Circulating tumor cells in early stage lung adenocarcinoma: a case series report and literature review

Numerical Assessment of the Efficiency of a New Minimally Invasive Probe for the Isolation of Circulating Tumor Cells

Liquid biopsy, particularly the isolation of circulating tumor cells (CTCs) from blood, is a promising approach in the fight against cancer. However, the main reason why CTCs are hardly used as biomarkers in the clinic is their complicated isolation from the patient's blood. Existing ex vivo systems use a small volume of blood and can therefore only isolate very few CTCs. To overcome this problem and increase the number of isolated CTCs, a new in vivo method-the BMProbe was introduced, which can isolate CTCs directly from the patient's bloodstream. This study investigates the efficiency of the BMProbe by using Computational Fluid Dynamics simulations to evaluate parameters influencing the attachment probability of CTCs to the probe surface. The analyzed parameters include screened blood volume, residence time, and wall normal rate. Additionally, the impact of probe geometry, vein diameter, and blood flow velocity on probe efficiency was examined. The numerical data suggest that the geometry has a strong influence on cell binding efficiency. Increasing the number of windings from 4 to 32 improves the transport of cells to the surface (negative wall normal rate) from 0 to -29 [mm2/s] and the screened blood volume by 138% but decreases the residence time of particles in the close vicinity of the probe by 77%. When compared to experimental data, the screened blood volume and the wall normal rate indicate cell attachment very well, whereas the residence time does not show a significant impact on the attachment of cells. For the 32-windings BMProbe, the screened blood volume is determined to be 130-313 mL, depending on the vein diameter, which is a multiple of the volume achieved by common CTC isolation techniques.

Perioperative change of circulating tumor cells in cytoreductive radical prostatectomy for oligometastatic hormone-sensitive prostate cancer: the preliminary safety evidence from long-term oncologic outcomes

Surgical manipulation has a risk of triggering the shedding of circulating tumor cells (CTCs) in patients with malignancies, However, perioperative change of circulating tumor cells in cytoreductive radical prostatectomy (CRP) for patients with oligometastatic hormone-sensitive prostate cancer (omHSPC) has not yet been well documented. This study aimed to assess whether CRP is a safe procedure for patients with omHSPC by monitoring the perioperative change of CTCs and investigating its impact on long-term oncologic outcomes. We have observed a significant decrease between the median CTC counts before and after surgery (6 vs. 4, p = 0.026). Comparing preoperative and postoperative CTC levels, seven patients increased (CTC increase group), one did not change and nineteen decreased (CTC non-increase group). PSA response rates in CTC increase group were lower than those in CTC non-increase group (73.0% vs 99.8%, p = 0.162), and nadir PSA was higher in CTC increase group (0.043 vs 0.003, p = 0.072). The CTC increase was positively correlated with the nadir PSA (r = 0.386, p = 0.047). The median follow-up period was 71.6 months, we found that there was no significant difference in clinical-pathological, operative variables or long-term oncologic outcomes between perioperative CTC increase and non-increase groups. In the entire cohort, the CTC level significantly decreased after surgery. There was no significant differences in long-term oncologic outcomes between the CTC increase and non-increase groups, implying that CRP potentially represents a safe procedure for the treatment of patients with omHSPC. The results need to be confirmed in a prospective large-scale clinical trial.

Liquid Biopsies in Lung Cancer

As lung cancer has the highest cancer-specific mortality rates worldwide, there is an urgent need for new therapeutic and diagnostic approaches to detect early-stage tumors and to monitor their response to the therapy. In addition to the well-established tissue biopsy analysis, liquid-biopsy-based assays may evolve as an important diagnostic tool. The analysis of circulating tumor DNA (ctDNA) is the most established method, followed by other methods such as the analysis of circulating tumor cells (CTCs), microRNAs (miRNAs), and extracellular vesicles (EVs). Both PCR- and NGS-based assays are used for the mutational assessment of lung cancer, including the most frequent driver mutations. However, ctDNA analysis might also play a role in monitoring the efficacy of immunotherapy and its recent accomplishments in the landscape of state-of-the-art lung cancer therapy. Despite the promising aspects of liquid-biopsy-based assays, there are some limitations regarding their sensitivity (risk of false-negative results) and specificity (interpretation of false-positive results). Hence, further studies are needed to evaluate the usefulness of liquid biopsies for lung cancer. Liquid-biopsy-based assays might be integrated into the diagnostic guidelines for lung cancer as a tool to complement conventional tissue sampling.

The Value of Circulating Tumor Cells and Tumor Markers Detection in Lung Cancer Diagnosis

OBJECTIVE

Circulating tumor cells are complete tumor cells with multi-scale analysis values that present a high potential for lung cancer diagnosis. To enhance the accuracy of lung cancer diagnosis, we detected circulating tumor cells by the innovated conical micro filter integrated microfluidic system.

METHODS

We recruited 45 subjects of study, including 22 lung cancer patients, 2 precancerous patients, the control group including 14 healthy participants, and 7 patients with lung benign lesions in this prospective study. We calculated the area under the receiver operating characteristic curve of circulating tumor cells, cytokeratin19 fragment, carcinoma embryonic antigen, squamous cell carcinoma, neuron-specific enolase, and their combination, respectively, while compared the circulating tumor cells levels between vein blood and arterial blood. A conical shape filter embedded in a microfluidic chip was used to improve the detection capability of circulating tumor cells.

RESULTS

The study indicated that the sensitivity, specificity, positive predictive value, and negative predictive value of circulating tumor cells detection were 81.8%, 90.5%, 90.0%, and 82.6%, respectively. The circulating tumor cells level of lung cancer patient was significantly higher than that of the control group (P < .05). The area under the curve of circulating tumor cells, cytokeratin19 fragment, carcinoma embryonic antigen, squamous cell carcinoma, and neuron-specific enolase alone was 0.838, 0.760, 0.705, 0.614, and 0.636, respectively. The combination area under the curve of the 4 tumor markers (cytokeratin19 fragment, carcinoma embryonic antigen, squamous cell carcinoma, and neuron-specific enolase) was 0.805 less than that of circulating tumor cells alone. Together, the total area under the curve of circulating tumor cell and the 4 tumor markers were 0.847, showing the highest area under the curve value among all biomarkers. In addition, this study found that there was no significant difference in positive rate of circulating tumor cell between arterial and venous blood samples.

CONCLUSION

The circulating tumor cells detection technology by conical micro filter integrated microfluidic could be used for lung cancer diagnosis with high sensitivity and specificity. Complementary combination of circulating tumor cells and conventional 4 lung cancer markers could enhance the clinical application accuracy. Venous blood should be used as a routine sample for circulating tumor cells detections.

Novel Circulating Tumour Cell-Related Risk Model Indicates Prognosis and Immune Infiltration in Lung Adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer (LC) and one of the leading causes of cancer-related death worldwide. LUAD has a low survival rate owing to tumour invasion and metastasis. Circulating tumour cells (CTCs) are precursors of distant metastasis, which are considered to adopt the characteristics of cancer stem cells (CSCs). Therefore, analysing the risk factors of LUAD from the perspective of CTCs may provide novel insights into the metastatic mechanisms and may help to develop diagnostic and therapeutic strategies.

Methods

A total of 447 patients from TCGA dataset were included in the training cohort, and 460 patients from the GEO dataset were included in the validation cohort. A CTC-related-gene risk model was constructed using LASSO penalty–Cox analysis, and its predictive value was further verified. Functional enrichment analysis was performed on differentially expressed genes (DEGs), followed by immune correlation analysis based on the results. In addition, western blot, CCK-8 and colony formation assays were used to validate the biological function of RAB26 in LUAD.

Results

A novel in-silico CTC-related-gene risk model, named the CTCR model, was constructed, which successfully divided patients into the high- and low-risk groups. The prognosis of the high-risk group was worse than that of the low-risk group. ROC analysis revealed that the risk model outperformed traditional clinical markers in predicting the prognosis of patients with LUAD. Further study demonstrated that the identified DEGs were significantly enriched in immune-related pathways. The immune score of the low-risk group was higher than that of the high-risk group. In addition, RAB26 was found to promote the proliferation of LUAD.

Conclusion

A prognostic risk model based on CTC-related genes was successfully constructed, and the relationship between DEGs and tumour immunity was analysed. In addition, RAB26 was found to promote the proliferation of LUAD cells.

Prognostic and Therapeutic Significance of Circulating Tumor Cell Phenotype Detection Based on Epithelial-Mesenchymal Transition Markers in Early and Midstage Colorectal Cancer First-Line Chemotherapy

Purpose

Epithelial-mesenchymal transition (EMT) is related to the process of metastasis and challenges the detection of circulating tumor cells (CTCs) based on epithelial cell adhesion molecules. Circulating tumor cells (CTCs) have been proven to be a prognostic indicator of colorectal cancer (CRC). Although there is evidence that CTC heterogeneity based on EMT markers is associated with disease progression, no standard recommendations have been established for clinical practice. This study is aimed at evaluating the prognostic significance of dynamic CTC detection based on EMT for early and midstage colorectal cancer patients.

Methods

101 patients with early to midterm CRC were admitted from January 2016 to September 2018. All patients underwent CRC radical surgery and standard chemotherapy. Patients in the postchemotherapy were able to epithelial mesenchymal transformed (EMT) CTC testing in peripheral blood using the CanPatrol™ system. Multiple CTC tests were performed according to patient's own condition and different follow-up time points. Based on patient's basic information and follow-up data, the Kaplan-Meier method was utilized to establish the progression-free survival model, and the log-rank test was utilized to compare the survival rates between the two groups.

Result

Total CTC change of the patient is the best method to predict whether progression-free survival progresses in tumor patients (Area = 0.857). The second detection of total number of CTCs (P < 0.01) detected after chemotherapy, epithelial CTCs (P = 0.032), the increased total number of CTCs (P < 0.01), and the increased number of mesenchymal CTCs (P = 0.015) are significantly related with patient's poor progression-free survival.

Conclusion

Analysis of the second CTC count and classification after follow-up are more related to the survival prognosis of the tumor. The joint analysis of CTC dynamic monitoring data is a good tool to judge patient's survival prognosis.

The Liquid Biopsy for Lung Cancer: State of the Art, Limitations and Future Developments

Simple Summary

During the development and progression of lung tumors, processes such as necrosis and vascular invasion shed tumor cells or cellular components into various fluid compartments. Liquid biopsies consist of obtaining a bodily fluid, typically peripheral blood, in order to isolate and investigate these shed tumor constituents. Circulating tumor cells (CTCs) are one such constituent, which can be isolated from blood and can act as a diagnostic aid and provide valuable prognostic information. Liquid-based biopsies may also have a potential future role in lung cancer screening. Circulating tumor DNA (ctDNA) is found in small quantities in blood and, with the recent development of sensitive molecular and sequencing technologies, can be used to directly detect actionable genetic alterations or monitor for resistance mutations and guide clinical management. While potential benefits of liquid biopsies are promising, they are not without limitations. In this review, we summarize the current state and limitations of CTCs and ctDNA and possible future directions.

Abstract

Lung cancer is a leading cause of cancer-related deaths, contributing to 18.4% of cancer deaths globally. Treatment of non-small cell lung carcinoma has seen rapid progression with targeted therapies tailored to specific genetic drivers. However, identifying genetic alterations can be difficult due to lack of tissue, inaccessible tumors and the risk of complications for the patient with serial tissue sampling. The liquid biopsy provides a minimally invasive method which can obtain circulating biomarkers shed from the tumor and could be a safer alternative to tissue biopsy. While tissue biopsy remains the gold standard, liquid biopsies could be very beneficial where serial sampling is required, such as monitoring disease progression or development of resistance mutations to current targeted therapies. Liquid biopsies also have a potential role in identifying patients at risk of relapse post treatment and as a component of future lung cancer screening protocols. Rapid developments have led to multiple platforms for isolating circulating tumor cells (CTCs) and detecting circulating tumor DNA (ctDNA); however, standardization is lacking, especially in lung carcinoma. Additionally, clonal hematopoiesis of uncertain clinical significance must be taken into consideration in genetic sequencing, as it introduces the potential for false positives. Various biomarkers have been investigated in liquid biopsies; however, in this review, we will concentrate on the current use of ctDNA and CTCs, focusing on the clinical relevance, current and possible future applications and limitations of each.

Metastasis Prevention: Focus on Metastatic Circulating Tumor Cells

Metastasis is the main cause of cancer death. Metastatic foci are derived from tumor cells that detach from the primary tumor and then enter the circulation. Circulating tumor cells (CTCs) are generally associated with a high probability of distant metastasis and a negative prognosis. Most CTCs die in the bloodstream, and only a few cells form metastases. Such metastatic CTCs have a stem-like and hybrid epithelial-mesenchymal phenotype, can avoid immune surveillance, and show increased therapy resistance. Targeting metastatic CTCs and their progenitors in primary tumors and their descendants, particularly disseminated tumor cells, represents an attractive strategy for metastasis prevention. However, current therapeutic strategies mainly target the primary tumor and only indirectly affect metastasis-initiating cells. Here, we consider potential methods for preventing metastasis based on targeting molecular and cellular features of metastatic CTCs, including CTC clusters. Also, we emphasize current knowledge gaps in CTC biology that should be addressed to develop highly effective therapeutics and strategies for metastasis suppression.

BCAR1 plays critical roles in the formation and immunoevasion of invasive circulating tumor cells in lung adenocarcinoma

Background: We investigated the roles of breast cancer anti-estrogen resistance 1 (BCAR1/p130Cas) in the formation and immunoevasion of invasive circulating tumor cells (CTCs) in lung adenocarcinoma (LUAD). Methods: Biomarkers of CTCs including BCAR1 and CD274, were evaluated by the CanPatrol method. Proteomics analysis of LUAD cells and exosomes after BCAR1 overexpression (BCAR1-OE) was performed by mass spectrometry. Cell functions and relevant signaling pathways were investigated after BCAR1 knockdown (BCAR1-KO) or BCAR1-OE in LUAD cells. Lastly, in vitro and in vivo experiments were performed to confirm the roles of BCAR1 in the formation and immunoevasion of CTCs. Results: High expression of BCAR1 by CTCs correlated with CD274 expression and epithelial-to-mesenchymal transition (EMT). RAC1, together with BCAR1, was found to play an important role in the carcinogenesis of LUAD. RAC1 functioned with BCAR1 to induce EMT and to enhance cell proliferation, colony formation, cell invasion and migration, and anoikis resistance in LUAD cells. BCAR1 up-regulated CD274 expression probably by shuttling the short isoform of BRD4 (BRD4-S) into the nucleus. CTCs, as well as tumor formation, were prohibited in nude mice xenografted with BCAR1-KO cells. The co-expression of BCAR1/RAC1 and BCAR1/CD274 was confirmed in LUAD. BCAR1 expression in LUAD is an indicator of poor prognosis, and it associates with immunoevasion. Conclusion: BCAR1, as a new target for the treatment of LUAD, plays roles in the formation and immunoevasion of invasive CTCs. The mechanism includes triggering EMT via RAC1 signaling and up-regulating CD274 expression by shuttling BRD4-S into the nucleus.

Circulating tumor cells with epithelial-mesenchymal transition markers as potential biomarkers for the diagnosis of lung cancer

BACKGROUND

Circulating tumor cells (CTCs) can be clustered into three subtypes according to epithelial-mesenchymal transition (EMT) markers: CTCs with epithelial markers (E-CTCs), CTCs with mesenchymal markers (M-CTCs), and CTCs with both markers (E&M-CTCs). CTC detection has clinical implications in the diagnosis of lung cancer (LC).

AIM

To clarify the diagnostic value of CTCs categorized by EMT markers in LC.

METHODS

The study included 106 patients with lung adenocarcinoma, including 42 ground-glass opacities (GGO) and 64 solid lesions, who underwent surgery between July 2015 and December 2019. Eleven patients with benign tumors and seventeen healthy controls were included. CTCs in peripheral blood and associated EMT markers were detected preoperatively using the CanPatrol^TM technique. The diagnostic power of CTCs for discriminating LC cases from controls was analyzed by the receiver operating characteristic (ROC) curve. The CytoploRare technique was used in 20 cases and 18 controls for validation, and Kappa values were calculated to evaluate consistency between techniques.

RESULTS

Of the 106 LC cases, 94 (89.6%) had at least one CTC. CTCs were detectable in 35 (83.3%) of 42 GGO cases. Total CTCs and E&M-CTCs were significantly more frequent in LC cases than in benign or healthy controls. The proportion of M-CTCs plus E&M-CTCs increased gradually from healthy controls, to benign controls, to LC cases. The area under the ROC curve of total CTCs and E&M-CTCs was > 0.8 and > 10.75, respectively. The combined sensitivity of total-CTCs and E&M-CTCs was 85.85% for LC patients (80.95% for GGO patients) and the specificity was 78.57%. The Kappa value was 0.415, indicating relative consistency between CanPatrol^TM and CytoploRare.

CONCLUSION

CTC detection is valuable for distinguishing LC from controls, and particularly E&M-CTC detection warrants further study.

High Expression of BCAR1 by Circulating Tumor Cells and Tumor Tissues Is Predictive of a Poor Prognosis of Early-Stage Lung Adenocarcinoma Potentially Due to Regulation of Epithelial-Mesenchymal Transition

OBJECTIVE

To clarify the clinical significance of breast cancer anti-estrogen resistance protein 1 (BCAR1) expression in circulating tumor cells (CTCs) in the peripheral blood and tumor tissues in patients with early stage lung adenocarcinoma (ES-LUAD).

METHODS

The study cohort included 60 patients with stage I LUAD (50 IA and 10 IB) who underwent surgery from November 2015 to November 2018 and 31 healthy controls. The expression levels of BCAR1 and markers of epithelial-mesenchymal transition (EMT) in peripheral blood CTCs were detected using CanPatrol^TM technology before surgery, and immunohistochemical analysis was used to detect BCAR1 expression in tumor tissues collected from 40 patients. The predictive power of BCAR1 expression in CTCs and tumor tissues on disease-free survival (DFS) was analyzed. The Cancer Genome Atlas (TCGA) database was used to study BCAR1 expression and overall survival as validation. The Gene Expression Profiling Interactive Analysis online tool was used to analyze the correlations between the expression levels of BCAR1 and EMT molecular markers.

RESULTS

Both the number and detection rates of BCAR1-negative CTCs and BCAR1-positive CTCs in peripheral blood of lung cancer patients were significantly higher as compared with healthy controls (p < 0.05). BCAR1-positive CTCs more commonly co-expressed both epithelial and mesenchymal markers. Kaplan-Meier analysis demonstrated that patients with BCAR1(++) CTCs in peripheral blood before surgery were more prone to recurrence or metastasis after 2 years. COX analysis showed that patients with higher abundance of BCAR1(++) CTCs had a poorer prognosis (hazard ratio [HR] = 1.712, 95% confidence interval [CI] = 1.077-2.272, p = 0.023). Furthermore, high BCAR1 expression in tumor tissues was predictive of a poor prognosis (HR = 2.654, 95% CI = 1.239-5.686, p = 0.012), as validated by TCGA database (HR = 2.217, 95% CI = 1.069-4.595, p = 0.032). In addition, BCAR1 expression in LUAD tissues from TCGA was significantly positively correlated with the expression of both epithelial markers (e.g., ck8/18/19) and mesenchymal markers (e.g., vimentin and twist).

CONCLUSION

BCAR1 may have a "dual impact" on EMT markers in tumor tissues and CTCs due to micro-environmental disparities, resulting in important clinical significance, which can potentially guide accurate treatment of LUAD.

Correlations between 13 Trace Elements and Circulating Tumor Cells in Patients with Colorectal Cancer in Guangzhou, China

We established a method of determining 13 trace elements (TEs) in whole blood, determined the levels of the TEs in patients with colorectal cancer (CRC), and examined the correlations between the TEs and circulating tumor cells (CTCs). A total of 93 CRC patients and 48 control subjects in Guangzhou, China, were included. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the blood levels of 13 TEs. CTCs of 13 CRC patients were examined using CanPatrol™. The levels of Mg, Fe, Zn, Se, Sr, Mo, and Ba in CRC patients were lower than those in control subjects (all, P < 0.05). The levels of Mg, Fe, Zn, Se, and Ba decreased with increasing TNM stage. The reductions of Zn and Se levels were higher in early-stage than late-stage CRC patients. The levels of Cu and Ni were higher in CRC patients than in control subjects (both, P < 0.05). The Cu level increased with increased TNM stage, and Ni level was higher in early-stage CRC patients as compared with late-stage CRC patients. Consequently, the TE levels showed differences as the process of TNM stage of CRC patients. There were correlations between the amount of CTCs and epithelial-CTCs (E-CTCs) and interstitial-CTCs (M-CTCs) (P < 0.05). The levels of Mg, Cr, Fe, Cu, Zn, Se, Sr, and Ba were correlated with the number of CTCs (P < 0.05). Specific TE patterns in whole blood may assist in the early diagnosis of CRC. The combined determination of TE levels and CTCs may be useful as an adjunct to staging and guiding treatments.

[Present and Future of Efficacy Biomarkers in Immune Checkpoint Inhibitors of Small Cell Lung Cancer]

近年来，免疫治疗在小细胞肺癌领域取得了令人瞩目的突破，为患者带来生存获益。然而，现有的临床研究结果表明试验组通常在治疗开始3个月-6个月以后方可看出获益的趋势，因此如何筛选优势人群是免疫治疗研究的重点。目前已有的临床试验对生物标记物进行了不断地探索，但结果不尽一致。我们亟需有力可靠的疗效预测指标有效地筛选优势人群、扩大受益群体。故本文将对小细胞肺癌免疫治疗疗效预测指标的现状及未来的发展前进方向展开阐述。

Clinical Impact of the Epithelial-Mesenchymal Transition in Lung Cancer as a Biomarker Assisting in Therapeutic Decisions

Lung cancer is one of the most common solid cancers and represents the leading cause of cancer death worldwide. Over the last decade, research on the epithelial-mesenchymal transition (EMT) in lung cancer has gained increasing attention. Here, we review clinical and histological features of non-small-cell lung cancer associated with EMT. We then aimed to establish potential clinical implications of EMT in current therapeutic options, including surgery, radiation, targeted therapy against oncogenic drivers, and immunotherapy.

Efficient isolation and quantification of circulating tumor cells in non-small cell lung cancer patients using peptide-functionalized magnetic nanoparticles

Background

Circulating tumor cells (CTCs) carry a wealth of information on primary and metastatic tumors critical for enhancing the understanding of the occurrence, progression and metastasis of non-small cell lung cancer (NSCLC). However, the low sensitivity of traditional tumor detection methods limits the application of CTCs in the treatment and disease surveillance of NSCLC. Therefore, CTCs isolation and detection with high sensitivity is highly desired especially for NSCLC patients, which is significant because of high occurrence and mortality. While it is very challenging because of the lower expression of CTC positive biomarkers such as epithelial cell adhesion molecules and cytokeratins (EpCAM and CKs), herein we report a method based on peptide-functionalized magnetic nanoparticles with high CTC capture efficiency, which demonstrates superiority in NSCLC clinical applications.

Methods

For analysis and comparison of the peptide-functionalized magnetic nanoparticles (TumorFisher, Nanopep Corp.) and the antibody-modified magnetic beads (CellSearch, Janssen Diagnostics, LLC), two NSCLC cell lines, A549 and NCI-H1975 were chosen to measure the binding affinity and capture efficiency. In order to compare the effect of the clinical application of these two detection systems, 7 early stage patients with NSCLC were enrolled in this study. To further explore the clinical utility of CTC counting in different stages, 81 NSCLC patients in stage I–IV were enrolled for CTC enumeration and statistical analysis.

Results

The binding affinities of the recognition peptide to A549 and NCI-H1975 are 76.7%±11.0% and 70.1%±4.8%, respectively, which is similar with the positive control group (anti-EpCAM antibodies). CTCs were captured in 5/7 (71.4%) of early stage NSCLC patients with NSCLC in TumorFisher system, which is higher than CellSearch, and the false negative of TumorFisher is much lower than CellSearch. In a larger clinical cohort, the CTC numbers of NSCLC patients varied in different stages and the overall detection rate of TumorFisher was 59/81 (72.8%), with the similar proportion in stage I (21/29, 72.4%), II (17/22, 77.3%) and III (16/21, 76.2%).

Conclusions

Highly efficient CTC isolation technique based on peptide-magnetic nanoparticles was firstly applied in NSCLC patients. Compared with the antibody-based the technique, the higher CTC detection rates (71.4%) in NSCLC patient blood samples were demonstrated for the patients in different stages, I–IV, especially in early stages. This indicates the feasibility of the clinical utility of this new technique in early stage screening, prognosis and therapy evaluation of NSCLC.

Possible role of circulating tumor cells in early detection of lung cancer

The prognosis of lung cancer varies highly depending on the disease stage at diagnosis, from a 5-year survival rate close to 90% in stage I, to 10% or less in stage IV disease. The enhancement of early diagnosis of this malignancy is mandatory to improve prognosis, because lung cancer patients stay long asymptomatic or few symptomatic after disease onset. Nowadays, liquid biopsy has emerged as a minimally-invasive tool to address the urgent need for real time monitoring, stratification, and personalized treatment of malignancies, including lung cancer. Liquid biopsy refers to a class of biomarkers, including circulating tumor cells (CTCs), cell-free circulating tumor DNA (ctDNA) and tumor-derived extracellular vesicles (tdEV). Since CTCs represent a crucial step in disease progression and metastasis, we reviewed here the scientific literature about the use of CTCs in early diagnosis of lung cancer; different techniques, and different strategies (e.g., source of analysis sample or high-risk groups of patients) were discussed showing the potential of implementing liquid biopsy in the clinical routine of non-metastatic lung cancer.

Prospective Study of the Clinical Impact of Epithelial and Mesenchymal Circulating Tumor Cells in Localized Prostate Cancer

Background

Although circulating tumor cells (CTCs) are considered as a surrogate marker in monitoring disease progression and treatment response in late stage prostate cancer (PCa), its clinical impact in localized PCa remains unclear, indicating the limitation that is simply based on cell count. This perspective observational study aimed to detect the epithelial-to-mesenchymal transition (EMT) subtypes of CTCs in localized PCa and analyze their clinical relevance and application in predicting PCa stages before surgery compared with the Partin table.

Patients and Methods

Between August 2017 and April 2019, 80 newly diagnosed localized PCa patients were enrolled in the study. Peripheral blood samples (5 mL) were collected prior to surgery. The CanPatrol^TM CTC enrichment technique, a size-based isolation method, was used to detect the EMT CTCs. Clinical relevance of the CTCs was analyzed with Spearman’s rank correlation test. Models to predict pathological were built with multivariate logistic regression. Receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis were performed to evaluate the accuracy of the prediction model.

Results

CTCs were detected in 55% of all patients. The biophenotypic CTCs were most valuable and closely correlated with PSA, Gleason score, D’Amico risk classification, and pathological stage in localized PCa. The mesenchymal subtype was rare in this population but associated with seminal vesicle invasion, while the epithelial subtype had limited clinical significance. In addition, the biophenotypic CTCs combined with traditional clinical variables were analyzed by multivariate logistic regression to predict organ-confined disease before surgery, of which the AUC reached 0.818 and was superior to the Partin table 2017 in our cohort.

Conclusion

This study highlights the clinical impact of the biophenotypic CTCs in localized PCa, which was most closely related to clinical variables and could help to predict pathology outcomes before surgery.

[Research Advances in the Mechanism of Invasion and Metastasis of Circulating Tumor Cells in Lung Cancer]

近年来，随着液体活检技术兴起，循环肿瘤细胞（circulating tumor cell, CTC）在癌症患者的早期诊断、疗效评估及预后评价等方面显示出重要的价值。CTC的产生导致肿瘤发生远处转移及患者的预后不良。因此，阐明CTC的产生、进入循环系统及其免疫逃逸的机制尤为重要。目前，精准诊疗成为提高肺癌患者预后的重要努力方向。针对肺癌CTC有望为肺癌精准诊疗提供有力的理论依据与重要手段。现对上述热点问题的最新研究进展进行综述。

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.

Effect of autologous NK cell immunotherapy on advanced lung adenocarcinoma with EGFR mutations

This study investigated the efficiency of natural killer (NK) cell immunotherapy on non-small cell lung cancer with and without EGFR mutations in order to evaluate the response rate (RR) and progression-free survival (PFS). Among the 48 patients recruited, 24 were clinically confirmed to be EGFR mutation positive. The study group was treated with autologous NK cell immunotherapy. Comparisons of the lymphocyte number, serum tumour-related biomarkers, circulating tumour cells (CTC), Karnofsky Performance Status (KPS) and survival curves were carried out before and after NK cell immunotherapy. The safety and short-term effects were evaluated, followed by median PFS and RR assessments. The serum CEA and CA125 values were found lower in the NK cell therapy group than that of the non-NK treatment group (p < 0.05). The χ² test showed a 75% RR of the study group A, significantly higher than that of the control group B (16.7%; p < 0.01). The RR of groups C (58.3%) and D (41.7%) were not statistically significant. The p values of the 4 groups were 0.012, 0.012, 0.166 and 1 from group A to group D, respectively. The median PFS was 9 months in EGFR mutation positive group undergoing NK cell infusion interference. By evaluating the changes in immune function, tumour biomarkers, CTC, KPS and PFS, we demonstrated that NK cell therapy had better clinical therapeutic effects on EGFR mutation-positive lung adenocarcinoma.

Distribution of circulating tumor cell phenotype in early cervical cancer

Background and objective: Circulating tumor cells (CTCs) can be classified into three phenotypes based on epithelial-to-mesenchymal transition (EMT) markers, including epithelial CTCs, mesenchymal CTCs, and mixed phenotypic CTCs. This study is aimed to analyze the correlation between CTC phenotypes and the clinicopathological features of patients with early cervical cancer.

Methods: Peripheral blood samples were obtained from 90 patients with early cervical cancer. CTCs were isolated and classified. The correlations of CTC counts and CTC phenotypes with clinicopathological features of patients were analyzed.

Results: The positivity rate for CTCs in patients with stage I-IIA cervical cancer was 90%. An increased CTC number was observed in patients with FIGO stage II, pelvic lymph node metastasis, and lymphovascular involvement. There were 38.89% epithelial CTCs, 23.33% mesenchymal CTCs, and 14.44% mixed phenotypic CTCs, Mesenchymal CTCs were more common in patients with FIGO stage II, pelvic lymph node metastasis, lymphovascular involvement, and deep stromal invasion.

Conclusion: CTCs with mesenchymal phenotypes are closely related to pelvic lymph node metastasis and lymphatic vascular invasion in stage I-IIA cervical cancer. Detection of circulating tumor cell phenotypes is helpful for the early diagnosis of cervical cancer micro-metastasis and for the assessment of disease status.

Prognostic and clinicopathological significance of circulating tumor cells in osteosarcoma

Osteosarcoma is the most common form of primary malignant bone tumor, with metastasis playing an essential role in determining a patient's prospects for survival. It is essential that new and better molecular targets that respond effectively to therapies and are predictive of the risk of tumor metastasis are identified. We have therefore undertaken the present prospective study to ascertain the clinical significance of circulating tumor cells (CTCs) in osteosarcoma patients. Peripheral blood was obtained from patients both pre- and post-surgery then processed using a CanPatrol™ system, an enrichment technique allowing isolation of CTCs by virtue of their size at baseline. Multiplex RNA in situ hybridization (RNA-ISH) was subsequently conducted to characterize the CTCs based on various molecular markers including MTA1, CD45, EpCAM, CK8, CK19, Vimentin and Twist. MTA1 expression was further validated by immunohistochemistry of the tumor tissue. Besides defining a diagnosis and prognosis for osteosarcoma patients, the correlation between CTC count and their molecular and clinicopathological characteristics was found to assist in the analysis of the response of patients to neoadjuvant chemotherapy. Our results revealed that the number of CTCs was significantly higher at baseline in metastatic patients than in those whose osteosarcomas were localized. The variation was attributed to the neoadjuvant chemotherapy treatment. A cut-off value of 7 CTCs/5 mL was found to effectively distinguish patients who had either a favorable or unfavorable prognosis. Notably, the ratio of mesenchymal CTCs at baseline was found to be higher in metastatic vs. localized osteosarcoma patients. In addition, the expression of MTA1 was higher in mesenchymal CTCs than the other CTC phenotypes. Furthermore, immunohistochemical analysis demonstrated a higher expression of MTA1 in tumor tissues from metastatic osteosarcoma patients. Taken together, our findings conclusively establish that the number and molecular phenotype of CTCs are predictive of tumor metastasis and the response of patients to neoadjuvant chemotherapy.

Deep multi-region whole-genome sequencing reveals heterogeneity and gene-by-environment interactions in treatment-naive, metastatic lung cancer

Our understanding of genomic heterogeneity in lung cancer is largely based on the analysis of early-stage surgical specimens. Here we used endoscopic sampling of paired primary and intrathoracic metastatic tumors from 11 lung cancer patients to map genomic heterogeneity inoperable lung cancer with deep whole-genome sequencing. Intra-patient heterogeneity in driver or targetable mutations was predominantly in the form of copy number gain. Private mutation signatures, including patterns consistent with defects in homologous recombination, were highly variable both within and between patients. Irrespective of histotype, we observed a smaller than expected number of private mutations, suggesting that ancestral clones accumulated large mutation burdens immediately prior to metastasis. Single-region whole-genome sequencing of from 20 patients showed that tumors in ever-smokers with the strongest tobacco signatures were associated with germline variants in genes implicated in the repair of cigarette-induced DNA damage. Our results suggest that lung cancer precursors in ever-smokers accumulate large numbers of mutations prior to the formation of frank malignancy followed by rapid metastatic spread. In advanced lung cancer, germline variants in DNA repair genes may interact with the airway environment to influence the pattern of founder mutations, whereas similar interactions with the tumor microenvironment may play a role in the acquisition of mutations following metastasis.

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.

[Advances on Recognizing and Managing Tumor Heterogeneity]

肿瘤异质性是恶性肿瘤的特征之一，可使肿瘤的生长速度、侵袭与转移、药物敏感性、预后等各方面产生差异。肿瘤驱动基因和靶向药物的发现发展开启了战胜肿瘤的希望之门，然而异质性的存在又让肿瘤治疗陷入了难以攻克的困境。在肿瘤复发、进展演化的过程中肿瘤异质性如影随形，纷繁复杂。凭借不断进步的检测技术认识和理解肿瘤异质性，针对肿瘤异质性的原因和表型，定制治疗方案已成为当今精准医疗领域的重点范畴。本综述对肿瘤异质性进行了分析和探讨，从而更好的帮助我们了解肿瘤异质性，有利于我们通过多种手段对抗肿瘤异质性。

Nanotechnology-Based Strategies for Early Cancer Diagnosis Using Circulating Tumor Cells as a Liquid Biopsy

Circulating tumor cells (CTCs) are cancer cells that shed from a primary tumor and circulate in the bloodstream. As a form of “tumor liquid biopsy”, CTCs provide important information for the mechanistic investigation of cancer metastasis and the measurement of tumor genotype evolution during treatment and disease progression. However, the extremely low abundance of CTCs in the peripheral blood and the heterogeneity of CTCs make their isolation and characterization major technological challenges. Recently, nanotechnologies have been developed for sensitive CTC detection; such technologies will enable better cell and molecular characterization and open up a wide range of clinical applications, including early disease detection and evaluation of treatment response and disease progression. In this review, we summarize the nanotechnology-based strategies for CTC isolation, including representative nanomaterials (such as magnetic nanoparticles, gold nanoparticles, silicon nanopillars, nanowires, nanopillars, carbon nanotubes, dendrimers, quantum dots, and graphene oxide) and microfluidic chip technologies that incorporate nanoroughened surfaces and discuss their key challenges and perspectives in CTC downstream analyses, such as protein expression and genetic mutations that may reflect tumor aggressiveness and patient outcome.