Circulating endothelial cells as a biomarker in non-small cell lung cancer patients: correlation with clinical outcome

Circulating Tumor-Derived Endothelial Cells: An Effective Biomarker for Breast Cancer Screening and Prognosis Prediction

Background

Circulating tumor-derived endothelial cell (CTEC) is a new potential tumor biomarker to be associated with cancer development and treatment efficacy. However, few evidences are available for breast cancer.

Methods

Eighty-nine breast cancer patients were recruited, and preoperative and postoperative blood samples were collected. Besides, 20 noncancer persons were enrolled as controls. An improved subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) method was adopted to codetect CD31+ aneuploid CTEC and CD31− aneuploid circulating tumor cell (CTC). Then, the clinical significance of CTCs and CTECs on breast cancer screening and prognosis prediction was evaluated and compared.

Results

The positive rate of CTCs and CTECs in newly diagnosed breast cancer patients was 68.75% and 71.88%. Among detected aneuploid circulating rare cells, CTEC accounts for a greater proportion than CTC in breast cancer patients. CTEC-positive rate and level were significantly higher in breast cancer patients with lymph node metastasis (LNM) than those without LNM (P=0.043), while there was no significant difference in CTC. CTEC (area under the curve, AUC = 0.859) had better performance than CTC (AUC = 0.795) to distinguish breast cancer patients from controls by receiver operator characteristic curve analysis. Preoperative CTEC count ≥ 2 was a significant risk factor for reducing PFS of breast cancer patients.

Conclusions

CTECs may function as a reliable supplementary biomarker in breast cancer screening and prognosis prediction.

Prognostic value of CEC count in HER2-negative metastatic breast cancer patients treated with bevacizumab and chemotherapy: a prospective validation study (UCBG COMET)

BACKGROUND

Proof of concept studies has reported that circulating endothelial cell (CEC) count may be associated with the outcome of HER2-negative metastatic breast cancer (mBC) patients treated by chemotherapy and the anti-VEGF antibody bevacizumab. We report the results obtained in an independent prospective validation cohort (COMET study, NCT01745757).

METHODS

The main baseline criteria were HER2-negative mBC, performance status 0-2 and no prior chemotherapy for metastatic disease. CECs were detected by CellSearch® from 4 ml of blood at baseline and after 4 weeks of weekly paclitaxel and bevacizumab therapy. CEC counts (considered both as a continuous variable and using the previously described 20 CEC/4 ml cutoff) were associated with clinical characteristics and progression-free survival (PFS).

RESULTS

CEC count was obtained in 251 patients at baseline and in 207 patients at 4 weeks. Median baseline CEC count was 22 CEC/4 ml (range 0-2231). Baseline CEC counts were associated with performance status (p = 0.02). No statistically significant change in CEC counts was observed between baseline and 4 weeks of therapy. High baseline CEC count was associated with shorter PFS in univariate and multivariate analyses (continuous: p < 0.001; dichotomized: HR 1.52, 95% CI [1.15-2.02], p = 0.004). CEC counts at 4 weeks had no prognostic impact.

CONCLUSION

This study confirms that CEC count may be associated with the outcome of mBC patients treated with chemotherapy and bevacizumab. However, discrepancies with previous reports in terms of both the timing of CEC count and the direction of the prognostic impact warrant further clinical investigation.

Circulating endothelial cells and microparticles as diagnostic and prognostic biomarkers in small-cell lung cancer

OBJECTIVES

It has been proposed that circulating endothelial cells (CECs) and microparticles (MPs) may be useful for the assessment of patients with non-small-cell lung cancer (NSCLC). However, little is known about the potential clinical relevance of these biomarkers in small-cell lung cancer (SCLC). Therefore, we investigated the utility of baseline levels of CECs and MPs in SCLC patients.

MATERIALS AND METHODS

An immunomagnetic separation (IMS) technique was used to isolate and quantify CECs in the peripheral blood, while plasma samples were analyzed using flow cytometry for the measurement of circulating MPs.

RESULTS

We prospectively collected data from 56 patients and 41 healthy individuals. Forty-three patients presented at initial diagnosis and 13 patients presented at relapse. Baseline levels of CECs and MPs were significantly higher in SCLC patients either at initial diagnosis or at relapse than in healthy subjects (p < 0.0002 and p < 0.007, respectively). However, estimated tumor volume (ETV) was significantly correlated with basal MP values (p < 0.0001) but not with pretreatment CECs (p =  0.57). The amount of baseline CECs and MPs was significantly lower in patients with an objective response (OR, n = 23) than in those with progressive disease (PD, n = 15) after treatment (p =  0.016 and 0.05, respectively). With cut-off values of 110 cells/mL for CECs and 1257 events/μL for MPs according to receiver operating characteristics (ROC) analysis, baseline levels of these biomarkers were not significantly correlated with either progression-free survival (PFS) or overall survival (OS). However, patients with 6-month PFS displayed significantly decreased pretreatment CEC counts (p =  0.042), whereas basal MP values significantly increased in 1-year survivors compared with those in non-survivors (p =  0.05).

CONCLUSION

Our results suggest that baseline CECs and MPs may be predictive biomarkers of tumor response and long-term survival in SCLC patients.

CD31-labeled circulating endothelial cells as predictor in anlotinib-treated non-small-cell lung cancer: Analysis on ALTER-0303 study

Our previous studies revealed that the level of activated circulating endothelial cells (aCECs) was correlated with the progression‐free survival (PFS) in antiangiogenesis therapy. Anlotinib displayed affirmatory efficacies in several clinical trials of non‐small‐cell lung cancer (NSCLC). To find a marker predicting the efficacy of anlotinib treatment, we investigated the correlations of aCECs with PFS and overall survival (OS) in patients with NSCLC treated with anlotinib and the impact of anlotinib on human umbilical vascular endothelial cells (HUVECs). The blood samples of 78 patients with NSCLC were collected. aCECs were identified by flow cytometry as CD45⁻/CD146⁺/CD31⁺ cells and CD45⁻/CD146⁺/CD105⁺ cells. The mean value of baseline aCECs counts was defined as the cutoff value, according to which patients were divided into high and low baseline groups. Statistical correlation between high baseline CD31‐labeled aCECs counts and number of metastatic lesions (>3) (χ² = 4.905, P = .027) was analyzed. The 49 patients treated with anlotinib were stratified according to the ratio of minimal aCECs counts at any time points to baseline (aCECs min/baseline) as <1 or ≥1. Interestingly, the patients with aCECs (CD31) min/baseline <1 displayed longer PFS [HR = 0.439, 95%CI (0.211‐0.912), P = .023]. The biological effect of anlotinib on HUVECs was investigated using MTT assays. Western blot analysis was conducted to evaluate the expression levels of CD31 and CD105 under anlotinib treatment and the underlying mechanisms. In vitro experiment data demonstrated that CD31 exhibited more sensitive changes than CD105 under anlotinib treatment through PI3K‐AKT pathway. Thus, our finding provides new insights into the mechanism by which the CD31‐labeled aCECs are a more sensitive marker for predicting the efficiency of anlotinib treatment.

Optimized multiparametric flow cytometric analysis of circulating endothelial cells and their subpopulations in peripheral blood of patients with solid tumors: a technical analysis

Background

Circulating endothelial cells (CECs) and their subpopulations could be potential novel biomarkers for various malignancies. However, reliable enumerable methods are warranted to further improve their clinical utility. This study aimed to optimize a flow cytometric method (FCM) assay for CECs and subpopulations in peripheral blood for patients with solid cancers.

Patients and methods

An FCM assay was used to detect and identify CECs. A panel of 60 blood samples, including 44 metastatic cancer patients and 16 healthy controls, were used in this study. Some key issues of CEC enumeration, including sample material and anticoagulant selection, optimal titration of antibodies, lysis/wash procedures of blood sample preparation, conditions of sample storage, sufficient cell events to enhance the signal, fluorescence-minus-one controls instead of isotype controls to reduce background noise, optimal selection of cell surface markers, and evaluating the reproducibility of our method, were integrated and investigated. Wilcoxon and Mann–Whitney U tests were used to determine statistically significant differences.

Results

In this validation study, we refined a five-color FCM method to detect CECs and their subpopulations in peripheral blood of patients with solid tumors. Several key technical issues regarding preanalytical elements, FCM data acquisition, and analysis were addressed. Furthermore, we clinically validated the utility of our method. The baseline levels of mature CECs, endothelial progenitor cells, and activated CECs were higher in cancer patients than healthy subjects (P<0.01). However, there was no significant difference in resting CEC levels between healthy subjects and cancer patients (P=0.193).

Conclusion

We integrated and comprehensively addressed significant technical issues found in previously published assays and validated the reproducibility and sensitivity of our proposed method. Future work is required to explore the potential of our optimized method in clinical oncologic applications.

Prognostic value of circulating tumor cells in advanced gastric cancer patients receiving chemotherapy

The identification of circulating tumor cells (CTCs) may provide important prognostic information in several types of solid tumors, including gastric cancer. The aim of this study was to investigate whether CTC count may be used to predict survival in patients with advanced gastric cancer treated with chemotherapy. The CELLection™ Epithelial Enrich kit was used to isolate and purify CTCs from samples of peripheral blood. Immunofluorescent staining was used for CTC counting. High CTC counts were associated with poor tumor differentiation and high serum CEA levels (P=0.021 and 0.005, respectively). After 3 months, 16 patients with decreasing CTC counts after the first cycle of chemotherapy obtained complete response, partial response or stable disease, while 13 patients with increasing CTC counts developed progressive disease. The patients with decreasing CTC counts also exhibited longer progression-free survival (PFS) (P≤0.001) and overall survival (OS) (P=0.002) compared with those with increasing CTC counts. Among all 59 patients, those with a CTC count of ≤2 cells/5 ml blood exhibited longer PFS (P≤0.001) and OS (P≤0.001) compared with those with a CTC count of >2 cells/5 ml blood. The multivariate analysis suggested that an increase of the CTC count after the first cycle of chemotherapy was only an independent prognostic marker of poor PFS (P=0.019). However, a baseline CTC count of >2 cells/5 ml blood was an independent poor prognostic marker for PFS (P=0.008) and OS (P=0.001) in all 59 patients. Our study suggested that patients with a low baseline CTC count or decrease of the CTC count after the first cycle of chemotherapy may benefit significantly from palliative chemotherapy. In conclusion, CTC count may be a good chemotherapy monitoring marker and an ideal prognostic marker for patients receiving palliative chemotherapy.

Understanding the Pathophysiology and Challenges of Development of Medical Countermeasures for Radiation-Induced Vascular/Endothelial Cell Injuries: Report of a NIAID Workshop, August 20, 2015

After the events of September 11, 2001, a decade of research on the development of medical countermeasures (MCMs) to treat victims of a radiological incident has yielded two FDA-approved agents to mitigate acute radiation syndrome. These licensed agents specifically target the mitigation of radiation-induced neutropenia and infection potential, while the ramifications of the exposure event in a public health emergency incident could include the entire body, causing additional acute and/or delayed organ/tissue injuries. Anecdotal data as well as recent findings from both radiation accident survivors and animal experiments implicate radiation-induced injury or dysfunction of the vascular endothelium leading to tissue and organ injuries. There are significant gaps in our understanding of the disease processes and progression, as well as the optimum approaches to develop medical countermeasures to mitigate radiation vascular injury. To address this issue, the Radiation and Nuclear Countermeasures Program of the National Institute of Allergy and Infectious Diseases (NIAID) organized a one-day workshop to examine the current state of the science in radiation-induced vascular injuries and organ dysfunction, the natural history of the pathophysiology and the product development maturity of potential medical countermeasures to treat these injuries. Meeting presentations were followed by a NIAID-led open discussion among academic investigators, industry researchers and government agency representatives. This article provides a summary of these presentations and subsequent discussion from the workshop.

Prognostic value of circulating endothelial cells in non-small cell lung cancer patients: a systematic review and meta-analysis

BACKGROUND

Circulating endothelial cells (CECs) have been indicated as a potential biomarker of vascular damage in a variety of cancers. Several studies have revealed CECs may reflect the extent of tumor angiogenesis; however, the role of CECs in the prognosis of non-small cell lung cancer (NSCLC) is undetermined to date. A meta-analysis has been prepared to determine whether the base level of CECs and the changes of CECs after therapy (∆CECs: post-therapeutic value minus the pre- therapeutic value) could be considered as a prognostic tool for patients with NSCLC.

METHODS

Systematic reviews of studies published before April 30 2015 were conducted on the association between the levels of CECs or ∆CECs and the prognosis of NSCLC in several data bases. Hazard ratios (HRs) and the 95% confidence intervals (CIs) were used to collate the data. Similarly, heterogeneity and publication bias were also evaluated.

RESULTS

A total of nine studies, containing eight prospective studies and one retrospective study, involving 515 patients was identified. Patients with higher level of CECs counts at baseline were associated with longer progression-free survival (PFS) (HR 0.71, 95% CI: 0.529-0.891). ∆CECs could also be considered a prognostic indicator in NSCLC patients (HR 0.575, 95% CI: 0.401-0.75). The former and the later are without a significant heterogeneity in the data (I(2)=21.2% and 0.0%, P=0.274 and 0.870, respectively). However, there was no correlation between the base level of CECs and the overall survival (OS) (HR 0.914, 95% CI: 0.560-1.267, I(2)=43.6%, P=0.150).

CONCLUSIONS

Higher levels of CECs counts at baseline and the ensuing decrease after therapy demonstrated a positive correlation with longer PFS in NSCLC patients. But this phenomenon has not been found in OS. From a certain perspective, CECs counts and ∆CECs could be potential prognostic indicators for NSCLC patients.

Circulating endothelial cells for evaluation of tumor response in non-small cell lung cancer patients receiving first-line chemotherapy

BACKGROUND

Circulating endothelial cells (CECs) reflect the neovascularization in the tumor mass. We therefore investigated the potential role of CEC kinetics after first-line chemotherapy in advanced non-small cell lung cancer (NSCLC) patients.

METHODS

Peripheral blood samples were obtained from 45 healthy subjects and 51 naïve patients with advanced NSCLC. Quantification of CD146+ CECs was performed using immunomagnetic separation (IMS).

RESULTS

Pretreatment and posttreatment CEC levels in NSCLC patients were significantly higher than in healthy subjects (p&lt;0.0001). An objective response was achieved after chemotherapy with partial response (PR) or stable disease (SD) in 26 patients, whereas the remaining 25 patients had progressive disease (PD). Baseline CEC levels were significantly higher in PR/SD patients than in PD patients (p = 0.039). After chemotherapy, CEC count significantly decreased in PR/SD patients (p = 0.014) and increased in patients with PD (p = 0.019). Moreover, there was a significant difference in the percentage change of CEC counts between the 2 groups (p = 0.0016). No significant difference in the median progression-free survival and overall survival (OS) was observed between patients with high baseline CEC counts and those with low baseline CEC levels. However, patients with high percentage change in CEC count had longer OS than those with low percentage change after chemotherapy (p = 0.05).

CONCLUSIONS

Changes in CEC counts after chemotherapy reflect tumor response in advanced NSCLC patients. Moreover, high percentage changes in CEC counts after chemotherapy may predict longer OS in advanced NSCLC. High baseline CEC levels might be an indicator of tumor response in advanced NSCLC patients after first-line chemotherapy.