoma

We aim to reveal the clinical significance and potential usefulness of dynamic monitoring of CTCs to track therapeutic responses and improve survival for advanced ESCC patients. Peripheral blood (PB) (n = 389) and azygos vein blood (AVB) (n = 13) samplings were recruited prospectively from 88 ESCC patients undergoing curative surgery from 2017 to 2022. Longitudinal CTC enumeration was performed with epithelial (EpCAM/pan-cytokeratins/MUC1) and mesenchymal (vimentin) markers at 12 serial timepoints at any of the pre-treatment, all of the post-treatments/pre-surgery, post-surgery follow-ups for 3-year, and relapse. Longitudinal real-time CTC analysis in PB and AVB suggests more CTCs are released early at pre-surgery and 3-month post-surgery into the circulation from the CTRT group compared to the up-front surgery group. High CTC levels at pre-treatments, 1-/3-month post-surgery, unfavorable changes of CTC levels between all post-treatment/pre-surgery and 1-month or 3-month post-surgery (Hazard Ratio (HR) = 6.662, p < 0.001), were independent prognosticators for curative treatment. The unfavorable pre-surgery CTC status was independent prognostic and predictive for neoadjuvant treatment efficacy (HR = 3.652, p = 0.035). The aggressive CTC clusters were more frequently observed in AVB compared to PB. Its role as an independent prognosticator with relapse was first reported in ESCC (HR = 2.539, p = 0.068). CTC clusters and longitudinal CTC monitoring provide useful prognostic information and potential predictive biomarkers to help guide clinicians in improving disease management.

Epithelial-mesenchymal transition classification of circulating tumor cells predicts clinical outcomes in progressive nasopharyngeal carcinoma

Background

Liquid biopsy facilitates the enrichment and isolation of circulating tumor cells (CTCs) in various human cancers, including nasopharyngeal carcinoma (NPC). Characterizing CTCs allows observation of the evolutionary process of single tumor cells undergoing blood-borne dissemination, such as epithelial-mesenchymal transition. However, the prognostic value of phenotypic classification of CTCs in predicting the clinical outcomes of NPC remains poorly understood.

Patients and methods

A total of 92 patients who met the inclusion criteria were enrolled in the present study. The CanPatrol™ CTC technology platform was employed to isolate CTCs, and an RNA in situ hybridization-based system was used for phenotypic classification. Kaplan–Meier survival curves were used for univariate survival analysis, and the log-rank test was performed for between-group comparisons of the survival curves.

Results

CTCs were detected in 88.0% (81/92) of the enrolled patients with NPC. The total CTC number did not vary between the T and N stages or between Epstein–Barr virus DNA-positive and -negative cases. The numbers of total CTCs and epithelial/mesenchymal (E/M) hybrid CTCs decreased significantly at 3 months post concurrent chemoradiotherapy (P=0.008 and P=0.023, respectively), whereas the numbers of epithelial or mesenchymal CTCs did not decrease. E/M hybrid-predominant cases had lower disease-free survival (P=0.043) and distant metastasis-free survival (P=0.046) rates than non-E/M hybrid-predominant cases.

Conclusion

CTC classification enables a better understanding of the cellular phenotypic alterations responsible for locoregional invasion and distant metastasis in NPC. E/M hybrid-predominant CTC distribution predicts unfavorable clinical outcomes in patients with progressive NPC.

Prognostic Biomarkers for Survival in Nasopharyngeal Carcinoma: A Systematic Review of the Literature

This systematic review aims to identify prognostic molecular biomarkers which demonstrate strong evidence and a low risk of bias in predicting the survival of nasopharyngeal carcinoma (NPC) patients. The literature was searched for on PubMed to identify original clinical studies and meta-analyses which reported associations between molecular biomarkers and survival, including ≥150 patients with a survival analysis, and the results were validated in at least one independent cohort, while meta-analyses must include ≥1000 patients with a survival analysis. Seventeen studies fulfilled these criteria-two studies on single nucleotide polymorphisms (SNPs), three studies on methylation biomarkers, two studies on microRNA biomarkers, one study on mutational signature, six studies on gene expression panels, and three meta-analyses on gene expressions. The comparison between the hazard ratios of high-risk and low-risk patients along with a multivariate analysis are used to indicate that these biomarkers have significant independent prognostic values for survival. The biomarkers also indicate a response to certain treatments and whether they could be used as therapeutic targets. This review highlights that patients' genetics, epigenetics, and signatures of cancer and immune cells in the tumor microenvironment (TME) play a vital role in determining their survival.

The Prognostic Impact of Combined Tumor-Infiltrating Lymphocytes and Pretreatment Blood Lymphocyte Percentage in Locally Advanced Nasopharyngeal Carcinoma

Purpose

To explore the prognostic impact of combined tumor-infiltrating lymphocytes (TILs) and pretreatment peripheral lymphocyte percentage (LYM%) among patients with locally advanced nasopharyngeal carcinoma (LA-NPC).

Patients and Methods

TILs and pretreatment LYM% were retrospectively assessed in 253 LA-NPC patients who underwent chemoradiation therapy between January 2012 and December 2017. According to TILs and LYM% status, the patients were divided into three groups: high-risk group (HRG) (TILs–LYM% score = 0), middle-risk group (MRG) (TILs–LYM% score = 1), and low-risk group (LRG) (TILs–LYM% score = 2). The relationship between TILs level and LYM%, and also the associations of TILs–LYM% status with clinicopathological factors and survival, were evaluated.

Results

As a continuous variable, LYM% was significantly higher in TILs-high group. High TILs or high LYM% alone was significantly related to better 3-year disease-free survival (DFS), overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRRFS), respectively. Kaplan–Meier analysis and log-rank tests also revealed significant decreases in DFS, OS, DMFS, and LRRFS among LA-NPC patients with TILs–LYM% score of 0, 1, and 2 (all P <0.05). Further multivariate analyses showed that TILs–LYM% score was an independent factor affecting survival of the patients, and HRG (TILs–LYM% score = 0) had increased hazard ratios (HRs) for disease (HR = 6.89, P <0.001), death (HR = 8.08, P = 0.008), distant metastasis (HR = 7.66, P = 0.001), and local relapse (HR = 5.18, P = 0.013) compared with LRG (TILs–LYM% score = 2). In receiver operating characteristics (ROC) analyses, TILs–LYM% score had a higher area under the ROC curve (AUC) for the prediction of DFS than did TILs or LYM% alone.

Conclusions

A positive correlation was found between TILs level and pretreatment blood lymphocyte percentage. Moreover, TILs–LYM% score can be considered as a novel independent prognostic indicator of survival outcome among patients with LA-NPC.

Liquid Biopsy to Detect Minimal Residual Disease: Methodology and Impact

One reason why some patients experience recurrent disease after a curative-intent treatment might be the persistence of residual tumor cells, called minimal residual disease (MRD). MRD cannot be identified by standard radiological exams or clinical evaluation. Tumor-specific alterations found in the blood indirectly diagnose the presence of MRD. Liquid biopsies thus have the potential to detect MRD, allowing, among other things, the detection of circulating tumor DNA (ctDNA), circulating tumor cells (CTC), or tumor-specific microRNA. Although liquid biopsy is increasingly studied, several technical issues still limit its clinical applicability: low sensitivity, poor standardization or reproducibility, and lack of randomized trials demonstrating its clinical benefit. Being able to detect MRD could give clinicians a more comprehensive view of the risk of relapse of their patients and could select patients requiring treatment escalation with the goal of improving cancer survival. In this review, we are discussing the different methodologies used and investigated to detect MRD in solid cancers, their respective potentials and issues, and the clinical impacts that MRD detection will have on the management of cancer patients.

A systematic review and recommendations on the use of plasma EBV DNA for nasopharyngeal carcinoma

INTRODUCTION

Nasopharyngeal carcinoma (NPC) is an endemic malignancy in Southeast Asia, particularly Southern China. The classical non-keratinising cell type is almost unanimously associated with latent Epstein-Barr virus (EBV) infection. Circulating plasma EBV DNA can be a useful biomarker in various clinical aspects, but comprehensive recommendations and international guidelines are still lacking. We conducted a systematic review of all original articles on the clinical application of plasma EBV DNA for NPC; we further evaluated its strengths and limitations for consideration as standard recommendations.

METHODS

The search terms 'nasopharyngeal OR nasopharynx', and 'plasma EBV DNA OR cell-free EBV OR cfEBV' were used to identify full-length articles published up to December 2020 in the English literature. Three authors independently reviewed the article titles, removed duplicates and reviewed the remaining articles for eligibility.

RESULTS

A total of 81 articles met the eligibility criteria. Based on the levels of evidence and grades of recommendation assessed, it is worth considering the inclusion of plasma EBV DNA in screening, pre-treatment work-up for enhancing prognostication and tailoring of treatment strategy, monitoring during radical treatment, post-treatment surveillance for early detection of relapse, and monitoring during salvage treatment for recurrent or metastatic NPC. One major limitation is the methodology of measurement requiring harmonisation for consistent comparability.

CONCLUSIONS

The current comprehensive review supports the inclusion of plasma EBV DNA in international guidelines in the clinical aspects listed, but methodological issues must be resolved before global application.

Hallmark microRNA signature in liquid biopsy identifies hepatocellular carcinoma and differentiates it from liver metastasis

Purpose: This study aims to develop a liquid biopsy assay to identify HCC and differentially diagnose hepatocellular carcinoma (HCC) from colorectal carcinoma (CRC) liver metastasis. Methods: Thirty-two microRNAs (“HallMark-32” panel) were designed to target the ten cancer hallmarks in HCC. Quantitative PCR and supervised machine learning models were applied to develop an HCC-specific diagnostic model. One hundred thirty-three plasma samples from intermediate-stage HCC patients, colorectal cancer (CRC) patients with liver metastasis, and healthy individuals were examined. Results: Six differentially expressed microRNAs (“Signature-Six” panel) were identified after comparing HCC and healthy individuals. The microRNA miR-221-3p, miR-223-3p, miR-26a-5p, and miR-30c-5p were significantly down-regulated in the plasma of HCC samples, while miR-365a-3p and miR-423-3p were significantly up-regulated. Machine learning models combined with HallMark-32 and Signature-Six panels demonstrated promising performance with an AUC of 0.85-0.96 (p ≤ 0.018) and 0.84-0.93 (p ≤ 0.021), respectively. Further modeling improvement by adjusting sample quality variation in the HallMark-32 panel boosted the accuracy to 95% ± 0.01 and AUC to 0.991 (95% CI 0.96-1, p = 0.001), respectively. Even in alpha fetoprotein (AFP)-negative (< 20ng/mL) HCC samples, HallMark-32 still achieved 100% sensitivity in identifying HCC. The Cancer Genome Atlas (TCGA, n=372) analysis demonstrated a significant association between HallMark-32 and HCC patient survival. Conclusion: To the best of our knowledge, this is the first report to utilize circulating miRNAs and machine learning to differentiate HCC from CRC liver metastasis. In this setting, HallMark-32 and Signature-Six are promising non-invasive tests for HCC differential diagnosis and distinguishing HCC from healthy individuals.

MicroRNAs from Liquid Biopsy Derived Extracellular Vesicles: Recent Advances in Detection and Characterization Methods

Liquid biopsies have become a convenient tool in cancer diagnostics, real-time disease monitoring, and evaluation of residual disease. Yet, the information still encrypted in the variety of tumor-derived molecules identified in biofluids has proven difficult to decipher due to the technological limitations imposed by their biological nature. Such is the case of extracellular vesicle (EV) encapsulated ncRNAs, which have gained traction in recent years as biomarkers. Due to their resilience towards degrading factors they may act as suitable disease indicators. This review addresses the less described issues in this context. We present an overview of less investigated biofluids that can be used for EV isolation in addition to different isolation approaches to overcome the technical challenges these specimens harbor. Furthermore, we summarize the latest technological advances providing improvement to ncRNA detection and analysis. Thereby, this review summarizes the current state-of-the-art methodologies regarding EV and EV derived miRNA analysis and how they compare to current approaches.

Liquid Biopsy Serial Monitoring of Treatment Responses and Relapse in Advanced Esophageal Squamous Cell Carcinoma

(1) Background: Early predictive markers to track treatment responses are needed for advanced esophageal squamous cell carcinoma (ESCC) patients. We examined the prognostication and risk stratification role of liquid biopsy serial monitoring for this deadly cancer. (2) Methods: Circulating tumor cells (CTCs) and plasma cell-free DNA (cfDNA) were isolated from 60 ESCC patients treated by chemotherapy (CT) at five serial timepoints: baseline (CTC1/cfDNA1), CT pre-cycle III (CTC2/cfDNA2), CT post-cycle IV, end of CT and relapse. (3) Results: In 45/57 ESCC patients with evaluable CTC counts at CT pre-cycle III, positive CTC2 (≥3 CTCs) is independently associated with response at interim reassessment and progression-free survival (PFS) in multivariate analysis. In 42/57 ESCC patients with changes of CTC1/CTC2 and cfDNA1/cfDNA2, patients categorized into four risk groups based on the number of favorable and unfavorable changes of CTC1/CTC2 and cfDNA1/cfDNA2, were independently associated with overall survival (OS) by multivariate analysis. (4) Conclusions: CTC counts at pre-cycle III are independently associated with response at interim reassessment and PFS. Combined changes of CTC counts and cfDNA levels from baseline to pre-cycle III are independently associated with OS. Longitudinal liquid biopsy serial monitoring provides complementary information for prediction and prognosis for CT responses in advanced ESCC.