Perioperative detection of circulating tumour cells in patients with lung cancer

Overview of the Role of Liquid Biopsy in Non-small Cell Lung Cancer (NSCLC)

Solid tumour tissue has traditionally been used for cancer molecular diagnostics. Recently, biomarker assessment in blood or liquid biopsies has become relevant because it allows genotyping in a less invasive and costly manner. In addition, it is a very useful technique in cases with insufficient tumour samples. Recent data have shown that this method can provide the baseline molecular characteristics of the tumour and resistance changes that emerge during cancer treatment. In terms of diagnostic application, the platforms available for clinical use in lung cancer focus on the isolation and detection of circulating DNA (ctDNA) and generally cover a limited number of mutations in genes such as epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS) and BRAF, as well as anaplastic lymphoma kinase (ALK) rearrangements. In parallel, there are plasma genotyping platforms based on next-generation sequencing (NGS) techniques, which are much broader in scope, allowing multiple genes to be studied simultaneously in a more efficient manner. More recently, promising research scenarios for liquid biopsy have emerged, such as its utility for early diagnosis and evaluation of minimal residual disease after oncological treatment. In light of these advances, knowledge of the benefits and limitations of liquid biopsy, as well as awareness of emerging information on new indications for this technique in non-small cell lung cancer (NSCLC), are of paramount importance in developing more effective management strategies for patients with this neoplasm.

Endovascular image-guided sampling of tumor-draining veins provides an enriched source of oncological biomarkers

Introduction

Circulating tumor-derived biomarkers can potentially impact cancer management throughout the continuum of care. This small exploratory study aimed to assess the relative levels of such biomarkers in the tumor-draining vascular beds in patients with solid tumors compared to levels in their peripheral veins.

Methods

Using an endovascular image-guided approach, we obtained blood samples from peripheral veins and other vascular compartments–including the most proximal venous drainage from solid tumors–from a set of nine oncology patients with various primary and metastatic malignancies. We then interrogated these samples for a panel of oncological biomarkers, including circulating tumor cells (CTCs), exosome-derived microRNAs (miRNAs), circulating tumor DNA (ctDNA) mutations, and certain cancer-related proteins/biochemical markers.

Results

We found substantially higher levels of CTCs, certain miRNAs, and specific ctDNA mutations in samples from vascular beds closer to the tumor compared with those from peripheral veins and also noted that some of these signals were altered by treatment procedures.

Discussion

Our results indicate that tumor-proximal venous samples are highly enriched for some oncological biomarkers and may allow for more robust molecular analysis than peripheral vein samples.

Circulating tumour cells and circulating cell-free DNA in patients with lung cancer: a comparison between thoracotomy and video-assisted thoracoscopic surgery

INTRODUCTION

The type of lung cancer surgery impacts on tumour manipulation during surgery and may drive dissemination of cancer cells into the vasculature, thus facilitating metastatic spread. The aim of this study was to investigate the impact of surgically induced trauma using peripheral blood from preoperative and postoperative patients with non-small cell lung cancer (NSCLC) undergoing thoracotomy or video-assisted thoracoscopic surgery (VATS) resection.

METHODS

Imaging flow cytometry was used to measure circulating cancer-associated cells (CCs). Circulating cell-free DNA (ccfDNA) isolation was performed using Promega dsDNA HS Assay Kit. DNA integrity measurements were calculated by the ALU247 to ALU115 ratio and cytokine levels measured using the Luminex screening assay.

RESULTS

CCs were increased in postoperative blood samples in 54 patients with NSCLC. Patients who underwent thoracotomy instead of VATS had higher numbers of EpCAM (p=0.004) and PanCK-labelled (p=0.03) CCs postoperatively. ccfDNA and DNA integrity index were also significantly increased in postoperative samples (p=0.0009 and p=0.04), with concomitant increase in interleukin 6 and interleukin 10 levels in the same cohorts (p=0.0004 and p=0.034, respectively).

CONCLUSIONS

In this study we have shown the potential clinical utility of several biomarkers from liquid biopsies to guide perioperative management, as well as provide a snapshot of the type of surgical resection in terms of circulating tumour cell release. Obtaining reliable readouts from blood can provide crucial information for disease progression, as well as being of prognostic value monitoring patients' response to treatment.

The matrix-dependent 3D spheroid model of the migration of non-small cell lung cancer: a step towards a rapid automated screening

In vitro 3D cell culture systems utilizing multicellular tumor spheroids (MCTS) are widely used in translational oncology, including for studying cell migration and in personalized therapy. However, early stages of cellular migration from MCTS and cross-talk between spheroids are overlooked, which was addressed in the current study. Here, we investigated cell migration from MCTS derived from human non-small cell lung cancer (NSCLC) cell line A549 cultured on different substrates, collagen gel or plastic, at different time points. We found that migration starts at 4–16 h time points after the seeding and its speed is substrate-dependent. We also demonstrated that co-culture of two NSCLC-derived MCTS on collagen gel, but not on plastic, facilitates cell migration compared with single MTCS. This finding should be considered when designing MCTS-based functional assays for personalized therapeutic approach and drug screenings. Overall, our work characterizes the in vitro 3D cell culture model resembling NSCLC cell migration from the clusters of CTCs into surgical wound, and describes microscopy-based tools and approaches for image data analysis with a potential for further automation. These tools and approaches also might be used to predict patterns of CTCs migration based on ex vivo analysis of patient biopsy in a 3D culture system.

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.

A Review of Circulating Tumour Cell Enrichment Technologies

Simple Summary

Circulating tumour cells (CTCs) are cancer cells shed into the bloodstream from tumours and their analysis can provide important insights into cancer detection and monitoring, with the potential to direct personalised therapies for the patient. These CTCs are rare in the blood, which makes their detection and enrichment challenging and to date, only one technology (the CellSearch) has gained FDA approval for determining the prognosis of patients with advanced breast, prostate and colorectal cancers. Here, we review the wide range of enrichment technologies available to isolate CTCs from other blood components and highlight the important characteristics that new technologies should possess for routine clinical use.

Abstract

Circulating tumour cells (CTCs) are the precursor cells for the formation of metastatic disease. With a simple blood draw, liquid biopsies enable the non-invasive sampling of CTCs from the blood, which have the potential to provide important insights into cancer detection and monitoring. Since gaining FDA approval in 2004, the CellSearch system has been used to determine the prognosis of patients with metastatic breast, prostate and colorectal cancers. This utilises the cell surface marker Epithelial Cell Adhesion Molecule (EpCAM), to enrich CTCs, and many other technologies have adopted this approach. More recently, the role of mesenchymal-like CTCs in metastasis formation has come to light. It has been suggested that these cells are more aggressive metastatic precursors than their epithelial counterparts; however, mesenchymal CTCs remain undetected by EpCAM-based enrichment methods. This has prompted the development of a variety of ‘label free’ enrichment technologies, which exploit the unique physical properties of CTCs (such as size and deformability) compared to other blood components. Here, we review a wide range of both immunocapture and label free CTC enrichment technologies, summarising the most significant advantages and disadvantages of each. We also highlight the important characteristics that technologies should possess for routine clinical use, since future developments could have important clinical implications, with the potential to direct personalised therapies for patients with cancer.

Identification of Cancer-Associated Circulating Cells in Anal Cancer Patients

Whilst anal cancer accounts for less than 1% of all new cancer cases, incidence rates have increased by up to 70% in the last 30 years with the majority of cases driven by human papilloma virus (HPV) infection. Standard treatment for localised anal cancer is chemoradiotherapy (CRT). Localised progression is the predominant pattern of relapse but well under 50% of cases are salvaged by surgery, predominantly because confirming recurrence within post-radiation change is very challenging. Identifying cancer-associated circulating cells (CCs) in peripheral blood could offer a corroborative method of monitoring treatment efficacy and identifying relapse early. To study this, nucleated cells were isolated from the blood of patients with anal cancer prior to, during, and after CRT and processed through the Amnis^® ImageStream^®X Mk II Imaging Flow Cytometer, without prior enrichment, using Pan-cytokeratin (PCK), CD45 antibodies and making use of the DNA dye DRAQ5. Analysis was undertaken using IDEAS software to identify those cells that were PCK-positive and DRAQ5-positive as well as CD45-negative; these were designated as CCs. CCs were identified in 7 of 8 patients; range 60-876 cells per mL of blood. This first report of the successful identification of CCs in anal cancer patients raises the possibility that liquid biopsies will find a future role as a prognostic/diagnostic tool in this patient group.

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.

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

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

Lack of association between Screencell-detected circulating tumour cells and long-term survival of patients undergoing surgery for non-small cell lung cancer: A pilot clinical study

Circulating tumour cells (CTCs) are cancer cells of epithelial origin that are present in peripheral blood samples. ScreenCell detection of CTCs and the association with long term survival in non-small cell lung cancer (NSCLC) patients was evaluated in the present study. A total of 33 patients undergoing surgical resection for NSCLC were recruited. Patients were followed up for 5-years post-operatively. Pre-operative patient bloods samples were processed using ScreenCell. CTCs were detected in 26 (79%) patients. In patients who were positive for CTCs, a total of 9 (35%) patients succumbed to the disease, whereas in patients negative for CTCs, a total of 4 (57%) patients succumbed to the disease (P=0.29). No association was identified between positive CTCs and poorer survival (Chi-squared 1.47, P=0.23; hazard ratio, 0.42; 95% confidence interval: 0.1-1.7). The presence of CTCs detected with ScreenCell does not influence prognosis in patients with NSCLC that was operated on. The high rate of CTC detection is encouraging in supporting this technology to aid early lung cancer diagnosis.

Analysis of Released Circulating Tumor Cells During Surgery for Non-Small Cell Lung Cancer

PURPOSE

Tumor cells from patients with lung cancer are expelled from the primary tumor into the blood, but difficult to detect in the peripheral circulation. We studied the release of circulating tumor cells (CTCs) during surgery to test the hypothesis that CTC counts are influenced by hemodynamic changes (caused by surgical approach) and manipulation.

EXPERIMENTAL DESIGN

Patients undergoing video-assisted thoracic surgery (VATS) or open surgery for (suspected) primary lung cancer were included. Blood samples were taken before surgery (T0) from the radial artery (RA), from both the RA and pulmonary vein (PV) when the PV was located (T1) and when either the pulmonary artery (T2 open) or the PV (T2 VATS) was dissected. The CTCs were enumerated using the CellSearch system. Single-cell whole-genome sequencing was performed on isolated CTCs for aneuploidy.

RESULTS

CTCs were detected in 58 of 138 samples (42%) of 31 patients. CTCs were more often detected in the PV (70%) compared with the RA (22%, P < 0.01) and in higher counts (P < 0.01). After surgery, the RA but not the PV showed less often CTCs (P = 0.02). Type of surgery did not influence CTC release. Only six of 496 isolated CTCs showed aneuploidy, despite matched primary tumor tissue being aneuploid. Euploid so-called CTCs had a different morphology than aneuploid.

CONCLUSIONS

CTCs defined by CellSearch were identified more often and in higher numbers in the PV compared with the RA, suggesting central clearance. The majority of cells in the PV were normal epithelial cells and outnumbered CTCs. Release of CTCs was not influenced by surgical approach.

Tumor-proximal liquid biopsy to improve diagnostic and prognostic performances of circulating tumor cells

Circulating tumor cell (CTC) detection and numeration are becoming part of the common clinical practice, especially for breast, colon, and prostate cancer. However, their paucity in peripheral blood samples is an obstacle for their identification. Several groups have tried to improve CTC recovery rate by developing highly sensitive cellular and molecular detection methods. However, CTCs are still difficult to detect in peripheral blood. Therefore, their recovery rate could be increased by obtaining blood samples from vessels close to the drainage territories of the invaded organ, when the anatomical situation is favorable. This approach has been tested mostly during tumor resection surgery, when the vessels nearest to the tumor are easily accessible. Moreover, radiological (including echo‐guided based and endovascular techniques) and/or endoscopic routes could be utilized to obtain CTC samples close to the tumor in a less invasive way than conventional biopsies. The purpose of this article is to summarize the available knowledge on CTC recovery from blood samples collected close to the tumor (i.e., in vessels located in the drainage area of the primary tumor or metastases). The relevance of such an approach for diagnostic and prognostic evaluations will be discussed, particularly for pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, and non‐small‐cell lung cancer.

Liquid Biopsies in Lung Cancer: Four Emerging Technologies and Potential Clinical Applications

Background: Liquid biopsies offer a promising alternative to tissue samples, providing non-invasive diagnostic approaches or serial monitoring of disease evolution. However, certain challenges remain, and the full potential of liquid biopsies has yet to be reached. Here we report several methodological approaches to interrogate liquid biopsies using circulating tumour cell (CTC) enumeration and characterisation, transcriptomics, Raman spectroscopy, and copy number instability (CNI) scores using blood samples of lung cancer (LC) patients. Methods: We choose LC; since it still is the most common cause of cancer-related mortality worldwide, and therefore there is a need for development of new non-invasive diagnostic/prognostic technologies. Changes in gene expression were assessed using RNA-seq, and in CTCs using ImageStream, an imaging flow-cytometer. CNI scores, from paired tissue/ctDNA were also explored. Raman spectroscopy was used to provide chemical fingerprints of plasma samples. Results: CTCs were detected in all LC patients (n = 10). We observed a significant increase in CTC levels in LC patients (n = 10) compared to controls (n = 21). A similar CNI was noted in the tissue and plasma of 2 patients, where higher CNI scores corresponded with poorer outcome. Significant changes in Raman spectra (carotenoid concentrations) were noted in LC patients (n = 20) compared to controls (n = 10). RNA-seq revealed differential expression of 21 genes between LC cases and controls in both LC tissue and blood samples. Conclusions: Liquid biopsies can potentially provide a more comprehensive picture of the disease compared to a single tissue biopsy. CTC enumeration is feasible and sensitive for LC patients. Molecular profiling of CTCs is also possible from total blood. CNI scores and Raman spectra require further investigation. Further work is being undertaken to explore these methods of detection in a larger LC cohort.

Differential expression of mTOR components in endometriosis and ovarian cancer: Effects of rapalogues and dual kinase inhibitors on mTORC1 and mTORC2 stoichiometry

Endometriosis is a well‑known risk factor for ovarian cancer. The genetic changes that characterise endometriosis are poorly understood; however, the mechanistic target of rapamycin (mTOR) pathway is involved. In this study, we investigated the expression of key mTOR components in endometriosis and the effects of rapalogues using an endometrioid ovarian carcinoma cell line (MDAH 2774) as an in vitro model. Gene expression of mTOR, DEPTOR, Rictor and Raptor was assessed by qPCR in 24 endometriosis patients and in silico in ovarian cancer patients. Furthermore, the effects of Rapamycin, Everolimus, Deforolimus, Temsirolimus, Resveratrol, and BEZ235 (Dactolisib, a dual kinase inhibitor) on mTOR signalling components was assessed. mTOR showed a significant increase in the expression in endometriosis and ovarian endometrioid adenocarcinoma patients compared to non‑affected controls. DEPTOR, an inhibitor of mTOR, was downregulated in the advanced stages of ovarian cancer (III and IV) compared to earlier stages (I and II). Treatment of MDAH‑2774 cells with the mTOR inhibitors resulted in the significant upregulation of DEPTOR mRNA, whereas treatment with rapamycin and BEZ‑235 (100 nM) resulted in downregulation of the mTOR protein expression after 48 h of treatment. None of the treatments resulted in translocation of mTOR from cytoplasm to nucleus. Upregulation of DEPTOR is a positive prognostic marker in ovarian cancer and is increased in response to mTOR pathway inhibition suggesting that it functions as a tumour suppressor gene in endometrioid ovarian carcinoma. Collectively, our data suggest the mTOR pathway as a potential connection between endometriosis and ovarian cancer and may be a potential target in the treatment of both conditions.

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.