The role of circulating tumor cells in evaluation of prognosis and treatment response in advanced non-small-cell lung cancer

The detection of circulating tumor cells indicates poor therapeutic efficacy and prognosis in patients with nonsmall cell lung cancer: A systematic review and meta-analysis

OBJECTIVE

The efficacy and prognostic value of circulating tumor cells (CTCs) in nonsmall cell lung cancer (NSCLC) are controversial based on the existing research. This systematic review and meta-analysis evaluated the significance of CTCs in NSCLC therapy monitoring and prognosis prediction, supporting their potential as clinical biomarkers.

METHODS

We conducted a comprehensive search of PubMed, Embase, Web of Science, The Cochrane Library, WanFang Data, CNKI, and VIP through September 20, 2023. Inclusion criteria were cohort studies involving NSCLC patients, focusing on peripheral blood CTCs, and assessing outcomes such as pre- and posttreatment CTC rates or levels, progression-free survival (PFS), and overall survival (OS). Two reviewers independently extracted the data and assessed risk of bias using the Newcastle-Ottawa Scale. We utilized Review Manager 5.4.1 for meta-analysis, calculating pooled odds ratios (ORs) for dichotomous outcomes, mean differences for continuous variables and hazard ratios (HRs) for survival data, applying fixed- or random-effects models based on heterogeneity assessed by the I2 statistic. This study was registered in PROSPERO (No. CRD42023450035).

RESULTS

Twenty-two eligible studies with a total of 1674 NSCLC patients were included. Meta-analysis results showed that the CTCs-positive rate (OR = 0.59, 95% CI 0.45 to 0.77, p = 0.0001) and CTCs count (mean difference = -3.10, 95% CI -5.52 to -0.69, p = 0.01) were significantly decreased after antitumor treatment. Compared with the CTCs nonreduced group, the CTC-reduced group showed better PFS (HR = 1.71, 95% CI 1.35 to 2.17, p < 0.00001) and OS (HR = 1.50, 95% CI 1.21 to 1.86, p = 0.0003) after treatment. PFS and OS in CTC-positive groups were lower than those in the CTCs-negative group pretreatment (HR = 2.49, 95% CI 1.78 to 3.47, p < 0.00001; HR = 1.80, 95% CI 1.29 to 2.52, p = 0.0006) and posttreatment (HR = 3.36, 95% CI 2.12 to 5.33, p < 0.00001; HR = 3.31, 95% CI 1.75 to 6.27, p = 0.0002).

CONCLUSIONS

CTCs can be used as a biomarker to monitor NSCLC efficacy, predict prognosis and guide follow-up treatment.

Biomarkers and experimental models for cancer immunology investigation

The rapid advancement of tumor immunotherapies poses challenges for the tools used in cancer immunology research, highlighting the need for highly effective biomarkers and reproducible experimental models. Current immunotherapy biomarkers encompass surface protein markers such as PD-L1, genetic features such as microsatellite instability, tumor-infiltrating lymphocytes, and biomarkers in liquid biopsy such as circulating tumor DNAs. Experimental models, ranging from 3D in vitro cultures (spheroids, submerged models, air-liquid interface models, organ-on-a-chips) to advanced 3D bioprinting techniques, have emerged as valuable platforms for cancer immunology investigations and immunotherapy biomarker research. By preserving native immune components or coculturing with exogenous immune cells, these models replicate the tumor microenvironment in vitro. Animal models like syngeneic models, genetically engineered models, and patient-derived xenografts provide opportunities to study in vivo tumor-immune interactions. Humanized animal models further enable the simulation of the human-specific tumor microenvironment. Here, we provide a comprehensive overview of the advantages, limitations, and prospects of different biomarkers and experimental models, specifically focusing on the role of biomarkers in predicting immunotherapy outcomes and the ability of experimental models to replicate the tumor microenvironment. By integrating cutting-edge biomarkers and experimental models, this review serves as a valuable resource for accessing the forefront of cancer immunology investigation.

The Utilization of Optically Induced Dielectrophoresis (ODEP)-Based Cell Manipulation in a Microfluidic System for the Purification and Sorting of Circulating Tumor Cells (CTCs) with Different Sizes

The analysis of circulating tumor cells (CTCs) at the molecular level holds great promise for several clinical applications. For this goal, the harvest of high-purity, size-sorted CTCs with different subtypes from a blood sample are important. For this purpose, a two-step CTC isolation protocol was proposed, by which the immunomagnetic beads-based cell separation was first utilized to remove the majority of blood cells. After that, an optically induced dielectrophoresis (ODEP) microfluidic system was developed to (1) purify the CTCs from the remaining magnetic microbeads-bound blood cells and to (2) sort and separate the CTCs with different sizes. In this study, the ODEP microfluidic system was designed and fabricated. Moreover, its optimum operation conditions and performance were explored. The results exhibited that the presented technique was able to purify and sort the cancer cells with two different sizes from a tested cell suspension in a high-purity (93.5% and 90.1% for the OECM 1 and HA22T cancer cells, respectively) manner. Overall, this study presented a technique for the purification and sorting of cancer cells with different sizes. Apart from this application, the technique is also useful for other applications in which the high-purity and label-free purification and sorting of cells with different sizes is required.

Circulating Tumour Cells: Detection and Application in Advanced Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is one of the deadliest diseases worldwide. Tissue biopsy is the current gold standard for the diagnosis and molecular profiling of NSCLC. However, this approach presents some limitations due to inadequate tissue sampling, and intra- and intertumour heterogenicity. Liquid biopsy is a noninvasive method to determine cancer-related biomarkers in peripheral blood, and can be repeated at multiple timepoints. One of the most studied approaches to liquid biopsies is represented by circulating tumour cells (CTCs). Several studies have evaluated the prognostic and predictive role of CTCs in advanced NSCLC. Despite the limitations of these studies, the results of the majority of studies seem to be concordant regarding the correlation between high CTC count and poor prognosis in patients with NSCLC. Similarly, the decrease of CTC count during treatment may represent an important predictive marker of sensitivity to therapy in advanced NSCLC. Furthermore, molecular characterization of CTCs can be used to provide information on tumour biology, and on the mechanisms involved in resistance to targeted treatment. This review will discuss the current status of the clinical utility of CTCs in patients with advanced NSCLC, highlighting their potential application to prognosis and to treatment decision making.

Liquid Biopsies for Early Response Evaluation of Radium-223 in Metastatic Prostate Cancer

PURPOSE

Reliable biomarkers for response monitoring during radium-223 treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) are lacking. Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), obtained from liquid biopsies, are shown to have prognostic value in mCRPC. The aim of this study was to determine the value of CTCs and ctDNA for response evaluation of radium-223.

METHODS

In this prospective multicenter study, longitudinal blood draws and imaging were performed in 28 patients with mCRPC and predominantly bone disease, who were treated with radium-223. CTCs were counted (CELLSEARCH CTC test), while fraction of ctDNA was estimated by measuring aneuploidy of cell-free DNA (cfDNA; modified Fast Aneuploidy Screening Test-Sequencing System). CTC counts and aneuploidy score (AS) were categorized as low (<5) and high (≥5). Primary and secondary clinical end points were failure-free survival (FFS), and overall survival (OS) and development of extraosseous metastases, respectively. Additionally, CTC count and AS were related to alkaline phosphatase (ALP) and total tumor volume in bone (TTVbone) on positron emission tomography-computed tomography with 68gallium prostate-specific membrane antigen.

RESULTS

FFS was longer in patients with a low CTC count or AS either at baseline or after 12 weeks, whereas for OS, only a significant association with CTC count was observed. Liquid biopsy results correlated well with ALP and TTVbone at baseline, but not with change in both parameters after three cycles of radium-223. AS and CTC count were significantly correlated.

CONCLUSION

CTC count and AS of cfDNA at baseline and during treatment predict clinical response to radium-223 in patients with mCRPC, warranting future evaluation of their value in treatment guidance.

Liquid Biopsy in Lung Cancer: Biomarkers for the Management of Recurrence and Metastasis

Liquid biopsies have emerged as a promising tool for the detection of metastases as well as local and regional recurrence in lung cancer. Liquid biopsy tests involve analyzing a patient's blood, urine, or other body fluids for the detection of biomarkers, including circulating tumor cells or tumor-derived DNA/RNA that have been shed into the bloodstream. Studies have shown that liquid biopsies can detect lung cancer metastases with high accuracy and sensitivity, even before they are visible on imaging scans. Such tests are valuable for early intervention and personalized treatment, aiming to improve patient outcomes. Liquid biopsies are also minimally invasive compared to traditional tissue biopsies, which require the removal of a sample of the tumor for further analysis. This makes liquid biopsies a more convenient and less risky option for patients, particularly those who are not good candidates for invasive procedures due to other medical conditions. While liquid biopsies for lung cancer metastases and relapse are still being developed and validated, they hold great promise for improving the detection and treatment of this deadly disease. Herein, we summarize available and novel approaches to liquid biopsy tests for lung cancer metastases and recurrence detection and describe their applications in clinical practice.

Circulating tumour cells in patients with lung cancer universally indicate poor prognosis

BACKGROUND

In lung cancer, the relevance of various circulating tumour cell (CTC) subgroups in different lung cancer subtypes is unclear. We performed a comprehensive meta-analysis to assess the prognostic value of CTCs in the different histological types of lung cancer, with particular respect to CTC subtypes, cut-offs and time points of CTC enumeration.

METHODS

We searched MEDLINE, Web of Science and Embase alongside relevant studies evaluating the prognostic value of CTCs in lung cancer patients. A random-effects model was used for meta-analysis, calculating hazard ratios (HRs), 95% confidence intervals and p-values.

RESULTS

27 studies enrolling 2957 patients were included. CTC detection indicates poor prognosis, especially in small cell lung cancer (SCLC) patients (overall survival HR 3.11, 95% CI 2.59-3.73) and predicts a worse outcome compared to nonsmall cell lung cancer patients. Epithelial CTCs predict a worse outcome for lung cancer than mesenchymal CTCs or epithelial-mesenchymal hybrids.

CONCLUSION

CTCs indicate poor prognosis in patients with primary lung cancer, with CTCs in SCLC having a more pronounced prognostic effect. The prognostic value of CTCs detected by different markers varies; most evidence is available for the strong negative prognostic effect of epithelial CTCs.

Detection of circulating rare cells benefitted the diagnosis of malignant solitary pulmonary nodules

INTRODUCTION

Solitary pulmonary nodules (SPNs) are challenging in differentiating between benignancy and malignancy. Therefore, more effective non-invasive biomarkers are urgently needed. The purpose of this investigation was to examine whether circulating rare cells (CRCs) could facilitate the differentiation between benign and malignant SPNs as well as its sensitivity and specificity.

METHODS

164 patients diagnosed with SPNs, 24 healthy volunteers, and 25 patients diagnosed with advanced-stage lung cancer were included. CT/PET-CT images, serum tumor markers, and biopsy results were collected. The CRCs were examined using subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) and their relationship with malignant or benign SPNs was analyzed.

RESULTS

The total CRC numbers from patients with malignant SPNs diagnosed by biopsy were significantly greater compared to those with benign SPNs (P < 0.0001), but not significantly different from patients with advanced lung cancer (P > 0.05). The total CRCs, with a cut-off value of 21.5 units, showed 67.6% sensitivity and 73.3% specificity [area under curve (AUC) 95% CI, 0.778 (0.666-0.889)] in discriminating benign and malignant SPNs and the triploid CRCs exhibited a high positive likelihood ratio of 8.4, which suggested that CRCs appeared to have a distinct advantage in discriminating benign and malignant SPNs compared to CT/PET-CT images and serum tumor markers and could be a potential screening indicator for lung cancer in the high-risk population.

CONCLUSIONS

SE-iFISH could effectively detect CRCs including circulating tumor cells (CTCs) and circulating tumor-derived endothelial cells (CTECs) and the detection of CRCs could benefit the differentiation of patients with benign and malignant SPNs.

Tumour burden and efficacy of immune-checkpoint inhibitors

Accumulating evidence suggests that a high tumour burden has a negative effect on anticancer immunity. The concept of tumour burden, simply defined as the total amount of cancer in the body, in contrast to molecular tumour burden, is often poorly understood by the wider medical community; nonetheless, a possible role exists in defining the optimal treatment strategy for many patients. Historically, tumour burden has been assessed using imaging. In particular, CT scans have been used to evaluate both the number and size of metastases as well as the number of organs involved. These methods are now often complemented by metabolic tumour burden, measured using the more recently developed 2-deoxy-2-[¹⁸F]-fluoro-D-glucose (FDG)-PET/CT. Serum-based biomarkers, such as lactate dehydrogenase, can also reflect tumour burden and are often also correlated with a poor response to immune-checkpoint inhibitors. Other circulating markers (such as circulating free tumour DNA and/or circulating tumour cells) are also attracting research interest as surrogate markers of tumour burden. In this Review, we summarize evidence supporting the utility of tumour burden as a biomarker to guide the use of immune-checkpoint inhibitors. We also describe data and provide perspective on the various tools used for tumour burden assessment, with a particular emphasis on future therapeutic strategies that might address the issue of inferior outcomes among patients with cancer with a high tumour burden.

Progress and application of circulating tumor cells in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) has the highest morbidity and mortality worldwide among malignant tumors. NSCLC is a great threat to health and well-being. Biopsy is the gold standard to diagnose lung cancer, but traditional biopsy methods cannot fully reflect the true condition of tumors. There is growing evidence that a single-point biopsy fails to reveal the complete landscape of the tumor due to intratumor heterogeneity, but it is impractical to complete multiple biopsies that are separated both spatially and temporally. Liquid biopsy heralds that a new era is coming. Circulating tumor cells (CTCs) are tumor cells that circulate in the peripheral blood after being shed from primary or metastatic tumors. CTCs constitute a considerable portion of a liquid biopsy, which contributes to the diagnosis, assessment of prognosis, and therapy of NSCLC. Herein, this review discusses the technologies for detection and enrichment of CTCs as well as clinical applications involving CTCs.

Monitoring levels of vimentin-positive circulating cancer stem cells and tumor cells in patients with advanced EGFR-mutated non-small cell lung cancer

OBJECTIVES

Circulating tumor cells (CTCs) are associated with tumor spread, whereas cancer stem cells may be related to drug resistance. However, few studies have analyzed the levels of circulating cancer stem cells (CCSCs) and CTCs in patients with advanced non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Treatment-naïve patients with EGFR-mutated NSCLC who received epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy were recruited prospectively. The cell surface vimentin antibody was used for CTC detection and CD133 antibody for CCSC detection. CCSC and CTC levels were measured as cell count per 4 mL of blood, before treatment, after 2 and 12 weeks of treatment, and at disease progression. Data on clinical characteristics and outcomes were also collected.

RESULTS

At diagnosis (n = 29), the median CCSC and CTC levels were 0 (interquartile range, 0-2) and 3 (2-9), respectively. After 12 weeks, the CCSC and CTC levels were lower than those at diagnosis (CCSC: 0 (0-0), p = 0.14; CTC: 1 (0-4), p = 0.048). At disease progression, the median CCSC and CTC levels were 0 (0-1) and 1 (0-2), respectively. Patients with higher CCSC and CTC levels at diagnosis had a numerically shorter progression-free survival.

CONCLUSION

In patients with EGFR-mutated NSCLC, CCSC and CTC levels became lower after 12 weeks of EGFR-TKI therapy and remained low at disease progression. High pre-treatment CCSC and CTC levels may be associated with a trend towards poor treatment outcomes.

Jinfukang regulates integrin/Src pathway and anoikis mediating circulating lung cancer cells migration

ETHNOPHARMACOLOGICAL RELEVANCE

Metastasis is the main cause of death in lung cancer patients. Circulating tumor cells (CTCs) may be an important target of metastasis intervention. Previous studies have shown that Jinfukang could prevent the recurrence and metastasis of lung cancer, and we have established a circulating lung tumor cell line CTC-TJH-01. However, whether Jinfukang inhibition of lung cancer metastasis is related to CTCs is still unknown.

AIM OF THE STUDY

To further explore the mechanism of Jinfukang in anti-metastasis of lung cancer from the perspective of intervention of CTCs.

MATERIALS AND METHODS

CTC-TJH-01 and H1975 cells were treated with Jinfukang. Cell viability was detected by CCK8, and the cell apoptosis was detected by flow cytometry. Transwell was used to detected cell migration and invasion. Cell anoikis was detected by anoikis detection kit. Protein expression was analysis by Western blot.

RESULTS

Jinfukang could inhibit the proliferation, migration and invasion of CTC-TJH-01 and H1975 cells. Besides, Jinfukang could also induce anoikis in CTC-TJH-01 and H1975 cells. Analysis of the mRNA expression profile showed ECM-receptor interaction and focal adhesion were regulated by Jinfukang. Moreover, it was also find that Jinfukang significantly inhibited integrin/Src pathway in CTC-TJH-01 and H1975 cells. When suppress the expression of integrin with ATN-161, it could promote Jinfukang to inhibit migration and induce anoikis in CTC-TJH-01 and H1975 cells.

CONCLUSIONS

Our results indicate that the migration and invasion of CTCs are inhibited by Jinfukang, and the mechanism may involve the suppression of integrin/Src axis to induce anoikis. These data suggest that Jinfukang exerts anti-metastatic effects in lung cancer may through anoikis.

Correlations between circulating tumor cell phenotyping and 18F-fluorodeoxyglucose positron emission tomography uptake in non-small cell lung cancer

PURPOSE

The epithelial-to-mesenchymal transition (EMT) phenotype-based subsets of circulating tumor cells (CTCs) might be predictors of tumor progression. We evaluated the clinical properties of different phenotypic CTCs in patients with non-small cell lung cancer (NSCLC). Secondly, we explored the association between different phenotypic CTCs and the uptake of 18F-fluorodeoxyglucose (FDG) by the primary tumor on a positron emission tomographic (PET) scan.

METHODS

Venous blood samples from 34 pathologically confirmed Stage IIB-IVB NSCLC patients were collected prospectively. CTCs were immunoassayed using a SE-i·FISH®CTC kit. We identified CTCs into cytokeratin positive (CK⁺) and cytokeratin negative (CK^-) phenotypes. CTC classifications were correlated with the maximum standardized uptake value (SUVmax) measured by 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Overall survival (OS) and progression-free survival (PFS) curves were produced using the Kaplan-Meier method.

RESULTS

CTCs were detected in 91.2% of NSCLC patients. CTC counting was associated with TNM stage (P = 0.014) and distant metastasis (P = 0.007). The number of CK^-CTCs was also positively associated with TNM stage (P = 0.022) and distant metastasis (P = 0.007). Both total CTC counting and CK^-CTC counting did not show association with SUVmax value (P = 0.959, P = 0.903). Kaplan-Meier survival analysis demonstrated that patients with ≥ 7 CTCs had shorter OS (P = 0.003) and PFS (P = 0.001) relative to patients with < 7 CTCs). Notably, the number of CK^-CTCs can act as independent risk factors for PFS (P = 0.044) and OS (P = 0.043) in NSCLC patients. However, SUVmax value was not associated with OS (P = 0.895) and PFS (P = 0.686).

CONCLUSION

The CTC subpopulations could be useful evidence for testing metastasis and prognosis in NSCLC patients. The SUVmax value of the primary tumor was not related to prognosis in patients with NSCLC.

The Validity and Predictive Value of Blood-Based Biomarkers in Prediction of Response in the Treatment of Metastatic Non-Small Cell Lung Cancer: A Systematic Review

With the introduction of targeted therapies and immunotherapy, molecular diagnostics gained a more profound role in the management of non-small cell lung cancer (NSCLC). This study aimed to systematically search for studies reporting on the use of liquid biopsies (LB), the correlation between LBs and tissue biopsies, and finally the predictive value in the management of NSCLC. A systematic literature search was performed, including results published after 1 January 2014. Articles studying the predictive value or validity of a LB were included. The search (up to 1 September 2019) retrieved 1704 articles, 1323 articles were excluded after title and abstract screening. Remaining articles were assessed for eligibility by full-text review. After full-text review, 64 articles investigating the predictive value and 78 articles describing the validity were included. The majority of studies investigated the predictive value of LBs in relation to therapies targeting the epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) receptor (n = 38). Of studies describing the validity of a biomarker, 55 articles report on one or more EGFR mutations. Although a variety of blood-based biomarkers are currently under investigation, most studies evaluated the validity of LBs to determine EGFR mutation status and the subsequent targeting of EGFR tyrosine kinase inhibitors based on the mutation status found in LBs of NSCLC patients.

Docetaxel-loaded D-α-tocopheryl polyethylene glycol-1000 succinate liposomes improve lung cancer chemotherapy and reverse multidrug resistance

In this study, D-alpha-tocopheryl polyethylene glycol-1000 succinate (TPGS)-coated docetaxel-loaded liposomes were developed to reverse multidrug resistance (MDR) and enhance lung cancer therapy. Evaluations were performed using human lung cancer A549 and resistant A549/DDP cells. The reversal multidrug resistant effect was assessed by P-gp inhibition assay, cytotoxicity, cellular uptake, and apoptosis assay. The tumor xenograft model was built by subcutaneous injection of A549/DDP cells in the right dorsal area of nude mice. The tumor volumes and body weights were measured every other day. The TPGS-coated liposomes showed a concentration- and time-dependent cytotoxicity and significantly enhanced the cytotoxicity of docetaxel in A549/DDP cells. Confocal laser scanning images indicated that higher concentrations of coumarin-6 were successfully delivered into the cytoplasm, and the TPGS-coated liposomes enhanced intracellular drug accumulation by inhibiting overexpressed P-glycoprotein. The TPGS-coated liposomes were shown to induce apoptosis. Furthermore, in vivo anti-tumor studies revealed that TPGS-coated docetaxel-loaded liposomes had outstanding anti-tumor efficacy in an A549/DDP xenograft model. The TPGS-coated liposomes, compared with PEG-coated liposomes, showed significant advantages in vitro and in vivo. The TPGS-coated liposomes were able to reverse MDR and enhance lung cancer therapy. Graphical abstract .

Circulating Tumor Cell Number Is Associated with Primary Tumor Volume in Patients with Lung Adenocarcinoma

Background

Circulating tumor cells (CTCs) are frequently detected in patients with advanced-stage malignant tumors and could act as a predictor of poor prognosis. However, there is a paucity of data on the relationship between CTC number and primary tumor volume in patients with lung cancer. Therefore, our study aimed to evaluate the relationship between CTC number and primary tumor volume in patients with lung adenocarcinoma.

Methods

We collected blood samples from 21 patients with treatment-naive lung adenocarcinoma and 73 healthy individuals. To count CTCs, we used a CTC enrichment method based on fluid-assisted separation technology. We compared CTC numbers between lung adenocarcinoma patients and healthy individuals using propensity score matching, and performed linear regression analysis to analyze the relationship between CTC number and primary tumor volume in lung adenocarcinoma patients.

Results

CTC positivity was significantly more common in lung adenocarcinoma patients than in healthy individuals (p<0.001). The median primary tumor volume in CTC-negative and CTC-positive patients was 10.0 cm³ and 64.8 cm³, respectively. Multiple linear regression analysis showed that the number of CTCs correlated with primary tumor volume in lung adenocarcinoma patients (β=0.903, p=0.002). Further subgroup analysis showed a correlation between CTC number and primary tumor volume in patients with distant (p=0.024) and extra-thoracic (p=0.033) metastasis (not in patients with distant metastasis).

Conclusion

Our study showed that CTC numbers may be associated with primary tumor volume in lung adenocarcinomas patients, especially in those with distant metastasis.

Circulating tumor cells prior to initial treatment is an important prognostic factor of survival in non-small cell lung cancer: a meta-analysis and system review

Background

Our study aimed to verify the prognostic value of circulating tumor cells (CTCs) prior to initial treatment on survival of non-small cell lung cancer (NSCLC) by using meta-analysis and system review of published studies.

Materials and methods

The PubMed, EMBASE and Cochrane Library were searched, respectively, to identify all studies that addressed the issues of CTCs prior to initial treatment and progression-free survival (PFS) and overall survival (OS). Finally, ten citations were included for analysis and assessment of publication bias by using review manager 5.3 statistical software and STATA 15.0.

Results

Randomized model analyzing multivariate Cox Proportional Hazards Regression indicated that higher abundance of CTCs significantly predicts poorer prognosis of lung cancer cases basing both on PFS (Z = 2.31, P = 0.02) and OS of advanced cases (Z = 2.44, P = 0.01), and systematic study aslo indicated the similar results.

Conclusion

High CTCs prior to initial treatment can predict shorter PFS and OS in NSCLC, and further studies are warranted in the future.

Circulating tumor cells in patients with lung cancer: developments and applications for precision medicine

Lung cancer is the most common cause of cancer-related deaths, with most patients dying with distant metastases. Circulating tumor cells (CTCs) are cancer cells that have disseminated into the peripheral blood from primary or metastatic sites and present great potentials as prognostic biomarkers for guiding individualized treatment in lung cancer. To date, various methods have been developed to capture CTCs in peripheral blood, and some approaches for the detection of CTC in lung cancer have shown both high sensitivity and specificity. The CTC analyses offer much promise as a real-time 'liquid biopsy' for prognosis evaluation and therapy intervention in lung cancer. In this Review, we present and discuss the current status of CTC detection and applications in lung cancer.

The potential of monitoring treatment response in non-small cell lung cancer using circulating tumour cells

Introduction: Circulating tumor cell (CTC) counts represent an attractive strategy for monitoring response to therapy in patients with advanced non-small cell lung cancer (NSCLC). Changes in the CTCs number during the treatment have been proposed as a predictive biomarker of response to both chemotherapy and targeted therapies. Profiling of CTCs might also allow the assessment of the dynamics of predictive biomarkers such as EGFR, ALK, ROS1, and PD-L1, and provide relevant information in patients progressing on treatment with targeted agents including immunotherapeutics. Areas covered: A search of peer-reviewed literature in bibliographic databases was undertaken to discuss studies on CTCs and their predictive role in NSCLC. Expert opinion: To date, some challenges limit the clinical utility of CTCs in monitoring the response to treatment in NSCLC. The standardization of techniques for CTCs isolation and characterization and their validation on larger cohorts of patients might help to translate CTCs analysis in the clinic. However, studies on CTCs can provide information on molecular mechanisms involved in NSCLC progression and in the acquired resistance to treatments.

Prognostic Relevance of Circulating Tumor Cells and Circulating Cell-Free DNA Association in Metastatic Non-Small Cell Lung Cancer Treated with Nivolumab

The treatment of advanced non-small cell lung cancer (NSCLC) has been revolutionized by immune checkpoint inhibitors (ICIs). The identification of prognostic and predictive factors in ICIs-treated patients is presently challenging. Circulating tumor cells (CTCs) and cell-free DNA (cfDNA) were evaluated in 89 previously treated NSCLC patients receiving nivolumab. Blood samples were collected before therapy and at the first and second radiological response assessments. CTCs were isolated by a filtration-based method. cfDNA was extracted from plasma and estimated by quantitative PCR. Patients with baseline CTC number and cfDNA below their median values (2 and 836.5 ng from 3 mL of blood and plasma, respectively) survived significantly longer than those with higher values (p = 0.05 and p = 0.04, respectively). The two biomarkers were then used separately and jointly as time-dependent covariates in a regression model confirming their prognostic role. Additionally, a four-fold risk of death for the subgroup presenting both circulating biomarkers above the median values was observed (p < 0.001). No significant differences were found between circulating biomarkers and best response. However, progressing patients with concomitant lower CTCs and cfDNA performed clinically well (p = 0.007), suggesting that jointed CTCs and cfDNA might help discriminate a low-risk population which might benefit from continuing ICIs beyond progression.

Epithelial-mesenchymal transition and GALC expression of circulating tumor cells indicate metastasis and poor prognosis in non-small cell lung cancer

BACKGROUND

Circulating tumor cells (CTCs) is a promising biomarker for cancer prognosis and monitoring. Molecular characterizing of CTCs could provide beneficial information on the basis of CTCs counting.

OBJECTIVE

To investigate the epithelial-mesenchymal transition (EMT) phenotypes and GALC mRNA expression of CTCs in non-small cell lung cancer (NSCLC) patients.

METHODS

We analyzed the baseline number, EMT classification, and GALC expression of CTCs in 47 NSCLC patients using CanPatrol platform and RNA in situ hybridization technique.

RESULTS

CTCs were detected in 91.5% patients ranging 0-47/5 mL blood. Increased CTCs were associated with advanced tumor stages (6/5 mL) compared with early stages (3.5/5 mL). Patients with effective treatment response presented lower CTCs (3.5/5 mL) than patients with insufficient response (7/5 mL). Epithelial, hybrid and mesenchymal CTCs were detected in 55.4%, 78.7% and 61.7% patients, respectively. Patients with distant metastasis and poor curative outcomes presented higher level of EMT-CTCs. GALC expression was positive in CTCs of 80.6% patients and closely correlated with tumor number and distant metastasis and treatment outcomes.

CONCLUSIONS

EMT phenotypes and GALC expression of CTCs are correlated with cancer metastasis and therapeutic outcomes, suggesting them to be potential markers for the prognosis of NSCLC.

The Prognostic Role of Circulating Tumor Cells (CTCs) in Lung Cancer

Lung cancer affects over 1. 8 million people worldwide and is the leading cause of cancer related mortality globally. Currently, diagnosis of lung cancer involves a combination of imaging and invasive biopsies to confirm histopathology. Non-invasive diagnostic techniques under investigation include "liquid biopsies" through a simple blood draw to develop predictive and prognostic biomarkers. A better understanding of circulating tumor cell (CTC) dissemination mechanisms offers promising potential for the development of techniques to assist in the diagnosis of lung cancer. Enumeration and characterization of CTCs has the potential to act as a prognostic biomarker and to identify novel drug targets for a precision medicine approach to lung cancer care. This review will focus on the current status of CTCs and their potential diagnostic and prognostic utility in this setting.

Epithelial-mesenchymal transition phenotypes of circulating tumor cells correlate with the clinical stages and cancer metastasis in hepatocellular carcinoma patients

BACKGROUND

Epithelial-mesenchymal transition (EMT) plays a crucial role in circulating tumor cells (CTCs) dissemination and cancer metastasis.

OBJECTIVE

To investigate the EMT phenotypes of CTCs in hepatocellular carcinoma (HCC) patients and the clinical utility in the early diagnosis of HCC metastasis and progression.

METHODS

We retrospectively analyzed the count and EMT classification of CTCs detected by the CanPatrol® platform in 195 HCC patients. The clinical relevance with other pathological features was statistically evaluated.

RESULTS

CTCs were detected in 95% of the 195 HCC patients with a range of 0-86 CTCs. Total CTCs numbers were correlated with BCLC stages, metastasis and serum AFP levels. The AUC of the ROC curve was 0.861 (95% CI: 0.782-0.940) in discriminating metastatic HCC patients with non-metastatic patients. Epithelial, hybrid and mesenchymal CTCs were found in about 53%, 83% and 57% patients, respectively. The proportion of hybrid and mesenchymal CTCs was associated with ages, BCLC stages, metastasis and AFP levels. Besides, recurrent HCC patients presented higher CTCs count and increased hybrid and mesenchymal CTCs.

CONCLUSIONS

CTCs count and EMT classification are correlated with clinical stages and metastasis of HCC, suggesting that they may be potential markers for the early diagnosis of HCC metastasis and progression.

Liquid Biopsy in Lung Cancer: Clinical Applications of Circulating Biomarkers (CTCs and ctDNA)

Lung cancer is by far the leading cause of cancer death worldwide, with non-small cell lung cancer (NSCLC) accounting for the majority of cases. Recent advances in the understanding of the biology of tumors and in highly sensitive detection technologies for molecular analysis offer targeted therapies, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. However, our understanding of an individual patient’s lung cancer is often limited by tumor accessibility because of the high risk and invasive nature of current tissue biopsy procedures. “Liquid biopsy”, the analysis of circulating biomarkers from peripheral blood, such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), offers a new source of cancer-derived materials that may reflect the status of the disease better and thereby contribute to more personalized treatment. In this review, we examined the clinical significance and uniqueness of CTCs and ctDNA from NSCLC patients, isolation and detection methods developed to analyze each type of circulating biomarker, and examples of clinical studies of potential applications for early diagnosis, prognosis, treatment monitoring, and prediction of resistance to therapy. We also discuss challenges that remain to be addressed before such tools are implemented for routine use in clinical settings.

Molecular characterization of circulating tumor cells-from bench to bedside

Circulating tumor cells (CTCs) are cancer cells discovered in cancer patients' peripheral blood that successfully escape from the primary tumor site and/or metastases, struggle to survive in the bloodstream, and have potential for seeding metastases. Numerous methods have been proposed to capture CTCs. The value of CTCs as a means of understanding cancer metastasis and a major form of 'liquid biopsy' has been widely demonstrated. Recently, single-cell molecular analyses of CTCs have provided profound biological insights into tumor heterogeneity, mechanism of metastasis and tumor evolution. In addition, because CTC analysis is non-invasive, CTCs exhibit great potential as biomarkers for assessment of cancer prognosis and therapy response. In this review, we summarize modern technologies for CTC detection and isolation, single-cell genomic/transcriptomic characterization of CTCs, and prospective clinical applications of CTCs. We expect that, after further technical improvements in methods of detection and sequencing, CTC analyses will shed new light on the mechanisms driving cancer metastasis and benefit many cancer patients.

Circulating Cell-Free DNA and Circulating Tumor Cells as Prognostic and Predictive Biomarkers in Advanced Non-Small Cell Lung Cancer Patients Treated with First-Line Chemotherapy

Cell-free DNA (cfDNA) and circulating tumor cells (CTCs) are promising prognostic and predictive biomarkers in non-small cell lung cancer (NSCLC). In this study, we examined the prognostic role of cfDNA and CTCs, in separate and joint analyses, in NSCLC patients receiving first line chemotherapy. Seventy-three patients with advanced NSCLC were enrolled in this study. CfDNA and CTC were analyzed at baseline and after two cycles of chemotherapy. Plasma cfDNA quantification was performed by quantitative PCR (qPCR) whereas CTCs were isolated by the ScreenCell Cyto (ScreenCell, Paris, France) device and enumerated according to malignant features. Patients with baseline cfDNA higher than the median value (96.3 hTERT copy number) had a significantly worse overall survival (OS) and double the risk of death (hazard ratio (HR): 2.14; 95% confidence limits (CL) = 1.24–3.68; p-value = 0.006). Conversely, an inverse relationship between CTC median baseline number (6 CTC/3 mL of blood) and OS was observed. In addition, we found that in patients reporting stable disease (SD), the baseline cfDNA and CTCs were able to discriminate patients at high risk of poor survival. cfDNA demonstrated a more reliable biomarker than CTCs in the overall population. In the subgroup of SD patients, both biomarkers identified patients at high risk of poor prognosis who might deserve additional/alternative therapeutic interventions.