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

Prognostic Role of Circulating Tumor Cells in the Pulmonary Vein, Peripheral Blood, and Bone Marrow in Resectable Non-Small Cell Lung Cancer

Background

Studies of the prognostic role of circulating tumor cells (CTCs) in early-stage non-small cell lung cancer (NSCLC) are still limited. This study investigated the prognostic power of CTCs from the pulmonary vein (PV), peripheral blood (PB), and bone marrow (BM) for postoperative recurrence in patients who underwent curative resection for NSCLC.

Methods

Forty patients who underwent curative resection for NSCLC were enrolled. Before resection, 10-mL samples were obtained of PB from the radial artery, blood from the PV of the lobe containing the tumor, and BM aspirates from the rib. A microfabricated filter was used for CTC enrichment, and immunofluorescence staining was used to identify CTCs.

Results

The pathologic stage was stage I in 8 patients (20%), II in 15 (38%), III in 14 (35%), and IV in 3 (8%). The median number of PB-, PV-, and BM-CTCs was 4, 4, and 5, respectively. A time-dependent receiver operating characteristic curve analysis showed that PB-CTCs had excellent predictive value for recurrence-free survival (RFS), with the highest area under the curve at each time point (first, second, and third quartiles of RFS). In a multivariate Cox proportional hazard regression model, PB-CTCs were an independent risk factor for recurrence (hazard ratio, 10.580; 95% confidence interval, 1.637–68.388; p<0.013).

Conclusion

The presence of ≥4 PB-CTCs was an independent poor prognostic factor for RFS, and PV-CTCs and PB-CTCs had a positive linear correlation in patients with recurrence.

Characterisation of a subpopulation of CD133+ cancer stem cells from Chinese patients with oral squamous cell carcinoma

Cancer stem cells (CSCs) play a critical role in cancer development and growth. The aim of this study was to identify and isolate CSCs from populations of primary oral squamous cell carcinoma (OSCC) cells, which were obtained from OSCC specimens and identified by cell morphology and immunohistochemical staining for keratin. CD133⁺ cells detected by flow cytometry comprised 0.41 ± 0.06% of primary OSCC cells and were isolated from primary OSCC cell populations using magnetic-activated cell sorting, revealing that 93.39% of high-purity CD133⁺ cells were in the G0/G1 phase of the cell cycle. Additionally, the growth rate of CD133⁺ cells was higher than that of CD133⁻ cells, and in vivo tumourigenesis experiments showed that the tumourigenic ability of CD133⁺ cells was markedly stronger than that of CD133⁻ cells. Moreover, CD133⁺ cells showed increased chemotherapeutic resistance to cisplatin and higher self-renewal ability according to sphere-formation assay, as well as higher mRNA levels of stemness-associated genes, including NANOG, SOX2, ALDH1A1, and OCT4. These results indicated that OSCC cells, which share certain characteristics of CSCs, harbour CD133⁺ cells potentially responsible for OSCC aggressiveness, suggesting CD133 as a potential prognostic marker and therapeutic target.

The prognostic roles of circulating ALDH1+ tumor cell in the patients with non-small cell lung cancer

Circulating tumor cells can provide important diagnostic and prognostic information of the patients with non-small cell lung cancer (NSCLC). Aldehyde dehydrogenase 1 (ALDH1), a cancer stem cell marker, has been used in various tumors, including NSCLC. In the present study, we isolated the circulating ALDH1⁺ tumor cells from the NSCLC patients using ALDH1 as a potential marker. Higher percentage of ALDH1⁺ tumor cells was identified in blood samples from the NSCLC patients compared with normal controls. ALDH1⁺ cells were correlated with the poor prognosis of these patients by using Kaplan–Meier analysis. In the last, the tumorigenic properties of ALDH1⁺ tumor cells were determined in vitro and in vivo by using sphere assay and xenograft tumor mouse models. Our in vitro and in vivo experiments demonstrated that ALDH1 could drive the stemness of circulating NSCLC cells. Circulating ALDH1⁺ cells could be used as a prognostic marker for NSCLC.

Diagnostic role of circulating extracellular matrix-related proteins in non-small cell lung cancer

Background

Interactions between cancer cells and the surrounding microenvironment are crucial determinants of cancer progression. During this process, bi-directional communication among tumor cells and cancer associated fibroblasts (CAF) regulate extracellular matrix (ECM) deposition and remodeling. As a result of this dynamic process, soluble ECM proteins can be released into the bloodstream and may represent novel circulating biomarkers useful for cancer diagnosis. The aim of the present study was to measure the levels of three circulating ECM related proteins (COL11A1, COL10A1 and SPARC) in plasma samples of lung cancer patients and in healthy heavy-smokers controls and test whether such measurements have diagnostic or prognostic value.

Methods

Gene expression profiling of lung fibroblasts isolated from paired normal and cancer tissue of NSCLC patients was performed by gene expression microarrays. The prioritization of the candidates for the study of circulating proteins in plasma was based on the most differentially expressed genes in cancer associated fibroblasts. Soluble ECM proteins were assessed by western blot in the conditioned medium of lung fibroblasts and by ELISA assays in plasma samples.

Results

Plasma samples from lung cancer patients and healthy heavy-smokers controls were tested for levels of COL11A1 and COL10A1 (n = 57 each) and SPARC (n = 90 each). Higher plasma levels of COL10A1 were detected in patients (p ≤ 0.001), a difference that was driven specifically by females (p < 0.001). No difference in COL11A1 levels between patients and controls was found. SPARC levels were also higher in plasma patients than controls (p < 0.001) with good performance in discriminating the two groups (AUC = 0.744). No significant association was observed between plasma proteins levels and clinicopathological features or survival.

Conclusion

Soluble factors related to proficient tumor-stroma cross-talk are detectable in plasma of primary lung cancer patients and may represent a valuable complementary diagnostic tool to discriminate lung cancer patients from healthy heavy-smokers individuals as shown for the SPARC protein.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4772-0) contains supplementary material, which is available to authorized users.

Pancreatic cancer circulating tumor cells: applications for personalized oncology

INTRODUCTION

Pancreatic cancer (PC) is a highly lethal disease, in part because of early metastasis, late diagnosis, and limited treatment options. Circulating tumor cells (CTCs) are cancer cells that have achieved the metastatic step of intravasation, and are thus a unique source of biomarkers with potential applications in the staging, prognostication, and treatment of PC. Areas covered: This review describes the use of CTCs in PC, including isolation methods, the significance of CTC enumeration, and studies examining phenotypic and molecular characteristics of CTCs. We also speculate on future directions for PC CTC research such as single-cell analysis and CTC culture. Expert commentary: CTCs represent a potential unique serial source of cancer tissue via a convenient and minimally invasive blood draw. Recent development of isolation methods that allow for the release of viable CTCs with unaltered molecular characteristics has set the stage for single-cell analysis and ex vivo culture. Although there is significant potential for CTCs as a biomarker to impact PC from diagnosis to therapy, there still remain a number of challenges to the routine implementation of CTCs in the clinical management of PC.

Polymer nanofiber-based microchips for EGFR mutation analysis of circulating tumor cells in lung adenocarcinoma

Background

Circulating tumor cells (CTCs) detection, an approach considered to be “liquid biopsy”, is a potential alternative method in clinical use for early diagnosis of solid tumor progression.

Methods

In this study, we developed a poly (lactic-co-glycolic acid) (PLGA) – nanofiber (PN)-NanoVelcro chip as an efficient device for simple and rapid capture of CTCs from peripheral blood. We evaluated the device performance by assessing the capture efficiency and purity. Single CTC was isolated via laser microdissection system for subsequent genetic analysis, with an aim to find the concordance of epidermal growth factor receptor (EGFR) mutations between tumor tissue and CTCs.

Results

PN-NanoVelcro chip exhibits great performance in capture efficiency and high purity. The genetic analysis results showed that most EGFR mutation in tumor tissue could also be detected in CTCs.

Conclusion

Compared to computed tomography image results, CTC detection can be implemented throughout the course of diseases and provides an accurate and earlier diagnosis of tumor progression, which make it possible for patients to acquire suitable and timely treatment.

Molecular Detection of EMT Markers in Circulating Tumor Cells from Metastatic Non-Small Cell Lung Cancer Patients: Potential Role in Clinical Practice

Background

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related mortality; nevertheless, there are few data regarding detection of circulating tumor cells (CTCs) in NSCLC, compared to other kinds of cancers in which their prognostic roles have already been defined. This difference is likely due to detection methods based on the epithelial marker expression which ignore CTCs undergoing epithelial-mesenchymal transition (CTCs^EMT).

Methods

After optimization of the test with spiking experiments of A549 cells undergoing TGF-β1-induced EMT (A549^EMT), the CTCs^EMT were enriched by immunomagnetic depletion of leukocytes and then characterized by a RT-PCR assay based on the retrieval of epithelial and EMT-related genes. Blood samples from ten metastatic NSCLC patients before starting treatment and during chemotherapy were used to test this approach by longitudinal monitoring. Ten age- and sex-matched healthy subjects were also enrolled as controls.

Results

Recovery experiments of spiked A549^EMT cells showed that the RT-PCR assay is a reliable method for detection of CTCs^EMT. CTCs^EMT were detected in three patients at baseline and in six patients after four cycles of cysplatin-based chemotherapy. Longitudinal monitoring of three patients showed that the CTCs^EMT detection is related to poor therapeutic response.

Conclusions

The RT-PCR-based approach for the evaluation of CTCs^EMT phenotype could be a promising and inexpensive tool to predict the prognosis and the therapeutic response in NSCLC patients.