Circulating tumor cells in patients with recurrent or metastatic head and neck carcinoma: prognostic and predictive significance

Liquid Biopsy in Head and Neck Cancer: Its Present State and Future Role in Africa

The rising mortality and morbidity rate of head and neck cancer (HNC) in Africa has been attributed to factors such as the poor state of health infrastructures, genetics, and late presentation resulting in the delayed diagnosis of these tumors. If well harnessed, emerging molecular and omics diagnostic technologies such as liquid biopsy can potentially play a major role in optimizing the management of HNC in Africa. However, to successfully apply liquid biopsy technology in the management of HNC in Africa, factors such as genetic, socioeconomic, environmental, and cultural acceptability of the technology must be given due consideration. This review outlines the role of circulating molecules such as tumor cells, tumor DNA, tumor RNA, proteins, and exosomes, in liquid biopsy technology for the management of HNC with a focus on studies conducted in Africa. The present state and the potential opportunities for the future use of liquid biopsy technology in the effective management of HNC in resource-limited settings such as Africa is further discussed.

Improved Characterization of Circulating Tumor Cells and Cancer-Associated Fibroblasts in One-Tube Assay in Breast Cancer Patients Using Imaging Flow Cytometry

Circulating tumor cells (CTCs) and circulating cancer-associated fibroblasts (cCAFs) have been individually considered strong indicators of cancer progression. However, technical limitations have prevented their simultaneous analysis in the context of CTC phenotypes different from epithelial. This study aimed to analyze CTCs and cCAFs simultaneously in the peripheral blood of 210 breast cancer patients using DAPI/pan-keratin (K)/vimentin (V)/alpha-SMA/CD29/CD45/CD31 immunofluorescent staining and novel technology-imaging flow cytometry (imFC). Single and clustered CTCs of different sizes and phenotypes (i.e., epithelial phenotype K+/V- and epithelial-mesenchymal transition (EMT)-related CTCs, such as K+/V+, K-/V+, and K-/V-) were detected in 27.6% of the samples and correlated with metastases. EMT-related CTCs interacted more frequently with normal cells and tended to occur in patients with tumors progressing during therapy, while cCAFs coincided with CTCs (mainly K+/V- and K-/V-) in seven (3.3%) patients and seemed to correlate with the presence of metastases, particularly visceral ones. This study emphasizes the advantages of imFC in the field of liquid biopsy and highlights the importance of multimarker-based analysis of different subpopulations and phenotypes of cancer progression-related cells, i.e., CTCs and cCAFs. The co-detection of CTCs and cCAFs might improve the identification of patients at higher risk of progression and their monitoring during therapy.

Circulating tumor cell abundance in head and neck squamous cell carcinoma decreases with successful chemoradiation and cetuximab treatment

Head and neck squamous cell carcinoma (HNSCC) is a common and deadly cancer. Circulating tumor cell (CTC) abundance may a valuable, prognostic biomarker in low- and intermediate-risk patients. However, few technologies have demonstrated success in detecting CTCs in these populations. We prospectively collected longitudinal CTC counts from two cohorts of patients receiving treatments at our institution using a highly sensitive device that purifies CTCs using biomimetic cell rolling and dendrimer-conjugated antibodies. In patients with intermediate risk human papillomavirus (HPV)-positive HNSCC, elevated CTC counts were detected in 13 of 14 subjects at screening with a median of 17 CTC/ml (range 0.2-2986.5). A second cohort of non-metastatic, HPV- HNSCC subjects received cetuximab monotherapy followed by surgical resection. In this cohort, all subjects had elevated baseline CTC counts median of 73 CTC/ml (range 5.4-332.9) with statistically significant declines during treatment. Interestingly, two patients with recurrent disease had elevated CTC counts during and following treatment, which also correlated with growth of size and ki67 expression in the primary tumor. The results suggest that our device may be a valuable tool for evaluating the success of less intensive treatment regimens.

Recent advances in the use of liquid biopsy to fight central nervous system tumors

Brain tumors are considered one of the deadliest types of cancer, being challenging to treat, especially due to the blood-brain barrier, which has been linked to treatment resistance. The genomic classification of brain tumors has been helping in the diagnostic precision, however tumor heterogeneity in addition to the difficulties to obtain tissue biopsies, represent a challenge. The biopsies are usually obtained either via neurosurgical removal or stereotactic tissue biopsy, which can be risky procedures for the patient. To overcome these challenges, liquid biopsy has become an interesting option by constituting a safer procedure than conventional biopsy, which may offer valuable cellular and molecular information representative of the whole organism. Besides, it is relatively easy to obtain such as in the case of blood (venipuncture) and urine sample collection. In the present comprehensive review, we discuss the newest information regarding liquid biopsy in the brain tumors' field, methods employed, the different sources of bio-fluids and their potential circulating targets.

Current Status of Circulating Tumor Cells in Head and Neck Squamous Cell Carcinoma: A Review

OBJECTIVE

Circulating tumor cells (CTCs) are found in the blood of patients with cancer, including head and neck squamous cell carcinomas (HNSCCs). The aim is to review the most up-to-date status of CTCs for applications in patients with HNSCC.

DATA SOURCES

English articles in PubMed.

REVIEW METHODS

All the studies on CTCs in HNSCCs in the literature were reviewed.

CONCLUSIONS

There is emerging information on the diagnostic and prognostic value of CTCs in HNSCCs. Evidence also highlights the advantages of various downstream analysis approaches over circulating tumor DNA (ctDNA), such as single-CTC analysis, ex vivo, and in vivo expansion of CTCs. Multiple phenotypic surface markers (cytokeratins, EpCAM, vimentin, etc.), used for CTCs characterization using different immunoassays, could predict disease progression as well as patients' response to treatment efficacy. Immune checkpoint inhibitors' status in CTCs could also provide better insight into treatment. Clonal expansion of CTCs and single-cell analysis of CTCs are the most emerging fields nowadays which may offer an understanding of the mechanism of tumor evolution as well as therapeutic efficacy. Although several clinical trials are ongoing, limitations still exist in the detection and characterization of CTCs. Due to the lack of a gold standard protocol, the sensitivity and specificity of CTC enumeration methods vary.

IMPLICATIONS FOR PRACTICE

Prospective clinical trials are still needed before CTCs can be employed as diagnostic and prognostic markers in the clinical management of patients with HNSCC.

Clinical applications of liquid biopsy in HPV‐negative and HPV‐positive head and neck squamous cell carcinoma: advances and challenges

Head and neck squamous cell carcinomas (HNSCCs) represent the most common epithelial tumors that arise from mucosa of the oral cavity, pharynx, and larynx. The development of HNSCCs is usually associated with tobacco use, alcohol consumption, and human papillomavirus (HPV) infection. Most HNSCCs are diagnosed in advanced states, leading to a worse clinical outcome. Screening tests based on potential biomarkers associated with HNSCCs could improve this scenario. Liquid biopsy has emerged as a promising area of cancer investigation, offering a minimally invasive approach to track circulating biomarkers in body fluids that could potentially contribute to the diagnosis, predict prognosis, and monitor response to treatment. This review will discuss translational studies describing the clinical applications of liquid biopsy in HPV-negative and HPV-positive HNSCCs focused on circulating nucleic acids [cell-free DNA (cfDNA) and cell-free RNA (cfRNA)], circulating tumor cells (CTCs), and extracellular vesicles (EVs), which can be found in plasma, serum, and saliva.

Liquid Biopsy in Head and Neck Cancer: Current Evidence and Future Perspective on Squamous Cell, Salivary Gland, Paranasal Sinus and Nasopharyngeal Cancers

Simple Summary

Head and neck cancer is the sixth most common type of solid tumor and harbors a poor prognosis since most patients are diagnosed at an advanced stage. The study of different tumor components in the blood, saliva or other body fluids is called liquid biopsy. The introduction of novel diagnostic tools such as liquid biopsy could aid in achieving earlier diagnoses and more accurate disease monitoring during treatment. In this manuscript, the reader will find an in-depth review of the current evidence and a future perspective on the role of liquid biopsy in head and neck cancer.

Abstract

Head and neck cancer (HNC) is currently the sixth most common solid malignancy, accounting for a 50% five-year mortality rate. In the past decade, substantial improvements in understanding its molecular biology have allowed for a growing development of new biomarkers. Among these, the field of liquid biopsy has seen a sustained growth in HNC, demonstrating the feasibility to detect different liquid biomarkers such as circulating tumor DNA (ctDNA), circulating tumor cells (CTC), extracellular vesicles and microRNAs. Liquid biopsy has been studied in HPV-negative squamous cell carcinoma of the head and neck (SCCHN) but also in other subentities such as HPV-related SCCHN, EBV-positive nasopharyngeal cancer and oncogene-driven salivary gland cancers. However, future studies should be internally and externally validated, and ideally, clinical trials should incorporate the use of liquid biomarkers as endpoints in order to prospectively demonstrate their role in HNC. A thorough review of the current evidence on liquid biopsy in HNC as well as its prospects will be conducted.

Multiparametric Phenotyping of Circulating Tumor Cells for Analysis of Therapeutic Targets, Oncogenic Signaling Pathways and DNA Repair Markers

Simple Summary

Detection of circulating tumor cells (CTCs) has been established as an independent prognostic marker in solid cancer. In order to expand the clinical utility of this blood–based minimally invasive biomarker we established a protocol allowing multiparametric phenotyping of CTCs to analyze the expression levels of therapeutic target proteins. By applying this assay, we demonstrated intratumoral heterogeneity of PD–L1 expression in CTCs from head and neck cancer patients, an observation previously reported in tumor tissue specimens. We further verified the feasibility of applying the protocol to analyze the activation status of important oncogenic pathways and the extent of DNA repair following radiation. These promising preliminary results warrant further study and may lead to the implementation of this assay in clinical routine for improved treatment selection and monitoring.

Abstract

Detection of circulating tumor cells (CTCs) has been established as an independent prognostic marker in solid cancer. Multiparametric phenotyping of CTCs could expand the area of application for this liquid biomarker. We evaluated the Amnis^® brand ImageStream^®X MkII (ISX) (Luminex, Austin, TX, USA) imaging flow cytometer for its suitability for protein expression analysis and monitoring of treatment effects in CTCs. This was carried out using blood samples from patients with head and neck squamous cell carcinoma (n = 16) and breast cancer (n = 8). A protocol for negative enrichment and staining of CTCs was established, allowing quantitative analysis of the therapeutic targets PD–L1 and phosphorylated EGFR (phospho–EGFR), and the treatment response marker γH2AX as an indicator of radiation–induced DNA damage. Spiking experiments revealed a sensitivity of 73% and a specificity of 100% at a cut–off value of ≥3 CTCs, and thus confirmed the suitability of the ISX-based protocol to detect phospho–EGFR and γH2AX foci in CTCs. Analysis of PD–L1/–L2 in both spiked and patient blood samples further showed that assessment of heterogeneity in protein expression within the CTC population was possible. Further validation of the diagnostic potential of this ISX protocol for multiparametric CTC analysis in larger clinical cohorts is warranted.

Saliva Based Liquid Biopsies in Head and Neck Cancer: How Far Are We From the Clinic?

Head and neck cancer (HNC) remains to be a major cause of mortality worldwide because of confounding factors such as late-stage tumor diagnosis, loco-regional aggressiveness and distant metastasis. The current standardized diagnostic regime for HNC is tissue biopsy which fails to determine the thorough tumor dynamics. Therefore, due to the ease of collection, recent studies have focused on the utility of saliva based liquid biopsy approach for serial sampling, early diagnosis, prognosis, longitudinal monitoring of disease progression and treatment response in HNC patients. Saliva collection is convenient, non-invasive, and pain-free and offers repetitive sampling along with real time monitoring of the disease. Moreover, the detection, isolation and analysis of tumor-derived components such as Circulating Tumor Nucleic Acids (CTNAs), Extracellular Vesicles (EVs), Circulating Tumor Cells (CTCs) and metabolites from saliva can be used for genomic and proteomic examination of HNC patients. Although, these circulatory biomarkers have a wide range of applications in clinical settings, no validated data has yet been established for their usage in clinical practice for HNC. Improvements in isolation and detection technologies and next-generation sequencing analysis have resolved many technological hurdles, allowing a wide range of saliva based liquid biopsy application in clinical backgrounds. Thus, in this review, we discussed the rationality of saliva as plausible biofluid and clinical sample for diagnosis, prognosis and therapeutics of HNC. We have described the molecular components of saliva that could mirror the disease status, recent outcomes of salivaomics associated with HNC and current technologies which have the potential to improve the clinical value of saliva in HNC.

Circulating Tumor Cell Detection during Neoadjuvant Chemotherapy to Predict Early Response in Locally Advanced Oropharyngeal Cancers: A Prospective Pilot Study

Patients with locally advanced oropharyngeal carcinoma treated with neoadjuvant chemotherapy are reassessed both radiologically and clinically to adapt their treatment after the first cycle. However, some responders show early tumor progression after adjuvant radiotherapy. This cohort study evaluated circulating tumor cells (CTCs) from a population of locally advanced oropharyngeal carcinoma patients treated with docetaxel, cisplatin, and 5-fluorouracil (DCF) induction chemotherapy or DCF with a modified dose and fractioned administration. The counts and phenotypes of CTCs were assessed at baseline and at day 21 of treatment, after isolation using the RosetteSep^TM technique based on negative enrichment. At baseline, 6 out of 21 patients had CTCs (28.6%). On day 21, 5 out of 11 patients had CTCs (41.6%). There was no significant difference in the overall and progression-free survival between patients with or without CTCs at baseline (p = 0.44 and 0.78) or day 21 (p = 0.88 and 0.5). Out of the 11 patients tested at day 21, 4 had a positive variation of CTCs (33%). Patients with a positive variation of CTCs display a lower overall survival. Our findings suggest that the variation in the number of CTCs would be a better guide to the management of treatment, with possible early changes in treatment strategy.

Searching for New Molecular Targets for Oral Squamous Cell Carcinoma with a View to Clinical Implementation of Precision Medicine

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the eighth most common malignancy globally and is characterized by local invasiveness and high nodal metastatic potential. The OSCC incidence is also increasing, and the number of deaths is also rising steadily in Japan. The development of molecular markers to eradicate OSCC is an urgent issue for humankind. The increase in OSCC despite the declining smoking rate may be due to several viral infections through various sexual activities and the involvement of previously unfocused carcinogens, and genetic alterations in individual patients are considered to be more complicated. Given this situation, it is difficult to combat OSCC with conventional radiotherapy and chemotherapy using cell-killing anticancer drugs alone, and the development of precision medicine, which aims to provide tailor-made medicine based on the genetic background of each patient, is gaining attention. In this review article, the current status of the comprehensive search for driver genes and biomarkers in OSCC will be briefly described, and some of the candidates for novel markers of OSCC that were found will be outlined.

Application of liquid biopsy as multi-functional biomarkers in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is a molecularly heterogeneous disease, with a 5-year survival rate that still hovers at ~60% despite recent advancements. The advanced stage upon diagnosis, limited success with effective targeted therapy and lack of reliable biomarkers are among the key factors underlying the marginally improved survival rates over the decades. Prevention, early detection and biomarker-driven treatment adaptation are crucial for timely interventions and improved clinical outcomes. Liquid biopsy, analysis of tumour-specific biomarkers circulating in bodily fluids, is a rapidly evolving field that may play a striking role in optimising patient care. In recent years, significant progress has been made towards advancing liquid biopsies for non-invasive early cancer detection, prognosis, treatment adaptation, monitoring of residual disease and surveillance of recurrence. While these emerging technologies have immense potential to improve patient survival, numerous methodological and biological limitations must be overcome before their implementation into clinical practice. This review outlines the current state of knowledge on various types of liquid biopsies in HNSCC, and their potential applications for diagnosis, prognosis, grading treatment response and post-treatment surveillance. It also discusses challenges associated with the clinical applicability of liquid biopsies and prospects of the optimised approaches in the management of HNSCC.

Effects of Red Blood Cell Transfusions on Distant Metastases of Oral Squamous Cell Carcinomas

Simple Summary

Patients with distant metastasis of oral squamous cell carcinoma should be identified at an early stage of disease. In this study, we investigated if patients who received red blood cell transfusions are at risk for the development of distant metastasis. A positive correlation was found between RBC transfusion (HR = 2.42) and the occurrence of M+ in a multivariate regression model. Therefore, the administration of RBC can be considered as an independent prognostic factor and special attention should be paid to its detrimental effects in the perioperative management of OSCC patients.

Abstract

There is no consensus on the effect of red blood cell (RBC) transfusions on patients with oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the association between RBC administration and the occurrence of distant metastases (M+) after surgical treatment of OSCC. All medical records of patients who underwent primary surgery for OSCC in our department (2003–2019) were analyzed retrospectively (n = 609). Chi and Cox regression models were used to analyze the influence of transfusion on the development of M+, and survival rates. Kaplan–Meier curves were used for graphical presentation. A multitude of patient-specific factors showed a statistical impact in univariate analysis (transfusion, age, gender, diabetes, pT, pN, L, V, Pn, G, UICC, adjuvant therapy, free microvascular transplant, preoperative hemoglobin level). Transfusion status and pN stage were the only variables that showed a significant correlation to M+ in the multivariate Cox model. The hazard ratios for the occurrence of M+ were 2.42 for RBC transfusions and 2.99 for pN+. Administration of RBC transfusions was identified as a significant prognostic parameter for the occurrence of distant metastases after surgical treatment of OSCC. Hence, the administration of RBC transfusions should be considered carefully in the perioperative management.

Ex Vivo Expanded Circulating Tumor Cells for Clinical Anti-Cancer Drug Prediction in Patients with Head and Neck Cancer

Simple Summary

The conventional methods that seek to predict clinical treatment response are based on the number of circulating tumor cells (CTCs) present in liquid biopsies or genetic profiling of extracted CTCs. This paper presents a novel process by which CTCs can be extracted from blood samples taken from head and neck cancer patients and then expanded ex vivo to form organoids that can be tested with a panel of anti-cancer treatments. The resulting drug sensitivity profiles derived from cisplatin treatment of organoids were subsequently found to correlate with clinical treatment response to cisplatin in patients. CTCs extracted from liquid biopsies for ex vivo expansion negates the need for complicated and potentially risky biopsies of tumor material, thereby supporting the application of this procedure for checkups and treatment monitoring.

Abstract

The advanced-stage head and neck cancer (HNC) patients respond poorly to platinum-based treatments. Thus, a reliable pretreatment method for evaluating platinum treatment response would improve therapeutic efficiency and outcomes. This study describes a novel strategy to predict clinical drug responses in HNC patients by using eSelect, a lab-developed biomimetic cell culture system, which enables us to perform ex vivo expansion and drug sensitivity profiling of circulating tumor cells (CTCs). Forty liquid biopsies were collected from HNC patients, and the CTCs were expanded ex vivo using the eSelect system within four weeks. Immunofluorescence staining confirmed that the CTC-derived organoids were positive for EpCAM and negative for CD45. Two illustrative cases present the potential of this strategy for evaluating treatment response. The statistical analysis confirmed that drug sensitivity in CTC-derived organoids was associated with a clinical response. The multivariant logistic regression model predicted that the treatment accuracy of chemotherapy responses achieved 93.75%, and the area under the curves (AUCs) of prediction models was 0.8841 in the whole dataset and 0.9167 in cisplatin specific dataset. In summary, cisplatin sensitivity profiles of patient-derived CTCs expanded ex vivo correlate with a clinical response to cisplatin treatment, and this can potentially underpin predictive assays to guide HNC treatments.

IsoMAG-An Automated System for the Immunomagnetic Isolation of Squamous Cell Carcinoma-Derived Circulating Tumor Cells

BACKGROUND

detailed information about circulating tumor cells (CTCs) as an indicator of therapy response and cancer metastasis is crucial not only for basic research but also for diagnostics and therapeutic approaches. Here, we showcase a newly developed IsoMAG IMS system with an optimized protocol for fully automated immunomagnetic enrichment of CTCs, also revealing rare CTC subpopulations.

METHODS

using different squamous cell carcinoma cell lines, we developed an isolation protocol exploiting highly efficient EpCAM-targeting magnetic beads for automated CTC enrichment by the IsoMAG IMS system. By FACS analysis, we analyzed white blood contamination usually preventing further downstream analysis of enriched cells.

RESULTS

1 µm magnetic beads with tosyl-activated hydrophobic surface properties were found to be optimal for automated CTC enrichment. More than 86.5% and 95% of spiked cancer cells were recovered from both cell culture media or human blood employing our developed protocol. In addition, contamination with white blood cells was minimized to about 1200 cells starting from 7.5 mL blood. Finally, we showed that the system is applicable for HNSCC patient samples and characterized isolated CTCs by immunostaining using a panel of tumor markers.

CONCLUSION

Herein, we demonstrate that the IsoMAG system allows the detection and isolation of CTCs from HNSCC patient blood for disease monitoring in a fully-automated process with a significant leukocyte count reduction. Future developments seek to integrate the IsoMAG IMS system into an automated microfluidic-based isolation workflow to further facilitate single CTC detection also in clinical routine.

Immediate Sample Fixation Increases Circulating Tumour Cell (CTC) Capture and Preserves Phenotype in Head and Neck Squamous Cell Carcinoma: Towards a Standardised Approach to Microfluidic CTC Biomarker Discovery

Simple Summary

Circulating tumour cells (CTCs) have shown potential to act as markers of disease and prognosis in head and neck squamous cell carcinoma (HNSCC). However, there are a number of methods and devices reported to isolate and characterise CTCs. Translating CTC markers to clinical practice, for patient benefit, requires a reliable, reproducible and standardised approach. We report the benefit of the Parsortix microfluidic CTC enrichment platform in HNSCC. We demonstrate consistent cell capture rates between 10 and 100 cells/mL of whole blood. Analysis of gene expression with unfixed cells before and after Parsortix enrichment demonstrated a cell stress response and downregulation of key genes. We highlight the benefit of using a fixative blood collection tube (Transfix) to increase cell capture rate and preserve the CTC marker expression profile. Such evidence is crucial when designing sample processing protocols for large cohort multi-centre clinical trials investigating CTCs in any cancer type.

Abstract

Introduction: Research demonstrates strong evidence that circulating tumour cells (CTCs) can provide diagnostic and/or prognostic biomarkers in head and neck squamous cell carcinoma (HNSCC) and a potential tool for therapeutic stratification. However, the question still remains as to the optimum method of CTC enrichment and how this can be translated into clinical practice. We aimed to evaluate the Parsortix microfluidic device for CTC enrichment and characterisation in HNSCC, seeking to optimise a sample collection and processing protocol that preserves CTC integrity and phenotype. Method: Spiking experiments of the FaDu and SCC040 HNSCC cell lines were used to determine the Parsortix capture rate of rare “CTC-like” cells. Capture rates of cancer cells spiked into EDTA blood collections tubes (BCTs) were compared to the Transfix fixative BCT and Cytodelics whole blood freezing protocol. The Lexogen Quantseq library preparation was used to profile gene expression of unfixed cells before and after microfluidic enrichment and enriched cell line spiked Transfix blood samples. An antibody panel was optimised to enable immunofluorescence microscopy CTC detection in HNSCC patient Transfix blood samples, using epithelial (EpCAM) and mesenchymal (N-cadherin) CTC markers. Results: Across a spiked cell concentration range of 9–129 cells/mL, Parsortix demonstrated a mean cell capture rate of 53.5% for unfixed cells, with no significant relationship between spiked cell concentration and capture rate. Samples preserved in Transfix BCTs demonstrated significantly increased capture rates at 0 h (time to processing) compared to EDTA BCTs (65.3% vs. 51.0%). Capture rates in Transfix BCTs were maintained at 24 h and 72 h timepoints, but dropped significantly in EDTA BCTs. Gene expression profiling revealed that microfluidic enrichment of unfixed cell lines caused downregulation of RNA processing/binding gene pathways and upregulation of genes involved in cell injury, apoptosis and oxidative stress. RNA was successfully extracted and sequenced from Transfix preserved cells enriched using Parsortix, demonstrating epithelial specific transcripts from spiked cells. In a proof-of-concept cohort of four patients with advanced HNSCC, CTCs were successfully identified and visualised with epithelial and epithelial-mesenchymal phenotypes. Conclusion: We have optimised a protocol for detection of CTCs in HNSCC with the Parsortix microfluidic device, using Transfix BCTs. We report a significant benefit, both in terms of cell capture rates and preserving cell phenotype, for using a fixative BCT- particularly if samples are stored before processing. In the design of large cohort multi-site clinical trials, such data are of paramount importance.

Cell-free DNA and circulating tumor cell kinetics in a pre-clinical head and neck Cancer model undergoing radiation therapy

BACKGROUND

Monitoring circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs), known as liquid biopsies, continue to be developed as diagnostic and prognostic markers for a wide variety of cancer indications, mainly due to their minimally invasive nature and ability to offer a wide range of phenotypic and genetic information. While liquid biopsies maintain significant promising benefits, there is still limited information regarding the kinetics of ctDNA and CTCs following radiation therapy which remains a vital treatment modality in head and neck cancers. This study aims to describe the kinetics of ctDNA and CTCs following radiation exposure in a preclinical rabbit model with VX2 induced buccal carcinoma.

METHODS

Seven rabbits were inoculated with VX2 cells in the buccal mucosa and subjected to radiation. At selected time points, blood sampling was performed to monitor differing levels of ctDNA and CTC. Plasma ctDNA was measured with quantitative PCR for papillomavirus E6 while CTCs were quantified using an immunomagnetic nanoparticles within a microfluidic device. Comparisons of CTC detection with EpCAM compared to multiple surface markers (EGFR, HER2 and PSMA) was evaluated and correlated with the tumor size.

RESULTS

Plasma ctDNA reflects the overall tumor burden within the animal model. Analysis of correlations between ctDNA with tumor and lymph node volumes showed a positive correlation (R = 0.452 and R = 0.433 [p < 0.05]), respectively. Over the course of treatment, ctDNA levels declined and quickly becomes undetectable following tumor eradication. While during the course of treatment, ctDNA levels were noted to rise particularly upon initiation of radiation following scheduled treatment breaks. Levels of CTCs were observed to increase 1 week following inoculation of tumor to the primary site. For CTC detection, the use of multiple surface markers showed a greater sensitivity when compared to detection using only EpCAM. Plasma CTC levels remained elevated following radiation therapy which may account for an increased shedding of CTCs following radiation.

CONCLUSION

This study demonstrates the utility of ctDNA and CTCs detection in response to radiation treatment in a preclinical head and neck model, allowing for better understanding of liquid biopsy applications in both clinical practice and research development.

The scope of liquid biopsy in the clinical management of oral cancer

Oral squamous cell carcinoma (OSCC) is one of the most prevalent forms of head and neck cancer, and it remains a leading cause of death in developing countries. Failure to detect the disease at an early stage is the main reason for the lack of improvement in the overall survival rate over the decades. Even though tissue biopsy is considered as the gold standard for diagnosis and molecular workup, it is an invasive, expensive and time-consuming procedure. Besides, it may not indicate the genetic status of the entire tumour owing to the heterogeneity of the cancer. In this context, liquid biopsy could be quite useful as it provides a more representative picture of the circulating tumour cells, circulating tumour DNA, circulating RNA, and tumour-derived exosomes obtained from all types of body fluids. This technique provides real-time assessment of variations in the molecular profile of the whole tumour and enables the serial monitoring of the disease status. The method has many advantages, such as easy accessibility, reliability, reproducibility and the possibility for early detection of the disease. However, the concept is still in its infancy, and the research on its application in various tumours including OSCC is rapidly progressing.

Prognostic impact and potential predictive role of baseline circulating tumor cells in locally advanced head and neck squamous cell carcinoma

OBJECTIVES

The prognostic impact of circulating tumor cells (CTCs) or circulating tumor microemboli (CTM) in locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is yet to be determined, with conflicting results in previous trials. The role of induction chemotherapy (ICT) in the management of LA-HNSCC is controversial with no predictive biomarkers to guide treatment strategy in this scenario. The aim of this trial is to determine the prognostic impact of CTCs and CTM, their biomarkers expression by immunocytochemistry (ICC), and its potential role as predictors of ICT benefit in LA-HNSCC.

MATERIALS AND METHODS

Prospective study, with newly diagnosed stage III/IV non-metastatic LA-HNSCC patients treated with curative intent. Blood samples analyzed for CTCs and CTM before treatment using the ISET method.

RESULTS

A total of 83 patients were included. CTCs counts were an independent prognostic factor for overall survival (OS; HR: 1.17; 95 %CI: 1.05-1.31; p = 0.005) and progression free survival (PFS; HR:1.14; 95 %CI: 1.03-1.26; p = 0.007). Using the Lausen and Schumacher technique, 2.8 CTCs/mL for OS and 3.8 CTCs/mL for PFS were defined as the best cut-offs. CTM were detected in 27.7% of patients, correlating with worse PFS (HR = 2.70; IC95%: 1.30-5.58; p = 0.007). MRP-7 expression in CTM correlated with worse OS (HR = 3.49; 95 %CI: 1.01-12.04; p = 0.047) and PFS (HR = 3.62; 95 %CI: 1.08-12.13; p = 0.037). CTCs counts were predictive of complete response to treatment (OR = 0.74; 95 %CI: 0.58-0.95; p = 0.022) and high counts (cut-off 3.8/mL) and CTM were potential predictors of ICT benefit.

CONCLUSION

CTCs/CTM had significant prognostic impact and potential role as predictors of ICT benefit in LA-HNSCC.

Characterization and clinicopathological significance of circulating tumour cells in patients with oral squamous cell carcinoma

Circulating tumour cells (CTCs) are cancer cells released by cancer into the peripheral circulation. Haematogenous tumour spread is a hallmark of metastatic malignancy and a key factor in cancer recurrence and prognosis. CTCs have diagnostic and prognostic significance for a number of adenocarcinomas and melanoma. A review of the published peer-reviewed literature was performed to determine the clinical relevance of CTCs as a biomarker in the management of oral squamous cell carcinoma (OSCC). Fourteen studies met the eligibility criteria. With regard to patients with OSCC, this review found the following: (1) CTCs have been detected using multiple techniques; (2) the presence of CTCs does not appear to be related to tumour differentiation or size; (3) CTCs may be detected without lymph node involvement; (4) the detection of CTCs may be prognostic for both disease-free survival and overall survival; (5) quantification of CTCs may reflect the efficacy of therapy; (6) CTCs may be of value for ongoing patient monitoring. Preliminary evidence suggests that CTCs have diagnostic and prognostic potential as a biomarker for oral cancer management and warrant further investigation to determine their appropriate place in the management of OSCC patients.

Circulating Tumor Cells Correlate With Prognosis in Head and Neck Squamous Cell Carcinoma

Background:

To investigate the relationship of circulating tumor cells (CTCs) and the clinical characteristic parameters and prognosis in patients with head and neck squamous cell carcinoma (HNSCC).

Methods:

The retrospective clinical study included 95 patients with HNSCC who after surgery in Shanghai Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine between December 2015 and December 2016. All patients were followed up for survival until the end of June 2019. The CTCs detection was performed by negative enrichment (NE) immunofluorescence-in situ hybridization (im-FISH) of chromosome 8.

Results:

Patients with higher CTCs counts are associated with a worse prognosis with an area under the receiver operator characteristic (ROC) curve of 0.756 [95% confidence interval (CI) 0.640-0.872, p = 0.001]. The CTCs-positive rate of HNSCC patients was 58.9% (56/95) by using the cut-point of 3. Both the chi-square test and binary logistic regression analysis showed that the N stage and clinical stage were significantly associated with CTCs-positive in patients with HNSCC (p < 0.05). Further Non-parametric test analysis indicated that more CTCs counts were detected in late N and clinical stages patients (p < 0.001). The Kaplan-Meier survival analysis indicated that CTCs-positive were correlated with shorter progression-free survival (PFS) (p < 0.001) and overall survival (OS) (p = 0.001). Further, the CTCs-positive was an independent prognostic factor for PFS and OS according to the Cox multivariate regression analysis (p < 0.05).

Conclusion:

More CTCs were associated with N stage, clinical stage, poor prognosis in patients with HNSCC, which might be used as a prognostic biomarker.

Applicability of liquid biopsies to represent the mutational profile of tumor tissue from different cancer entities

Genetic investigation of tumor heterogeneity and clonal evolution in solid cancers could be assisted by the analysis of liquid biopsies. However, tumors of various entities might release different quantities of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) into the bloodstream, potentially limiting the diagnostic potential of liquid biopsy in distinct tumor histologies. Patients with advanced colorectal cancer (CRC), head and neck squamous cell carcinoma (HNSCC), and melanoma (MEL) were enrolled in the study, representing tumors with different metastatic patterns. Mutation profiles of cfDNA, CTCs, and tumor tissue were assessed by panel sequencing, targeting 327 cancer-related genes. In total, 30 tissue, 18 cfDNA, and 7 CTC samples from 18 patients were sequenced. Best concordance between the mutation profile of tissue and cfDNA was achieved in CRC and MEL, possibly due to the remarkable heterogeneity of HNSCC (63%, 55% and 11%, respectively). Concordance especially depended on the amount of cfDNA used for library preparation. While 21 of 27 (78%) tissue mutations were retrieved in high-input cfDNA samples (30-100 ng, N = 8), only 4 of 65 (6%) could be detected in low-input samples (<30 ng, N = 10). CTCs were detected in 13 of 18 patients (72%). However, downstream analysis was limited by poor DNA quality, allowing targeted sequencing of only seven CTC samples isolated from four patients. Only one CTC sample reflected the mutation profile of the respective tumor. Private mutations, which were detected in CTCs but not in tissue, suggested the presence of rare subclones. Our pilot study demonstrated superiority of cfDNA- compared to CTC-based mutation profiling. It was further shown that CTCs may serve as additional means to detect rare subclones possibly involved in treatment resistance. Both findings require validation in a larger patient cohort.

Circulating tumor cell analysis in locally advanced and metastatic squamous cell carcinoma of the head and neck

BACKGROUND

Circulating tumors cells (CTCs) are considered an early step towards metastasis and have been linked to poor prognosis in several types of cancer. CTCs in squamous cell carcinoma of the head and neck (SCCHN) have an unclear role.

METHODS

In this prospective study, patients with locally advanced or metastatic SCCHN had CTC counts assessed before starting systemic treatment using the CellSearch System. Select cases also had sequential CTC evaluation. Presence of CTCs was correlated with patient characteristics and outcomes.

RESULTS

Forty-eight patients enrolled, and 36 had evaluable clinical data and baseline CTC counts. Twenty-five patients had locally advanced disease (LAD) and 11 had metastatic disease. ≥1 CTCs were detected in six patients with LAD (24%) and four with metastatic disease (36%). On univariate analysis, smoking was associated with CTCs.

CONCLUSION

CTCs are not associated with prognosis in patients with LAD and metastatic disease; however, they are present in this patient population, and ≥1 CTCs is associated with a history of smoking.

LEVEL OF EVIDENCE

1b; individual prospective cohort study.

Liquid biopsy and their application progress in head and neck cancer: focus on biomarkers CTCs, cfDNA, ctDNA and EVs

Head and neck cancer (HNC) is the sixth leading cause of cancer death worldwide. Due to the low early diagnosis rate of HNC, local recurrence and high distant metastasis rate are the main reasons for treatment failure. Therefore, it is important to establish a method of diagnosis and monitoring, which is convenient, safe, reproducible, sensitive and specific. Compared with tissue biopsy, liquid biopsy is an emerging biopsy technique, which has the advantages of re-sampling, noninvasive and cost-effectiveness, and has shown good diagnostic and prognostic value in studies for various types of malignant solid tumors. This review introduces liquid biopsy, its research progress and prospects in HNC including early diagnosis, staging, grading, prognosis assessment and disease surveillance.

Review of emerging biomarkers in head and neck squamous cell carcinoma in the era of immunotherapy and targeted therapy

BACKGROUND

Biomarkers in head and neck squamous cell carcinoma (HNSCC) emerge rapidly in recent years, especially for new targeted therapies and immunotherapies.

METHODS

Recent, relevant peer-reviewed evidence were critically reviewed and summarized.

RESULTS

This review article briefly introduces essential biomarker concepts, including purposes and classifications (predictive, prognostic, and diagnostic markers), and the phases of biomarker development. We summarize current biomarkers in order of clinical utility; p16 and human papillomavirus status remain the most important and validated biomarkers in HNSCC. The rationale for biomarker study design continues to evolve with technological advances, especially whole-exome or whole-genomic sequencing. Noninvasive body fluid and liquid biopsy biomarkers appear to hold strong potential for development as tools for early cancer detection, cancer diagnosis, monitoring of disease recurrence, and outcome prediction. In light of discrepancies among different technologies, standardized approaches are needed.

CONCLUSION

Biomarkers from cancer tissue or blood in HNSCC could direct new anticancer therapies.

Direct comparison of size-dependent versus EpCAM-dependent CTC enrichment at the gene expression and DNA methylation level in head and neck squamous cell carcinoma

We directly compared two different approaches used for Circulating Tumor Cell (CTC) isolation, a size-dependent microfluidic system versus an EpCAM-dependent positive selection for downstream molecular characterization of CTC both at the gene expression and DNA methylation level in Head and Neck Squamous Cell Carcinoma (HNSCC). A size-dependent microfluidic device (Parsortix, ANGLE) and an EpCAM-dependent positive immune-magnetic isolation procedure were applied in parallel, using 10 mL PB from 50 HNSCC patients and 18 healthy donors. Total RNA was isolated from enriched CTCs and RT-qPCR was used to study the expression levels of CK-19, PD-L1, EGFR, TWIST1, CDH2 and B2M (reference gene). Real time methylation specific PCR (MSP) was used to study the methylation status of RASSF1A and MLL3 genes. In identical blood draws, the label-free size-dependent CTC-isolation system was superior in terms of sensitivity when compared to the EpCAM-dependent CTC enrichment, since a significantly higher percentage of identical PB samples was found positive at the gene expression and DNA methylation level, while the specificity was not affected. Our results indicate that future studies focused on the evaluation of clinical utility of CTC molecular characterization in HNSCC should be based on size-dependent enrichment approaches.

Nanomedical detection and downstream analysis of circulating tumor cells in head and neck patients

The establishment of novel biomarkers in liquid biopsies of cancer patients has come more into focus in prognostic and diagnostic research efforts. Due to their prognostic relevance disseminated tumor cells or circulating tumor cells are the subject of intensive research and are discussed as early diagnostic indicators for treatment failure and the formation of micrometastases. A potential association of this early-systemic tumor component with poor prognosis of cancer patients could be already demonstrated for various entities including breast, colon, lung, melanoma, ovarian and prostate cancers. Thus, the detection of circulating tumor cells seems to be also applicable for minimal-invasive monitoring of therapy progress in head and neck cancer patients. A major problem of the use in clinical routine is that circulating tumor cells could not be detected by modern imaging techniques. To overcome these limitations highly sensitive detection methods and techniques for their molecular characterization are urgently needed allowing mechanistic understanding and targeting of circulating tumor cells. Especially the medical application of nanotechnology (nanomedical methods) has made valuable contributions to the field. Here, we want to provide a comprehensive overview on (nanomedical) detection methods for circulating tumor cells and discuss their merits, pitfalls and future perspectives especially for head and neck solid squamous cell carcinoma (HNSCC) patients.

Detection of circulating tumor cells in patients with laryngeal cancer using ScreenCell: Comparative pre- and post-operative analysis and association with prognosis

The presence of circulating tumor cells (CTCs) in the blood of patients with metastatic breast, colorectal and prostate cancer have been widely investigated; however, few studies have examined CTCs in patients with laryngeal cancer. The present pilot study aimed to detect pre- and postoperative CTCs in the blood of patients with laryngeal cancer and evaluate the association with prognosis. Eight patients with laryngeal squamous cell carcinoma (LSCC) at stage III were included in the present study and underwent total or subtotal laryngectomy and radical bilateral neck lymph node dissection. Blood samples were collected from all patients before and after surgery at different time-points. The following processing steps were followed; preoperative blood sampling, surgery, postoperative blood sampling at 3, 6 and 12 month follow-ups, and prognostic association analysis. CTCs were retained on ScreenCell filters for cytological characterization. The presence of CTCs was associated with a less favorable prognosis, whereas a decrease of CTCs in the postoperative sampling was observed in patients who exhibited an improved therapeutic response. The results of the present pilot study revealed a possible association between the presence of CTCs and a less favorable prognosis in patients with LSCC; therefore, these preliminary findings may encourage further research into the incorporation of a liquid biopsy in the management of LSCC, as this may help identify patients with occult metastatic disease earlier and in a non-invasive manner. In addition, this approach may represent novel independent prognostic factor for use in the clinical evaluation of patients with LSCC.

Clinicopathological and prognostic significance of circulating tumor cells in head and neck squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND

The prognostic significance of circulating tumor cells (CTCs) in patients with head and neck squamous cell carcinoma (HNSCC) is still unclear. The objective of this study was to estimate its correlation with clinicopathological and prognostic significance in HNSCC.

MATERIALS AND METHODS

Two authors systematically searched the studies independently with keywords in PubMed, Web of science, Embase, the Cochrane database, the CNKI database, the Science citation index and the references of relevant studies (up to February 2019). Odds ratio (OR), risk ratio (RR), pooled hazard ratio (HR) and 95% confidence intervals (95%CI) were calculated as effect values.

RESULTS

Twenty studies containing 1054 patients with HNSCC were included in this meta-analysis. The CTC-positive rate was higher in the T3-T4 group (RR = 1.29, 95% CI [1.11, 1.49], I² = 47.3%), the N1-N3 group (RR = 1.18, 95% CI [1.02, 1.36], I² = 12.4%) and the III-IV group (RR = 1.13, 95% CI [1.02, 1.25], I² = 0%). Positive CTCs were significant associated with overall survival (HR = 1.37, 95% CI [0.59, 2.15], I² = 9.7%), progression-free survival (HR = 3.40, 95%CI [1.47, 5.32], I² = 0%), and disease-free survival (HR = 3.57, 95%CI [1.06, 6.08], I² = 81%).

CONCLUSION

Our meta-analysis results indicated that CTCs are significant associated with prognosis of patients with HNSCC. The presence of CTCs can be used as a monitoring tool for survival prognosis of HNSCC patients in the future.

Circulating Tumor Cells as a Prognostic Factor in Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: The CIRCUTEC Prospective Study

BACKGROUND

This prospective multicenter study evaluated the prognostic value of circulating tumor cells (CTCs) in relapsing nonoperable or metastatic head and neck squamous cell carcinoma (rHNSCC) treated by chemotherapy and cetuximab.

METHODS

In 65 patients suitable for analyses, peripheral blood was taken at day 0 (D0) D7, and D21 of treatment for CTC detection by CellSearch®, EPISPOT, and flow cytometry (FCM). Progression-free survival (PFS) was assessed with the Kaplan–Meier method and compared with the log-rank test (P &lt; 0.05).

RESULTS

At D0, CTCs were detected with EPISPOT, CellSearch, and FCM in 69% (45/65), 21% (12/58), and 11% (7/61) of patients, respectively. In the patients tested with all 3 methods, EPISPOT identified 92% (36/39), 92% (35/38), and 90% (25/28) of all positive samples at D0, D7, and D21, respectively. Median PFS time was significantly lower in (a) patients with increasing or stable CTC counts (36/54) from D0 to D7 with EPISPOTEGFR (3.9 vs 6.2 months; 95% CI, 5.0–6.9; P = 0.0103) and (b) patients with ≥1 CTC detected with EPISPOT or CellSearch® (37/51) (P = 0.0311), EPISPOT or FCM (38/54) (P = 0.0480), and CellSearch or FCM (11/51) (P = 0.0005) at D7.

CONCLUSIONS

CTCs can be detected before and during chemotherapy in patients with rHNSCC. D0–D7 CTC kinetics evaluated with EPISPOTEGFR are associated with the response to treatment. This study indicates that CTCs can be used as a real-time liquid biopsy to monitor the early response to chemotherapy in rHNSCC.

ClinicalTrials.gov Identifier

NCT02119559

Circulating Tumour Cell Biomarkers in Head and Neck Cancer: Current Progress and Future Prospects

Head and neck cancer (HNC) continues to carry a significant burden of disease both for patients and health services. Facilitating biomarker-led treatment decisions is critical to improve outcomes in this group and deliver therapy tailored to the individual tumour biological profile. One solution to develop such biomarkers is a liquid biopsy analysing circulating tumour cells (CTCs)-providing a non-invasive and dynamic assessment of tumour specific alterations in 'real-time'. A major obstacle to implementing such a test is the standardisation of CTC isolation methods and subsequent down-stream analysis. Several options are available, with a recent shift in vogue from positive-selection marker-dependent isolation systems to marker-independent negative-selection techniques. HNC single-CTC characterisation, including single-cell sequencing, to identify actionable mutations and gene-expression signatures has the potential to both guide the understanding of patient tumour heterogeneity and support the adoption of personalised medicine strategies. Microfluidic approaches for isolating CTCs and cell clusters are emerging as novel technologies which can be incorporated with computational platforms to complement current diagnostic and prognostic strategies. We review the current literature to assess progress regarding CTC biomarkers in HNC and potential avenues for future translational research and clinical implementation.

Evaluation of therapeutic efficacy with CytoSorter® circulating tumor cell-capture system in patients with locally advanced head and neck squamous cell carcinoma

Objective: This study aimed to investigate the feasibility of utilizing CytoSorter® system to detect circulating tumor cells (CTCs) and clinical value of CTCs in patients with locally advanced head and neck squamous cell carcinoma (LAHNSCC).

Methods: 31 patients with LAHNSCC, 12 healthy volunteers, and 6 patients with benign tumor serving as controls were enrolled in this study. CTCs were enriched with the CytoSorter®, a microfluidic based immune capture system. CTC detection was performed before and after induction chemotherapy, as well as after surgery and/or radiotherapy. Correlations between CTC enumerations at different time points and survival outcome and recurrence risk were evaluated. The correlation between CTCs and clinicopathological characteristics was appraised. Follow-up of patients continued until March 2019.

Results: While CTCs were not found in the controls, they were detected in 24 of 31 LAHNSCC patients. CTCs could be used to distinguish diseased people from the healthy (P<0.0001). CTCs were statistically associated with patient age (P=0.037, >60 years old vs<60 years old) and lymph node metastasis (P= 0.034, N0N1 VS N2N3). Most patients had significantly reduced CTCs at the end of treatment. Patients with partial remission of tumor after induction therapy had more CTCs than those with complete remission of tumor. Patients with higher CTCs counts prior to treatment had higher chance of developing local recurrence of tumor after treatment (P=0.0187).

Conclusion: CTCs were successfully isolated in LAHNSCC patients using CytoSorter® system with better sensibility. CTCs can be used to differentiate LAHNSCC patients from those with benign HNSCC tumor or healthy volunteers, and as markers to monitor patient’s response to treatment and predict the local tumor recurrence after treatment. CTC detection at baseline has the greatest prognostic potency in LAHNSCC patients.

Is small smarter? Nanomaterial-based detection and elimination of circulating tumor cells: current knowledge and perspectives

Circulating tumor cells (CTCs) are disseminated cancer cells. The occurrence and circulation of CTCs seem key for metastasis, still the major cause of cancer-associated deaths. As such, CTCs are investigated as predictive biomarkers. However, due to their rarity and heterogeneous biology, CTCs’ practical use has not made it into the clinical routine. Clearly, methods for the effective isolation and reliable detection of CTCs are urgently needed. With the development of nanotechnology, various nanosystems for CTC isolation and enrichment and CTC-targeted cancer therapy have been designed. Here, we summarize the relationship between CTCs and tumor metastasis, and describe CTCs’ unique properties hampering their effective enrichment. We comment on nanotechnology-based systems for CTC isolation and recent achievements in microfluidics and lab-on-a-chip technologies. We discuss recent advances in CTC-targeted cancer therapy exploiting the unique properties of nanomaterials. We conclude by introducing developments in CTC-directed nanosystems and other advanced technologies currently in (pre)clinical research.

The change in circulating tumor cells before and during concurrent chemoradiotherapy is associated with survival in patients with locally advanced head and neck cancer

BACKGROUND

This study aimed to evaluate the role of baseline circulating tumor cells (CTCs) before and during concurrent chemoradiotherapy and attempted to determine the impacts of CTCs on the outcomes in patients with head and neck squamous cell carcinoma.

METHODS

CTCs were detected using a negative selection strategy and flow cytometry protocol.

RESULTS

We observed a significant correlation between baseline CTCs and staging (P = 0.001). The CTC counts were significantly reduced within 2-4 weeks in 47 concurrent chemoradiotherapy responders (P < 0.001). Change of CTC counts correlates with progression-free survival (PFS, P = 0.01) and overall survival (OS, P = 0.01). CTC decline status was an independent prognostic factor in PFS (P = 0.03) and OS (P = 0.05) in multivariate analyses.

CONCLUSION

In chemoradiotherapy responders, CTCs are significantly reduced. CTC decline within the first month indicates a longer PFS and OS, suggesting that the dynamics of CTCs could be more important than CTC number alone.

Bone metastases from head and neck malignancies: Prognostic factors and skeletal-related events

BACKGROUND

We conducted a multicenter retrospective analysis to describe the characteristics, frequency of skeletal-related events (SREs), and prognosis of head and neck cancer (HNC) in patients with bone metastases (BM).

PATIENTS AND METHODS

The data of 192 HNC patients with BMs were collected. Analyses were conducted separately in 64 nasopharyngeal cancer (NPC) patients and in 128 non-NPC patients.

RESULTS

SREs occurred in 34 (27%) non-NPC and in 6 (9%) NPC patients, respectively. Median overall survival (OS) was 25 and 6 months in NPC and non-NPC patients, respectively. Locoregional recurrence (hazard ratio [HR] 2.33, 95% confidence interval (CI) 1.1-4.93), synchronous BM (HR 0.25, 95% CI 0.59-0.71) and bone-directed therapies (BDT) (HR 0.26, 95% CI 0.10-0.68) were independent prognostic factors for OS in NPC patients. Combined bone radiotherapy (RT) and BDT in NPC patients obtained longer survival (38 months) than either therapy alone (25 months) or neither of these therapies (8 months).

CONCLUSIONS

Patients with BMs from non-NPC have a poor prognosis and are at high risk of SREs. NPC patients with BMs are at relatively low risk of SREs. BDT may potentially improve survival, particularly when combined with bone RT. This last finding deserves prospective confirmation.

Circulating Tumour Cells (CTC), Head and Neck Cancer and Radiotherapy; Future Perspectives

Head and neck cancer is the seventh most common cancer in Australia and globally. Despite the current improved treatment modalities, there is still up to 50⁻60% local regional recurrence and or distant metastasis. High-resolution medical imaging technologies such as PET/CT and MRI do not currently detect the early spread of tumour cells, thus limiting the potential for effective minimal residual detection and early diagnosis. Circulating tumour cells (CTCs) are a rare subset of cells that escape from the primary tumour and enter into the bloodstream to form metastatic deposits or even re-establish themselves in the primary site of the cancer. These cells are more aggressive and accumulate gene alterations by somatic mutations that are the same or even greater than the primary tumour because of additional features acquired in the circulation. The potential application of CTC in clinical use is to acquire a liquid biopsy, by taking a reliable minimally invasive venous blood sample, for cell genotyping during radiotherapy treatment to monitor the decline in CTC detectability, and mutational changes in response to radiation resistance and radiation sensitivity. Currently, very little has been published on radiation therapy, CTC, and circulating cancer stem cells (CCSCs). The prognostic value of CTC in cancer management and personalised medicine for head and neck cancer radiotherapy patients requires a deeper understanding at the cellular level, along with other advanced technologies. With this goal, this review summarises the current research of head and neck cancer CTC, CCSC and the molecular targets for personalised radiotherapy response.

The Significance of Circulating Tumour Cells in the Clinic

BACKGROUND

Despite the hype about circulating tumour cells (CTCs) in the early 2000s and their potential in the diagnosis of metastasis, in recent years, the hope for personalised cancer management relies more on circulating tumour (ct)DNA that has entered the clinic in a much more efficient way. So far, approved methods for CTCs in the clinic only provide the counting of CTCs, which enables monitoring of the progression of metastatic breast, prostate, and colorectal cancer patients with therapy. Approved methods for ctDNA facilitate the analysis of specific mutations in lung cancer, thereby providing indications for potentially successful treatments. This situation inclined the balance towards molecular analysis in liquid biopsy, leveraged by new technologies and companies providing broader mutation and gene expression analysis towards the early diagnosis of cancer.

STUDY DESIGN

We conducted a search for the studies published to date that provide details about the significance of CTCs in the clinic.

RESULTS

Many studies and clinical trials have demonstrated the potential of CTCs in patient screening, early diagnosis, therapy resistance, and patient prognosis.

CONCLUSIONS

Large multi-centre studies are still needed to formally validate the clinical relevance of CTCs. Meticulous design of the clinical trials is a crucial point to achieve this long-sought objective.

Differential impact of circulating tumor cells on disease recurrence and survivals in patients with head and neck squamous cell carcinomas: An updated meta-analysis

Purpose

The prognostic impact of circulating tumor cells (CTC) on disease recurrence, progression and survivals in patients with head and neck squamous cell carcinoma (HNSCC) has not been adequately described. The objective of this study was to determine the impacts of the presence of CTC on loco-regional recurrence and survival of HNSCC patients by conducting a systematic review and meta-analysis.

Methods

A comprehensive search for articles published between 1990 and 2016 was conducted and data from these studies were extracted, using the MEDLINE, Cochrane Library, and EMBASE databases. The main outcomes were overall survival (OS) and recurrence-free survival (RFS) of HNSCC patients. Pooled hazard ratio (HR) and 95% confidence intervals (95%CI) were calculated using the random effect model for outcomes. The quality of the studies, heterogeneity and publication bias were assessed with the appropriate statistical methods.

Results

Six eligible studies with 429 patients were identified. The presence of CTC was significantly associated shorter RFS (HR = 4.88 [95%CI: 1.93–12.35], P < 0.001). However, it could not predict patients’ OS (HR = 1.92 [95%CI: 0.93–3.96], P = 0.078). The following analyses using univariable values of each study also made the similar results (HR = 1.70 [95%CI: 0.83–3.45] for OS, HR = 3.79 [95%CI: 2.02–7.13] for RFS). Heterogeneity and publication bias were not significant, except one enrolled study.

Conclusions

The presence of CTC is not a significant prognostic indicator for OS of patients with HNSCC, although it could reflect the outcomes of loco-regional disease.

Liquid Biopsy in Oral Cancer

Oral cancer is one of the most prevalent forms of cancer worldwide. Carcinogenesis is a complex process, in which heterogeneity plays an important role in the development and progression of the disease. This review provides an overview of the current biological and clinical significance of circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), and exosomes for diagnosis and prognosis of oral cancer. We highlight the importance of liquid biopsy—using blood and saliva—which represents a potential alternative to solid biopsy for diagnosis and prognosis. Moreover, liquid biomarkers allow for the real-time monitoring of tumour evolution and therapeutic responses, initiating the era of personalized medicine. However, in oral cancer, the impact of liquid biopsies in clinical settings is still limited, requiring further studies to discover the best scenario for its clinical use.

Multivalent Binding and Biomimetic Cell Rolling Improves the Sensitivity and Specificity of Circulating Tumor Cell Capture

Purpose: We aimed to examine the effects of multivalent binding and biomimetic cell rolling on the sensitivity and specificity of circulating tumor cell (CTC) capture. We also investigated the clinical significance of CTCs and their kinetic profiles in patients with cancer undergoing radiotherapy treatment.Experimental Design: Patients with histologically confirmed primary carcinoma undergoing radiotherapy, with or without chemotherapy, were eligible for enrollment. Peripheral blood was collected prospectively at up to five time points, including before radiotherapy, at the first week, mid-point and final week of treatment, as well as 4 to 12 weeks after completion of radiotherapy. CTC capture was accomplished using a nanotechnology-based assay (CapioCyte) functionalized with aEpCAM, aHER-2, and aEGFR.Results: CapioCyte was able to detect CTCs in all 24 cancer patients enrolled. Multivalent binding via poly(amidoamine) dendrimers further improved capture sensitivity. We also showed that cell rolling effect can improve CTC capture specificity (% of captured cells that are CK+/CD45-/DAPI+) up to 38%. Among the 18 patients with sequential CTC measurements, the median CTC decreased from 113 CTCs/mL before radiotherapy to 32 CTCs/mL at completion of radiotherapy (P = 0.001). CTCs declined throughout radiotherapy in patients with complete clinical and/or radiographic response, in contrast with an elevation in CTCs at mid or post-radiotherapy in the two patients with known pathologic residual disease.Conclusions: Our study demonstrated that multivalent binding and cell rolling can improve the sensitivity and specificity of CTC capture compared with multivalent binding alone, allowing reliable monitoring of CTC changes during and after treatment. Clin Cancer Res; 24(11); 2539-47. ©2018 AACR.

The potential for liquid biopsies in head and neck cancer

Head and neck cancers consist of a heterogeneous group of cancers that are difficult to treat successfully. Limited screening options result in patients being diagnosed at advanced stages at presentation, and difficulty with treatment options and post-treatment surveillance can lead to poor outcomes. In this setting, tools for early and precise detection of disease will be highly valuable. Liquid biopsies, or use of analytes in blood, saliva, and other body fluid samples, provide new avenues for cancer screening with the potential for early detection, treatment modification, and surveillance of head and neck cancers. Early studies of liquid biopsies in specific head and neck cancers have had encouraging results. Nevertheless, various challenges remain before its routine adoption into clinical use is feasible. With continued advancement in the field of liquid biopsies, there is great promise for clinical implementation and significant improvement in head and neck cancer care.

Circulating and disseminated tumor cells: diagnostic tools and therapeutic targets in motion

Enumeration of circulating tumor cells (CTCs) in peripheral blood with the gold standard CellSearchTM has proven prognostic value for tumor recurrence and progression of metastatic disease. Therefore, the further molecular characterization of isolated CTCs might have clinical relevance as liquid biopsy for therapeutic decision-making and to monitor disease progression. The direct analysis of systemic cancer appears particularly important in view of the known disparity in expression of therapeutic targets as well as epithelial-to-mesenchymal transition (EMT)-based heterogeneity between primary and systemic tumor cells, which all substantially complicate monitoring and therapeutic targeting at present. Since CTCs are the potential precursor cells of metastasis, their in-depth molecular profiling should also provide a useful resource for target discovery. The present review will discuss the use of systemically spread cancer cells as liquid biopsy and focus on potential target antigens.

Clinical applications of the CellSearch platform in cancer patients

The CellSearch® system (CS) enables standardized enrichment and enumeration of circulating tumor cells (CTCs) that are repeatedly assessable via non-invasive "liquid biopsy". While the association of CTCs with poor clinical outcome for cancer patients has clearly been demonstrated in numerous clinical studies, utilizing CTCs for the identification of therapeutic targets, stratification of patients for targeted therapies and uncovering mechanisms of resistance is still under investigation. Here, we comprehensively review the current benefits and drawbacks of clinical CTC analyses for patients with metastatic and non-metastatic tumors. Furthermore, the review focuses on approaches beyond CTC enumeration that aim to uncover therapeutically relevant antigens, genomic aberrations, transcriptional profiles and epigenetic alterations of CTCs at a single cell level. This characterization of CTCs may shed light on the heterogeneity and genomic landscapes of malignant tumors, an understanding of which is highly important for the development of new therapeutic strategies.

Integration of biomimicry and nanotechnology for significantly improved detection of circulating tumor cells (CTCs)

Circulating tumor cells (CTCs) have received a great deal of scientific and clinical attention as a biomarker for diagnosis and prognosis of many types of cancer. Given their potential significance in clinics, a variety of detection methods, utilizing the recent advances in nanotechnology and microfluidics, have been introduced in an effort of achieving clinically significant detection of CTCs. However, effective detection and isolation of CTCs still remain a tremendous challenge due to their extreme rarity and phenotypic heterogeneity. Among many approaches that are currently under development, this review paper focuses on a unique, promising approach that takes advantages of naturally occurring processes achievable through application of nanotechnology to realize significant improvement in sensitivity and specificity of CTC capture. We provide an overview of successful outcome of this biomimetic CTC capture system in detection of tumor cells from in vitro, in vivo, and clinical pilot studies. We also emphasize the clinical impact of CTCs as biomarkers in cancer diagnosis and predictive prognosis, which provides a cost-effective, minimally invasive method that potentially replaces or supplements existing methods such as imaging technologies and solid tissue biopsy. In addition, their potential prognostic values as treatment guidelines and that ultimately help to realize personalized therapy are discussed.

Navigation through inter- and intratumoral heterogeneity of endocrine resistance mechanisms in breast cancer: A potential role for Liquid Biopsies?

The majority of breast cancers are hormone receptor positive due to the expression of the estrogen and/or progesterone receptors. Endocrine therapy is a major treatment option for all disease stages of hormone receptor–positive breast cancer and improves overall survival. However, endocrine therapy is limited by de novo and acquired resistance. Several factors have been proposed for endocrine therapy failures, which include molecular alterations in the estrogen receptor pathway, altered expression of cell-cycle regulators, autophagy, and epithelial-to-mesenchymal transition as a consequence of tumor progression and selection pressure. It is essential to reveal and monitor intra- and intertumoral alterations in breast cancer to allow optimal therapy outcome. Endocrine therapy navigation by molecular profiling of tissue biopsies is the current gold standard but limited in many reasons. “Liquid biopsies” such as circulating-tumor cells and circulating-tumor DNA offer hope to fill that gap in allowing non-invasive serial assessment of biomarkers predicting success of endocrine therapy regimen. In this context, this review will provide an overview on inter- and intratumoral heterogeneity of endocrine resistance mechanisms and discuss the potential role of “liquid biopsies” as navigators to personalize treatment methods and prevent endocrine treatment resistance in breast cancer.

Clinicopathological and prognostic significance of circulating tumor cells in patients with head and neck cancer: a meta-analysis

Background

Many studies have assessed the clinical use of circulating tumor cells (CTCs) in head and neck cancer, but the clinicopathological and prognostic significance of CTCs is still unclear.

Materials and methods

Two authors systematically searched the studies independently with keywords in PubMed, MEDLINE, EMBASE, Science Citation Index Expanded and Cochrane Library (from inception to February 2017). The estimated hazard ratio (HR), risk ratio (RR) and their 95% confidence intervals (95% CIs) were set as effect measures. All analyses were performed by STATA 12.0.

Results

A total of 17 studies were included in this meta-analysis. Positive CTCs were significantly associated with poor overall survival (HR =2.80, 95% CI: 1.34–5.86), disease-free survival (HR =3.86, 95% CI: 2.03–7.36) and progression-free survival (HR =3.31, 95% CI: 1.71–6.42). CTC-positive patients tend to have higher recurrence (RR =2.13, 95% CI: 1.26–3.59) and regional lymph node metastasis (RR =1.18, 95% CI: 1.02–1.36) rate and a more advanced tumor stage (RR =1.16, 95% CI: 1.03–1.32).

Conclusion

Our meta-analysis has confirmed the significant prognostic value of CTCs in head and neck cancer patients. The presence of CTCs could be used as a monitoring tool for tumor status of head and neck cancer, especially for the early detection of the tumor recurrence and progression, advanced disease and the node metastasis.

Volatile Organic Compounds in the Breath of Oral Squamous Cell Carcinoma Patients: A Pilot Study

Objective

To assess the feasibility of detecting signature volatile organic compounds in the breath of patients with oral squamous cell carcinoma.

Study Design

Prospective cohort pilot study.

Setting

University hospital.

Subjects and Methods

Using gas chromatography and mass spectrometry, emitted volatile organic compounds in the breath of patients before and after curative surgery (n = 10) were compared with those of healthy subjects (n = 4). It was hypothesized that certain volatile organic compounds disappear after surgical therapy. A characteristic signature of these compounds for diseased patients was compiled and validated.

Results

Breath analyses revealed 125 volatile organic compounds in patients with oral cancer. A signature of 8 compounds that were characteristic for patients with oral cancer could be detected: 3 from this group presented were absent after surgery.

Conclusion

The presented results confirmed the hypothesis of an absence of cancer-associated volatile organic compounds in the breath after therapy. In this pilot study, we proved the feasibility of this test approach. Further studies should be initiated to establish protocols for usage in a clinical setting.