Circulating endothelial cells and endothelial progenitors as predictive markers of clinical response to bevacizumab-based first-line treatment in advanced colorectal cancer patients

Liquid biopsy in colorectal cancer

Liquid biopsy refers to a set of pathological samples retrieved from non-solid sources, such as blood, cerebrospinal fluid, urine, and saliva through non-invasive or minimally invasive approaches. In the recent decades, an increasing number of studies have focused on clinical applications and improving technological investigation of liquid biopsy biosources for diagnostic goals particularly in cancer. Materials extracted from these sources and used for medical evaluations include cells like circulating tumor cells (CTCs), tumor-educated platelets (TEPs), cell-free nucleic acids released by cells, such as circulating tumor DNA (ctDNA), cell-free DNA (cfDNA), cell-free RNA (cfRNA), and exosomes. Playing significant roles in the pathogenesis of human malignancies, analysis of these sources can provide easier access to genetic and transcriptomic information of the cancer tissue even better than the conventional tissue biopsy. Notably, they can represent the inter- and intra-tumoral heterogeneity and accordingly, liquid biopsies demonstrate strengths for improving diagnosis in early detection and screening, monitoring and follow-up after therapies, and personalization of therapeutical strategies in various types of human malignancies. In this review, we aim to discuss the roles, functions, and analysis approaches of liquid biopsy sources and their clinical implications in human malignancies with a focus on colorectal cancer.

Integration of liquid biopsy and immunotherapy: opening a new era in colorectal cancer treatment

Immunotherapy has revolutionized the conventional treatment approaches for colorectal cancer (CRC), offering new therapeutic prospects for patients. Liquid biopsy has shown significant potential in early screening, diagnosis, and postoperative monitoring by analyzing circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). In the era of immunotherapy, liquid biopsy provides additional possibilities for guiding immune-based treatments. Emerging technologies such as mass spectrometry-based detection of neoantigens and flow cytometry-based T cell sorting offer new tools for liquid biopsy, aiming to optimize immune therapy strategies. The integration of liquid biopsy with immunotherapy holds promise for improving treatment outcomes in colorectal cancer patients, enabling breakthroughs in early diagnosis and treatment, and providing patients with more personalized, precise, and effective treatment strategies.

Defining A Liquid Biopsy Profile of Circulating Tumor Cells and Oncosomes in Metastatic Colorectal Cancer for Clinical Utility

Simple Summary

Metastatic colorectal cancer (mCRC) is typified by its tumor heterogeneity and changing disease states, suggesting that personalized medicine approaches could be vital to improving clinical practice. As a minimally invasive approach, the liquid biopsy has the potential to be a powerful longitudinal prognostic tool. We investigated mCRC patients’ peripheral blood samples using an enrichment-free single-cell approach to capture the broader rare-event population beyond the conventionally detected epithelial-derived circulating tumor cell (CTC). Our analysis reveals a heterogenous profile of CTCs and oncosomes not commonly found in normal donor samples. We identified select rare cell types based on their distinct immunofluorescence expression and morphology across multiple assays. Lastly, we highlight correlations between enumerations of the blood-based analytes and progression-free survival. This study clinically validates an unbiased rare-event approach in the liquid biopsy, motivating future studies to further investigate these analytes for their prognostic potential.

Abstract

Metastatic colorectal cancer (mCRC) is characterized by its extensive disease heterogeneity, suggesting that individualized analysis could be vital to improving patient outcomes. As a minimally invasive approach, the liquid biopsy has the potential to longitudinally monitor heterogeneous analytes. Current platforms primarily utilize enrichment-based approaches for epithelial-derived circulating tumor cells (CTC), but this subtype is infrequent in the peripheral blood (PB) of mCRC patients, leading to the liquid biopsy’s relative disuse in this cancer type. In this study, we evaluated 18 PB samples from 10 mCRC patients using the unbiased high-definition single-cell assay (HDSCA). We first employed a rare-event (Landscape) immunofluorescence (IF) protocol, which captured a heterogenous CTC and oncosome population, the likes of which was not observed across 50 normal donor (ND) samples. Subsequent analysis was conducted using a colorectal-targeted IF protocol to assess the frequency of CDX2-expressing CTCs and oncosomes. A multi-assay clustering analysis isolated morphologically distinct subtypes across the two IF stains, demonstrating the value of applying an unbiased single-cell approach to multiple assays in tandem. Rare-event enumerations at a single timepoint and the variation of these events over time correlated with progression-free survival. This study supports the clinical utility of an unbiased approach to interrogating the liquid biopsy in mCRC, representing the heterogeneity within the CTC classification and warranting the further molecular characterization of the rare-event analytes with clinical promise.

Prognostic value of circulating endothelial cells in glioblastoma patients: a pilot study

Aim:

Glioblastoma (GB) is an aggressive tumor type and the detection of circulating endothelial cells (CECs) in peripheral blood has been related to angiogenesis.

Materials & methods:

A prospective single-center pilot study of CEC detection at diagnosis in 22 patients with GB was performed, using the US FDA-approved CellSearch system.

Results:

A CEC cutoff value was estimated using a receiver operating curve (ROC) and patients were classified into two groups: <40 CEC/4 ml and >40 CEC/4 ml blood. Median overall survival was 25.33 months for group 1 and 8.23 months for group 2 cases (p = 0.02). There was no correlation between CEC and PWI (perfusion-weighted imaging) RM.

Conclusion:

CEC detection has a prognostic value in GB cases at diagnosis.

Glioblastoma is an aggressive tumor type with a general poor prognosis. Endothelial cell detection in blood samples has been previously described as a marker of outcome in many tumor types. A US FDA-approved device, CellSearch, was used for CEC detection. The patients were split into two groups according to a cutoff value with the highest sensitivity and specificity, group 1 <40 and group 2 >40 CEC/4 ml blood. Patients with >40 CEC at diagnosis had a poorer overall survival; 25.33 months for group 1 and 8.23 months group 2 cases, which was statistically significant.

Liquid biopsy at the frontier of detection, prognosis and progression monitoring in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide and a leading cause of carcinogenic death. To date, surgical resection is regarded as the gold standard by the operator for clinical decisions. Because conventional tissue biopsy is invasive and only a small sample can sometimes be obtained, it is unable to represent the heterogeneity of tumor or dynamically monitor tumor progression. Therefore, there is an urgent need to find a new minimally invasive or noninvasive diagnostic strategy to detect CRC at an early stage and monitor CRC recurrence. Over the past years, a new diagnostic concept called “liquid biopsy” has gained much attention. Liquid biopsy is noninvasive, allowing repeated analysis and real-time monitoring of tumor recurrence, metastasis or therapeutic responses. With the advanced development of new molecular techniques in CRC, circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), exosomes, and tumor-educated platelet (TEP) detection have achieved interesting and inspiring results as the most prominent liquid biopsy markers. In this review, we focused on some clinical applications of CTCs, ctDNA, exosomes and TEPs and discuss promising future applications to solve unmet clinical needs in CRC patients.

Tumor Microenvironment in Metastatic Colorectal Cancer: The Arbitrator in Patients' Outcome

Simple Summary

Colorectal cancer accounts for approximately 10% of all annually diagnosed cancers worldwide being liver metastasis, the most common cause of death in patients with colorectal cancer. The interplay between tumor and stromal cells in the primary tumor microenvironment and at distant metastases are rising in importance as potential mechanisms of the tumor progression. In this review we discuss the new biomarkers derived from tumor microenvironment and liquid biopsy as emerging prognostic and treatments response markers for metastatic colorectal cancer. We also review the developing new clinical strategies based on tumor microenvironmental cells to tackle metastatic disease in metastatic colorectal cancer patients.

Abstract

Colorectal cancer (CRC) is one of the most common cancers in western countries. Its mortality rate varies greatly, depending on the stage of the disease. The main cause of CRC mortality is metastasis, which most commonly affects the liver. The role of tumor microenvironment in tumor initiation, progression and metastasis development has been widely studied. In this review we summarize the role of the tumor microenvironment in the liver pre-metastatic niche formation, paying attention to the distant cellular crosstalk mediated by exosomes. Moreover, and based on the prognostic and predictive capacity of alterations in the stromal compartment of tumors, we describe the role of tumor microenvironment cells and related liquid biopsy biomarkers in the delivery of precise medication for metastatic CRC. Finally, we evaluate the different clinical strategies to prevent and treat liver metastatic disease, based on the targeting of the tumor microenvironment. Specifically, targeting angiogenesis pathways and regulating immune response are two important research pipelines that are being widely developed and promise great benefits.

Genomic and epigenomic biomarkers in colorectal cancer: From diagnosis to therapy

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States. Despite ongoing efforts aimed at increasing screening for CRC and early detection, and development of more effective therapeutic regimens, the overall morbidity and mortality from this malignancy remains a clinical challenge. Therefore, identifying and developing genomic and epigenomic biomarkers that can improve CRC diagnosis and help predict response to current therapies are of paramount importance for improving survival outcomes in CRC patients, sparing patients from toxicity associated with current regimens, and reducing the economic burden associated with these treatments. Although efforts to develop biomarkers over the past decades have achieved some success, the recent availability of high-throughput analytical tools, together with the use of machine learning algorithms, will likely hasten the development of more robust diagnostic biomarkers and improved guidance for clinical decision-making in the coming years. In this chapter, we provide a systematic and comprehensive overview on the current status of genomic and epigenomic biomarkers in CRC, and comment on their potential clinical significance in the management of patients with this fatal malignancy, including in the context of precision medicine.

Pharmacogenomics, Pharmacokinetics and Circulating Proteins as Biomarkers for Bevacizumab Treatment Optimization in Patients with Cancer: A Review

Bevacizumab is a monoclonal antibody that targets VEGF-A and inhibits tumor angiogenesis. Bevacizumab is approved for the treatment of various cancer, including metastatic colorectal cancer (mCRC), ovarian cancer, lung cancer, and others. Thus, it is widely used in oncology, but contrary to other therapeutic classes, there is still a lack of validating predictive factors for treatment outcomes with these agents. In recent years, the research for factors predictive of anti-VEGF treatments and especially bevacizumab response has been one of the most competitive translational research fields. Herein, we review and present the available literature of the clinical use of biomarkers, pharmacogenomics (PG), and therapeutic drug monitoring (TDM) approaches that can be used for the optimization of bevacizumab use in the era of precision medicine.

CD276-Positive Circulating Endothelial Cells Do Not Predict Response to Systemic Therapy in Advanced Colorectal Cancer

CD276 can discriminate between tumor derived and normal CECs (circulating endothelial cells). We evaluated whether CD276⁺CEC is a clinically relevant biomarker to predict response to palliative systemic therapy in patients with metastatic colorectal cancer (mCRC). Samples were prospectively collected from patients with mCRC enrolled in the ORCHESTRA trial (NCT01792934). At baseline and after three cycles of 5-fluorouracil/leucovorin and oxaliplatin ± bevacizumab, CECs were measured by flowcytometry (CD34⁺CD45^negCD146⁺DNA⁺; and CD276⁺). A clinically relevant cut-off value of (CD276⁺)CECs was determined as 100% sensitivity (and 80% specificity in 95% confidence interval) identifying patients with progressive disease within 6 months. There were 182 baseline samples and 133 follow up samples available for analysis. CEC and CD276⁺CEC counts significantly increased during treatment from 48 to 90 CEC/4 mL (p = 0.00) and from 14 to 33 CD276⁺CEC/4 mL (p = 0.00) at baseline and at first evaluation, respectively. CEC and CD276⁺CEC counts were not predictive for poor response (area under the curve (AUC) 0.53 for CEC and AUC 0.52 for CD276⁺CEC). Despite numerical changes during therapy, CEC and CD276⁺CEC counts do not adequately predict poor response to first line palliative systemic therapy in patients with mCRC.

Endothelial cells in colorectal cancer

The dependence of tumor growth on neovascularization has become an important aspect of cancer biology. Tumor angiogenesis is one of the key mechanisms of tumorigenesis, growth and metastasis. The key events involved in this process are endothelial cell proliferation, migration, and vascular formation. Recent studies have revealed the importance of tumor-associated endothelial cells (TECs) in the development and progression of colorectal cancer (CRC), including epithelial proliferation, stem cell maintenance, angiogenesis, and immune remodeling. Decades of research have identified that the molecular basis of tumor angiogenesis includes vascular endothelial growth factors (VEGFs) and their receptor family, which are the main targets of antiangiogenesis therapy. VEGFs and their receptors play key roles in the pathology of angiogenesis, and their overexpression indicates poor prognosis in CRC. This article reviews the characteristics of the tumor vasculature and the role of TECs in different stages of CRC and immune remodeling. We also discuss the biological effects of VEGFs and their receptor family as angiogenesis regulators and emphasize the clinical implications of TECs in clinical treatment.

Predictive Biomarkers in Metastatic Colorectal Cancer: A Systematic Review

PURPOSE

The development and use of predictive biomarkers to guide treatment decisions are paramount not only for improving survival in patients with metastatic colorectal cancer (mCRC), but also for sparing them from unnecessary toxicity and reducing the economic burden of expensive treatments. We conducted a systematic review of published studies and evaluated the predictive biomarker landscape in the mCRC setting from a molecular and clinical viewpoint.

METHODS

Studies analyzing predictive biomarkers for approved therapies in patients with mCRC were identified systematically using electronic databases. Preclinical studies and those providing no relevant information were excluded.

RESULTS

A total of 173 studies comprising 148 biomarkers were selected for final analysis. Of all the biomarkers analyzed, 1.4% (two of 148) were explored in a prospective manner, whereas 98.6% (146 of 148) were evaluated in retrospective studies. Of the latter group, 78.8% (115 of 146) were not tested in subsequent phases, 9.6% (14 of 146) were tested in other retrospective cohorts, 8.9% (13 of 146) were retrospectively tested in at least one or more randomized cohorts, and only 2.7% (four of 146) were prospectively tested in a clinical trial. Finally, only 1.4% (two of 148) were validated sufficiently and are recognized as biomarkers for guiding treatment decision making in patients with mCRC. These markers were RAS mutational status for anti-EGFR antibodies and microsatellite instability status for anti-programmed cell death-1 drugs.

CONCLUSION

Despite notable efforts to identify predictive biomarkers for various therapies used in the mCRC setting, because of a lack of data beyond retrospective studies and successful biomarker-driven approaches, only two molecular biomarkers have thus far found their translation into the clinic, highlighting the imperative need for implementing novel strategies and additional research in this clinically important field.

Microsatellite instability and manifestations of angiogenesis in stage IV of sporadic colorectal carcinoma

Angiogenesis represents one of the critical mechanisms that facilitates carcinoma development. The study objective was to evaluate whether the microsatellite instability of colorectal carcinoma has impact on the angiogenesis activity in liver metastases.In a cohort of 80 randomly selected patients with stage IV colorectal carcinoma, 30% were recognized as microsatellite unstable (Microsatellite instability high-frequency (MSI-H)). The endothelial progenitor cell fraction (CD309+) was counted within the subpopulation of CD34+CD45+ cell and CD34+CD45- cells by flow cytometer. vascular endothelial growth factor (VEGF) factor levels were quantified in serum samples by enzyme-linked immunosorbent assay (ELISA). A control group consisted of 36 healthy volunteers. The relationship of genomic instability to angiogenesis activity was evaluated by multivariate analysis in comparison to the controls, adopting a P < .05 value as statistically significant.The expression of endothelial progenitor cells (EPCs) and VEGF was significantly higher in MSI-H compared to both microsatellite stability (MSS) patients and healthy controls (P < .008). Multi-parametric analysis showed microsatellite instability (OR=9.12, P < .01), metastases in both lobes (OR = 32.83, P < .001) and simultaneous metastases outside liver (OR = 8.32, P < .01), as independent factors associated with increased angiogenesis as assessed by measures of EPC and VEGF. A higher percentage of EPCs within the white blood cell fraction (total % EPCs / white blood cells (WBC)) and higher serum concentrations of VEGF were present in patients with MSI-H colorectal cancer, and not with MSS cancers (P < .001).MSI-H patients with colorectal cancer metastases are associated with the overexpression of circulating EPCs and VEGF, potentially driving angiogenesis. This should be considered in therapeutic decision-making.

Pharmacodynamic and Pharmacokinetic Markers For Anti-angiogenic Cancer Therapy: Implications for Dosing and Selection of Patients

Angiogenesis is integral to tumour growth and invasion, and is a key target for cancer therapeutics. However, for many of the licensed indications, only a modest clinical benefit has been observed for both monoclonal antibody and small-molecule tyrosine kinase inhibitor anti-angiogenic therapy. Pre-clinical and clinical studies have attempted to evaluate circulating, imaging, genomic, pharmacokinetic, and pharmacodynamic markers that may aid both the selection of patients for treatment and define dosing. Correct dosing is likely to be critical in the context of vascular normalization to allow better delivery of concomitant anti-cancer therapy and novel imaging techniques hold much promise in the early evaluation of pharmacodynamic response to improve efficacy.

Prognostic value of circulating endothelial cells in metastatic colorectal cancer

BACKGROUND

There is urgent need for improved staging in patients with metastatic colorectal cancer (mCRC). In this study, we evaluated the prognostic value of circulating endothelial cells (CEC) in comparison with circulating tumor cells (CTC) in patients with mCRC amenable for potentially curative surgery.

METHODS

A total of 140 patients were enrolled prospectively. CTC and CEC were measured with the CellSearch System (Veridex, NJ, USA). Cut-off values were determined using ROC analyses. Prognostic factors were identified by Cox proportional hazards models.

RESULTS

ROC analyses revealed ≥ 21 CEC as cut-off levels for detection, which was present in 68 (49%). CEC detection was associated with female gender (p = 0.03) only, whereas CTC detection was associated with presence of the primary tumor (p = 0.007), metastasis size (p < 0.001), bilobar liver metastases (p = 0.02), CEA (p < 0.001) and CA 19-9 levels (p < 0.001). On multivariate analysis only CEC detection (HR 1.81; p = 0.03) and preoperative CA19-9 levels (HR 2.28, p = 0.005) were revealed as independent predictors of poor survival.

CONCLUSIONS

CEC are of stronger prognostic value than CTC. Further studies are required to validate these results and to evaluate CEC as predictive biomarker for systemic therapy alone as well as in combination with other markers such as CA19-9.

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.

Correlation between circulating endothelial progenitor cells and serum carcinoembryonic antigen level in colorectal cancer

Circulating endothelial progenitor cells (cEPCs) play an important role in cancer development. Previous studies showed that serum carcinoembryonic antigen (CEA) levels and the number of circulating endothelial progenitor cells (cEPCs) in the peripheral blood are both involved in tumor neoangiogenesis, and can be used for monitoring tumor progression, recurrence, metastasis, and therapeutic responses. However, the clinical relevance of these biomarkers remains unknown. In this study, 40 colorectal cancer (CRC) patients and 17 healthy volunteers were recruited and the amount of cEPCs in the peripheral blood was measured by flow cytometry. The serum CEA level was determined by CEA-RIACT assay. Results showed that cEPC level positively correlated with the stage of the disease, but not with the age and gender of the patients. Moreover, patients with higher serum CEA levels had higher cEPC levels. These results provide clinical evidence for a correlation between two commonly used biomarkers. Further understanding the role of serum CEA in cEPC-mediated tumor vascularization may improve clinical CRC diagnosis and provide useful insights into the design of therapeutic interventions that target tumor vasculature.

Circulating endothelial cells and their subsets: novel biomarkers for cancer

Angiogenesis contributes to the growth of solid tumors. Antiangiogenic agents are widely used in various cancers and considerable efforts have been made in the development of novel biomarkers that can predict the outcome of an anticancer treatment. Of those, circulating endothelial cells (CECs) and their subsets constitute a surrogate tool for monitoring disease activity. However, owing to the lack of standardization on the phenotypes and detection of CECs and their subsets, results have always been inconsistent and uninterpretable. In this review, we focus on the biological characteristics in terms of physiology, phenotypes and detection of CECs along with their subsets; review the current scenario of CEC enumeration as a surrogate biomarker in clinical oncology; and explore their future potential applications.

Enrichment and Detection of Circulating Tumor Cells and Other Rare Cell Populations by Microfluidic Filtration

The current standard methods for isolating circulating tumor cells (CTCs) from blood involve EPCAM-based immunomagnetic approaches. A major disadvantage of these strategies is that CTCs with low EPCAM expression will be missed. Isolation by size using filter membranes circumvents the reliance on this cell surface marker, and can facilitate the capture not only of EPCAM-negative CTCs but other rare cells as well. These cells that are trapped on the filter membrane can be characterized by immunocytochemistry (ICC) , enumerated and profiled to elucidate their clinical significance. In this chapter, we discuss advances in filtration systems to capture rare cells as well as downstream ICC methods to detect and identify these cells. We highlight our recent clinical study demonstrating the feasibility of using a novel method consisting of automated microfluidic filtration and sequential ICC for detection and enumeration of CTCs, as well as circulating mesenchymal cells (CMCs), circulating endothelial cells (CECs), and putative circulating stem cells (CSCs). We hypothesize that simultaneous analysis of circulating rare cells in blood of cancer patients may lead to a better understanding of disease progression and development of resistance to therapy.

Serum anti-endothelial cell antibodies in patients with age-related macular degeneration treated with intravitreal bevacizumab

PURPOSE

To analyse the prevalence and changes in circulating anti-endothelial cell antibodies (AECA) during anti-vascular endothelial growth factor (anti-VEGF) therapy.

METHODS

Ninety-eight patients with exudative age-related macular degeneration (AMD) were treated with intravitreal bevacizumab. Fifty sex- and age-matched healthy subjects were used as controls. Serum AECA were detected using indirect immunofluorescence on primate skeletal muscle and cultivated human umbilical vein endothelial cells (HUVEC). These investigations were repeated at 4-week intervals within 8 months of follow-up.

RESULTS

At baseline examination, 30 of the 98 patients (30.6%) were positive for AECA. The titres of AECA ranged from 1:10 to 1:320. In the control group, AECA were present in only nine sera (18%) with titres ranging between 1:20 and 1:80 (p = 0.0000). The greatest rates of reduction of AECA titres were observed during the 'loading' phase of therapy. During the 'maintenance' phase, the rates of changes in serum AECA levels were less significant and remained constant. In follow-up period in 13 patients (13.3%), serum AECA were detected de novo in titres of 1:10 to 1:80. Statistical analysis did not show any significant correlation between the presence of AECA and activity of the disease.

CONCLUSIONS

There is growing evidence that AMD is an immune-mediated disease, and thus it cannot be excluded that AECA may be involved in its pathogenesis and progression. We also speculate that AECA develop in response to retinal damage and anti-VEGF therapy.

Clinical Significance of TLR1 I602S Polymorphism for Patients with Metastatic Colorectal Cancer Treated with FOLFIRI plus Bevacizumab

The purpose of this study was to evaluate the clinical significance of single-nucleotide polymorphisms in TLR1, TLR2, TLR6, and TAK1 in patients with metastatic colorectal cancer (mCRC). We genotyped 9 SNPs of TLR1, TLR2, TLR6, and TAK1 in mCRC patients treated with first-line FOLFIRI (combination therapy of irinotecan, 5-fluorouracil, and folinic acid) plus bevacizumab, using a discovery cohort (TRIBE trial, n = 228) and a validation cohort (FIRE-3 trial, n = 297), and analyzed for the association with response rate (RR), progression-free survival (PFS), and overall survival (OS). There was a significant association of TLR1 rs5743618 (T1805G) with the clinical outcome. In the TRIBE cohort, a homozygous wild-type genotype (T/T) associated with a significantly lower RR compared with variant T/G and G/G genotypes (43% vs. 62%, P = 0.025), and this observation was validated in the FIRE-3 cohort (46% vs. 65%, P = 0.021). In addition, those patients with the T/T genotype had significantly worse PFS (median, 8.2 vs. 10.5 months; HR, 1.57; 95% CI, 1.09-2.28, P = 0.014) and OS (median: 19.9 vs. 27.9 months; HR, 1.63; 95% CI, 1.14-2.35, P = 0.007), compared with those with other genotypes in the TRIBE cohort. These differences remained statistically significant in multivariate analysis. Our data suggest that TLR1 rs5743618 could serve as a predictor of clinical response to FOLFIRI plus bevacizumab in patients with mCRC. Mol Cancer Ther; 15(7); 1740-5. ©2016 AACR.

Flow cytometric analysis of circulating endothelial cells and endothelial progenitors for clinical purposes in oncology: A critical evaluation

Malignant tumors are characterized by uncontrolled cell growth and metastatic spread, with a pivotal importance of the phenomenon of angiogenesis. For this reason, research has focused on the development of agents targeting the vascular component of the tumor microenvironment and regulating the angiogenic switch. As a result, the therapeutic inhibition of angiogenesis has become an important component of anticancer treatment, however, its utility is partly limited by the lack of an established methodology to assess its efficacy in vivo. Circulating endothelial cells (CECs), which are rare in healthy subjects and significantly increased in different tumor types, represent a promising tool for monitoring the tumor clinical outcome and the treatment response. A cell population circulating into the blood also able to form endothelial colonies in vitro and to promote vasculogenesis is represented by endothelial progenitor cells (EPCs). The number of both of these cell types is extremely low and they cannot be identified using a single marker, therefore, in absence of a definite consensus on their phenotype, require discrimination using combinations of antigens. Multiparameter flow cytometry (FCM) is ideal for rapid processing of high numbers of cells per second and is commonly utilized to quantify CECs and EPCs, however, remains technically challenging since there is as yet no standardized protocol for the identification and enumeration of these rare events. Methodology in studies on CECs and/or EPCs as clinical biomarkers in oncology is heterogeneous and data have been obtained from different studies leading to conflicting conclusions. The present review presented a critical review of the issues that limit the comparability of results of the most significant studies employing FCM for CEC and/or EPC detection in patients with cancer.

Significance and therapeutic implications of endothelial progenitor cells in angiogenic-mediated tumour metastasis

Cancer conveys profound social and economic consequences throughout the world. Metastasis is responsible for approximately 90% of cancer-associated mortality and, when it occurs, cancer becomes almost incurable. During metastatic dissemination, cancer cells pass through a series of complex steps including the establishment of tumour-associated angiogenesis. The human endothelial progenitor cells (hEPCs) are a cell population derived from the bone marrow which are required for endothelial tubulogenesis and neovascularization. They also express abundant inflammatory cytokines and paracrine angiogenic factors. Clinically hEPCs are highly correlated with relapse, disease progression, metastasis and treatment response in malignancies such as breast cancer, ovarian cancer and non-small-cell lung carcinoma. It has become evident that the hEPCs are involved in the angiogenesis-required progression and metastasis of tumours. However, it is not clear in what way the signalling pathways, controlling the normal cellular function of human BM-derived EPCs, are hijacked by aggressive tumour cells to facilitate tumour metastasis. In addition, the actual roles of hEPCs in tumour angiogenesis-mediated metastasis are not well characterised. In this paper we reviewed the clinical relevance of the hEPCs with cancer diagnosis, progression and prognosis. We further summarised the effects of tumour microenvironment on the hEPCs and underlying mechanisms. We also hypothesized the roles of altered hEPCs in tumour angiogenesis and metastasis. We hope this review may enhance our understanding of the interaction between hEPCs and tumour cells thus aiding the development of cellular-targeted anti-tumour therapies.

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.

A phase 1 study of lenvatinib, multiple receptor tyrosine kinase inhibitor, in Japanese patients with advanced solid tumors

Purpose

This phase 1 study aimed to assess the tolerability, safety, pharmacokinetics (PK), pharmacodynamics, and preliminary efficacy of lenvatinib capsules in Japanese patients with solid tumors when administered orally up to 24 mg on a once-daily (QD) continuous schedule.

Methods

Patients were enrolled in one of the two sequential cohorts (20 or 24 mg) of lenvatinib on a 28-day cycle based on the conventional 3 + 3 dose escalation design. Adverse events (AEs) were graded using the Common Terminology Criteria for Adverse Events, version 4.0. Tolerability was judged based on dose-limiting toxicities (DLTs) during Cycle 1. The drug was defined as tolerable when the incidence of DLTs was less than 33 %.

Results

Nine patients received lenvatinib [20 mg (n = 3); 24 mg (n = 6)]. No DLTs were observed. The most common AEs were thrombocytopenia, blood thyroid stimulating hormone increased, and hypertension (89 %), followed by leukopenia, headache, and proteinuria (78 %). The area under the concentration–time curve and maximum observed concentration increased dose proportionally. The PK profiles were similar to those in non-Japanese phase 1 studies. One patient with leiomyosarcoma showed a partial response, and three patients have maintained stable disease for more than 6 months.

Conclusions

The 24-mg QD continuous dose of lenvatinib was determined to be tolerable with encouraging anti-tumor activity in Japanese patients with solid tumors.

Preoperative biomarkers of tumour vascularity are elevated in patients with glioblastoma multiforme

We investigated the correlation between the circulating and imaging biomarkers of tumour vascularity, and examined whether they are prognostic of outcomes in patients with glioblastoma multiforme (GBM). Despite the increasing use of anti-angiogenic agents within neuro-oncology, there are still no validated biomarkers to monitor for a treatment response or relapse. The pre- and postoperative circulating endothelial cell (CEC) and progenitor cell (CEP) levels were assessed. Preoperative perfusion-weighted MRI (PWI) was also performed, and the relative cerebral blood volume (rCBV) histogram statistics of the contrast-enhancing tumour were analysed. A novel PWI parameter (rCBVload) was developed to estimate the total volume of perfused tumour vessels, and it was hypothesised that this parameter would correlate with CEC and CEP concentrations. In total, 24 GBM patients were included. The mean preoperative CEC concentration was significantly higher in GBM patients than the controls (p=0.019), and it then declined significantly postoperatively (p=0.009). The preoperative CEP levels were significantly correlated with the median tumour rCBV (Spearman rank-order coefficient=0.526; p=0.039). Neither CEC nor CEP was correlated with the total tumour vessel volume, as measured by rCBVload. None of the biomarkers that were investigated showed a significant correlation with progression-free or overall survival. We conclude that CEC are potentially useful biomarkers to monitor GBM patients during treatment. We found that CEC are increased in the presence of GBM, and that CEP levels appear to be proportional to tumour vascularity, as measured on PWI. However, in this study, none of the biomarkers of GBM vascularity were highly prognostic of patient outcomes.

Clinical significance of circulating endothelial cells in patients with severe sepsis or septic shock

BACKGROUND

Endothelial damage developing in severe sepsis or septic shock results in multiorgan dysfunction. An increased circulating endothelial cell (CEC) count represents a novel marker of endothelial damage, which has been reported in cases of severe sepsis or septic shock. The aim of this study was to evaluate the clinical significance of CECs in patients with severe sepsis or septic shock.

METHODS

CECs were evaluated and quantified by flow cytometry using plasma collected from patients with severe sepsis or septic shock who were admitted to a medical intensive care unit from February 2011 to August 2011.

RESULTS

During the study period, 77 patients were enrolled. The median CEC count was 350 cells/ml (range 0-15 984 cells/ml). There was no significant difference between cases of severe sepsis and septic shock [163 cells/ml (0-15 984 cells/ml) vs 363 cells/ml (0-7884 cells/ml), p = 0.507]. There were no correlations between the number of CECs and inflammatory markers. CEC counts were significantly increased in non-survivors compared to survivors [588.5 cells/ml (1-15 984 cells/ml) vs 292 cells/ml (0-12 882 cells/ml), p = 0.044] within 28 days. The sequential-related organ failure assessment score, CEC counts ≥ 500 cells/ml and blood lactate levels were significantly associated with 28 day mortality.

CONCLUSIONS

CEC counts were higher in non-survivors of severe sepsis or septic shock and could be used as a biomarker to predict the prognosis in these patients.

Increased pre-surgical numbers of endothelial progenitor cells and circulating endothelial cells in colorectal cancer fail to predict outcome

INTRODUCTION

The endothelium and angiogenesis are therapeutic targets in cancer. Response to treatment may be assessed by laboratory plasma markers such as circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), von Willebrand factor (vWf), soluble E selectin, vascular endothelial growth factor (VEGF) and angiogenin. We hypothesised that these markers, obtained before surgery, would predict 2-year outcome after surgery with or without anti-angiogenic therapy for colorectal cancer (CRC).

METHODS

We recruited 154 patients with CRC, of whom 51 were treated with surgery alone, 74 were treated with standard chemotherapy (5-fluorouracil) and 29 were treated with standard chemotherapy plus anti-VEGF therapy (Avastin). Peripheral blood was taken before surgery. CD34(+)/CD45(-)/CD146(+) CECs and CD34(+)/CD45(-)/CD309 [KDR](+) EPCs were measured by flow cytometry and plasma markers by ELISA.

RESULTS

After a mean of 2.1 years follow-up (range 1.9-2.3 years), 52 of the patients (33.7 %) experienced a poor outcome (radiological and/or histological evidence of tumour spread or recurrence, or death [n = 26]). In univariate analysis, poor outcome was linked to Dukes' stage (p < 0.001), American Joint Committee on Cancer (AJCC) stage (p < 0.001), type of treatment (surgery alone, standard chemotherapy with or without anti-antigenic therapy) (p = 0.047), CECs (p < 0.02) and EPCs (p < 0.01). In subsequent binary logistic regression analysis, only Dukes' stage (hazard ratio 2.3, 95 % confidence interval 1.0-5.3, p = 0.047) and modified AJCC stage (4.62, 1.88-11.33, p < 0.001) predicted a poor outcome.

CONCLUSION

Endothelial cell markers (CECs, EPCs, vWf, soluble E selectin) and growth factors (VEGF and angiogenin), measured before surgery, have nothing extra to offer in predicting 2-year outcome in colorectal cancer when compared to Dukes' or AJCC stage.

Bevacizumab: A dose review

Angiogenesis is a key process in cancer development and has been described has a hallmark of cancer. Two dose-intensities were approved for cancer treatment by the Food and Drug Administration and European Medicines Agency: 2.5mg/kg/week dose equivalent and 5mg/kg/week dose equivalent. While bevacizumab has shown its effectiveness in clinical trials, pharmacodynamics is not fully understood and a dose-effect relationship has not been proven in vivo. Direct trials comparing high or low doses are rare with potential dose-effect toxicity. Discordant data have been reported on the efficacy of doses. This review discusses the dose of bevacizumab via the analysis of studies that led to the approval of bevacizumab in clinical practice. Optimization of doses schemes could reduce potential dose-effect toxicities, potentiate synergetic effects with chemotherapy and permit the prescription to a larger population with a better cost-effectiveness ratio.

Circulating endothelial cells and their subpopulations: role as predictive biomarkers in antiangiogenic therapy for colorectal cancer

Several anticancer therapies have been developed to block angiogenesis, a key mechanism in tumor growth and metastasis. The predominantly cytostatic action of these compounds makes an assessment of their clinical activities inadequate if based only on the reduction of the tumor dimensions, as this may not reflect their true biologic efficacy. Thus, it is crucial to identify biomarkers that permit the recognition of potentially responsive subjects and to spare toxicity in those who are unlikely to benefit from treatment. Circulating endothelial cells (CECs) have been recently indicated as potential surrogate biomarkers of angiogenesis in several types of cancer. The possibility of rapidly quantifying these cells represents a promising tool for monitoring the clinical outcome of tumors with the potential to assess response to various treatments. However, the identification and quantification of CECs is technically difficult and not well standardized. A variety of methods to detect CECs in patients with solid tumors have been used; these are based on different technical approaches, combinations of surface markers, sample handling, and staining protocols. With an expanding interest in the field of potential clinical applications for CECs in oncology, the development of standardized protocols for analysis is mandatory. The aim of this review was to critically summarize the available data concerning the clinical value of CECs and their subpopulations as biomarkers of antiangiogenic therapy in patients with metastatic colorectal cancer.

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

BACKGROUND

Circulating endothelial cells (CECs) have been proposed as a biomarker for the assessment of patients with solid tumors. However, few data are available in non-small cell lung cancer (NSCLC). We therefore analyzed the clinical significance of CECs in newly diagnosed NSCLC patients. In addition, we tried to determine the prognostic value of CECs in NSCLC.

METHODS

In this prospective study, 151 newly diagnosed NSCLC patients and 25 healthy volunteers were included. Furthermore, 25 patients with a partial response (n=15) or stable disease (n=10) after treatment were evaluated at recurrence with a mean follow-up of 117 days (range: 47-364 days). CECs were counted using magnetic beads coupled to a specific antibody against CD146.

RESULTS

The pre-treatment CEC count was significantly higher in patients with all histological subtypes of NSCLC than in healthy volunteers (p&lt;0.0001). High baseline CEC counts were significantly correlated with advanced clinical stages (p=0.026), weight loss (p=0.03), and poorly differentiated NSCLC (p=0.02). The amount of CECs increased significantly at recurrence compared with their amount after treatment in 20/21 assessable patients (p=0.0001). Nevertheless, there was no significant correlation between baseline CEC count and median duration of progression-free survival (p=0.402).

CONCLUSIONS

Increased CEC counts were present in patients with newly diagnosed NSCLC compared with healthy subjects. Elevated levels of baseline CECs correlated with high-risk factors in NSCLC. In addition, increased CEC count during follow-up seems to be correlated with recurrence in NSCLC patients.

Quantification of circulating endothelial cells as a predictor of response to chemotherapy with platinum and pemetrexed in patients with advanced non-squamous non-small cell lung carcinoma

INTRODUCTION

Circulating endothelial cells (CEC) play an important role in tumor neovascularization and may have prognostic value in cancer patients. This study was designed to investigate the role of CEC as a marker for predicting platinum plus pemetrexed first-line chemotherapy efficacy in advanced non-squamous non-small cell lung cancer (NSCLC).

METHODS

A prospective study was performed whose main objective was to study whether the numbers of CEC at baseline and prior to the second and third cycle of chemotherapy were response predictors. Sixty-nine patients received cisplatin plus pemetrexed, and peripheral blood samples were performed at baseline and after second and third cycle. Separation and CEC count were performed using inmunomagnetic separation (CellSearch).

RESULTS

The CEC count in 4 mL of peripheral blood was obtained prior to the first, second, and third cycle of treatment. Baseline levels and evolution of CEC were correlated with response to treatment according to RECIST criteria after three cycles of treatment. Sixty-nine patients were included: 43 (64.2 %) received cisplatin/pemetrexed and 24 (35.8 %) carboplatin/pemetrexed. Range of baseline CEC: 8-965 (mean of 153 cel/4 mL). The results after 3 cycles were: 25 partial responses (36.2 %), 17 cases of stabilization of disease (24.6 %), 16 of progressive disease (23.2 %) and 11 non-evaluables (16 %). No significant relationship between the baseline CEC count and response was found (p value = 0.831). Increase >50 % between the first and second cycle was correlated significantly with progression disease (p = 0.008). Patients who had a baseline CEC count greater than the mean (>153 cells/4 mL) showed longer progression-free survival and global survival without statistical significance.

CONCLUSIONS

In this homogeneous group of patients with NSCLC, there is no correlation between response to treatment and CEC baseline levels. The increase in CEC numbers after the first cycle could be a negative predictive factor.

Effect of standard chemotherapy and antiangiogenic therapy on plasma markers and endothelial cells in colorectal cancer

Introduction:

The importance of the endothelium in angiogenesis and cancer is undisputed, and its integrity may be assessed by laboratory markers such as circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), plasma von Willebrand factor (vWf), soluble E selectin, vascular endothelial growth factor (VEGF) and angiogenin. Antiantigenic therapy may be added to standard cytotoxic chemotherapy as a new treatment modality. We hypothesised that additional antiangiogenic therapy acts in a contrasting manner to that of standard chemotherapy on the laboratory markers.

Methods:

We recruited 68 patients with CRC, of whom 16 were treated with surgery alone, 32 were treated with surgery followed by standard chemotherapy (5-flurouracil), and 20 were treated with surgery followed by standard chemotherapy plus anti-VEGF therapy (Avastin). Peripheral blood was taken before surgery, and again 3 months and 6 months later. CD34⁺/CD45⁻/CD146⁺ CECs and CD34⁺/CD45⁻/CD309[KDR]⁺ EPCs were measured by flow cytometry, plasma markers by ELISA.

Results:

In each of the three groups, CECs and EPCs fell at 3 months but were back at pre-surgery levels at 6 months (P<0.05). VEGF was lower in both 3-and 6-month samples in the surgery-only and surgery plus standard chemotherapy groups (P<0.05), but in those on surgery followed by standard chemotherapy plus anti-VEGF therapy, low levels at 3 months (P<0.01) increased to pre-surgery levels at 6 months. In those having surgery and standard chemotherapy, soluble E selectin was lower, whereas angiogenin was higher at 6 months than at baseline (both P<0.05).

Conclusions:

We found disturbances in endotheliod cells regardless of treatment, whereas VEGF returned to levels before surgery in those on antiangiogenic therapy. These observations may have clinical and pathophysiological implications.

Predictive and prognostic value of circulating endothelial cells in non-small cell lung cancer patients treated with standard chemotherapy

PURPOSE

Monitoring circulating endothelial cells (CECs) count reflects the tumor vasculature in cancer patients and might be a predictor of response to chemotherapy. We therefore investigated the clinical significance of changes in CECs count after three cycles of platinum-based chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

Peripheral blood samples were collected from 89 naive NSCLC patients at diagnosis and after chemotherapy. The CECs were quantified by an immuno-magnetic technique and fluorescent microscopy. After chemotherapy, patients were assessed according to the response evaluation criteria in solid tumors as partial response (PR), stable disease (SD) or progression disease (PD).

RESULTS

Baseline CECs levels were significantly higher in PR patients (n = 62) than those in patients with SD/PD (n = 27) (p = 0.0007). Although there was no significant correlation between baseline CECs levels and progression-free survival (PFS) (p = 0.287), patients with high percentage change in CECs count after chemotherapy had significantly longer PFS than those with low percentage change (p = 0.048). Regarding treatment efficacy, CECs count significantly decreased after chemotherapy in comparison with CECs count at baseline in patients with PR (p < 0.0001). By contrast, CECs levels after chemotherapy were significantly higher than those at diagnosis in patients with PD (p = 0.002). Moreover, there was no significant change between pre- and post-treatment CECs amount in patients with SD (p = 0.681).

CONCLUSIONS

Baseline CECs levels might be an early predictive biomarker for treatment efficacy in advanced NSCLC patients. Our results suggest the change in CECs count after chemotherapy as a prognostic factor for tumor response and PFS in NSCLC.

What could Nintedanib (BIBF 1120), a triple inhibitor of VEGFR, PDGFR, and FGFR, add to the current treatment options for patients with metastatic colorectal cancer?

Increasing knowledge of the pro-angiogenic processes involved in the progression of metastatic colorectal cancer (mCRC) has resulted in the clinical development of several anti-angiogenic agents, with bevacizumab currently being the only approved agent for mCRC. Nintedanib (BIBF 1120) has been shown to block the vascular endothelial growth factor receptor (VEGFR), the platelet-derived growth factor receptor (PDGFR), and the fibroblast growth factor receptor (FGFR). By targeting FGFR signaling, nintedanib may overcome resistance to previous anti-VEGF treatments, and may represent a better approach in patients with high basal levels of circulating FGFs. In this article, the angiogenic mechanisms implicated in mCRC are reviewed (focusing on the signaling pathways activated by VEGFR, PDGFR, and FGFR), along with the clinical data for nintedanib in the context of other anti-angiogenic tyrosine kinase inhibitors under clinical development for mCRC. Biomarkers that could predict response to nintedanib are also discussed.

Tumor vascularity in prostate cancer: an update on circulating endothelial cells and platelets as noninvasive biomarkers

In order to individually tailor prostate cancer (PCa) treatment, clinicians need better tools to predict prognosis and treatment response. Given the relationship between angiogenesis and cancer progression, circulating endothelial cells (CECs) and their progenitors have logically been proposed as potential biomarkers. The utility of their baseline levels and kinetics has been investigated for years. However, owing to a lack of standardization and validation of CEC and circulating endothelial progenitors enumeration protocols, results have been inconsistent in prostate and other cancers. Similarly, platelets play a significant part in cancer progression, yet the role of platelet-related biomarkers in PCa is unclear. While there have been a number of theoretically interesting platelet-related markers proposed, limited research has been conducted in PCa patients. Currently, CECs and platelets do not have a clear role as biomarkers in routine PCa care. Given the theoretical merits of these cells, prospective trials are warranted.

Comparative cost-effectiveness of bevacizumab-irinotecan-fluorouracil versus irinotecan-fluorouracil in first-line metastatic colorectal cancer

PURPOSE

To evaluate the cost-effectiveness of the addition of bevacizumab to the irinotecan-fluorouracil (Douillard regimen-CPT-FUFA-) in first-line treatment of metastatic colorectal cancer in a single-institution population.

METHODS

Controlled, nonrandomized retrospective observational study. Treatment-naïve metastatic colorectal cancer patients received CPT-FUFA (January 2000-December 2003; control group) and bevacizumab_CPT-FUFA (January 2007-December 2010; study group). Variables related to: patient, clinical response (number of disease progression or death events, progression-free survival) and treatment (antineoplastic dose reduction, incremental cost/treated patient associated with the addition of bevacizumab).

STATISTICAL ANALYSIS

median progression-free survival (Kaplan-Meier method), and hazard ratio (Cox regression). Survival curves were compared (Mantel-Haenszel test).

RESULTS

In all, 69 patients were included: 32 (57.2 years -95%CI: 54.0-60.5-, 65.6% men) in CPT-FUFA group and 37 (68.1 years - 95%CI: 65.5-70.7-, 78.4% men) in bevacizumab_CPT-FUFA group. The disease progression or death events were 29 (90.6%) in CPT-FUFA group and 34 (91.9%) in bevacizumab_CPT-FUFA group. Median progression-free survival was 10.1 months (95%CI: 7.1-12.2) in CPT-FUFA and 11.0 months (95%CI: 7.6-12.6) in bevacizumab_CPT-FUFA (hazard ratio = 1.22; 95%CI: 0.7-2.1). Dose reductions: irinotecan and fluorouracil 11% (range: 4-20) in 5/32 (15.6%) CPT-FUFA patients and 25% (range: 8-35) in 18/37 (48.6%) bevacizumab_CPT-FUFA patients; Bevacizumab 30% (range: 4-50) in 20/37 (54.1%) bevacizumab_CPT-FUFA patients. The incremental cost associated with the addition of bevacizumab was 12,696.5 (IC95%:10,860.8-14,532.1) euros/patient.

CONCLUSION

The addition of bevacizumab to the irinotecan-fluorouracil regimen, does not improve progression-free survival in our study population but increases costs per treated patient. These results potentially compromise the cost-effectiveness of the Bevacizumab_CPT-FUFA regimen.

From bench to bedside: lessons learned in translating preclinical studies in cancer drug development

The development of targeted agents in oncology has rapidly expanded over the past 2 decades and has led to clinically significant improvements in the treatment of numerous cancers. Unfortunately, not all success at the bench in preclinical experiments has translated to success at the bedside. As preclinical studies shift toward defining proof of mechanism, patient selection, and rational drug combinations, it is critical to understand the lessons learned from prior translational studies to gain an understanding of prior drug development successes and failures. By learning from prior drug development, future translational studies will provide more clinically relevant data, and the underlying hope is that the clinical success rate will improve and the treatment of patients with ineffective targeted therapy will be limited.

Prognostic value of CD109+ circulating endothelial cells in recurrent glioblastomas treated with bevacizumab and irinotecan

BACKGROUND

Recent data suggest that circulating endothelial and progenitor cells (CECs and CEPs, respectively) may have predictive potential in cancer patients treated with bevacizumab, the antibody recognizing vascular endothelial growth factor (VEGF). Here we report on CECs and CEPs investigated in 68 patients affected by recurrent glioblastoma (rGBM) treated with bevacizumab and irinotecan and two Independent Datasets of rGBM patients respectively treated with bevacizumab alone (n=32, independent dataset A: IDA) and classical antiblastic chemotherapy (n=14, independent dataset B: IDB).

METHODS

rGBM patients with KPS ≥50 were treated until progression, as defined by MRI with RANO criteria. CECs expressing CD109, a marker of tumor endothelial cells, as well as other CEC and CEP subtypes, were investigated by six-color flow cytometry.

RESULTS

A baseline count of CD109+ CEC higher than 41.1/ml (1(st) quartile) was associated with increased progression free survival (PFS; 20 versus 9 weeks, P=0.008) and overall survival (OS; 32 versus 23 weeks, P=0.03). Longer PFS (25 versus 8 weeks, P=0.02) and OS (27 versus 17 weeks, P=0.03) were also confirmed in IDA with CD109+ CECs higher than 41.1/ml but not in IDB. Patients treated with bevacizumab with or without irinotecan that were free from MRI progression after two months of treatment had significant decrease of CD109+ CECs: median PFS was 19 weeks; median OS 29 weeks. The presence of two non-contiguous lesions (distant disease) at baseline was an independent predictor of shorter PFS and OS (P<0.001).

CONCLUSIONS

Data encourage further studies on the predictive potential of CD109+ CECs in GBM patients treated with bevacizumab.

Personalizing colon cancer therapeutics: targeting old and new mechanisms of action

The use of pharmaceuticals for colon cancer treatment has been increasingly personalized, in part due to the development of new molecular tools. In this review, we discuss the old and new colon cancer chemotherapeutics, and the parameters that have been shown to be predictive of efficacy and safety of these chemotherapeutics. In addition, we discuss how alternate pharmaceuticals have been developed in light of a potential lack of response or resistance to a particular chemotherapeutic.

Characterization of CD45-/CD31+/CD105+ circulating cells in the peripheral blood of patients with gynecologic malignancies

PURPOSE

Circulating endothelial cells (CEC) have been widely used as a prognostic biomarker and regarded as a promising strategy for monitoring the response to treatment in several cancers. However, the presence and biologic roles of CECs have remained controversial for decades because technical standards for the identification and quantification of CECs have not been established. Here, we hypothesized that CECs detected by flow cytometry might be monocytes rather than endothelial cells.

EXPERIMENTAL DESIGN

The frequency of representative CEC subsets (i.e., CD45(-)/CD31(+), CD45(-)/CD31(+)/CD146(+), CD45(-)/CD31(+)/CD105(+)) was analyzed in the peripheral blood of patients with gynecologic cancer (n = 56) and healthy volunteers (n = 44). CD45(-)/CD31(+) cells, which are components of CECs, were isolated and the expression of various markers (CD146, CD105, vWF, and CD144 for endothelial cells; CD68 and CD14 for monocytes) was examined by immunocytochemistry.

RESULTS

CD45(-)/CD31(+)/CD105(+) cells were significantly increased in the peripheral blood of patients with cancer, whereas evaluation of CD45(-)/CD31(+)/CD146(+) cells was not possible both in patients with cancer and healthy controls due to the limited resolution of the flow cytometry. Immunocytochemistry analyses showed that these CD45(-)/CD31(+)/CD105(+) cells did not express vWF and CD146 but rather CD144. Furthermore, CD45(-)/CD31(+)/CD105(+) cells uniformly expressed the monocyte-specific markers CD14 and CD68. These results suggest that CD45(-)/CD31(+)/CD105(+) cells carry the characteristics of monocytes rather than endothelial cells.

CONCLUSIONS

Our data indicate that CD45(-)/CD31(+)/CD105(+) circulating cells, which are significantly increased in the peripheral blood of patients with gynecologic cancer, are monocytes rather than endothelial cells. Further investigation is required to determine the biologic significance of their presence and function in relation with angiogenesis.

Angiogenin outperforms VEGF, EPCs and CECs in predicting Dukes' and AJCC stage in colorectal cancer

BACKGROUND

Circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), Willebrand factor (vWf), soluble E-selectin, vascular endothelial growth factor (VEGF) and angiogenin are of interest in cancer vascular biology. However, few studies have looked at more than one in combination. We set out to determine which would be best in predicting the Dukes' and American Joint Committee on Cancer (AJCC) scores in colorectal cancer patients.

METHODS

We recruited 154 patients with colorectal cancer, 29 healthy controls and 26 patients with benign bowel disease. CD34(+) /CD45(-) /CD146(+) CECs and CD34(+) /CD45(-) /CD309[KDR](+) EPCs were measured by flow cytometry, plasma markers by ELISA.

RESULTS

All research indices were raised in colorectal cancer (P < 0·05) compared to control groups. Although CECs (P < 0·05), EPCs (P < 0·01) and angiogenin (P < 0·01) increased stepwise across the four Dukes' stages and four AJCC stages, only angiogenin remained significant in multiple regression analysis (P = 0·003 for Dukes, P = 0·01 for AJCC). Angiogenin levels were higher in Dukes' stages C and D compared to stage A, and AJCC stages 4-6 and 7-10 compared to stage 1 (all P < 0·05). Adding a second research marker to angiogenin did not markedly improve this relationship.

CONCLUSION

Although we found disturbances in endotheliod cells and plasma markers of the endothelium and growth factors, only angiogenin levels were independently associated with progression of the Dukes' stage and AJCC stage, with the association with Duke's stage being stronger. We suggest that angiogenin is a potential biomarker in risk stratification for colorectal cancer, and may aid clinical decision making.

KRAS as prognostic biomarker in metastatic colorectal cancer patients treated with bevacizumab: a pooled analysis of 12 published trials

The significance of KRAS in advanced colorectal cancer (CRC) treated with bevacizumab (B) is not well understood. We conducted a systematic review and pooled analysis of published trials with the aim to assess the predictive and prognostic role of KRAS status in patients treated with B. We performed a systematic search of PubMed, EMBASE, Web of Science, and Cochrane Register of Controlled Trials. The primary endpoints included objective response rate (RR), progression-free survival (PFS), and overall survival (OS). The odds ratio (OR) for RR and hazard ratios (HRs) were calculated or extracted by published data either using a fixed effect model or a random effect model. A total of 12 studies were included. A total of 2,266 patients were analysed (54 % were KRAS wt). The pooled RRs for KRAS wild-type (wt) versus mutated (mut) patients were 54.8 and 48.3 %, respectively (OR 1.42, P = 0.02). Median PFS was significantly longer in KRAS wt patients compared with that in KRAS mut patients (HR = 0.85; 95 % confidence interval (CI) 0.74-0.98; P = 0.02). Similarly, median OS was significantly better in wt KRAS patients compared with that in mut KRAS patients (HR = 0.65; 95 % CI 0.46-0.92; P = 0.01). This pooled analysis of 12 published studies shows that KRAS wt status is a good prognostic factor for B-based chemotherapy. Also, KRAS wt CRC is associated with a better RR with B plus chemotherapy than mut counterpart.

Biomarkers for anti-angiogenic therapy in cancer

Angiogenesis, the development of new vessels from existing vasculature, plays a central role in tumor growth, survival, and progression. On the molecular level it is controlled by a number of pro- and anti-angiogenic cytokines, among which the vascular endothelial growth factors (VEGFs), together with their related VEGF-receptors, have an exceptional position. Therefore, the blockade of VEGF signaling in order to inhibit angiogenesis was deemed an attractive approach for cancer therapy and drugs interfering with the VEGF-ligands, the VEGF receptors, and the intracellular VEGF-mediated signal transduction were developed. Although promising in pre-clinical trials, VEGF-inhibition proved to be problematic in the clinical context. One major drawback was the generally high variability in patient response to anti-angiogenic drugs and the rapid development of therapy resistance, so that, in total, only moderate effects on progression-free and overall survival were observed. Biomarkers predicting the response to VEGF-inhibition might attenuate this problem and help to further individualize drug and dosage determination. Although up to now no definitive biomarker has been identified for this purpose, several candidates are currently under investigation. This review aims to give an overview of the recent developments in this field, focusing on the most prevalent tumor species.

Molecular markers to predict outcome to antiangiogenic therapies in colorectal cancer: current evidence and future perspectives

Angiogenesis is a universal requirement for the growth of solid tumours beyond the limits of oxygen diffusion from the existing vasculature. The expression and function of proangiogenic and antiangiogenic factors are altered in solid malignancies to drive net neoangiogenesis. Vascular endothelial growth factor (VEGF) has been confirmed in several clinical trials as an important therapeutic target in colorectal cancer (CRC) treatment. However, given that the efficacy of antiangiogenic agents appears to be limited to a subset of patients, the identification of who will obtain the greater benefit from this therapy or suffer from specific toxicities and when or for how long they should be administered in the treatment algorithm are major open questions for clinicians and challenges for present and future research. Current evidence indicates some predictive value for particular circulating measures, such as an increase in VEGF, a decrease in vascular endothelial growth factor receptor 2 (VEGFR-2) or circulating endothelial cells, tissue biomarkers, microvessel density, KRAS and BRAF gene mutations or polymorphisms affecting components of the VEGF pathway. Many questions relating to these and other surrogate biomarkers, however, remain unanswered and their clinical usefulness has yet to be proven. This review will focus on the present status of knowledge and future perspectives for developing molecular tools to foresee and monitor antiangiogenic therapy activity in CRC patients.

A multi-histology trial of fostamatinib in patients with advanced colorectal, non-small cell lung, head and neck, thyroid, and renal cell carcinomas, and pheochromocytomas

PURPOSE

A multi-cohort phase II study of fostamatinib, an oral multi-kinase inhibitor, was conducted to determine the response rate in patients with advanced colorectal (CRC), thyroid, non-small cell lung, head and neck, and renal cell carcinomas, and pheochromocytomas.

METHODS

Patients received 200 mg fostamatinib BID in 4-week cycles with response assessed every 2 cycles. Blood was collected for pharmacokinetic analysis and measurements of circulating tumor cells and circulating endothelial (progenitor) cells (CE(P)Cs).

RESULTS

A total of 37 patients (22 CRC), median of 4 prior therapies, were enrolled. Due to toxicities in four of the first five patients, the study was amended to incorporate a dose escalation phase for each histology. The maximum-tolerated dose was established at 50 mg BID in CRC but was not established for the other cancers. Common grade 3/4 toxicities included transaminitis, hyperbilirubinemia, and hypertension. Pharmacokinetic profile was similar to previous reports. Seventy-three percent of CRC patients had liver involvement and 91 % had prior anti-angiogenic therapy. Patients with abnormal liver tests at baseline were more likely to experience grade ≥ 2 hepatotoxicity than those with normal tests (44 vs. 0 %). No responses were observed; disease stabilization rate was 27 % in CRC. Reduction in CECs following treatment was associated with a better disease stabilization rate (75 vs. 0 %) in CRC.

CONCLUSION

Fostamatinib had limited anti-tumor activity in this first clinical trial in patients with advanced refractory solid tumors; reduction in CECs and CEPs was indicative of anti-angiogenic effects. Abnormal liver testing at baseline appeared to influence drug tolerability.

Targeted therapies in colorectal cancer-an integrative view by PPPM

In developed countries, colorectal cancer (CRC) is the third most common malignancy, but it is the second most frequent cause of cancer-related death. Clinicians are still faced with numerous challenges in the treatment of this disease, and future approaches which target the molecular features of the disorder will be critical for success in this disease setting. Genetic analyses of many solid tumours have shown that up to 100 protein-encoding genes are mutated. Within CRC, numerous genetic alterations have been identified in a number of pathways. Therefore, understanding the molecular pathology of CRC may present information on potential routes for treatment and may also provide valuable prognostic information. This will be particularly pertinent for molecularly targeted treatments, such as anti-vascular endothelial growth factor therapies and anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy. KRAS and BRAF mutations have been shown to predict response to anti-EGFR therapy. As EGFR can also signal via the phosphatidylinositol 3-kinase (PI3K) kinase pathway, there is considerable interest in the potential roles of members of this pathway (such as PI3K and PTEN) in predicting treatment response. Therefore, a combined approach of new techniques that allow identification of these biomarkers alongside interdisciplinary approaches to the treatment of advanced CRC will aid in the treatment decision-making process and may also serve to guide future therapeutic approaches.