Circulating vascular endothelial growth factor in patients with colorectal cancer

Circulating vascular endothelial growth factor and cancer risk: A bidirectional mendelian randomization

In observational studies, circulating vascular endothelial growth factor (VEGF) has been reported to be associated with certain types of cancer. The purpose of this study was to verify whether there is a causal relationship between circulating VEGF and different types of cancer and the direction of the causal relationship. Summary statistical data were obtained from the corresponding genome-wide association studies (GWASs) to investigate the causal relationship between circulating VEGF and the risk of several cancers, including breast cancer, ovarian cancer, lung cancer, colorectal cancer, anus and anal canal cancer, prostate cancer, esophageal cancer, kidney cancer, bladder cancer, thyroid cancer, malignant neoplasm of the brain and malignant neoplasm of the liver and intrahepatic bile ducts. A two-sample bidirectional Mendelian randomization (MR) analysis and sensitivity tests were used to evaluate the validity of causality. A causal relationship was detected between circulating VEGF and colorectal cancer (OR 1.21, 95% CI 1.11–1.32, p < 0.000) and colon adenocarcinoma (OR 1.245, 95% CI 1.10–1.412, p < 0.000). Suggestive evidence of association was detected in VEGF on malignant neoplasms of the rectum (OR 1.16, 95% CI 1.00–1.34, p = 0.049). No causal relationship was found between circulating VEGF and other types of cancer, nor was there a reverse causal relationship from tumors to VEGF (p > 0.05). Circulating VEGF has a causal relationship with specific types of cancer. Our findings highlight and confirm the importance of circulating VEGF in the prevention and treatment of colorectal cancer.

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.

Following Chemotherapy: Serum Cytokine (Tumor Necrosis Factor, Interleukin-2, Interleukin-11), Immunoglobulin, Complement, Vascular Endothelial Growth Factor Levels, and the Systemic Symptoms like Capillary Leak Syndrome

Several problems such as myalgia, arthralgia, fever, dyspnea, generalized edema, and pleural effusion can occur in cancer patients following the chemotherapy, especially at the first cycle of the first chemotherapy treatment. Although it is assumed that some cytokines are associated with the development of these symptoms and signs, their pathophysiology has not been discovered completely yet. They are usually mild, but they may rarely progress to the severe stage of "Systemic Capillary Leak Syndrome" with a high mortality rate. The objective of this study was to investigate the association between the serum levels of interleukin-2 (IL-2), interleukin-11 (IL-11), tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), and these symptoms and signs. A total of 44 cancer patients who had neither heart, lung, liver, renal, or thyroid disease were recruited into this study. Their symptoms and signs were examined and questioned before the first cycle of the first chemotherapy treatment and the 24 h after this chemotherapy. All participant's serum samples were taken, and the VEGF, TNF, IL-2, and IL-11 levels were studied. There was no association between the chemotherapeutic drugs, and the symptoms and signs such as edema, dyspnea, coughing, and flu-like symptoms. There was a significant decrease in IL-11 levels in the other treatment group compared with the group receiving paclitaxel, docetaxel, gemcitabine, and vinorelbine in the first day following chemotherapy (P = .006). However, no relation was observed between the symptoms and signs, the response to the chemotherapy, and the serum levels of VEGF, TNF, IL-2, and IL-11. These symptoms and life-threatening syndrome have been a current topic between the clinicians. Although some drugs and mediators are accused, its pathophysiology has not been discovered completely yet. In this study, we could not detect any association between the symptoms, signs, and the cytokine levels following the chemotherapy.

Genetic variation determines VEGF-A plasma levels in cancer patients

Angiogenesis is essential in tumor biology and is regulated by vascular endothelial growth factor (VEGF) ligands and receptors. Here we aimed to discover genetic variants associated with levels of circulating angiogenic proteins in cancer patients. Plasma was collected at baseline in 216 pancreatic and 114 colorectal cancer patients. Thirty-one angiogenic proteins were measured by ELISA. 484,523 Single Nucleotide Polymorphisms (SNP) were tested for association with plasma levels for each protein in pancreatic cancer patients. Three top-ranked hits were then genotyped in colorectal cancer patients, where associations with the same proteins were measured. The results demonstrated rs2284284 and MCP1 (P-value = 6.7e–08), rs7504372 and VEGF-C (P-value = 9.8e–09), and rs7767396 and VEGF-A (P-value = 5.8e–09) were SNP-protein pairs identified in pancreatic cancer patients. In colorectal cancer patients, only rs7767396 (A > G) and VEGF-A was validated (P-value = 5.18e–05). The AA genotype of rs7767396 exhibited 2.04–2.3 and 2.7–3.4-fold higher VEGF-A levels than those with AG and GG genotypes. The G allele of rs7767396 reduces binding of the NF-AT1 transcription factor. In conclusion, a common genetic variant predicts the plasma levels of VEGF-A in cancer patients through altered binding of NF-AT1.

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.

Serum Levels of Vascular Endothelial Growth Factor and Insulin-like Growth Factor Binding Protein-3 in Obstructive Sleep Apnea Patients: Effect of Continuous Positive Airway Pressure Treatment

Background and Aim:

Hypoxia, a major feature of obstructive sleep apnea (OSA), modifies Vascular Endothelial Growth Factor (VEGF) and Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) levels, which contribute to atherogenesis and occurrence of cardiovascular (CV) events. We assessed and compared serum levels of VEGF and IGFBP-3 in newly diagnosed OSA patients and controls, to explore associations with anthropometric and sleep parameters and to study the effect of continuous positive airway pressure (CPAP) treatment on these levels.

Materials and Methods:

Serum levels of VEGF and IGFBP-3 were measured in 65 OSA patients and 31 age- and body mass index- matched controls. In OSA patients, measurements were repeated after 6 months of CPAP therapy. All participants were non-smokers, without any comorbidities or systemic medication use.

Results:

At baseline, serum VEGF levels in OSA patients were higher compared with controls (p<0.001), while IGFBP-3 levels were lower (1.41±0.56 vs. 1.61±0.38 μg/ml, p=0.039). VEGF levels correlated with apnea-hypopnea index (r=0.336, p=0.001) and oxygen desaturation index (r=0.282, p=0.007). After 6 months on CPAP treatment, VEGF levels decreased in OSA patients (p<0.001), while IGFBP-3 levels increased (p<0.001).

Conclusion:

In newly diagnosed OSA patients, serum levels of VEGF are elevated, while IGFBP-3 levels are low. After 6 months of CPAP treatment these levels change. These results may reflect an increased CV risk in untreated OSA patients, which is ameliorated after CPAP therapy.

Circulating TGF-β1 and VEGF and risk of cancer among liver transplant recipients

Transplant recipients have elevated cancer risk, perhaps partly due to direct carcinogenic effects of immunosuppressive medications. Experimental evidence indicates that calcineurin inhibitors given to transplant recipients increase cellular expression of transforming growth factor β1 (TGF-β1) and vascular endothelial growth factor (VEGF), which could promote cancer. To assess the potential role of these pathways in the transplantation setting, we conducted a case–control study nested in a cohort of liver recipients. Cases had nonmelanoma skin cancer (N = 84), cancer of the lung (N = 29), kidney (N = 20), or colorectum (N = 17), or melanoma (N = 3). We selected N = 463 recipients without cancer as controls. TGF-β1 and VEGF levels were measured in sera obtained, on average, approximately 3 years before case diagnosis/control selection. We also measured platelet factor 4 (PF4), a marker of ex vivo platelet degranulation, because TGF-β1 and VEGF can be released from platelets, and we developed a statistical model to isolate the platelet-derived fraction from the remaining circulating component. Compared with controls, lung cancer cases had higher levels of TGF-β1 (median 22.8 vs. 19.4 ng/mL, P = 0.02) and VEGF (277 vs. 186 pg/mL, P = 0.02). However, lung cancer cases also had higher platelet counts (P = 0.08) and PF4 levels (P = 0.02), while residual serum levels of TGF-β1 and VEGF, after accounting for PF4, were unassociated with lung cancer (P = 0.40 and P = 0.15, respectively). Associations were not seen for other cancers. In conclusion, TGF-β1 and VEGF levels were increased in association with lung cancer among transplant recipients, which may be explained by increased platelet counts and platelet degranulation in lung cancer cases.

A pharmacokinetic binding model for bevacizumab and VEGF165 in colorectal cancer patients

PURPOSE

To characterize the population pharmacokinetics of bevacizumab, its binding properties to VEGF165 and the effect of demographic data and VEGF-A polymorphisms on the interplay between bevacizumab serum pharmacokinetics and VEGF165 serum concentrations in patients with colorectal cancer stage IV.

METHODS

Bevacizumab and VEGF165 data were collected from 19 adult patients with metastatic colorectal cancer enrolled in an observational clinical study. Bevacizumab was administered with one of the following combinations: 5-FU/Leucovorin/Irinotecan, 5-FU/Leucovorin/Oxaliplatin, Capecitabine/Irinotecan at doses ranging from 5 to 10 mg/kg every 2 or 3 weeks. Data analysis was performed using nonlinear mixed-effects modeling implemented in NONMEM 7.3.

RESULTS

A target-mediated drug disposition model adequately described bevacizumab concentration changes over time and its binding characteristics to VEGF165. The estimated clearance of bevacizumab was 0.18 L/day, the free VEGF165 levels at baseline were 212 ng/L, and the elimination rate constant of free VEGF165 was 0.401 day(-1). Body weight was allometrically included in all PK parameters.

CONCLUSION

The final model adequately described the pre- and post-dose concentrations of total bevacizumab and free VEGF165 in patients with colorectal cancer. Model parameters were consistent with those previously reported for patients with solid tumors. Correlations between the binding affinity of bevacizumab and the VEGF-2578C/A and VEGF-634G/C polymorphisms were noticed.

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.

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.

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.

Prognostic value of vascular endothelial growth factor expression in resected gastric cancer

BACKGROUND AND AIMS

Vascular endothelial growth factor (VEGF) is a potential prognostic biomarker for patients with resected gastric cancer. However, its role remains controversial. The objective of this study was to conduct a systematic review and meta-analysis of published literature.

METHODS

Relevant literature was identified using Medline and survival data from published studies were collected following a methodological assessment. Quality assessment of eligible studies and meta-analysis of hazard ratio (HR) were performed to review the correlation of VEGF overexpression with survival and recurrence in patients with gastric cancer.

RESULTS

Our meta-analysis included 44 published studies with 4,794 resected patients. VEGF subtype for the prediction of overall survival (OS) included tissue VEGF (HR=2.13, 95% CI 1.71-2.65), circulating VEGF (HR=4.22, 95% CI 2.47-7.18), tissue VEGF-C (HR=2.21, 95% CI 1.58-3.09), tissue VEGF-D (HR=1.73, 95% CI 1.25-2.40). Subgroup analysis showed that HRs of tissue VEGF for OS were, 1.78 (95% CI 0.90-3.51) and 2.31 (95% CI 1.82-2.93) in non-Asians and Asians, respectively. The meta-analysis was also conducted for disease free survival (DFS) and disease specific survival (DSS).

CONCLUSION

Positive expression of tissue VEGF, circulating VEGF, VEGF-C and VEGF-D were all associated with poor prognosis in resected gastric cancer. However, VEGF demonstrated no significant prognostic value for non-Asian populations. Circulating VEGF may be better than tissue VEGF in predicting prognosis.

Collaborating with the enemy: function of macrophages in the development of neoplastic disease

Due to the profile of released mediators (such as cytokines, chemokines, growth factors, etc.), neoplastic cells modulate the activity of immune system, directly affecting its components both locally and peripherally. This is reflected by the limited antineoplastic activity of the immune system (immunosuppressive effect), induction of tolerance to neoplastic antigens, and the promotion of processes associated with the proliferation of neoplastic tissue. Most of these responses are macrophages dependent, since these cells show proangiogenic properties, attenuate the adaptive response (anergization of naïve T lymphocytes, induction of Treg cell formation, polarization of immune response towards Th2, etc.), and support invasion and metastases formation. Tumor-associated macrophages (TAMs), a predominant component of leukocytic infiltrate, "cooperate" with the neoplastic tissue, leading to the intensified proliferation and the immune escape of the latter. This paper characterizes the function of macrophages in the development of neoplastic disease.

Immune microenvironmental shift along human colorectal adenoma-carcinoma sequence: is it relevant to tumor development, biomarkers and biotherapeutic targets?

Human colorectal carcinoma (CRC) is one of the leading cancers. Every year, the WHO estimates a total of 945,000 new CRC cases, with 492,000 deaths worldwide. Most CRCs arise from the main premalignant lesion, colorectal adenomas, and the progression of colorectal adenoma to CRCs may take a long-term time course. The development of human CRCs is not only determined by the adenomatous cells, but also by the interaction between adenomatous cells and host immune environment. In response to tumor initiation or invasion, many inflammatory cells and components will be inevitably activated and form an inflammatory microenvironment surrounding the CRC tumors. Accumulative evidence has revealed that inflammatory response plays a key role in the development of human CRCs by implicating in many aspects including in determining the microenvironmental immune function shift from immunosurveillance to immunosuppression and significantly influences the progression of precancerous lesions to cancers. In this review, the functional changes of immune microenvironment from precancerous stage (adenoma) to cancer stage are summarized, and their potential as predictive biomarkers and biotherapeutic significance in preventing the development of CRCs are discussed.

Preoperative Vascular Endothelial Growth Factor Levels as a Prognostic Marker for Stage II or III Colorectal Cancer Patients

Background

The aim of the present study was to determine whether serum vascular endothelial growth factor (VEGF) can provide prognostic information independent of carcinoembryonic antigen levels in patients undergoing curative surgery.

Methods

Serum samples were collected from 158 patients with colorectal cancer and from 100 controls. Serum and tissue levels of VEGF were measured by enzyme-linked immunosorbent assay. Serum VEGF levels in colorectal cancer patients were compared with those in healthy controls, and we retrospectively assessed the association between serum VEGF levels and clinicopathologic findings and survival.

Results

VEGF expression was significantly higher in colorectal cancer tissue compared with nontumor tissue. Mean serum VEGF levels in patients were significantly higher than those in controls, and significantly higher in patients with large tumors, lymph node involvement, and distant metastases.

Conclusion

Elevated serum VEGF was significantly associated with poor survival, but was only an independent risk factor for poor survival in Stage II and/or III disease. Elevated serum VEGF is significantly associated with development of colorectal cancer, and lymph or distant invasive phenotypes and survival, especially in Stage II and III patients.

Ligand-based 3D-QSAR studies of diaryl acyl-sulfonamide analogues as human umbilical vein endothelial cells inhibitors stimulated by VEGF

Diaryl acylsulfonamide derivatives were reported as Human Umbilical Vein Endothelial cell (HUVEC) inhibitors, stimulated by Vascular Endothelial Growth Factor (VEGF). VEGF has angiogenic property to cause colorectal cancer. A ligand-based 3D-QSAR technique was carried out on diaryl acylsulfonamide derivatives by using Comparative Molecular Field Analysis (CoMFA) studies to find relations between biological activities of inhibitors and their structures. In absence of binding mechanism for the ligand with VEGF receptor, current study hopes to shed some light on the inhibition mechanism of the ligands with HUVEC. 3D-QSAR technique was applied to a set of fifty ligands in order to facilitate the design of more potent inhibitors. However, the maximum cross-validated correlation coefficient value was found to be 0.417. The value is relatively low when compared to the usual acceptable cross-validated correlation coefficient, but no further improvements were observed by applying different available options. Therefore, the final model was used for further analysis. Additionally, the resulted CoMFA model was validated by an external set of 10 compounds yielding surprisingly, a satisfactory correlation coefficient value (r(2) (pred) ) 0.80. Moreover, the analysis of the individual generated 3D contours helped in understanding the possible structural modifications of molecules to improve the inhibitory potency.

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.

Cytokeratin 20 and vascular endothelial growth factor as molecular markers in Egyptian patients with colorectal cancer

PURPOSE

To investigate the expression of cytokeratin 20 (CK20) and vascular endothelial growth factor (VEGF) in the peripheral blood of colorectal cancer (CRC) patients, and correlate the findings with the pathologic data of the patients.

METHODS

This study was carried out on 50 subjects, 40 patients with histologically confirmed colorectal carcinoma undergoing elective surgery and 10 healthy individuals matched for age and sex. Total RNA extraction followed by real time quantitative RT-PCR and real time TaqMan quantitative assay for peripheral blood expression of CK20 and VEGF was done for both patients and controls.

RESULTS

(1) Statistically significant high levels of CK20,VEGF, CEA (p = 0.000 each) and CA19-9 (p = 0.002) in CRC patients when compared with controls; (2) Statistically significant increase in the expression of CK20 in advancing CRC stage C (p = 0.001) and with LN metastasis (p = 0.000); (3) Statistically significant increase in the expression of VEGF in advancing CRC stage C (p = 0.002), pathologic grade (p = 0.038), and with LN metastasis (p = 0.004); and (4) statistically positive correlation between CK20 and VEGF expressions, and also between these markers and CEA level.

CONCLUSION

CK20 and VEGF expressions in peripheral blood of CRC patients are promising molecular markers for CRC progression and metastasis.

Platelet-derived growth factor (subtype BB) is elevated in patients with colorectal carcinoma

PURPOSE

Platelet-derived growth factor-BB plays a role in the development of vascular and lymphatic vessels in tumors. In this study plasma levels of platelet-derived growth factor-BB were assessed preoperatively in patients with adenomas and colorectal cancer to determine whether platelet-derived growth factor-BB is a useful marker or prognostic indicator.

METHODS

Patients with adenomas and colorectal cancer undergoing resection were assessed. Clinical and pathologic data and preoperative blood samples were collected. Plasma platelet-derived growth factor-BB levels (median, 95 percent confidence interval for median) were determined and the Kruskal-Wallis test and Mann-Whitney U test were used for analysis.

RESULTS

One hundred seventy-nine patients were studied (91 with colorectal cancer, 88 with adenomas). Preoperative colorectal cancer platelet-derived growth factor-BB levels were higher (1,771.1 pg/ml; confidence intervals, 1,429-2,065) than in the benign neoplasm group (1083 pg/ml; confidence intervals, 933-1,192, P < 0.001). In patients with colorectal cancer, a direct relationship was noted between platelet-derived growth factor-BB levels and disease severity. Despite the increase in platelet-derived growth factor-BB noted with increasing stage, the differences between the Stages 1, 2, 3, and 4 groups were not significant.

CONCLUSION

Platelet-derived growth factor-BB levels were greater in patients with colorectal cancer (vs. patients with adenoma) and rose with increasing disease severity. Unfortunately, however, the modest differences between categories do not permit accurate stage determination.

Macrophage migration inhibitory factor promotes colorectal cancer

A growing body of evidence implicates macrophage migration inhibitory factor (MIF) in tumorigenesis and metastasis. In this study, we investigated whether MIF expression was associated with clinicopathologic features of colorectal carcinoma (CRC), especially in tumors with hepatic metastasis, and whether neutralization of endogenous MIF using anti-MIF therapeutics would inhibit tumor growth and/or decrease the frequency of colorectal hepatic metastases in a mouse colon carcinoma model. The concentration of serum MIF was positively correlated with an increased risk of hepatic metastasis in human patients with CRC (R = 1.25, 95% confidence internal = 1.02-1.52, P = 0.03). MIF was also dramatically upregulated in human colorectal tissue, with 20-40 times as many MIF-positive cells found in the mucosa of patients with CRC than in normal tissue (P < 0.001 ANOVA). Moreover, in those patients with metastatic colorectal cancer in the liver, MIF-positive cells were similarly increased in the diseased hepatic tissue. This increased MIF expression was restricted to diseased tissue and not found in areas of the liver with normal morphology. In subsequent in vitro experiments, we found that addition of recombinant MIF to colonic cell lines significantly increased their invasive properties and the expression of several genes (for example, matrix metalloproteinase 9 and vascular endothelial growth factor) known to be upregulated in cancerous tissue. Finally, we treated mice that had been given CT26 colon carcinoma cell transplants with anti-MIF therapeutics--either the MIF-specific inhibitor ISO-1 or neutralizing anti-MIF antibodies--and observed a significant reduction in tumor burden relative to vehicle-treated animals. Taken together, these data demonstrate that MIF expression was not only correlated with the presence of colorectal cancer but also may play a direct role in cancer development.

Clinical significance of plasma and serum vascular endothelial growth factor in asthma

BACKGROUND

Vascular endothelial growth factor (VEGF) is a mediator of airway inflammation and remodeling in asthma.

PURPOSE

We investigated whether VEGF levels are elevated in plasma and serum obtained from patients with asthma and evaluated whether levels of plasma VEGF correlated with those of serum VEGF.

METHODS

We measured levels of plasma and serum VEGF in patients with stable asthma or with acute asthma and examined the correlation between plasma and serum VEGF concentration with initial forced expiratory volume in 1 second (FEV(1)).

RESULTS

We found that levels of VEGF in plasma or in serum were significantly increased in stable asthmatic patients and even higher in acute asthmatic patients compared with the levels in healthy control subjects. The levels of serum VEGF correlated significantly with those of plasma VEGF. Additionally, the circulating VEGF levels were significantly inversely correlated with the percent predicted FEV(1).

CONCLUSION

These results suggest that the overproduction of VEGF is implicated in asthma exacerbation and that measurement of either plasma or serum VEGF level can be a valid index in asthmatic patients. Therefore, the changes in the VEGF levels in peripheral blood of asthmatic patients can be used as a measure for progression of asthma during treatment.

Post-collection, pre-measurement variables affecting VEGF levels in urine biospecimens

Angiogenesis, the development and recruitment of new blood vessels, plays an important role in tumour growth and metastasis.Vascular endothelial growth factor (VEGF) is an important stimulator of angiogenesis.Circulating and urinary VEGF levels have been suggested as clinically useful predictors of tumour behaviour, and investigations into these associations are ongoing.Despite recent interest in measuring VEGF levels in patients, little is known about the factors that influence VEGF levels in biospecimens. To begin to address this question, urine samples were collected from patients with solid tumours undergoing radiotherapy and healthy volunteers.Four factors were examined for their effects on VEGF concentrations as measured by chemiluminescent immunoassay: time from sample collection to freezing, number of specimen freeze–thaw cycles, specimen storage tube type and the inclusion or exclusion of urinary sediment. The results of this study indicate that time to freeze up to 4 hrs, number of freeze–thaw cycles between one and five, and different types of polypropylene tubes did not have statistically significant effects on measured urinary VEGF levels. Urinary sediment had higher VEGF levels than supernatant in five of six samples from healthy patients.It is not clear whether there is an active agent in the sediment causing this increase or if the sediment particles themselves are affecting the accuracy of the assay.Therefore, we recommend centrifuging urine, isolating the supernatant, and freezing the sample in polypropylene microcentrifuge tubes or cryogenic vials within 4 hrs of collection.In addition, we recommend the use of samples within five freeze–thaw cycles.

Comparison of angiogenic factor levels in tumor drainage and peripheral venous blood from colorectal cancer patients

BACKGROUND

The main objective of this study was to determine whether there was a correlation in the levels of various angiogenesis-related factors between the tumor drainage and peripheral venous blood and whether appraisal of angiogenic factor levels in the tumor drainage venous blood could provide better prognostic information for patients with colorectal cancer than assessment of the peripheral venous blood.

METHODS

Plasma levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor, and endostatin were measured and compared in both tumor drainage and peripheral venous blood from 52 patients with colorectal cancer. Plasma levels of angiogenesis-related factors were also correlated with tumor stage and clinical outcomes.

RESULTS

The plasma endostatin level was significantly higher in peripheral blood than in tumor drainage venous blood (P < .001). The plasma VEGF level was significantly correlated with plasma endostatin levels (P = .028 in tumor drainage venous blood and P = .002 in peripheral venous blood). In both tumor drainage and peripheral venous blood, the VEGF level (but not the basic fibroblast growth factor or endostatin level) was significantly correlated with tumor stage and disease recurrence. However, in multivariate analysis, only plasma VEGF level in tumor drainage venous blood remained an independent predictor of disease recurrence.

CONCLUSIONS

The plasma VEGF level in tumor drainage venous blood provided better prognostic information than that in peripheral venous blood. The plasma endostatin level was paradoxically significantly higher in peripheral than in tumor drainage blood, and this strongly suggests additional sources of endostatin in peripheral blood.

[New prognostic and predictive factors in advanced colorectal cancer]

Cancer patients often show a clinical tendency to thromboembolic events. This tendency is due to tumor cell-related factors together with the damage of the vascular endothelial exerted by chemotherapy treatment. Gastrointestinal tumors especially contribute to these types of events. More recently, the implication of tumor angiogenesis in clotting/fibrynolisys and plasminogen systems activation has been addressed in cancer patients. Finally, some hemostasis and angiogenesis-related factors such as platelets, von Willebrand factor, fibrinogen, plasminogen activator inhibitor type-1, D dimer, and vascular endotelial growth factor have been highlighted as new potential response and survival predictors in colorectal cancer patients. In this review article, the current evidence supporting the use of these proteins in assessing prognosis in colorectal cancer patients is critically exposed and discussed.

Profile of plasma angiogenic factors before and after hepatectomy for colorectal cancer liver metastases

BACKGROUND

Circulating angiogenic factors in patients with colorectal cancer liver metastases may promote tumor growth and contribute to liver regeneration after partial hepatectomy.

METHODS

We analyzed blood samples from 26 patients with colorectal cancer liver metastases before and after liver resection and used samples from 20 healthy controls as a reference. Plasma levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and hepatocyte growth factor (HGF) were measured, and levels were correlated with recurrence.

RESULTS

The median preoperative levels of all four factors were significantly higher and more variable in colorectal cancer liver metastasis patients than in controls. HGF and bFGF levels increased significantly 3 days and 1 month after hepatectomy, respectively, and returned to near preoperative levels at 3 months. Postoperative VEGF and EGF levels remained relatively stably increased over 3 months. After a median follow-up of 19 months, 10 patients (42%) experienced recurrence. Higher preoperative VEGF and HGF levels correlated with subsequent recurrence (P = .018 and .021, respectively), and a preoperative adjusted total value of all four factors accurately identified patients at low, moderate, and high risk of recurrence (P = .034). Patients who experienced disease recurrence also had relatively higher bFGF levels 3 months after operation (P = .035).

CONCLUSIONS

Plasma angiogenic factors are increased in patients with colorectal cancer liver metastases and remain increased at least 3 months after partial hepatectomy. Measurement of certain factors before and after hepatic resection can predict recurrence. Targeted biological agents may counteract the tumor-promoting effects of these circulating factors on subclinical disease.

Association of interleukin-8 and plasminogen activator system in the progression of colorectal cancer

The aim of this study was to investigate the relationship of Interleukin-8 (IL-8) with vascular endothelial growth factor (VEGF) and plasminogen activator system (PA system) in the progression of colorectal cancer (CRC). In eighty-seven patients with CRC, the levels of IL-8, and VEGF as representative angiogenic factors and urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1), and PAI-2 as representative invasive factors were quantitatively assayed in tumor and adjacent normal tissues. The levels of IL-8, VEGF, and PA system factors in tumor tissues were all significantly higher than those in normal tissues. The IL-8 level was significantly associated with tumor size, depth of infiltration, Dukes stage, and liver metastasis, and also significantly correlated with the levels of VEGF, uPAR, uPA, and PAI-1. The VEGF level was significantly associated with tumor size, vascular involvement. The levels of uPAR and PAI-1 were significantly associated with tumor size and depth of infiltration, and the uPAR level was associated with liver metastasis. The VEGF level was significantly correlated with the levels of uPAR and PAI-1. These results reveal that IL-8, VEGF, and PA system factors are contributed to tumor growth, invasion, and metastasis in CRC. Univariate analysis revealed that high levels of IL-8, VEGF, and uPAR were significantly associated with a shorter overall survival time; however, multivariate analysis identified only liver metastasis as an independent prognostic factor. In conclusion, IL-8 is responsible to tumor progression and liver metastasis of CRC, and the activation of PAS induced by IL-8 as well as VEGF may play an important role in the progression of CRC.

Results of a phase I trial of sorafenib (BAY 43-9006) in combination with oxaliplatin in patients with refractory solid tumors, including colorectal cancer

BACKGROUND

Sorafenib (BAY 43-9006), a multiple kinase inhibitor, has been shown to inhibit tumor growth and tumor angiogenesis by targeting Raf kinase, vascular endothelial growth factor receptor, and platelet-derived growth factor receptor. In phase I studies, sorafenib demonstrated single-agent activity in patients with advanced solid tumors and was successfully combined with oxaliplatin in preclinical studies. This phase I study investigated the safety, pharmacokinetics, and efficacy of sorafenib in combination with oxaliplatin.

PATIENTS AND METHODS

Twenty-seven patients with refractory solid tumors were enrolled in the initial dose-escalation part (cohorts 1, 2A, and 2B) and 10 additional patients with oxaliplatin-refractory colorectal cancer were subsequently enrolled in an extension part (cohort 3). Oxaliplatin 130 mg/m2 was given on day 1 of a 3-week cycle and oral sorafenib was administered continuously from day 4 of cycle 1 at 200 mg twice daily (cohort 1) or 400 mg twice daily (cohorts 2A, 2B, and 3).

RESULTS

Adverse events were generally mild to moderate and the maximum tolerated dose was not reached. Common adverse events were diarrhea (52% of patients in the dose-escalation part and 20% in the extension part), sensory neuropathy (44% and 20%), and dermatologic toxicities (41% and 80%). No pharmacokinetic interaction between sorafenib and oxaliplatin was detectable. Two patients with gastric cancer had a partial response. Forty-three percent of patients in cohorts 1 and 2A/B and 78% of patients in cohort 3 exhibited stable disease for >or=10 weeks.

CONCLUSION

Continuous oral sorafenib 400 mg twice daily was safely combined with oxaliplatin without detectable drug interactions and showed preliminary antitumor activity in this phase I study. This dose is recommended for phase II studies.

Microarray versus conventional prediction of lymph node metastasis in colorectal carcinoma

BACKGROUND

The authors investigated whether microarray-based gene expression analysis of primary tumor biopsy material could be used to predict lymph node status in patients with colorectal carcinoma (CRC). Lymphatic metastasis strongly determines treatment algorithms in CRC. Currently, postoperative histology results are needed to determine lymph node status. Reliable preoperative information would be useful to advance treatment strategies.

METHODS

In specimens from 66 patients with CRC from the Erlangen Registry of Colorectal Cancer, 41 shock-frozen samples of International Union Against Cancer (UICC) Stage I-II CRC and 25 samples of UICC Stage III CRC were microdissected manually, RNA was isolated, and gene chips (HG-U133A; Affymetrix) were hybridized. Prediction rates for lymphatic metastasis were calculated using conventional clinicopathologic parameters, gene expression data, and a combination of both. Prediction error, specificity, and sensitivity were analyzed using six different statistical classifiers.

RESULTS

Analysis of conventional parameters produced a positive prediction rate that ranged between 53% and 61%, sensitivity of 42%, and specificity of 72%. Microarray prediction rates were between 62% and 67% for lymphatic metastasis. Specificity was between 76% and 83%, and sensitivity was between 38% and 48%, depending on the statistical procedure. The conventional estimates were improved by 9-12% when array data were added.

CONCLUSIONS

Current data show that the prediction of lymphatic metastasis can be improved by gene expression profiling of the primary tumor biopsy, alone or in combination with conventional parameters. Gene expression profiling may become valuable increasingly in planning treatment for patients with CRC.

Preoperative serum vascular endothelial growth factor is not a marker for subsequent recurrence during long-term follow-up of colorectal cancer patients

BACKGROUND

Serum vascular endothelial growth factor has been associated with stage of disease in colorectal cancer patients. We investigated whether preoperative serum vascular endothelial growth factor can provide any relevant clinical prognostic information during long-term follow-up of colorectal cancer patients.

METHODS

Preoperative serum samples of 79 colorectal cancer patients and serum of 28 healthy controls were stored at -80 degrees C until later vascular endothelial growth factor analysis by enzyme-linked immunosorbent assay technique and carcinoembryogenic antigen concentration measurement were performed. There were three patient groups for comparison: 21 patients with overt liver metastases, 18 patients who developed recurrent disease after initial curative surgery, and 40 patients who remained disease-free for at least five years.

RESULTS

We could not demonstrate any significant difference in serum vascular endothelial growth factor values between the patient groups and controls, nor between the three patient groups (Mann-Whitney U test). There was no relevant correlation between serum vascular endothelial growth factor and carcinoembryogenic antigen concentrations (Pearson r = 0.2; P = 0.07).

CONCLUSION

Although vascular endothelial growth factor has been shown in previous studies to be a potent inducer of angiogenesis and metastases formation, the present data demonstrate that preoperative serum vascular endothelial growth factor concentration does not provide any relevant individual prognostic information in patients with colorectal cancer.

Clinical significance of VEGF-A, -C and -D expression in esophageal malignancies

Vascular endothelial growth factors (VEGF)-A, -C and -D are members of the proangiogenic VEGF family of glycoproteins. VEGF-A is known to be the most important angiogenic factor under physiological and pathological conditions, while VEGF-C and VEGF-D are implicated in the development and sprouting of lymphatic vessels, so called lymphangiogenesis. Local tumor progression, lymph node metastases and hematogenous tumor spread are important prognostic factors for esophageal carcinoma (EC), one of the most lethal malignancies throughout the world. We found solid evidence in the literature that VEGF expression contributes to tumor angiogenesis, tumor progression and lymph node metastasis in esophageal squamous cell carcinoma (SCC), and many authors could show a prognostic value for VEGF-assessment. In adenocarcinoma (AC) of the esophagus angiogenic properties are acquired in early stages, particularly in precancerous lesions like Barrett's dysplasia. However, VEGF expression fails to give prognostic information in AC of the esophagus. VEGF-C and -D were detected in SCC and dysplastic lesions, but not in normal mucosa of the esophagus. VEGF-C expression might be associated with lymphatic tumor invasion, lymph node metastases and advanced disease in esophageal SCC and AC. Therapeutic interference with VEGF signaling may prove to be a promising way of anti-angiogenic co-treatment in esophageal carcinoma. However, concrete clinical data are still pending.

[Markers in patients with squamous cell carcinoma of the oral cavity. Expression and long-term follow-up of VEGF, FLT-1 and Tie2 in serum]

OBJECTIVE

The quantification of serum or plasma levels of angiogenic factors in patients with malignancies aims at the description of these factors or their receptors and allows a tissue independent study of biological tumor behavior.

METHODS

In 51 patients with untreated squamous cell carcinoma of the oral cavity (SCCOC) and 10 healthy controls, plasma levels of VEGF and serum levels of the VEGF-receptor FLT-1 and the Ang1-receptor Tie2 were measured. Using an ELISA technique, the concentration of these factors was measured preoperatively and postoperatively over a period of 5 weeks.

RESULTS

No statistically significant correlation could be found between the serum and plasma levels and the clinical or pathological parameters. There was no difference between the patients with SCCOC and healthy controls.

CONCLUSIONS

In patients with SCCOC, plasma levels of VEGF and serum levels of FLT-1 and Tie-2 do not provide any further information on the biological tumor behavior like proliferation or expression of metastases.

Vascular endothelial growth factor in esophageal cancer

Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis of many solid malignancies. The influence of angiogenesis and VEGF expression on progression and recurrence of esophageal cancer has been investigated over the last years. This article reviews the prognostic significance of VEGF expression, microvessel density (MVD), and lymphangiogenic factors in squamous cell carcinoma (SCC), Barrett's dysplasia, and adenocarcinoma (AC) of the esophagus, their predictive value for treatment response to chemo-radiotherapy and new anti-angiogenic treatment strategies.

Valores séricos de factor de crecimiento del endotelio vascular en pacientes con cáncer colorrectal y su significación pronóstica

BACKGROUND AND OBJECTIVE

Thirty per cent of patients with histologically node-negative colorectal cancer die from disseminated disease. Actually disease stage is the most useful prognostic parameter although it is not sufficient. Vascular endothelial growth factor (VEGF) is an angiogenic cytokine involved in the progression of tumors. In our study we tried to know the prognostic significance of pre and postoperative serum VEGF levels in patients with colorectal cancer.

PATIENTS AND METHOD

Cohort study that included 52 patients with colorectal cancer surgically treated in our Department from 1998 to 2000. Serum VEGF and CEA levels were determined the day before surgery and 30 days after it.

RESULTS

Preoperative serum VEGF levels (428.5 [38.5] pg/ml) were higher than in control patients (p=0.008). Serum VEGF levels fallen significantly after surgery (343 [31.2] pg/ml; p=0.001). Pre and postoperative serum VEGF levels in poorly differentiated neoplasms were higher than in well differentiated ones (p=0.009 and p=0.008 respectively). Pre and postoperative serum CEA and VEGF levels were significantly associated with cancer relapse (p=0.037, p=0.017, p=0.048 and p=0.001, respectively). In multivariate analysis only postoperative serum VEGF levels were associated with colorectal cancer relapse (p=0.003; HR=1.007; 95% CI, 1.002-1.012). Pre and postoperative CEA levels (p<0.001 and p=0.001 respectively) and postoperative VEGF levels (p=0.001), were associated with mortality. In multivariate analysis only tumor stage (p=0.01) and postoperative serum VEGF levels (p=0.02) were associated with mortality. Postoperative serum VEGF determination and pre and postoperative CEA levels raise specificity and positive predictive values to 100% in relation to mortality.

CONCLUSIONS

Pre and postoperative serum VEGF determination has prognostic significance, regardless of tumor stage, in patients with colorectal cancer. In survival methods, postoperative VEGF levels >343 pg/ml are significantly with tumor relapse and mortality. These results suggest the use of serum VEGF levels as a prognostic and monitoring factor besides CEA.

Antiangiogenesis: the fifth cancer treatment modality?

PURPOSE/OBJECTIVES

To describe the biologic process of angiogenesis and the potential role of antiangiogenesis therapy in cancer treatment.

DATA SOURCES

Published articles, conference proceedings, and computerized databases.

DATA SYNTHESIS

Angiogenesis is the development of blood vessels. Antiangiogenic agents prevent the development of blood vessels, therefore preventing one mode of cancer metastasis. Clinical trials must be conducted to ascertain the most powerful antiangiogenic therapies. Trials combine chemotherapy, biotherapy, and radiotherapy with antiangiogenic therapy.

CONCLUSIONS

Information from animal studies has revealed that antiangiogenesis is a viable option in treating cancer and preventing metastasis. Although human studies are rare, preliminary results are promising, especially when antiangiogenesis is used in combination with current cancer treatment modalities.

IMPLICATIONS FOR NURSING

Nurses are in a unique position to teach patients about new treatments for cancer. Nurses must be knowledgeable about angiogenesis and the availability of potential antiangiogenesis agents. Nurses will be vital in collecting data in clinical trials, considering the subjective data that will be obtained.

Effects of major liver resection, with or without recombinant bactericidal/permeability-increasing protein (rBPI21), on the angiogenic profile of patients with metastatic colorectal carcinoma

BACKGROUND

Surgery induces a process of wound healing, which has immunological and angiogenic aspects. Bactericidal/permeability-increasing protein (BPI) is found in azurophilic granules of human neutrophils, which is bactericidal and neutralizes lipo-polysaccharide (LPS). This may reduce postoperative infectious complications. In addition, BPI has been shown to be an inhibitor of angiogenesis.

METHODS

A total of 18 patients with metastasized colorectal carcinoma to the liver were double blind randomized. The levels of the pro-angiogenic factors interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) and the angiogenesis inhibitor endostatin were investigated after liver surgery with perioperative administration of either rBPI(21) or placebo.

RESULTS

The highest IL-6 levels were found during the first 24 hr and reached peak levels already at 2 hr postoperatively in both groups. In both groups VEGF levels decreased sharply in the postoperative hours, returning to baseline levels in the days afterwards. In both groups, an immediate decrease in endostatin levels was observed which remained significantly low. RBPI(21) transiently influenced IL-6 and VEGF.

CONCLUSIONS

RBPI(21) only marginally affected IL-6 and VEGF levels. Surgery per se induced an immediate immune response (IL-6) and an immediate angiogenic response, reflected in an initial VEGF decrease and a longer lasting decrease of endostatin. These findings demonstrate the dynamics of tissue responses in the first phase of wound healing.

Clinical significance of angiogenesis in gastrointestinal cancers: a target for novel prognostic and therapeutic approaches

OBJECTIVE

To review the current data on the prognostic and therapeutic implications of tumor angiogenesis in gastrointestinal cancers.

SUMMARY BACKGROUND DATA

Numerous studies have evaluated the prognostic value of tumor angiogenesis and the potential role of antiangiogenic therapy in various gastrointestinal cancers.

METHODS

A Medline literature search was conducted using "angiogenesis" or the names of various angiogenic factors in combination with the names of gastrointestinal cancers as the key words.

RESULTS

Several studies have demonstrated a significant prognostic impact of tumor microvessel density and tumor expression of angiogenic factors, in particular vascular endothelial growth factor (VEGF), in various gastrointestinal cancers. A few studies have suggested that circulating VEGF might be a useful prognostic marker. However, results were not consistent across all studies and were limited by the retrospective nature of most studies. Antiangiogenic therapy has been shown to be effective against all common gastrointestinal cancers in preclinical studies, but currently there are few clinical data with regard to antiangiogenic therapy in gastrointestinal cancers.

CONCLUSIONS

There is mounting evidence to suggest that assessment of tumor angiogenesis might provide a novel approach of prognostication in patients with gastrointestinal cancers. However, current results from retrospective studies need to be validated by prospective studies. Antiangiogenic therapy is a promising strategy of cancer treatment that might be particularly useful in combination therapy for unresectable cancers or as an adjuvant therapy for resectable tumors.

The role of circulating IL-8 and VEGF protein in the progression of gastric cancer

Both vascular endothelial growth factor (VEGF) and interleukin 8 (IL-8) play an important role in the progression of gastric cancer (GC). In this study, we investigated whether circulating levels of VEGF or IL-8 in drainage veins of GC patients were correlated with any clinicopathological factors. Thirty-seven patients with primary GC who underwent gastrectomy at our department between 1999 and 2002 were analyzed. Blood samples were drawn from a peripheral vein just before surgery and from a drainage vein immediately after laparotomy. Plasma VEGF levels were significantly higher than those in 10 healthy controls. There was no correlation between VEGF levels in drainage veins and any clinicopathological variable, whereas there was a significant relationship in the case of VEGF levels in peripheral veins; the levels were higher in patients with venous invasion. We found a significant relationship between IL-8 levels in drainage veins and both tumor size and lymph node metastasis, whereas no significant relationship between IL-8 levels in peripheral veins and any variable was found. There was no correlation between VEGF and IL-8 levels in drainage veins. Large tumors, deeply invasive tumors, lymph node involvement, venous invasion and high IL-8 levels in drainage veins were all significantly associated with shorter disease-free survival, although multivariate analysis revealed that lymph node involvement was the only independent prognostic factor. In conclusion, the measurement of IL-8 levels in drainage veins of GC patients may reflect production mainly by the primary lesion and is valuable as an indicator of risk for recurrent disease.

Clinical significance of angiogenesis in gastrointestinal cancers: a target for novel prognostic and therapeutic approaches

OBJECTIVE

To review the current data on the prognostic and therapeutic implications of tumor angiogenesis in gastrointestinal cancers.

SUMMARY BACKGROUND DATA

Numerous studies have evaluated the prognostic value of tumor angiogenesis and the potential role of antiangiogenic therapy in various gastrointestinal cancers.

METHODS

A Medline literature search was conducted using "angiogenesis" or the names of various angiogenic factors in combination with the names of gastrointestinal cancers as the key words.

RESULTS

Several studies have demonstrated a significant prognostic impact of tumor microvessel density and tumor expression of angiogenic factors, in particular vascular endothelial growth factor (VEGF), in various gastrointestinal cancers. A few studies have suggested that circulating VEGF might be a useful prognostic marker. However, results were not consistent across all studies and were limited by the retrospective nature of most studies. Antiangiogenic therapy has been shown to be effective against all common gastrointestinal cancers in preclinical studies, but currently there are few clinical data with regard to antiangiogenic therapy in gastrointestinal cancers.

CONCLUSIONS

There is mounting evidence to suggest that assessment of tumor angiogenesis might provide a novel approach of prognostication in patients with gastrointestinal cancers. However, current results from retrospective studies need to be validated by prospective studies. Antiangiogenic therapy is a promising strategy of cancer treatment that might be particularly useful in combination therapy for unresectable cancers or as an adjuvant therapy for resectable tumors.

The angiogenic switch for vascular endothelial growth factor (VEGF)-A, VEGF-B, VEGF-C, and VEGF-D in the adenoma-carcinoma sequence during colorectal cancer progression

Angiogenesis is essential for tumour growth and metastasis. It is controlled by angiogenic factors, one of the most important being vascular endothelial growth factor (VEGF)-A. Although its role has been demonstrated in many tumour types including colorectal carcinoma (CRC), the importance of the newer family members in adenoma, invasive tumour growth, and progression to a metastatic phenotype has been poorly characterized in CRC. The aim of this study was to determine the role and timing of the VEGF angiogenic switch during CRC progression. We measured the gene expression of VEGF ligands (VEGF-A, VEGF-B, VEGF-C, and VEGF-D) and their receptors (VEGFR-1, VEGFR-2, and VEGFR-3), in normal colorectal tissues (n = 20), adenomas (n = 10), and in CRC (n = 71) representing different Duke's stages using ribonuclease protection assay, semi-quantitative relative reverse transcriptase polymerase chain reaction, together with the pattern of their expression by immunohistochemistry. VEGF-A mRNA was the most abundant in colorectal tissue, followed by VEGF-B, VEGF-C, and VEGF-D. VEGF-A and VEGF-B mRNAs were significantly more abundant in adenomas (p = 0.0003 and p = 0.04 respectively) compared with normal tissues, while VEGF-A and VEGF-C were significantly increased in carcinomas compared with normal tissues (p = 0.0006 and p = 0.0009 respectively). A significantly greater amount of VEGF-C mRNA was present in carcinomas compared with adenomas (p = 0.03), whereas there was a significant reduction of VEGF-B in carcinomas compared with adenomas (p = 0.0002). VEGF-D mRNA was significantly more abundant in normal tissues than in adenomas (p = 0.0001) and carcinomas (p < 0.0001). In normal tissues distant from the primary tumour, there was a significantly greater amount of VEGF-A and VEGF-D mRNA in patients with Duke's B and Duke's C respectively, compared with Duke's A stage tumours (p = 0.04 and p = 0.01 respectively). Immunohistochemistry showed low basal levels of all ligands in histologically normal tissues and their expression in the epithelium of tumours reflected the levels of mRNA expression identified. VEGF-A and VEGF-C mRNA levels correlated significantly with tumour grade (p = 0.01 and p = 0.01 respectively) and tumour size (p = 0.001 and p = 0.01 respectively), but not with patient age, sex, presence of infiltrative margin, lymphocytic response, vascular invasion, Duke's stage, or lymph node involvement (p > 0.05). VEGF-B mRNA correlated with an infiltrative margin (p = 0.04) but no other clinicopathological variable, and expression of VEGF-D demonstrated no association with any parameter examined. VEGFR-1 was significantly correlated with tumour grade (p = 0.02), Duke's stage (p < 0.001), and lymph node involvement (p = 0.004), VEGFR-2 with lymph node involvement (p = 0.02), and VEGFR-3 did not correlate with any of the clinicopathological variables tested. These results suggest that VEGF-A and VEGF-B play a role early in tumour development at the stage of adenoma formation and that VEGF-C plays a role in advanced disease when there is more likelihood of metastatic spread. The finding of increased levels of VEGF-A and VEGF-D expression in normal tissues collected from a site distant from the primary tumour indicates changes in the surrounding tumour environment that may enhance the subsequent spread of tumour cells.

Effect of tumor removal on mucosal protein synthesis in patients with colorectal cancer

It is currently controversial whether mucosal hyperproliferation is involved in colorectal cancerogenesis. The purpose of the present study was to examine protein synthetic rate as an indicator of potential tissue proliferation in grossly normal rectal mucosa from cancer-bearing subjects and to compare this rate with that in mucosa from subjects posttumor removal. Six postabsorptive patients with localized rectal cancer and five postsurgical control subjects received a primed constant infusion of [1-(13)C]leucine (0.16 micromol/kg min, 9.6 micromol/kg prime). Forceps biopsies from the mucosa were taken after 3 and 6 h. Protein synthesis was calculated from protein-bound leucine enrichment (determined by capillary GC-combustion IRMS) and from the enrichment of free intracellular leucine (determined by GC-quadrupole MS). In cancer-bearing subjects, mucosal protein synthesis amounted to 1.28 +/- 0.24%/h. This rate was significantly higher (P < 0.05) than the corresponding rate of mucosa from patients after cancer removal (0.69 +/- 0.09%/h). These findings do not support the concept that colorectal cancer originates from a proliferative disease of the whole colon. Increased mucosal protein synthesis appears to depend on the presence of the tumor itself and should therefore be considered a secondary phenomenon.

Vascular endothelial growth factor in the cerebrospinal fluid of infants who died of sudden infant death syndrome: evidence for antecedent hypoxia

OBJECTIVES

Recurrent hypoxemia has been proposed as an important pathophysiological mechanism underlying sudden infant death syndrome (SIDS). However, conflicting results emerged when xanthines were used as markers for hypoxia. The vascular endothelial growth factor (VEGF) gene is highly sensitive to changes in tissue partial oxygen tension, and changes in genomic and protein expression occur even after changes in oxygenation within the physiologic range.

METHODS

For determining whether hypoxia precedes SIDS, VEGF levels were measured using an enzyme-linked immunosorbent assay in the cerebrospinal fluid (CSF) of 51 SIDS infants and in 33 additional control infants who died of an identifiable cause. In addition, 6 rats that had a chronically implanted catheter in the lateral ventricle were exposed to a short hypoxic challenge, and VEGF concentrations were measured in CSF at various time points for 24 hours. Another set of 6 rats were killed with a pentobarbital overdose, and VEGF CSF levels were obtained at different time points after death.

RESULTS

Mean VEGF concentrations in CSF were 308.2 +/- 299.1 pg/dL in the SIDS group and 85.1 +/- 82.9 pg/dL in those who died of known causes. Mean postmortem delay averaged 22 hours for both groups. In rat experiments, hypoxic exposures induced time-dependent increases in VEGF, peaking at 12 hours and returning to baseline at 24 hours. Postmortem duration in the animals was associated with gradual increases in VEGF that reached significance only at 36 hours.

CONCLUSIONS

We conclude that VEGF CSF concentrations are significantly higher in infants who die of SIDS. We postulate that hypoxia is a frequent event that precedes the sudden and unexpected death of these infants.

Elevated serum vascular endothelial growth factor and decreased survival in advanced laryngeal carcinoma

PURPOSE

The purpose of this study was to determine whether serum vascular endothelial growth factor (s-VEGF) levels at the time of diagnosis correlate with any known tumor variables and overall survival in patients with advanced laryngeal squamous cell carcinoma. Comparisons with a cohort of normal healthy controls were also performed to determine the potential usefulness of s-VEGF as a screening tool.

EXPERIMENTAL DESIGN

Serum from patients enrolled in the VA Laryngeal Cooperative Study #258 (n = 183), as well as normal healthy controls (n = 40) was used in this analysis. Quantitative enzyme-linked immunosorbent assays (ELISA) for VEGF were performed in duplicate on each serum sample. Demographic and survival data were available for each patient enrolled in the study. Univariate analyses, multivariate Cox regression analyses, and Kaplan-Meier survival analysis were used.

RESULTS

The mean serum concentration of s-VEGF for the healthy control group was 47.83 +/- 0.13 pg/mL. For all patients enrolled in the VA Cooperative Study, regardless of treatment group, the mean s-VEGF level was 317.22 +/- 25.46 pg/mL. The patients randomly assigned to the surgical arm (n = 97) had a mean value of 315.44 +/- 30.44 pg/mL. Those randomly assigned to the induction chemotherapy arm (n = 86) had a mean s-VEGF level of 319.22 +/- 42.11 pg/mL. Serum VEGF levels were significantly elevated in patients with laryngeal carcinoma compared with healthy controls (p < .001). The serum VEGF levels in each arm of the trial were also elevated versus the healthy controls (p < .001, surgery arm plus radiotherapy; p < .001, chemotherapy plus radiotherapy). In a univariate analysis, elevated s-VEGF correlated with poor Karnofsky performance status for all patients with advanced laryngeal carcinoma (p < .008). High s-VEGF levels also correlated with a poor performance score in patients on the chemotherapy arm of the VA Laryngeal Trial (p < .004). Elevated s-VEGF levels in the surgical plus radiotherapy arm correlated with node-positive disease (p = .047) and supraglottic location of the tumor (p = .022). In a multivariate analysis using all known tumor variables and s-VEGF levels, elevated s-VEGF levels and infiltrating growth pattern correlated with decreased survival for all evaluated patients with advanced laryngeal carcinoma (p = .065, and p = .018, respectively).

CONCLUSIONS

Serum VEGF levels are significantly elevated in patients with advanced laryngeal carcinoma versus healthy controls. Elevated pretreatment s-VEGF levels tended to indicate a more aggressive disease state and a poorer overall survival in advanced laryngeal carcinoma.

Tumour markers as early predictors of response to chemotherapy in advanced colorectal carcinoma

BACKGROUND

To evaluate the reliability and validity of serum carcinoembryonic antigen (CEA), tissue polypeptide-specific antigen (TPS), vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in monitoring palliative chemotherapy in advanced colorectal cancer (ACRC).

METHODS

Serum was prospectively collected from 87 patients with ACRC treated with first-line 5-fluorouracil and leucovorin before and 2, 4 and 10 weeks after induction.

RESULTS

Eight patients had normal baseline TPS levels, and these patients had a favourable outcome with prolonged survival and a higher rate of objective responses than patients with elevated TPS levels. At 10 weeks, all responders had a decreasing TPS value. The sensitivity for a decrease of >25% using TPS was 83% and 86% for objective and subjective responses, respectively, and the specificity was 65% and 72%, respectively. CEA had, in the same setting, a sensitivity of 45% and 46%, respectively, and the specificity was 88%. VEGF was elevated in 54% of the patients and bFGF in 15% of the patients. The VEGF values decreased during therapy in 94% of the patients, but the changes in serial VEGF values did not correlate with survival or response. Tumour markers used together did not enhance the predictive values of TPS alone.

CONCLUSIONS

Repeated measurements of CEA, VEGF and bFGF in serum are of limited value in monitoring chemotherapy in ACRC. TPS seems to be of greater interest, but does not predict exactly which patients are going to have a positive outcome of palliative chemotherapy.