Circulating tumor cells as biomarkers in head and neck cancer: recent advances and future outlook

Circulating tumor cells are a good predictor of tumor recurrence in clinical patients with gastric cancer

Circulating tumor cells (CTCs) as a liquid biopsy have great potential in clinical applications and basic cancer research, but their clinical use in gastric cancer remains unclear. This study investigated whether CTCs could be used as a potential prognosis predictor in patients with gastric cancer. A total of 120 patients with pathologically confirmed gastric cancer were enrolled from January 1, 2015, to December 1, 2019. All patients were initially diagnosed without previous treatment, and then the number of CTCs was detected using the NEimFISH method before radical surgical resection. Regular follow-up was performed in all patients, and the correlations between the number of CTCs and clinical endpoints, such as disease-free survival (DFS) and overall survival (OS), were evaluated. The univariate and multivariate hazard ratios were calculated using the Cox proportional hazard model. Based on the number of CTCs, we defined CTCs ≥ 2 per 7.5 mL of whole blood as the positive group and CTCs < 2 as the negative group. Among the 120 patients who underwent CTC detection before surgery, the rate of CTC-positive patients was 64.17% (77/120) of which stage I and II patients accounted for 22.50% and stage III patients accounted for 41.67% (P = 0.014). By detecting CTCs before surgery and at the time of recurrence, the number of CTCs tends to increase concomitantly with disease progression (median: 2 VS 5 per 7.5 mL). Multivariate analysis showed that age (HR, 0.259; 95% CI, 0.101-0.662; P = 0.005), D-dimer (HR, 3.146; 95% CI, 1.169-8.461; P = 0.023), and lymph node metastasis (HR, 0.207; 95% CI, 0.0071-0.603; P = 0.004) were factors correlated with CTCs. In addition, the median follow-up of all the patients was 38.0 months (range of 28-80 months); the DFS in CTC-positive patients was significantly shorter than that of the CTC-negative patients, and a significant difference was found based on the Cox proportional hazard regression model analysis (44.52 ± 2.83 m vs. 74.99 ± 2.78 m, HR = 4.550, P = 0.018). The OS was shorter in the CTC-positive group than in the CTC-negative group before the operation, but the result was not significant based on the Cox proportional hazard regression model analysis (47.58 ± 2.46 m vs. 70.68 ± 3.53 m, HR = 2.261, P = 0.083). The number of CTCs tends to increase concomitantly with disease progression. In addition, the detection of CTCs was an independent predictor of shorter DFS in gastric cancer. However, the relationship between CTCs and OS needs to be determined in future studies.

Magnetically-activated, nanostructured cellulose for efficient capture of circulating tumor cells from the blood sample of head and neck cancer patients

In this report, the relative efficiency of cellulose nanocrystals (CNCs) and nanofibers (CNFs) to capture circulating tumor cells (CTCs) from the blood sample of head and neck cancer (HNC) patients was evaluated. Detection and enumeration of CTCs are critical for monitoring cancer progression. Both types of nanostructured cellulose were chemically modified with Epithelial Cell Adhesion Molecule (EpCAM) antibody and iron oxide nanoparticles. The EpCAM antibody facilitated the engagement of CTCs, promoting entrapment within the cellulose cage structure. Iron oxide nanoparticles, on the other hand, rendered the cages activatable via the use of a magnet for the capture and separation of entrapped CTCs. The efficiency of the network structures is shown in head and neck cancer (HNC) patients' blood samples. It was observed that the degree of chemical functionalization of hydroxyl groups located within the CNCs or CNFs with anti-EpCAM determined the efficiency of the system's interaction with CTCs. Further, our result indicated that inflexible scaffolds of nanocrystals interacted more efficiently with CTCs than that of the fibrous CNF scaffolds. Network structures derived from CNCs demonstrated comparable CTC capturing efficiency to commercial standard, OncoDiscover®. The output of the work will provide the chemical design principles of cellulosic materials intended for constructing affordable platforms for monitoring cancer progression in 'real time'.

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.

Circulating tumor cells in blood as a prognostic biomarker in tongue squamous cell carcinoma

OBJECTIVE

The study aimed to evaluate the role of circulating tumor cells (CTCs) as a prognostic biomarker of tongue squamous cell carcinoma (TSCC).

STUDY DESIGN

CTC levels in the peripheral blood of 50 patients with TSCC at baseline (i.e., before treatment) and of 8 healthy donors were determined using the NanoVelcro system. The relationship between CTC levels and clinicopathologic parameters and clinical outcomes such as recurrence, metastasis, and death during follow-up (mean 17 months) was analyzed.

RESULTS

CTCs levels were closely correlated with TSCC clinical staging (P = .002), N staging (P = .007), and progression status (P = .002) in TSCC patients. Receiver operating characteristic (ROC) analysis revealed that the count of CTC ≥4 (area under curve: 0.832 [95% confidence interval 0.695-0.950]; sensitivity: 0.83; specificity: 0.75; P < .001) was a better prognostic marker than TNM stage (area under curve: 0.692 [0.536-0.848]; sensitivity: 0.83; specificity: 0.55; P = .023). In addition, univariate and multivariate analysis showed that the CTC was an important and independent predictive factor for overall survival and disease-free survival (P < .001).

CONCLUSIONS

CTC was an independent prognostic indicator in patients with TSCC. CTC may be used as an auxiliary parameter to predict the prognosis of TSCC.

Circulating tumor cells as a predictor for poor prognostic factors and overall survival in treatment naïve oral squamous cell carcinoma patients

OBJECTIVE

The aim of this study was to investigate the presence of circulating tumor cells (CTCs) and their correlation with prognostic factors and clinical outcomes in treatment-naive patients with oral squamous cell carcinoma.

STUDY DESIGN

CTCs were isolated using OncoDiscover technique from presurgically obtained peripheral blood of 152 patients with treatment naïve oral squamous cell carcinoma. Sensitivity analysis was performed by including 40 healthy controls. CTCs cutoff values for clinicopathologic factors were obtained from receiver operating characteristic curves. Multivariate models determined the significance of CTC as independent variables. Kaplan-Meier analysis differentiated in overall survival between CTC values corresponding to the stage.

RESULTS

Sensitivity, specificity, and accuracy of CTC detection were 94.32%, 98%, and 95.17%, respectively. Platform differentiated true positives at >3.5 CTCs (P < .00001). CTCs above 20.5 were suggestive of nodal metastasis (P < .0001) with a linear trend for detecting occult metastasis (P = .061). Early and advanced stages could be differentiated by >13.5 CTCs (P < .0001). Elevated CTCs were significantly associated with extranodal extension (>21.45 CTCs, P = .025), perineural invasion (>19.35 CTCs, P = .049), and depth of invasion (>12.5 CTCs, P = .0038). Median survival was reduced by 19 months when CTCs were >13.

CONCLUSIONS

Preoperative CTC levels demonstrated a strong correlation with adverse clinicopathology factors and suggested its role as a sensitive prognostic marker to predict survival outcome and disease progress.

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.

Detection of peripheral blood circulating tumor cells in oral squamous cell carcinoma and its clinical significance

OBJECTIVES

This study aims to investigate the diagnostic value of peripheral blood circulating tumor cells (CTCs) in oral squamous cell carcinoma (OSCC) and its correlation with the clinicopathological features of OSCC.

METHODS

Ninety-three patients diagnosed as OSCC in the First Affiliated Hospital of Zhengzhou University from May 2019 to May 2020 were selected as the experimental group, and 20 healthy volunteers were employed as the control group. The CTCs value of peripheral blood of the patients were measured by CTCs detection technology, and its clinical significance was analyzed.

RESULTS

The CTCs values in the experimental group were higher than those in the control group, and the difference was statistically significant (P<0.000 1). The CTCs value in the peripheral blood of patients in the experimental group were not correlated with gender, site of onset, and presence or absence of peripheral tissue infiltration (P>0.05), but was correlated with age (P=0.022), tumor T stage (P=0.02), tumor N stage (P=0.007 5), tumor M stage (P=0.013), clinical stage (P=0.029), early or late stage (P=0.022), tumor differentiation degree (P<0.001), and node metastasis (P=0.006 4). The AUC value of CTCs in OSCC diagnosis was 0.925, and the energy efficiency was statistically significant [P=0.000, 95%CI (0.876, 0.974)]. When the CTC value was 8.450 FU/3 mL, the maximum value of the Yoden index was 0.853, and the sensitivity and specificity of OSCC diagnosis were 90.3% and 95.0%, respectively. The AUC value of CTCs in the diagnosis of OSCC metastasis was 0.691, and the energy efficiency was statistically significant [P=0.000, 95%CI (0.580, 0.803)]. When the blood CTC value was 12.250 FU/3 mL, the maximum value of Yoden index was 0.367, the sensitivity was 63.6%, and the specificity was 73.3%. Multivariate regression analysis showed that buccal tumor was negatively correlated with CTCs in patients with OSCC (P=0.001 08), N2 stage (P=0.000 74) and M stage (P=0.026 38). High differentiation (P<0.000 1) and moderate differentiation (P=0.001 5) were negatively correlated with CTCs values in patients with OSCC.

CONCLUSIONS

Peripheral blood CTCs has important clinical value for early screening, auxiliary diagnosis, evaluation of metastasis, and determination of malignant degree, progression, and pathological grade of OSCC and a relatively reliable tumor detection indicator.

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.

Liquid biopsy in head and neck squamous cell carcinoma: circulating tumor cells, circulating tumor DNA, and exosomes

Introduction: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide. Due to a lack of reliable markers, HNSCC patients are usually diagnosed at a late stage, which will lead to a worse outcome. Therefore, it is critical to improve the clinical management of cancer patients. Nowadays, the development of liquid biopsy enables a minimally invasive manner to extract molecular information from HNSCCs. Thus, this review aims to outline the clinical value of liquid biopsy in early detection, real-time monitoring, and prognostic evaluation of HNSCC. Areas covered: This comprehensive review focused on the characteristics as well as clinical applications of three liquid biopsy markers (CTCs, ctDNA, and exosomes) in HNSCC. What is more, it is promising to incorporate machine learning and 3D organoid models in the liquid biopsy of HNSCC. Expert opinion: Liquid biopsy provides a noninvasive technique to reflect the inter and intra-lesional heterogeneity through the detection of tumor cells or materials released from the primary and secondary tumors. Recently, some evolving technologies have the potential to combine with liquid biopsy to improve clinical management of HNSCC patients.

From Bench to Bedside in Tongue Muscle Cancer Invasion and Back again: Gross Anatomy, Microanatomy, Surgical Treatments and Basic Research

Tongue squamous cell carcinoma is the most common malignancy in the oral cavity. Despite advances in diagnosis and treatment, the prognosis of advanced states has not significantly improved. Depth of invasion, pattern of invasion such as tumor budding grade, lingual lymph node metastasis in early stages, collective cell migration and circulating tumor cells in peripheral blood are some examples of the mechanisms that are currently receiving increasing attention in the evaluation of the prognosis of tongue cancers. Anatomic-based surgery showed that it is possible to improve loco-regional control of tongue cancer. In patients with a "T-N tract involvement", there is significantly more distant recurrence (40%) in patients undergoing a compartmental tongue surgery. In general, the neoplastic infiltration of the lingual muscles is traced back to the finding of neoplastic tissue along the course of a muscle; however, the muscle fibers, due to their spatial conformation and the organization of the extracellular matrix, could influence the movement of tumor cells through the muscle, leaving its three-dimensional structure unchanged. We need to exclude the possibility that tongue muscle fibers represent a mechanism for the diffusion of cancer cells without muscle invasion.

Dynamics of cell-free tumour DNA correlate with treatment response of head and neck cancer patients receiving radiochemotherapy

PURPOSE

Definitive radiochemotherapy (RCTX) with curative intent is one of the standard treatment options in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Despite this intensive therapy protocol, disease recurrence remains an issue. Therefore, we tested the predictive capacity of liquid biopsies as a novel biomarker during RCTX in patients with HNSCC.

MATERIAL AND METHODS

We sequenced the tumour samples of 20 patients with locally advanced HNSCC to identify driver mutations. Subsequently, we performed a longitudinal analysis of circulating tumour DNA (ctDNA) dynamics during RCTX. Deep sequencing and UMI-based error suppression for the identification of driver mutations and HPV levels in the plasma enabled treatment-response monitoring prior, during and after RCTX.

RESULTS

In 85% of all patients ctDNA was detectable, showing a significant correlation with the gross tumour volume (p-value 0.032). Additionally, the tumour allele fraction in the plasma was negatively correlated with the course of treatment (p-value <0.05). If ctDNA was detectable at the first follow-up, disease recurrence was seen later on. Circulating HPV DNA (cvDNA) could be detected in three patients at high levels, showing a similar dynamic behaviour to the ctDNA throughout treatment, and disappeared after treatment.

CONCLUSIONS

Monitoring RCTX treatment-response using liquid biopsy in patients with locally advanced HNSCC is feasible. CtDNA can be seen as a surrogate marker of disease burden, tightly correlating with the gross tumour volume prior to the treatment start. The observed kinetic of ctDNA and cvDNA showed a negative correlation with time and treatment dosage in most patients.

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.

Clinical significance of circulating tumor cells in patients with locally advanced head and neck squamous cell carcinoma

The present study aimed to investigate the clinical relevance of circulating tumor cells (CTCs) in patients with locally advanced head and neck squamous cell carcinoma (LA‑HNSCC), particularly in patients with nasopharyngeal and hypopharyngeal squamous cell carcinoma. CTCs were isolated using negative immunomagnetic bead enrichment and were identified by fluorescence in situ hybridization. Youden's index and the receiver operating characteristic (ROC) curve were used to select the optimal CTC baseline value. χ2 test or Fisher's test were used to determine the association between CTC counts and clinical parameters, curative effects and prognosis. The Kaplan‑Meier estimator was used to analyze overall survival (OS) and progression‑free survival (PFS). In the present study, 356 peripheral blood samples (178 pretreatment samples and 178 post‑treatment samples) from 178 patients were examined. The results revealed that the pretreatment CTC detection rate was 73.8%. The minimum, maximum and median CTC counts were 1, 22 and 2/3.2 ml, respectively. The number of polyploid CTCs was associated with distant metastasis (P=0.026). In addition, patients with undetectable CTCs, and decreasing or negative CTCs post‑treatment tended to have a good prognosis (P<0.05). For nasopharyngeal squamous cell carcinoma, the PFS of patients with increased CTCs and CTCs ≥2/3.2 ml after treatment was significantly lower (P<0.05). For hypopharyngeal squamous cell carcinoma, it was suggested that CTCs with a cutoff value of 3 may be used to evaluate PFS and OS before and after treatment. In conclusion, CTCs may be used to monitor disease progression and the response to chemoradiotherapy for patients with LA‑HNSCC. Furthermore, CTCs are a better predictor of the prognosis of hypopharyngeal squamous cell carcinoma than that of nasopharyngeal squamous cell carcinoma.

Serum Lactate Dehydrogenase Contributes to Prognostic Assessment in Patients With Oligometastatic Cancer and Brain Involvement

BACKGROUND/AIM

The aim of this study was to analyze the prognostic impact of serum lactate dehydrogenase (LDH) in patients with oligometastatic brain metastases, arbitrarily defined as max. Four brain lesions and 5 metastatic lesions overall.

PATIENTS AND METHODS

This was a retrospective single institution analysis. Overall, 42 patients were identified from a prospectively maintained database.

RESULTS

Seventeen patients (40%) had extracranial metastases. Twelve patients (29%) had elevated LDH (≥255 U/l). Their median survival was significantly shorter than that of patients with normal LDH. Due to an interaction with performance status, this result was separately confirmed in patients with performance status ≥70.

CONCLUSION

Oligometastatic disease is not always correctly diagnosed, because all radiological modalities are limited by certain thresholds for detection of small metastases. We hypothesize that LDH is associated with survival, because this biomarker may reflect the total burden of malignant disease. Future studies should examine whether or not ablative local treatment of oligometastases is warranted in patients with elevated LDH.