Clinical significance of plasma vascular endothelial growth factor in gastrointestinal cancer

A phase II study to explore biomarkers for the use of mFOLFOX6/XELOX plus bevacizumab as a first-line chemotherapy in patients with metastatic colorectal cancer (WJOG7612GTR)

BACKGROUND

The purpose of this prospective study was to assess the ability of plasma vascular endothelial growth factor-A short isoforms (pVEGF-Asi) to predict bevacizumab (BV) efficacy and to explore other circulating biomarkers in metastatic colorectal cancer (mCRC) patients treated with modified FOLFOX6/XELOX plus BV (mFOLFOX6/XELOX + BV).

PATIENTS AND METHODS

Pre-treatment plasma samples were collected from 100 mCRC patients receiving first-line chemotherapy with mFOLFOX6/XELOX + BV. The plasma levels of 11 angiogenesis-associated molecules, including pVEGF-Asi and 22 cancer-associated gene mutations in circulating tumor DNA, were analyzed. For the primary endpoint, we assumed that the hazard ratio (HR) for progression-free survival (PFS) calculated using a Cox proportional hazards model was <1.15, comparing patients with a high versus those with a low pVEGF-Asi level divided according to the median pVEGF-Asi value.

RESULTS

The median value of pVEGF-Asi was 37 (range 6.5-262) pg/ml. The HR for PFS between the high and low pVEGF-Asi patient groups was 1.3 [95% confidence interval (CI) 0.8-2.1; log rank, P = 0.25], which was larger than the predefined threshold of 1.15. The multivariate analysis demonstrated that PFS was significantly associated with plasma intercellular adhesion molecule-1 (pICAM-1) (≥190.0 versus <190.0 ng/ml; HR 2.1; 95% CI 1.3-3.5), RAS (mutant versus wild; HR 2.5; 95% CI 1.5-4.3), and FBXW7 (mutant versus wild; HR 2.8; 95% CI 1.2-6.8), whereas overall survival was significantly associated with pICAM-1 (HR 2.0; 95% CI 1.1-3.7) and RAS (HR 2.6; 95% CI 1.5-4.6).

CONCLUSIONS

The addition of BV was unable to compensate for the poor PFS associated with a high pVEGF-Asi level, suggesting that pVEGF-Asi is unlikely to be a good predictive biomarker of the efficacy of mFOLFOX6/XELOX + BV therapy. The clinical significance of circulating ICAM-1, mutant RAS, and mutant FBXW7 levels should be studied further.

Serum Levels of Stromal Cell-Derived Factor-1α and Vascular Endothelial Growth Factor Predict Clinical Outcomes in Head and Neck Squamous Cell Carcinoma Patients Receiving TPF Induction Chemotherapy

Chemokines, such as stromal cell-derived factor-1α (SDF-1α) and vascular endothelial growth factor (VEGF), are associated with clinical outcomes in several cancer types. This study aimed to investigate the role of SDF-1α and VEGF in the prognosis of patients with head and neck squamous cell carcinoma (HNSCC) who underwent TPF induction chemotherapy (docetaxel, cisplatin, and 5-fluorouracil). A total of 77 HNSCC patients were enrolled and circulating SDF-1α and VEGF values were examined at two time points for each patient, including pre-TPF treatment (treatment-naïve) and post-TPF treatment but before chemoradiotherapy. The median progression-free survival (PFS) and overall survival (OS) were 18.1 and 32.9 months, respectively. Decreased SDF-1α and VEGF levels after TPF treatment, post-TPF SDF-1α < 1500 pg/mL and VEGF value < 150 pg/mL were independent prognostic factors for better PFS and OS in univariate and multivariate analyses. A combination of SDF-1α and VEGF values may predict clinical outcomes significantly. Our study confirmed the role of SDF-1α and VEGF in the disease progression of HNSCC, and that decreased SDF-1α and VEGF after TPF treatment and lower post-TPF SDF-1α and VEGF values were associated with better prognosis in HNSCC patients who received induction chemotherapy with TPF followed by chemoradiotherapy.

The prothrombotic state in cancer

Neoplasms result from changes in the mechanisms of growth, differentiation, and cellular death. Cancers are of high clinical relevance due to their prevalence and associated morbidity and mortality. The clinical and biological diversity of cancer depends mainly on cellular origin and degree of differentiation. These changes result from alterations in molecular expression that generate a complex clinical, biochemical, and morphologic phenotype. Although cancer is associated with a hypercoagulable state, few cancers result in a thrombotic event. Many factors influence thrombotic incidence, such as advanced disease, central catheter placement, chemotherapy, neoplasia, and surgery. The pro-coagulant state is associated with anomalies in the vascular wall, blood flow, blood constituents (tissue factor, thrombin), coagulation state, and cell growth factors. Tumor cells perpetuate this phenomenon by releasing tissue factor, inflammatory cytokines, and growth factors. These changes favor cellular activation that gives rise to actions involving coagulation, inflammation, thrombosis, tumor growth, angiogenesis, and tumor metastases. These, in turn, are closely linked to treatment response, tumor aggressiveness, and host survival. Activation of the coagulation cascade is related to these phenomena through molecules that interact in these processes. As such, it is necessary to identify these mediators to facilitate treatment and improve outcomes.

Silk Fibroin As an Immobilization Matrix for Sensing Applications

The development of flexible, biocompatible, and environment-friendly sensors has attracted a significant amount of scientific interest for the past few decades. Among all the natural materials, silk fibroin (SF), due to its tunable biodegradability, biocompatibility, ease of processing, presence of functional groups, and controllable dimensions, has opened up opportunities for immobilizing multitudinous biomolecules and conformability to the skin, among other attractive opportunities. The silk fibroins also offer good physical properties, such as superior toughness and tensile strength. The sensors made of SF as an immobilization matrix have demonstrated excellent analytical performance, sensing even at low concentrations. The significant advantage of silk fibroins is the presence of functional groups along with a controllable conformation transition that enables immobilization of receptor molecules using silk fibroins as an immobilization matrix enables us to entrap the receptor molecules without using any chemical reagents. This review encompasses a detailed discussion on sensors, the advantages of using silk fibroins as an immobilization matrix for various receptors, their applications, and the future research scope in this state-of-the-art technology based upon the explorable applications for silk fibroin-based sensors.

Lower plasma vascular endothelial growth factor A in major depressive disorder not normalized after antidepressant treatment: A case control study

OBJECTIVE

Vascular endothelial growth factor A is a growth factor with pro-angiogenic and neurotrophic properties. Anti-vascular endothelial growth factor A treatments, used to treat cancers and opthalmic diseases, are known to induce depressive symptoms. Thus, we hypothesized that vascular endothelial growth factor A plasma levels are low in patients experiencing a major depressive episode in the context of major depressive disorder, which consequently increase after antidepressant treatment. The aim of this study was to compare plasma vascular endothelial growth factor A levels in patients with major depressive episode-major depressive disorder before and after antidepressant treatment.

METHODS

Vascular endothelial growth factor A fasting plasma levels of 469 major depressive episode-major depressive disorder patients were compared with healthy controls. Depressed patients were assessed for remission after 3 and 6 months of antidepressant treatment. Bivariate and multivariate analyses adjusted for sex, age, body mass index and tobacco use were performed.

RESULTS

As compared to healthy controls, major depressive episode patients had lower vascular endothelial growth factor A, 66.0 (38.3) pg/mL (standard deviation) vs 83.2 (49.2) pg/mL, p < 0.0001. Plasma vascular endothelial growth factor A levels did not change after antidepressant treatment, even in remitters, and remained lower than those of healthy controls, 64.9 (39.3) pg/mL vs 83.2 (49.2) pg/mL, p < 0.0001.

CONCLUSION

Depressed patients with major depressive disorder have lower plasma vascular endothelial growth factor A levels than healthy controls during their major depressive episode and after remission following antidepressant treatment. New strategies targeting enhancement of plasma vascular endothelial growth factor A could be promising for the prevention and treatment of major depressive disorder.

DNA aptamer immobilized hydroxyapatite for enhancing angiogenesis and bone regeneration

In this study, we developed aptamer-conjugated hydroxyapatite (Apt-HA) that promotes bone regeneration and angiogenesis. The 3R02 bivalent aptamer specific to vascular endothelial growth factor (VEGF) was grafted to the hydroxyapatite (HA) surface. Apt-HA was tested for its VEGF protein capture ability to determine the optimal aptamer concentration immobilized on the HA. Apt-HA showed higher VEGF protein capture ability, and faster growth of human umbilical vein endothelial cell (HUVEC) compared to a neat HA with no cytotoxic effects on human osteoblasts. To examine in vivo angiogenesis and bone regeneration, Apt-HA and HA were bilaterally implanted into rabbit tibial metaphyseal defects and analyzed after eight weeks using micro-CT, histology, and histomorphometry. Apt-HA showed significantly increased the volume of new bones, the percentage of bone, and the density of bone mineral in cortical bone. Apt-HA also exhibited the enhanced bone formation at the cortical region in a histomorphometric analysis. Finally, Apt-HA showed significantly increased blood vessel number compared to a neat HA. In summary, the engineered Apt-HA has potential as a bone graft material that may simultaneously promote bone regeneration and angiogenesis. STATEMENT OF SIGNIFICANCE: This work presents a functional hydroxyapatite bone graft using a DNA-based aptamer which overcomes the limitations of existing bone graft materials, which use bound signaling peptides. DNA aptamer immobilized hydroxyapatite enhances the in vitro proliferation of human umbilical vascular endothelial cells as well as in vivo angiogenesis and bone regeneration. DNA aptamer immobilized hydroxyapatite shows no cytotoxic effect on human osteoblasts.

Flexible Biosensors for the Impedimetric Detection of Protein Targets Using Silk-Conductive Polymer Biocomposites

To expand the applications of flexible biosensors in point-of-care healthcare applications beyond monitoring of biophysical parameters, it is important to devise strategies for the detection of various proteins and biomarkers. Here, we demonstrate a flexible, fully organic, biodegradable, label-free impedimetric biosensor for the critical biomarker, vascular endothelial growth factor (VEGF). This biosensor was constructed by photolithographically patterning a conducting ink consisting of a photoreactive silk sericin coupled with a conducting polymer. These functional electrodes are printed on flexible fibroin substrates that are controllably thick and can be free-standing, or conform to soft surfaces. Detection was accomplished via the antibody to VEGF which was immobilized within the conducting matrix. The results indicated that the developed flexible biosensor was highly sensitive and selective to the target protein, even in challenging biofluids such as human serum. The biosensors themselves are biocompatible and degradable. Through this work, the developed flexible biosensor based on a simple and label-free strategy can find practical applications in the monitoring of wound healing or early disease diagnosis.

The Influence of Breast Cancer on the Distribution of Cherry Angiomas on the Anterior Thoracic Wall: A Case Series Study

BACKGROUND/AIMS

Cherry angiomas (CAs) are one of the most common vascular manifestations of the skin. By and large, these benign lesions often only represent an aesthetic problem. In the literature, few authors have focused on the pathogenesis of these lesions, and some risk factors have been identified, such as the presence of cutaneous and non-skin neoplasias. In this study, the correlation between the distribution of CAs and breast cancer was investigated.

METHODS

We carried out a study whereby 50 women with unilateral breast cancer and the presence of CAs on the anterior thoracic wall were evaluated, with a particular focus on the difference in the number of CAs between the two haemithoraces. The data was elaborated using the Wilcoxon signed-rank test in order to evaluate whether there was a statistical significance in the distribution of CAs.

RESULTS

In 31 patients we found that the number of CAs was greater on the cancerous breast than on the contralateral one (p value <0.0001). This was confirmed both in the group of patients suffering from ductal breast cancer and in the group with early invasive breast tumours.

CONCLUSION

It is not clear whether CAs develop prior to or following breast cancer, indicating the possibility that this cutaneous manifestation could take on a predictive, prognostic development or represent only an epiphenomenon. Further in-depth studies into the pathogenesis of CAs and the relationship with breast cancer could lead to noteworthy diagnostic-therapeutic advances.

The crucial role of blood VEGF kinetics in patients with locally advanced esophageal squamous cell carcinoma receiving curative concurrent chemoradiotherapy

Background

To evaluate the role of blood vascular endothelial growth factor (VEGF) kinetics in patients with locally advanced esophageal squamous cell carcinoma (ESCC) receiving curative concurrent chemoradiotherapy (CCRT).

Methods

A total of 97 locally advanced ESCC patients were enrolled. All the patients had their blood drawn at three time points to determine their levels of VEGF, including pre-chemotherapy (day 0), post-chemotherapy (day 5), and pre-cycle 2 chemotherapy (day 28). The VEGF levels were evaluated according to the day 0 value, day 5 value, day 28 value, day 5/day 0 ratio, day 28/day 0 ratio, and day 28/day 5 ratio. A VEGF cut-off level of 80 pg/mL was applied.

Results

In the analysis of progression-free survival (PFS), the patients less than 60 years old had significantly superior PFS compared to those more than 60 years old. Patients who had VEGF < 80 pg/mL at day 28 and a day 28/day 5 ratio < 1 had better PFS than those with VEGF > 80 pg/mL and a day 28/day 5 ratio > 1, respectively. In the analysis of overall survival (OS), patients with N0–1 status had significantly superior OS compared to those with N2–3 status. Furthermore, patients who had VEGF < 80 pg/mL at day 28, a day 5/day 0 ratio < 1, and a day 28/day 5 ratio < 1 had superior OS compared to those patients with VEGF > 80 pg/mL, a day 5/day 0 ratio > 1, and a day 28/day 5 ratio > 1, respectively. In the multivariate analysis, only VEGF < 80 pg/mL at day 28 and a day 28/day 5 ratio < 1 represented independent prognostic factors of superior PFS and OS.

Conclusions

Our study suggests that VEGF kinetics is a prognostic factor for locally advanced ESCC patients receiving curative CCRT. For these patients, lower post-treatment VEGF levels and decreasing levels of VEGF during CCRT are significantly associated with better clinical outcomes.

Serum cytokine levels in breast cancer patients during neoadjuvant treatment with bevacizumab

A high concentration of circulating vascular endothelial growth factor (VEGF) in cancer patients is associated with an aggressive tumor phenotype. Here, serum levels of 27 cytokines and blood cell counts were assessed in breast cancer patients receiving neoadjuvant chemotherapy with or without bevacizumab (Bev) in a randomized cohort of 132 patients with non-metastatic HER2-negative tumors. Cytokine levels were determined prior to treatment and at various time-points. The cytotoxic chemotherapy regimen of fluorouracil, epirubicin, and cyclophosphamide (FEC) had a profound impact on both circulating white blood cells and circulating cytokine levels. At the end of FEC treatment, the global decrease in cytokine levels correlated with the drop in white blood cell counts and was significantly greater in the patients of the Bev arm for cytokines, such as VEGF-A, IL-12, IP-10 and IL-10. Among patients who received Bev, those with pathological complete response (pCR) exhibited significantly lower levels of VEGF-A, IFN-γ, TNF-α and IL-4 than patients without pCR. This effect was not observed in the chemotherapy-only arm. Certain circulating cytokine profiles were found to correlate with different immune cell types at the tumor site. For the Bev arm patients, the serum cytokine levels correlated with higher levels of cytotoxic T cells at the end of the therapy regimen, which was indicative of treatment response. The higher response rate for Bev-treated patients and stronger correlations between serum cytokine levels and infiltrating CD8T cells merits further investigation.

Potential Impact of Vascular Endothelial Growth Factor Gene Variation (-2578C>A) on Breast Cancer Susceptibility in Saudi Arabia: a Case-Control Study

Aim:

VEGF gene polymorphisms can induce either increase or inhibition of VEGF secretion, with altered promoter activity. The VEGF rs699947 SNP is located in the promoter region and is associated with susceptibility to breast carcinoma development. Here, we investigated the association of the -2578C>A polymorphism in the VEGF gene with breast cancer risk in Saudi women.

Methodology:

Genotyping of the VEGF-gene variation (-2578A>C) was performed using the amplification refractory mutation system PCR. We investigated the association of VEGF gene variants with different clinicopathological features of breast cancer patients.

Results:

A significant difference was observed in genotype distribution among the breast cancer cases and sex matched healthy controls (p=0.03). The frequencies of the three genotypes CC, CA, AA found in the patient samples were 37%, 45% and 18% and in the healthy controls were 54%,37%, and 09% respectively. An increased risk of developing breast cancer in Saudi women was associated with the VEGF −2578 AA genotype (OR = 2.91, 95 % CI, 1.18-7.20; p = 0.01; RR 1.78 (1.01-3.11 p=0.01), the VEGF −2578 A allele (OR = 1.79, 95 % CI, 1.17-2.73; p = 0.004: RR 1.35 1.07-1.71) and the VEGFR-(CA+ AA) (OR 1.99 1.13-3.51; RR 1.401.0-1.85). Thus the A allele increased the risk of BC when compared with C allele. When we stratified groups of patients according to the status of tumor markers, stage, age and metastasis, statistically significant associations with −2578 C/A SNP were revealed.

Conclusion:

Our data showed a significant association of the VEGF -2578C>A polymorphism with BC susceptibility in Saudi women. The VEGF -2578AA homozygote significantly increases the risk and can be useful as a predisposing genetic marker. Further studies with larger sample sizes are necessary to confirm our findings.

Evaluation of Detection Methods and Values of Circulating Vascular Endothelial Growth Factor in Lung Cancer

Lung cancer is the deadliest cancer in the world. Angiogenesis plays a crucial role of the incidence, progression, and metastasis in lung cancer. Angiogenesis inhibitors are used to treat non-small cell lung cancer (NSCLC) patients, and the molecular biomarkers are also being assessed to predict treatment response/therapeutic response and patients' prognosis. Vascular endothelial growth factor (VEGF) is a signal protein produced by cells that stimulates angiogenesis. Due to its predictive values of prognosis on NSCLC, a large number of methods have been developed and evaluated to detect VEGF levels in a variety of studies. In this article, we review the detection methods designed to measure the VEGF levels in different body fluids and prognosticate the value of VEGF in treatment, diagnosis and survival in lung cancer.

Circulating Angiogenesis Regulators in Cancer Patients

Background/Aims

To date, numerous studies have demonstrated that several angiogenesis regulators circulate in the blood and may function as endocrine factors in cancer patients. This review aims to give a comprehensive insight into the possible clinical value of circulating angiogenesis regulators, mainly basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF), angiogenin, pleiotrophin, thrombospondin (TSP) and endostatin (ES) in cancer patients.

Methods

A computerized (MEDLINE) and a manual search based on the reference lists of the publications were performed to identify articles published on this topic.

Results

In a detailed literature search, approximately 100 publications were found up to the end of 1999. Circulating angiogenic factors such as bFGF, VEGF, HGF and angiogenin have been evaluated not only as diagnostic and/or prognostic factors but also as predictive factors in cancer patients. On the other hand, little is known about the clinical significance of negative regulators. Neither the source nor the mechanism of protein externalization has been clarified in detail.

Conclusions

Although there are no known factors with established clinical utility, circulating angiogenesis regulators may be useful in several situations. They could be used to determine the risk of developing cancer, to screen for early detection, to distinguish benign from malignant disease, and to distinguish between different types of malignancies. In patients with established malignancies such factors might be used to determine prognosis, to predict the response to therapy, and to monitor the clinical course. Further investigations are warranted to assess the specific utility of each factor.

Validation of Blood Collection Procedures for the Determination of Circulating Vascular Endothelial Growth Factor (VEGF) in Different Blood Compartments

Aims of the study.

Studies on circulating VEGF have reported mixed results, possibly due to a lack of standardization of the pre-analytical phase. The aim of our investigation was to standardize the sampling procedure for the determination of VEGF in different blood fractions.

Basic procedures.

We evaluated various clotting times for obtaining serum in 30 subjects, as well as different procedures for the preparation of plasma Edinburgh anticoagulant mixture (EDTA, PGE1, theophylline) and CTAD. VEGF was also assayed in lysed whole blood. In vitro platelet activation was monitored by measuring the levels of PF4. VEGF and PF4 were measured using commercially available enzyme-linked immunoassays.

Main findings.

Clotting time increased the release of VEGF, which reached a plateau between 2 and 4 hours. The percent increase of VEGF at 2 hours ranged from 118% to 4515% (median 327%) compared to samples centrifuged within 10 min from withdrawal. VEGF was not different and PF4 was very low or undetectable in Edinburgh plasma and CTAD plasma, while it was significantly higher in sodium citrate plasma. VEGF in CTAD plasma was not correlated with platelet count or leukocytes. Serum VEGF did not correlate with the leukocyte number, but it correlated significantly with the platelet count.

Principal conclusions.

The procedures for sample collection described above are highly standardized and easy to perform in a routine setting. We therefore suggest systematic evaluation of VEGF in CTAD plasma, in serum (clotting for 2 hours at room temperature) and in whole blood, until prospective controlled clinical studies will have clarified in which blood compartment(s) VEGF provides clinically relevant information.

Vascular Endothelial Growth Factor Levels in Serum and Plasma following Esophageal Cancer Resection - Relationship to Platelet Count

In patients with cancer circulating vascular endothelial growth factor (VEGF) may be tumor-derived and have prognostic significance. Activated platelets may also be a source of VEGF, releasing it in serum formation. Debate exists as to whether serum or plasma VEGF (S-VEGF, P-VEGF) is the most appropriate surrogate marker of tumor angiogenesis. As healing wounds produce VEGF that can spill over into the circulation, we aimed to investigate the potential confounding effects of cancer surgery on both perioperative S-VEGF and P-VEGF levels and to evaluate their relationship with platelet count. S-VEGF, P-VEGF and platelet counts were measured in 23 patients undergoing esophageal cancer resection. Samples were taken preoperatively and six weeks following surgery. Seven patients were also sampled on postoperative days 1, 5 and 10. VEGF was assayed using a commercial enzyme linked immunosorbent assay. S-VEGF and P-VEGF both rose after surgery (S-VEGF; day 5: 1017 [446–1224] pg/mL and day 10: 1231 [626–2046] pg/mL versus pre-op: 329 [189–599] pg/mL. P-VEGF; day 1: 55 [46–104] pg/mL and day 10: 58 [20–154] pg/mL versus pre-op: 23 [13–46] pg/mL), falling towards pre-operative levels by six weeks. Platelet count correlated with S-VEGF (rho=0.281; p<0.05, Spearman's rank) and P-VEGF (rho=0.330; p<0.01, Spearman's rank). Platelets may contribute to VEGF levels in plasma as well as in serum. The effects of surgery on S-VEGF or P-VEGF levels are mainly transient. Care must be exercised when interpreting circulating VEGF levels in the early postoperative period.

Assessment of the Value of Preoperative Serum Levels of CA 242 and CEA in the Staging and Postoperative Survival of Colorectal Adenocarcinoma Patients

Introduction

CEA is the most frequently used tumor marker in colorectal cancer. There may be an improvement in its efficacy when used in association with CA 242.

Aim

The purpose of this study was to evaluate the efficacy of preoperative serum levels of the tumor markers CA 242 and CEA in the staging and postoperative follow-up of colorectal adenocarcinoma patients.

Patients and Methods

Of a series of 134 patients with colorectal adenocarcinomas 90 underwent radical surgery and 44 palliative surgery. The control group consisted of 22 organ donors. The cutoff serum levels utilized were 5 ng/mL for CEA and 20 U/mL for CA 242. The mortality during follow-up was recorded in order to determine the duration of survival. The data were submitted to statistical analysis using diagnostic tests, the chi-square test, survival analysis (Kaplan and Meier) and ROC curves. A significance level of p ≤ 0.05 was applied.

Results

The sensitivity of CEA in Dukes’ stages A, B, C and D was 27.8%, 32.4%, 32.1% and 66.7%, respectively. The sensitivity of CA 242 was 11.1%, 16.2%, 30.8% and 50%. When both markers were combined, the sensitivity was 33.3%, 48.6%, 40.7% and 72.5%. In the group of patients who underwent radical surgery the mean survival was 60.47 months for those with high preoperative CEA levels, 52.22 months for those with high preoperative CA 242 levels, and 44.80 months for those with elevated levels of both markers. There was a statistically significant difference in survival between patients undergoing radical surgery with elevated CA 242 levels, especially when CEA was also elevated, and patients without elevated CA 242.

Conclusion

Preoperative serum levels of CA 242 showed less efficacy than CEA levels for the staging of colorectal adenocarcinoma patients. Elevated preoperative serum levels of CA 242 alone were related to poor survival, especially in association with high levels of CEA.

Monitoring response to anti-angiogenic mTOR inhibitor therapy in vivo using 111In-bevacizumab

BACKGROUND

The ability to image vascular endothelial growth factor (VEGF) could enable prospective, non-invasive monitoring of patients receiving anti-angiogenic therapy. This study investigates the specificity and pharmacokinetics of 111In-bevacizumab binding to VEGF and its use for assessing response to anti-angiogenic therapy with rapamycin. Specificity of 111In-bevacizumab binding to VEGF was tested in vitro with unmodified radiolabelled bevacizumab in competitive inhibition assays. Uptake of 111In-bevacizumab in BALB/c nude mice bearing tumours with different amounts of VEGF expression was compared to that of isotype-matched control antibody (111In-IgG1κ) with an excess of unlabelled bevacizumab. Intratumoural VEGF was evaluated using ELISA and Western blot analysis. The effect of anti-angiogenesis therapy was tested by measuring tumour uptake of 111In-bevacizumab in comparison to 111In-IgG1κ following administration of rapamycin to mice bearing FaDu xenografts. Uptake was measured using gamma counting of ex vivo tumours and effect on vasculature by using anti-CD31 microscopy.

RESULTS

Specific uptake of 111In-bevacizumab in VEGF-expressing tumours was observed. Rapamycin led to tumour growth delay associated with increased relative vessel size (8.5 to 10.3, P = 0.045) and decreased mean relative vessel density (0.27 to 0.22, P = 0.0015). Rapamycin treatment increased tumour uptake of 111In-bevacizumab (68%) but not 111In-IgGκ and corresponded with increased intratumoural VEGF165.

CONCLUSIONS

111In-bevacizumab accumulates specifically in VEGF-expressing tumours, and changes after rapamycin therapy reflect changes in VEGF expression. Antagonism of mTOR may increase VEGF in vivo, and this new finding provides the basis to consider combination studies blocking both pathways and a way to monitor effects.

Sorafenib improves lipiodol deposition in transarterial chemoembolization of Chinese patients with hepatocellular carcinoma: a long-term, retrospective study

Objective

Though synergy of sorafenib and transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) is well discussed in previous reports, association of lipiodol retention by sorafenib addition to TACE with the survival outcomes remain elusive. Therefore, we studied the impact of sorafenib addition to TACE on survival outcomes mediated by lipiodol retention.

Materials and Methods

This is a long-term, retrospective, single-center study using medical records of patients diagnosed with HCC at the Department of Interventional Radiology of Zhengzhou University Affiliated Cancer Hospital (China) between April 2004 and March 2012.

Results

Lipiodol deposition of > 50% was significantly increased in TACE + sorafenib group (70.87%) compared to TACE alone group (45.11%) (P = 0.0001). Significant increase in lipiodol deposition with sorafenib treatment was observed compared to TACE alone group (OR = 0.449, P = 0.041). The median overall survival in TACE + sorafenib and TACE alone groups were 38 months [95% CI = 9.772-56.228] and 31 months [95% CI = 21.855-40.145] respectively. Also, the hazard of death was comparatively greater in TACE alone group than TACE + sorafenib group [HR = 1.071]. Response rate to the therapy significantly increased after sorafenib administration to TACE patients, [compared to TACE alone treatment [69/103 (66.99%)] vs 55/133 (41.35%)], P = 0.0001.

Conclusions

Lipiodol deposition is significantly increased upon sorafenib addition after TACE. However, there was no significant impact of lipiodol deposition on the survival benefits exerted by the synergistic combination and hence, future prospective trails are warranted to validate the findings of this study.

Circulating VEGF and eNOS variations as predictors of outcome in metastatic colorectal cancer patients receiving bevacizumab

Novel predictive biomarkers are needed to improve patient selection and optimize the use of bevacizumab (B) in metastatic colorectal cancer. We analyzed the potential of five circulating biomarkers to predict B efficacy and monitor response. Peripheral blood samples collected at baseline, at the first clinical evaluation and at progression were available for 129 patients enrolled in the prospective multicentric ITACa trial and randomized to receive FOLFOX4/FOLFIRI (CT) with (64 patients) or without B (65 patients). VEGF-A, eNOS, EPHB4, COX2 and HIF-1α mRNA levels were measured by qRT-PCR. Baseline marker expression levels and their modulation during therapy were analyzed in relation to objective response, progression-free survival and overall survival (OS). VEGF and eNOS expression was significantly correlated in both groups (Spearman’s correlation coefficient = 0.80; P < 0.0001 and 0.75; P < 0.0001, respectively). B-treated patients with >30% reduction in eNOS and VEGF levels from baseline to the first clinical evaluation showed better OS than the others (median OS 31.6 months, 95% CI 21.3–49.5 months and median OS 14.4 months, 95% CI 9.0–22.7 months, respectively, HR 0.38, 95% CI 0.19–0.78, P = 0.008). A reduction in eNOS and VEGF expression from baseline to the first clinical evaluation may indicate a response to B.

Six Novel Loci Associated with Circulating VEGF Levels Identified by a Meta-analysis of Genome-Wide Association Studies

Vascular endothelial growth factor (VEGF) is an angiogenic and neurotrophic factor, secreted by endothelial cells, known to impact various physiological and disease processes from cancer to cardiovascular disease and to be pharmacologically modifiable. We sought to identify novel loci associated with circulating VEGF levels through a genome-wide association meta-analysis combining data from European-ancestry individuals and using a dense variant map from 1000 genomes imputation panel. Six discovery cohorts including 13,312 samples were analyzed, followed by in-silico and de-novo replication studies including an additional 2,800 individuals. A total of 10 genome-wide significant variants were identified at 7 loci. Four were novel loci (5q14.3, 10q21.3, 16q24.2 and 18q22.3) and the leading variants at these loci were rs114694170 (MEF2C, P = 6.79x10^-13), rs74506613 (JMJD1C, P = 1.17x10^-19), rs4782371 (ZFPM1, P = 1.59x10^-9) and rs2639990 (ZADH2, P = 1.72x10^-8), respectively. We also identified two new independent variants (rs34528081, VEGFA, P = 1.52x10^-18; rs7043199, VLDLR-AS1, P = 5.12x10^-14) at the 3 previously identified loci and strengthened the evidence for the four previously identified SNPs (rs6921438, LOC100132354, P = 7.39x10^-1467; rs1740073, C6orf223, P = 2.34x10^-17; rs6993770, ZFPM2, P = 2.44x10^-60; rs2375981, KCNV2, P = 1.48x10^-100). These variants collectively explained up to 52% of the VEGF phenotypic variance. We explored biological links between genes in the associated loci using Ingenuity Pathway Analysis that emphasized their roles in embryonic development and function. Gene set enrichment analysis identified the ERK5 pathway as enriched in genes containing VEGF associated variants. eQTL analysis showed, in three of the identified regions, variants acting as both cis and trans eQTLs for multiple genes. Most of these genes, as well as some of those in the associated loci, were involved in platelet biogenesis and functionality, suggesting the importance of this process in regulation of VEGF levels. This work also provided new insights into the involvement of genes implicated in various angiogenesis related pathologies in determining circulating VEGF levels. The understanding of the molecular mechanisms by which the identified genes affect circulating VEGF levels could be important in the development of novel VEGF-related therapies for such diseases.

Vascular Endothelial Growth Factor (VEGF) is a protein with a fundamental role in development of vascular system. The protein, produced by many types of cells, is released in the blood. High levels of VEGF have been observed in different pathological conditions especially in cancer, cardiovascular, and inflammatory diseases. Therefore, identifying the genetic factors influencing VEGF levels is important for predicting and treating such pathologies. The number of genetic variants associated with VEGF levels has been limited. To identify new loci, we have performed a Genome Wide Association Study meta-analysis on a sample of more than 16,000 individuals from 10 cohorts, using a high-density genetic map. This analysis revealed 10 variants associated with VEGF circulating levels, 6 of these being novel associations. The 10 variants cumulatively explain more than 50% of the variability of VEGF serum levels. Our analyses have identified genes known to be involved in angiogenesis related diseases and genes implicated in platelet metabolism, suggesting the importance of links between this process and VEGF regulation. Overall, these data have improved our understanding of the genetic variation underlying circulating VEGF levels. This in turn could guide our response to the challenge posed by various VEGF-related pathologies.

Vascular endothelial growth factor polymorphisms and a synchronized examination of plasma and tissue expression in epithelial ovarian cancers

In this study, we have analyzed six genetic polymorphisms of the VEGF-A gene and correlated the genetic data with plasma and tissue expression of VEGF-A in epithelial ovarian carcinomas. A total of 130 cases including 95 malignant carcinomas, 17 low malignant potential and 18 benign tumours were studied. rs699947, rs833061, rs1570360, rs2010963, rs1413711 and rs3025039 were studied by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma levels of VEGF-A were estimated by enzyme-linked immunosorbent assay (ELISA) and tissue expression of VEGF-A by immunohistochemistry (IHC). Four polymorphisms of the above excluding rs699947 and rs3025039 showed significant association with malignancy, and we observed the presence of positive correlation between haplotype CCGGCC and increased expression of VEGF-A in both plasma and tissues which also correlated with poor prognosis and recurrence suggesting a probable increase in resistance to treatment in such carriers. Highly upregulated tissue expression of VEGF-A was seen in all epithelial ovarian carcinomas with intensity of expression increasing from benign to malignant cases. ELISA data from our study showed an increase in circulating levels of VEGF-A in malignancies. VEGF-A plasma levels can be employed as a biomarker for high-grade malignancy in epithelial ovarian cancers alongside tissue expression and CA-125 levels. This study is unique due to the fact that a simultaneous analysis of plasma and tissue expression has been demonstrated and is a first such study in epithelial ovarian cancers and representing the Indian population (South-east Asian) synchronized with genetic polymorphism data as well.

G-quadruplex DNAzyme-based electrochemiluminescence biosensing strategy for VEGF165 detection: Combination of aptamer-target recognition and T7 exonuclease-assisted cycling signal amplification

The expression profile of vascular endothelial growth factor (VEGF) is highly correlated with the occurrence and development of cancer. This work reports an electrochemiluminescence (ECL) approach for highly sensitive detection of VEGF165. This approach comprises aptamer-target recognition, T7 exonuclease (T7 Exo)-assisted cycling signal amplification and efficient quenching of ECL of CdS:Eu nanocrystals (NCs) by using DNAzyme. In this assay, CdS:Eu NCs were used as the ECL substrate, A guanine (G)-rich single-stranded DNA (ssDNA) sequence and VEGF165 aptamer were co-immobilized on the surface of the CdS:Eu NCs modified glassy carbon electrode. After recognition and binding to VEGF165, the aptamer moved away from the electrode surface and induced the proposed cyclic cleavage of the target DNA with T7 Exo. A large amount of G-rich ssDNA was released on the CdS:Eu film and folded into G-quadruplex/hemin DNAzyme in the presence of hemin and K(+), consequently decreasing the ECL intensity of CdS:Eu. A good linearity was obtained for VEGF165 detection within the range of 1 pM to 20 nM with a detection limit of 0.2 pM. This assay could be a universal and promising protocol for detection of various biomarkers for early clinical diagnosis.

Polyunsaturated fatty acids augment tumoricidal action of 5-fluorouracil on gastric cancer cells by their action on vascular endothelial growth factor, tumor necrosis factor-α and lipid metabolism related factors

INTRODUCTION

Gastric cancer is the second most common cause of cancer-related mortality worldwide. 5-fluorouracil (5-FU) is a commonly used anti-cancer drug. Various polyunsaturated fatty acids (PUFAs) are known to have tumoricidal action both in vitro and in vivo. Though PUFAs are known to augment the cytotoxic action of anti-cancer drugs, the exact mechanism is not clear.

MATERIAL AND METHODS

The human gastric cancer cell line MGC (undifferentiated) and human gastric cancer cell line SGC (semi-differentiated) were either 5-FU alone or a combination of 5-FU + PUFAs and their proliferation, and ability to secrete tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) and lipid metabolism-related factors lipoprotein lipase (LPL), peroxisome proliferator-activated-γ (PPAR-γ), and CCAAT enhancer-binding protein (C/EBP) were investigated and analyzed.

RESULTS

It was noted that combined treatment of 5-FU + PUFAs on gastric carcinoma (MGC and SGC) cells produced a significant growth inhibitory action compared with either agent alone by inhibiting the production of TNF-α and VEGF and a simultaneous increase in the expression of LPL, PPAR-γ, and C/EBP.

CONCLUSIONS

Based on the results of the present study, it is concluded that PUFAs enhance the tumoricidal action of the anti-cancer drug 5-FU by acting on anti-angiogenic factors and enzymes involved in lipid metabolism.

Vascular endothelial growth factor a inhibition in gastric cancer

Angiogenesis is a vital process in the progression and metastasis of solids tumors including gastric adenocarcinoma. Tumors induce angiogenesis by secreting proangiogenic molecules such as vascular endothelial growth factor A (VEGF-A), and VEGF-A inhibition has become a common therapeutic strategy for many cancers. Several drugs targeting the VEGF-A pathway have been approved for clinical use in selected solid tumors, and several anti-VEGF-A strategies have been examined for gastric cancer. Phase II studies suggested that bevacizumab, an anti-VEGF antibody, can increase the efficacy of chemotherapy for advanced gastric cancer, but two international phase III trials failed to show an overall survival benefit. Two more recent international phase III trials have examined ramucirumab, an antibody targeting the primary receptor for VEGF-A, as second-line therapy for advanced gastric cancer and found a survival benefit both as single agent therapy and when combined with chemotherapy. Finally, correlative science studies suggest that the VEGF-A pathway may have varying importance in gastric cancer progression depending on ethnicity or race. This article will review the preclinical and clinical studies on the role of the VEGF-A pathway inhibition in gastric cancer.

Circulating biomarkers in advanced colorectal cancer patients randomly assigned to three bevacizumab-based regimens

The need to identify biomarkers for bevacizumab-based treatment in advanced colorectal cancer is imperative. The aim of this study was to investigate the prognostic role of circulating VEGF, PDGF, SDF-1, osteopontin and CEA in patients randomly assigned to three bevacizumab-based regimens. Plasma samples from 50 patients treated at a single Institution were analysed using the multiplex assay BioPlex™ 2200 (Bio-Rad Laboratories, Inc, Berkeley, CA, USA) at baseline, before first three cycles and subsequently every three cycles until disease progression. Prognostic analyses of baseline values were performed using multivariable Cox models, including disease extension >10 cm or ≤10 cm (measured as the sum of the diameters for all target lesions) as adjustment factor. The association between progression-free and overall survival and biomarkers modulation during treatment was studied using multivariable Cox models, which included summary statistics synthesizing during-treatment modulation together with disease extension. The biomarkers significantly associated with disease extension were baseline CEA (p = 0.012) and SDF-1 (p = 0.030). High values of VEGF and SDF-1 tended to be associated with worse prognosis, especially in terms of overall survival. The negative prognostic trend was more marked for baseline CEA as compared to other biomarkers; increasing values during treatment was significantly related to worse prognosis independently of disease extension (p = 0.007 and 0.016 for progression-free and overall survival, respectively). VEGF is related to bevacizumab pharmacodynamics and is associated to other angiogenic cytokines; some of the proposed biomarkers such as SDF-1 and CEA should be further validated for prognosis assessment and monitoring of bevacizumab-based treatment of advanced colorectal cancer.

Plasma vascular endothelial growth factor 165 in advanced non-small cell lung cancer

Currently, there is no serum marker that is routinely recommended for lung cancer. Therefore, the aim of the present study was to demonstrate that plasma vascular endothelial growth factor 165 (VEGF 165) may be a potential marker for advanced lung cancer. Lung cancer is the leading cause of cancer-related mortality worldwide, therefore, it is important to develop novel diagnostic techniques. The present prospective case control study included two groups of patients; a control group of healthy volunteers and a second group of patients with advanced non-small cell lung cancer (NSCLC). The plasma VEGF 165 levels were measured at baseline by ELISA prior to the first-line gemcitabine-cisplatin regimen. The high VEGF 165 expression level cut-off was >703 pg/ml, and the primary endpoint was used to compare the plasma VEGF 165 levels between the NSCLC patients and the control group subjects. The secondary endpoint was used to identify the correlations between high VEGF 165 levels and; clinical response (CR), progression-free survival (PFS) and overall survival (OS) in the advanced NSCLC patients. In total, patients with advanced NSCLC (n=35) were compared with a control group of age- and gender-matched healthy subjects (n=34). The follow-up period was between Oct 2009 and Oct 2012, with a median follow-up time of 10.5 months. The median plasma VEGF 165 level was 707 pg/ml in the NSCLC patients versus 48 pg/ml in the healthy control subjects (P<0.001). However, no significant correlation was found between the plasma VEGF 165 levels and CR (P<0.5), median PFS (P=1.00) or OS (P=0.70). Therefore, it was concluded that plasma VEGF 165 may serve as a potential diagnostic marker for advanced NSCLC.

Tissue-based biomarkers predicting outcomes in metastatic colorectal cancer: a review

Although there have been recent advances in the treatment of metastatic colorectal cancer, particularly with systemic chemotherapy, new biological agents and surgical metastasectomy, the disease remains difficult to treat. To personalise the management of mCRC and optimise patient outcomes, it is vital to acquire a deeper understanding of its natural history and mechanisms behind disease progression. This may be achieved by extensive study of tumour biomarkers: proteins or genetic alterations within neoplastic cells or their surrounding stroma that may be used to predict patient outcomes, disease trajectory and response to various therapies. The discovery of mutant Kirsten-RAS in determining patients who may be refractory to anti-epidermal growth factor receptor treatments has reinvigorated and reiterated the importance of our attempts to individualise cancer care. While many biomarkers have been studied and shown promise in the setting of mCRC, they are, with the exception of K-ras testing not used currently in a clinical setting due to conflicting results, small patient samples and methodological variations. Larger, multi-centric studies with uniform methods of tumour marker study are required to effectively tailor systemic therapies and select appropriate candidates for surgical metastasectomy.

Analysis of the mRNA expression of chemotherapy-related genes in colorectal carcinoma using the danenberg tumor profile method

The establishment of individualized chemotherapy for colorectal carcinoma based on the expression of genes involved in chemotherapeutic sensitivity or prognosis is necessary. To achieve this, the expression profiles of genes within tumors and their relationship to clinicopathological factors must be elucidated. Here, we selected 10 genes (TS, DPD, TP, FPGS, GGH, DHFR, ERCC1, TOPO-1, VEGF, and EGFR), examined differences in their mRNA expression between the upper and lower thirds of tumors by laser-captured microdissection and real-time RT-PCR (the Danenberg tumor profile), and analyzed the relationships between their expression profiles and clinicopathological factors. Interestingly, the mRNA expression of DPD, TP, and VEGF was significantly higher in the lower third than in the upper third of tumors (P = 0.044, 0.023, and 0.013, resp.). Furthermore, increased ERCC1 mRNA expression in the lower third of tumors correlated with recurrence (P = 0.049), and VEGF mRNA expression was significantly higher in cases with recurrence than in cases without recurrence, both in the upper and lower thirds of tumors (P = 0.018 and 0.036, resp.). These results implied that heterogeneity in DPD, TP, and VEGF expression may exist in colorectal carcinoma and that ERCC-1 and VEGF may be markers predicting recurrence after curative operation.

Prognostic and predictive value of serum vascular endothelial growth factor (VEGF) in squamous cell carcinoma of the head and neck

INTRODUCTION

This study aimed to investigate the prognostic and predictive value of serum vascular endothelial growth factor (VEGF) in head and neck squamous cell carcinoma (HNSCC).

METHOD

Preoperative and 6-month postoperative serum VEGF levels were measured using a quantitative sandwich enzyme immunoassay technique in 55 consecutive patients with HNSCC and two control groups. The first control group included normal, healthy, age- and sex-matched individuals (n = 20), while the second control group included the patients who had history of HNSCC and were free of disease for at least 5 years (n = 25).

RESULTS

The mean baseline serum VEGF concentrations of the 55 patients with HNSCC and the first and the second control groups were 437.86, 42.56, and 48.03 pg/ml, respectively (P < 0.001). After a median follow-up of 75 months, 15 patients of the study group developed recurrent disease and 40 patients remained free of disease. The mean preoperative and 6-month postoperative serum VEGF levels for the 40 patients who did not have recurrent disease were respectively 327.69 and 153.50 pg/ml compared to 731.72 and 692.96 pg/ml for the 15 patients with recurrent disease (P < 0.001). High (≥540 pg/ml) serum VEGF level was associated with poor overall survival (P < 0.001). Moreover, multivariate analysis showed node stage (P < 0.001) and preoperative serum VEGF level (P = 0.020) as significant, independent prognostic factors for overall survival.

CONCLUSION

Preoperative or postoperative elevated serum levels of VEGF are highly predictive for disease recurrence and are associated with poor disease-free and overall survival of patients with HNSCC.

Development for High‐Accuracy In Vitro Assay of Vascular Endothelial Growth Factor Using Nanomagnetically Labeled Immunoassay

Nanomagnetically labeled immunoassays have been demonstrated to be promisingly applied in clinical diagnosis. In this work, by using antibody‐functionalized magnetic nanoparticles and a high‐temperature superconducting quantum interference device ac magnetosusceptometer, the assay properties for vascular endothelial growth factor (VEGF) in serum are investigated. By utilizing the assay method so‐called immunomagnetic reduction, the properties of assaying VEGF are explored. In addition, the VEGF concentrations in serum samples of normal people and patients with either colorectal or hepatocellular cancer are detected. The experimental results show that the low‐detection limit for assaying VEGF is 10 pg/mL, which is much lower than the clinical cut‐off VEGF concentration of 50 pg/mL for diagnosing malignancy. Besides, there are no significant interference effects on assaying VEGF from hemoglobin, conjugated bilirubin, and triglyceride. The VEGF concentrations in serum samples donated by normal people and patients with hepatocellular carcinoma or colorectal cancer are detected. A clear difference in VEGF concentrations between these two groups is found. These results reveal the feasibility of applying nanomagnetically labeled immunoassay to clinics.

Clinical imaging of tumor angiogenesis

Angiogenesis is an integral part of tumor growth and invasion. This has led to the emergence of several antiangiogenic therapies and stimulated efforts to accurately evaluate the extent of angiogenesis before and in response to anticancer treatment. The most commonly used approach has been the assessment of new vessel formation in histological samples. However, it is becoming apparent that this is insufficient for a full understanding of tumor physiology and for in vivo guidance of cancer management. Imaging has the potential to provide noninvasive and repeatable assessment of the angiogenic process. Imaging approaches use a variety of modalities and are aimed at either assessment of the functional integrity of tumor vasculature or assessment of its molecular status. This review summarizes the aims and methods of clinical tumor angiogenesis imaging, including present technologies and ones that will be developed within the next 5-10 years.

Serum vascular endothelial growth factor and angiopoietin-2 are associated with the severity of systemic inflammation rather than the presence of hemoptysis in patients with inflammatory lung disease

PURPOSE

Vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) are major mediators of angiogenesis and are induced by tissue inflammation and hypoxia. The purpose of this study was to investigate whether serum VEGF and Ang-2 are associated with the presence of hemoptysis and the extent of systemic inflammation in patients with inflammatory lung diseases.

MATERIALS AND METHODS

We prospectively enrolled 52 patients with inflammatory lung disease between June 2008 and October 2009.

RESULTS

The median values of VEGF and Ang-2 were 436 pg/mL and 2383 pg/mL, respectively. There was a significant positive correlation between serum Ang-2 and VEGF levels. VEGF levels were not significantly different according to the presence of hemoptysis. C-reactive protein (CRP) and Ang-2 level were significantly higher in patients without hemoptysis (n=26) than in those with hemoptysis (n=26; p<0.001 and p<0.001, respectively). CRP and arterial oxygen tension (PaO₂) were significantly correlated with both serum VEGF (p=0.032 and p=0.016, respectively) and Ang-2 levels (p<0.001 and p=0.041, respectively), after adjusting for other factors. Age and the absence of hemoptysis were factors correlated with serum Ang-2 levels.

CONCLUSION

Our study suggests that serum VEGF and Ang-2 levels are associated with PaO₂ and the severity of inflammation rather than the presence of hemoptysis in patients with inflammatory lung diseases. Thus, hemoptysis may not be mediated by increased serum levels of VEGF and Ang-2 in patients with inflammatory lung diseases, and further studies are required to determine the mechanisms of hemoptysis.

Targeted therapies for gastric cancer: current status

Gastric cancer represents one of the most common cancers internationally. Unfortunately the majority of patients still present at an advanced stage, and despite advances in diagnostic and treatment strategies, outcomes still remain poor with high mortality rates despite a decline in incidence. Whilst the utility of classical chemotherapy agents has been explored thoroughly (and continues to be investigated, alone or in various combinations), advances have been slow and the efficacy of these agents has reached a plateau. As such, the focus of recent study has shifted toward developing a greater understanding of the molecular biology of carcinogenesis and the cancer cell phenotype, and, in turn, the development of rationally designed drugs that target molecular aberrancies in signal transduction pathways specific to gastric cancer. These targets include circulating growth and angiogenic factors, cell surface receptors, and other molecules that comprise downstream intracellular signalling pathways, including receptor tyrosine kinases. Therapeutic advances in this area significantly lag behind other solid organ malignancies such as breast and colorectal cancer. This article reviews the role of targeted therapies in gastric cancer, including rationale and mechanism of action, current and emerging data, as single-agent therapy or in combination regimens. A recently published randomized phaseIII trial supporting the use of trastuzumab, an anti-human epidermal growth factor receptor 2 (HER2)/neu monoclonal antibody, in a selected population of patients is discussed. Therapies that have been evaluated in phase II trials are also reviewed, as well as promising new therapies currently being investigated in preclinical or phase I studies. There is optimism that targeted therapies, whether as single-agent therapy or in combination with traditional therapies, including chemotherapy, radiotherapy and surgery, may yet have an impact on improvement of the overall prognosis of gastric cancer.

Neoadjuvant treatment in rectal cancer: actual status

Neoadjuvant (preoperative) concomitant chemoradiotherapy (CRT) has become a standard treatment of locally advanced rectal adenocarcinomas. The clinical stages II (cT3-4, N0, M0) and III (cT1-4, N+, M0) according to International Union Against Cancer (IUCC) are concerned. It can reduce tumor volume and subsequently lead to an increase in complete resections (R0 resections), shows less toxicity, and improves local control rate. The aim of this review is to summarize actual approaches, main problems, and discrepancies in the treatment of locally advanced rectal adenocarcinomas.

Targeting the tumor microenvironment: focus on angiogenesis

Tumorigenesis is a complex multistep process involving not only genetic and epigenetic changes in the tumor cell but also selective supportive conditions of the deregulated tumor microenvironment. One key compartment of the microenvironment is the vascular niche. The role of angiogenesis in solid tumors but also in hematologic malignancies is now well established. Research on angiogenesis in general, and vascular endothelial growth factor in particular, is a major focus in biomedicine and has led to the clinical approval of several antiangiogenic agents including thalidomide, bevacizumab, sorafenib, sunitinib, pazopanib, temesirolimus, and everolimus. Indeed, antiangiogenic agents have significantly changed treatment strategies in solid tumors (colorectal cancer, renal cell carcinoma, and breast cancer) and multiple myeloma. Here we illustrate important aspects in the interrelationship between tumor cells and the microenvironment leading to tumor progression, with focus on angiogenesis, and summarize derived targeted therapies.

Vascular endothelial growth factor in the aqueous humour in eyes with myopic choroidal neovascularization

PURPOSE

To determine the concentration of vascular endothelial growth factor (VEGF) in the aqueous humour of eyes with myopic choroidal neovascularization (mCNV).

METHODS

Aqueous humour samples were obtained from 21 eyes of 21 patients with mCNV and from 21 eyes of 21 patients with cataract without CNV or other ocular or systemic diseases (control group). The VEGF concentration in the aqueous humour was measured using an enzyme-linked immunosorbent assay.

RESULTS

The VEGF concentrations in the aqueous humour of eyes with mCNV ranged from < 20.6 to 200 pg/ml (median 35 pg/ml). The concentrations in the control group ranged from 26 to 218 pg/ml (median 100 pg/ml). The difference between the two VEGF concentrations in the aqueous humour was significant (p < 0.001, Mann--Whitney rank sum test).

CONCLUSION

The VEGF concentration in the aqueous humour of patients with mCNV is lower than in normal controls. VEGF might localize in or around the CNV in eyes with mCNV.

Potential of soluble CD26 as a serum marker for colorectal cancer detection

Colorectal cancer is characterized by a low survival rate even though the basis for colon cancer development, which involves the evolution of adenomas to carcinoma, is known. Moreover, the mortality rates continue to rise in economically transitioning countries although there is the opportunity to intervene in the natural history of the adenoma–cancer sequence through risk factors, screening, and treatment. Screening in particular accounted for most of the decline in colorectal cancer mortality achieved in the USA during the period 1975-2000. Patients show a better prognosis when the neoplasm is diagnosed early. Among the variety of screening strategies, the methods range from invasive and costly procedures such as colonoscopy to more low-cost and non-invasive tests such as the fecal occult blood test (guaiac and immunochemical). As a non-invasive biological serum marker would be of great benefit because of the performance of the test, several biomarkers, including cytologic assays, DNA and mRNA, and soluble proteins, have been studied. We found that the soluble CD26 (sCD26) concentration is diminished in serum of colorectal cancer patients compared to healthy donors, suggesting the potential utility of a sCD26 immunochemical detection test for early diagnosis. sCD26 originates from plasma membrane CD26 lacking its transmembrane and cytoplasmic domains. Some 90%–95% of sCD26 has been associated with serum dipeptidyl peptidase IV (DPP-IV) activity. DPP-IV, assigned to the CD26 cluster, is a pleiotropic enzyme expressed mainly on epithelial cells and lymphocytes. Our studies intended to validate this test for population screening to detect colorectal cancer and advanced adenomas are reviewed here.

Vascular endothelial growth factor in the circulation in cancer patients may not be a relevant biomarker

BACKGROUND

Levels of circulating vascular endothelial growth factor (VEGF) have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for artificial VEGF release by platelets activated ex vivo. We hypothesize that "true" circulating (c)VEGF levels in most cancer patients are low and unrelated to cancer load or tumour angiogenesis.

METHODOLOGY

We determined VEGF levels in PECT, a medium that contains platelet activation inhibitors, in citrate plasma, and in isolated platelets in 16 healthy subjects, 18 patients with metastatic non-renal cancer (non-RCC) and 12 patients with renal cell carcinoma (RCC). In non-RCC patients, circulating plasma VEGF levels were low and similar to VEGF levels in controls if platelet activation was minimized during the harvest procedure by PECT medium. In citrate plasma, VEGF levels were elevated in non-RCC patients, but this could be explained by a combination of increased platelet activation during blood harvesting, and by a two-fold increase in VEGF content of individual platelets (controls: 3.4 IU/10(6), non-RCC: 6.2 IU/10(6) platelets, p = 0.001). In contrast, cVEGF levels in RCC patients were elevated (PECT plasma: 64 pg/ml vs. 21 pg/ml, RCC vs. non-RCC, p<0.0001), and not related to platelet VEGF concentration.

CONCLUSIONS

Our findings suggest that "true" freely cVEGF levels are not elevated in the majority of cancer patients. Previously reported elevated plasma VEGF levels in cancer appear to be due to artificial release from activated platelets, which in cancer have an increased VEGF content, during the blood harvest procedure. Only in patients with RCC, which is characterized by excessive VEGF production due to a specific genetic defect, were cVEGF levels elevated. This observation may be related to limited and selective success of anti-VEGF agents, such as bevacizumab and sorafenib, as monotherapy in RCC compared to other forms of cancer.

Detection of autoantibodies against Rabphilin-3A-like protein as a potential biomarker in patient's sera of colorectal cancer

BACKGROUND

Rabphilin-3A-like (RPH3AL) protein functions in the regulation of hormone exocytosis, and mutations in the RPHA3L gene have been associated with tumorigenesis in colorectal cancer (CRC). We evaluated the potential use of anti-RPH3AL autoantibodies as a marker for CRC detection.

METHODS

Sera from 84 patients with CRC and 63 healthy controls were analysed for the presence of RPH3AL autoantibodies with a Western blotting assay.

RESULTS

The frequencies of RPH3AL autoantibodies in the early stage, advanced stage and all CRC patients were 64.7%, 78.0% and 72.6%, respectively. These values are significantly higher than the frequency of RPH3AL autoantibodies in healthy controls (15.9%, P<0.001). Although the presence of RPH3AL autoantibodies did not correlate with clinical parameters, RPH3AL autoantibodies were found in 69.4% (34/49) of CRC patients who were negative for carcinoembryonic antigen. The value of the area under the receiver operating characteristic curve of RPH3AL autoantibody was 0.84, which suggests that screening for these autoantibodies could potentially be used for CRC diagnosis.

CONCLUSION

Circulating RPH3AL autoantibodies are prevalent in patients with CRC, and detection of these autoantibodies might provide a novel non-invasive approach for CRC diagnosis.

Sensitivity estimates of blood-based tests for colorectal cancer detection: impact of overrepresentation of advanced stage disease

A large number of blood-based markers have been proposed for early detection of colorectal cancer (CRC). Their sensitivity for detecting CRC has mostly been evaluated in clinical settings, and found to be higher in more advanced stages compared with earlier stages of the disease. The aim of this study is to estimate the overall sensitivity of blood-based markers expected in screening settings, where the proportion of advanced stages is typically lower than in clinical settings. A systematic literature review was performed on studies evaluating sensitivity and specificity of blood-based markers for early detection of CRC. For each study, overall sensitivity expected in screening settings was estimated by weighting stage-specific sensitivities according to the stage distribution of CRC expected in the screening setting. The latter was derived from 12,605 CRC cases diagnosed in the German screening colonoscopy program during 2003-2007. Overall, 73 studies evaluating 55 blood-based markers were identified. Adjusted sensitivity was lower than reported sensitivity in 120 (90%) evaluations of different markers. Median absolute reduction in sensitivity after adjustment was 9.0% (interquartile range: 4.0-13.0) units, whereas median relative reduction was 19.5% (interquartile range: 11.3-33.3%). Blood-based markers for CRC detection reported from clinical settings showed higher sensitivities than expected in the screening setting in most cases, mainly due to substantially higher proportions of advanced stage cancers. Adjustment of sensitivity to the stage distribution expected in the screening setting is crucial to obtain realistic and comparable estimates of sensitivities.

The neoadjuvant therapy of colorectal hepatic metastases and the role of biologic sensitizing and resistance factors

Liver metastasis represents a common systemic complication of colorectal cancers (CRCs). Partial liver resection has been demonstrated to result in long-term survival in certain well-selected patients with otherwise well-controlled systemic disease. Neoadjuvant therapy has been demonstrated to result in improved resectability and potentially longer survival in patients with liver metastases from CRC. The addition of biologic agents to chemotherapy has been shown to improve response rates and overall survival in patients with metastatic CRC. Here, we are discussing the role of biologic agents in the treatment of patients with liver metastases from CRC. We also discuss the role of biomarkers for response and resistance to such novel therapies.