VEGF polymorphisms in early cervical cancer susceptibility, angiogenesis, and survival

The relationship between VEGF-460(T>C) polymorphism and cancer risk: A systematic review and meta-analysis based on 46 reports

BACKGROUND

Extensive studies on the link between single nucleotide polymorphisms (SNPs) in vascular endothelial growth factor (VEGF) and various malignancy risks produced conflicting results, notably for VEGF-460(T/C). To evaluate this correlation more comprehensively and accurately, we perform a meta-analysis.

METHODS

Through retrieving 5 databases (Web of Science (WoS), Embase, Pubmed, Wanfang database (Wangfang), and China National Knowledge Infrastructure (CNKI)) and applying hand search, citation search, and gray literature search, 44 papers included 46 reports were enrolled. To evaluate the relationship between VEGF-460 and cancer risk, we pooled odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Our results indicated that the VEGF-460 polymorphism is not related to malignancy susceptibility (dominant model, OR = 0.98, 95% CI = 0.87-1.09; recessive model, OR = 0.95, 95% CI = 0.82-1.10; heterozygous model, OR = 0.99, 95% CI = 0.90-1.10; homozygous model, OR = 0.92, 95% CI = 0.76-1.10; additive model, OR = 0.98, 95% CI = 0.90-1.07). While, in subgroup analysis, this SNP may reduce the risk of hepatocellular carcinoma.

CONCLUSION

this meta-analysis indicated that VEGF-460 was irrelevant to overall malignancy risk, but it might be a protective factor for hepatocellular carcinoma.

Prognostic Relevance of BRCA1 Expression in Survival of Patients With Cervical Cancer

Objective

BRCA1 expression can be lost by a variety of mechanisms including germline or somatic mutation and promotor hypermethylation. Given the potential importance of BRCA1 loss as a predictive and prognostic biomarker in several cancers, the objective of this study was to investigate BRCA1 expression using immunohistochemistry (IHC) in cervical cancer and its possible prognostic relevance.

Methods

Seventy patients with cervical cancer were enrolled in this study. Samples from each tumor were stained for BRCA1 and reviewed independently by gynecologic pathologists blinded to the BRCA status. Kaplan-Meier methods were used to estimate overall survival according to BRCA1 expression. Differentially expressed genes (DEGs) by BRCA1 expression were selected using GSE44001 dataset, which included 300 samples treated with radical hysterectomy. In addition, cox regression analysis with backward elimination was performed to select independent prognostic markers. Gene set enrichment analysis (GSEA) was done using these DEGs.

Results

BRCA1 IHC was positive in 62.9% (44/70) of cases. Patients with BRCA1 expression showed better overall survival (100% vs. 76.2%, HR 0.20, 95% CI 0.04 - 0.99, p = 0.028) than those without BRCA1 expression. Analysis of gene expression profiles according to BRCA1 expression identified 321 differentially expressed mRNAs. Gene set enrichment analysis results showed two dysregulated pathways (VEGF_A_UP.V1_DN and E2F1_UP.V1_UP). Of these DEGs, alterations of 20 gene signatures were found to be independently associated with survival outcomes of patients.

Conclusions

BRCA1 expression in cervical cancer tissue is associated with survival. In addition, the identification of specific gene alterations associated with BRCA1 expression could help to provide individualized prediction in these patients.

Catechin Metabolites along with Curcumin Inhibit Proliferation and Induce Apoptosis in Cervical Cancer Cells by Regulating VEGF Expression In-Vitro

Cervical cancer is the fourth most common cancer and the second cause of cancer-related death among women. Over the past two decades, green tea catechins and curcumin have received much attention for their role in preventing carcinogenesis. In this study, we evaluated the effects of the catechin metabolites and curcumin on cervical cancer cell proliferation and apoptosis. For this aim, the Ca Ski cell line was treated with different doses of catechin metabolites and curcumin. MTT assay and Flow cytometry were employed to investigate the cytotoxic effects of catechin metabolites and curcumin on the Ca Ski cell line. Real-time PCR and western blot were performed to evaluate the VEGF expression. Also, Real-Time PCR was performed to determine the expression level of microRNAs. Results showed that catechin metabolites along with curcumin reduce the VEGF expression. Further, miR-210 and miR-21 as oncogenic microRNAs were down-regulated, while it was reverse for miR-126 as a tumor-suppressor microRNA. Besides, MTT and Flow cytometry results showed that after using catechin metabolites with curcumin, cell survival was reduced by inducing apoptosis. In conclusion, catechin metabolites produced by intestinal microbiota besides the curcumin could serve as a promising therapeutic approach for women with cervical cancer.

MiR-628-5p Inhibits Cervical Carcinoma Proliferation and Promotes Apoptosis by Targeting VEGF

BACKGROUND

It has been reported that the dysregulation of microRNAs (miRNAs) is implicated in the biological processes of diverse diseases, including the tumorigenesis of human cancers. MicroRNA-628-5p (miR-628-5p) is differentially expressed and plays a critical role in several cancers, but the role of miR-628-5p in cervical cancer has not been well studied.

METHODS

The TCGA database and RT-qPCR were used to evaluate the expression profile of miR-628-5p in cervical cancer tissues. Transfection efficiency of synthetic miRNAs was detected using RT-qPCR. The biological effects of miR-628-5p on cervical cancer cells were assessed by the CCK-8 assay, flow cytometry, western blot analysis, and the tube formation assay. The expression levels of key proteins involved in cell apoptosis, the cell cycle and the PI3K pathway were analyzed by western blot analysis. Bioinformatic analysis and the luciferase reporter assay were performed to investigate the targeted relationship between miR-628-5p and vascular endothelial growth factor (VEGF).

RESULTS

MiR-628-5p was downregulated and negatively correlated with Ki-67 expression in cervical cancer tissues, and its low level predicted poor survival of patients. Functional assays indicated that miR-628-5p inhibited cell proliferation and promoted cell apoptosis. Mechanically, VEGF was verified to be a downstream target of miR-628-5p. Moreover, overexpression of VEGF could reverse the effects of miR-628-5p on VEGF/PI3K/AKT signaling, cell proliferation, apoptosis, the cell cycle and angiogenesis in cervical cancer.

CONCLUSIONS

MiR-628-5p inhibited cervical cancer cell proliferation and promoted apoptosis by targeting VEGF.

Molecular landscape of recurrent cervical cancer

Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.

Haplotype-based association of Vascular Endothelial Growth Factor gene polymorphisms with urothelial bladder cancer risk in Tunisian population

BACKGROUND/AIM

Accumulated data suggested that Vascular Endothelial Growth Factor is a major mediator in vasculogenesis, angiogenesis and recently in tumorigenesis. Therefore, we aimed to investigate for the first time the association between VEGF gene variants (-2549I/D (rs35569394), -2578C/A (rs699947), and +936C/T (rs3025039)) with urothelial bladder cancer (UBC) in Tunisian population.

METHODS

A total of 218 UBC patients and 204 controls were recruited and genotyped by Polymerase Chain Reaction technique. Odds ratios (OR) and 95% confidence intervals (CIs) were used to access the association between the VEGFA gene polymorphisms and UBC.

RESULTS

We found a significant decreased risk association of -2578 C/A polymorphism with UBC (OR (95% CI), 0.62 (0.41-0.94), P = .026) for CA genotype and (OR (95% CI), 0.40 (0.21-0.76), P = .005) for double homozygous mutant genotype. No associations were found in case of both polymorphic sites of VEGF, vis. -2549I/D and +936C/T, respectively. Haplotype analysis revealed a strong linkage disequilibrium between -2578C/A and -2549I/D and CIC combination is the significant haplotype associated with increased risk of UBC (OR (95% CI), 3.63 (1.47-8.97), P = .005). Regarding tumor grade/stage and family history of cancer, no associations were found for -2578C/A polymorphism.

CONCLUSION

CIC haplotype of VEGF gene may be important risk factor for UBC development in Tunisia.

Prognostic role of vascular endothelial growth factor in cervical cancer: a meta-analysis

The prognostic role of vascular endothelial growth factor (VEGF) in cervical cancer is controversial to date. The aim of this study was to evaluate the prognostic value of VEGF and VEGF-C in patients with cervical cancer. Relevant studies were identified by systematic search of the PubMed and Embase database. The primary data of eligible studies was hazard ratio (HR) with 95% confidence interval (95% CI) of survival outcomes, including overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS). Pooled HR (95% CI) was calculated to evaluate the prognostic role of VEGF and VEGF-C in cervical cancer patients. The methodological qualities of the included studies were assessed using REMARK. Fourteen eligible articles including 1306 patients were included in the meta-analysis. The pooled HRs (95% CIs) of VEGF for OS and DFS/PFS were 2.29 [1.27, 4.14] and 2.77 [1.37, 5.62], respectively. The HR (95% CI) of VEGF-C for OS was 3.94 [2.22, 6.99]. This meta-analysis suggested that high expressions of VEGF and VEGF-C were significantly associated with poor survival outcome in cervical cancer patients.

VEGF +936 C/T Genetic Polymorphism in Patients with Cervical Dysplasia

Aim. The present study aims to analyze the potential role of VEGF +936 C/T polymorphism in cervical intraepithelial neoplasia. Material and Method. One hundred and eighty-six patients were included in the study: 75 cases (patients diagnosed with CIN) and 111 controls (negative for both HPV testing and cytology). For each patient a single visit was scheduled when colposcopy was performed. From cervical specimen, cytology and HPV testing were performed and from peripheral blood VEGF +936 genotyping was determined. For statistical analysis purposes OR and chi-square were used at a level of significance of <0.05. Results. No link has been found in the detection of CT genotype in cases versus controls, OR = 0.8295, [0.42, 1.62]. An inverse correlation has been found between T allele and HSIL, OR = 0.2121, [0.0473, 0.9517], p = 0.0866. Conclusion. No link has been found between VEGF +936 C/T and cervical intraepithelial neoplasia.

Association of VEGF Gene Polymorphisms with the Risk and Prognosis of Cutaneous Squamous Cell Carcinoma

BACKGROUND Cutaneous squamous cell carcinoma (cSCC) is the second most common type of non-melanoma skin cancer (NMSC) globally. The aims of this study were to further systematically clarify the potential association of rs833061 (-460 C>T) and rs1570360 (-1154 G>A), two SNPs of VEGF, with the risk of cSCC and the prognostic impacts on cSCC patients. MATERIAL AND METHODS This hospital-based case-control study analyzed peripheral venous blood collected from 100 cSCC patients and 124 healthy controls, and gathered personal information on patients. Genotypes of the VEGF gene -460C>T and -1154G>A polymorphism were detected using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. Different distributions of allele frequencies and genotype in the case and control group were measured, comparing different genotype differences in the survival of patients with cSCC. RESULTS Distributions of allele frequencies and genotype of -460 C>T in the case and control group were statistically different; the TT + CT genotype was significantly correlated with a decrease risk of cSCC (OR=0.36, 95% CI=0.21-0.63, P<0.001). There was no difference in the distribution of allele frequencies and genotype of -1154 G>A between control and case groups. For -1154460C>T, the CC genotype was an adverse factor, associated with a significant decrease in the survival status of cSCC patients (P<0.001). For VEGF-1154 G>A, the AA genotype was significantly correlated with the reduced overall survival in cSCC patients, with the mean survival time of 23.88 months (P=0.009). CONCLUSIONS The VEGF gene -460 C>T polymorphism and -1154 G>A polymorphism may serve as potential genetic markers for the risk and prognosis of cSCC.

Correlation of volumetric perfusion CT parameters with hypoxia inducible factor-1 alpha expression in a rabbit VX2 tumor model

BACKGROUND

Hypoxia inducible factor-1 alpha (HIF-1α) plays a critical role in tumoral angiogenesis and HIF-1α overexpression is associated with an increased risk of patient mortality in many cancers. A number of studies have introduced perfusion computed tomography (CT) as a monitoring modality for antiangiogenic therapy.

PURPOSE

To investigate significance of volumetric perfusion CT parameters in relationship to HIF-1α expression in VX2 tumor rabbit models.

MATERIAL AND METHODS

Twenty VX2 carcinoma tumors of bilateral back muscles of 10 rabbits were evaluated with serial volumetric perfusion CT in 7, 10, and 14 days after tumor implantation. CT perfusion data were analyzed to calculate blood flow (BF), blood volume (BV), and permeability surface area product (PS) of whole tumor and non-necrotic peripheral area (periphery). Immunohistochemical analysis of HIF-1α expression and microvessel density (MVD) was performed.

RESULTS

HIF-1α was expressed in 12 tumors; two, three, and seven tumors classified as scores 1, 2 and 3, respectively. Mean MVD was 24.85 ± 13.7. PS of both the whole tumor and periphery showed positive correlations with HIF-1α score (r = 0.41, P = 0.046; r = 0.43, P = 0.002, respectively). BV of periphery showed a negative correlation with HIF-1α (r = -0.48, P = 0.040). There was strong positive correlation between HIF-1α expression and MVD (r = 0.82, P < 0.001).

CONCLUSION

In VX2 tumors, volumetric perfusion CT parameters were of limited value for the prediction of HIF-1α activity although HIF-1α expression was found to be weakly positively correlated with PS and negatively correlated with BV.

Nonsurgical management of cervical cancer: locally advanced, recurrent, and metastatic disease, survivorship, and beyond

Despite the declining incidence of cervical cancer as a result of the introduction of screening programs, globally it remains a leading cause of cancer-related death in women. Outcomes for patients who are diagnosed with anything but early-stage disease remain poor. Here we examine emerging strategies to improve the treatment of locally advanced disease. We discuss emerging biologic data, which are informing our investigation of new therapeutic interventions in persistent, recurrent, and metastatic cervical cancer. We recognize the importance of interventions to improve quality of life and to prevent long-term sequelae in women undergoing treatment. Finally, and perhaps most importantly, we recognize the need for global collaboration and advocacy to improve the outcome for all women at risk of and diagnosed with this disease.

Exploring the therapeutic rationale for angiogenesis blockade in cervical cancer

PURPOSE

This review highlights the molecular and pathologic evidence that cervical cancer is driven by angiogenesis and presents a summary of the recent clinical research in antiangiogenesis therapy for advanced cervical cancer with a focus on the use of bevacizumab.

METHODS

The articles chosen for this review reveal the rationale for antiangiogenesis agents in cervical cancer from 3 perspectives: pathologic, molecular, and clinical data.

FINDINGS

Several translational investigations have revealed that proangiogenic signaling cascades are active in cervical carcinogenesis and can be used to improve patient outcomes in advanced disease. For example, in a recently published study of patients with recurrent and metastatic cervical cancer, bevacizumab was the first targeted agent to improve overall survival in a gynecologic cancer when successfully combined with 2 different chemotherapy regimens.

IMPLICATIONS

Because of recent advances in screening, aggressive management of cervical intraepithelial neoplasia, and human papillomavirus vaccination, cervical cancer is preventable and curable with radical surgery plus lymphadenectomy surgery or chemoradiation plus brachytherapy if detected early. Unfortunately, for patients with metastatic or recurrent disease, effective therapeutic options are limited for this aggressive life-threatening condition. However, molecularly targeted agents have provided a critical opportunity to improve patient outcomes beyond optimizing cytotoxic chemotherapy regimens so that they may benefit from other agents or emergent therapies in the future.

Angiogenesis and antiangiogenic agents in cervical cancer

Standard treatment of cervical cancer (CC) consists of surgery in the early stages and of chemoradiation in locally advanced disease. Metastatic CC has a poor prognosis and is usually treated with palliative platinum-based chemotherapy. Current chemotherapeutic regimens are associated with significant adverse effects and only limited activity, making identification of active and tolerable novel targeted agents a high priority. Angiogenesis is a complex process that plays a crucial role in the development of many types of cancer. The dominant role of angiogenesis in CC seems to be directly related to human papillomavirus-related inhibition of p53 and stabilization of hypoxia-inducible factor-1α. Both of these mechanisms are able to increase expression of vascular endothelial growth factor (VEGF). Activation of VEGF promotes endothelial cell proliferation and migration, favoring formation of new blood vessels and increasing permeability of existing blood vessels. Since bevacizumab, a recombinant humanized monoclonal antibody binding to all isoforms of VEGF, has been demonstrated to significantly improve survival in gynecologic cancer, some recent clinical research has explored the possibility of using novel therapies directed toward inhibition of angiogenesis in CC too. Here we review the main results from studies concerning the use of antiangiogenic drugs that are being investigated for the treatment of CC.

Multiparametric monitoring of early response to antiangiogenic therapy: a sequential perfusion CT and PET/CT study in a rabbit VX2 tumor model

OBJECTIVES

To perform dual analysis of tumor perfusion and glucose metabolism using perfusion CT and FDG-PET/CT for the purpose of monitoring the early response to bevacizumab therapy in rabbit VX2 tumor models and to assess added value of FDG-PET to perfusion CT.

METHODS

Twenty-four VX2 carcinoma tumors implanted in bilateral back muscles of 12 rabbits were evaluated. Serial concurrent perfusion CT and FDG-PET/CT were performed before and 3, 7, and 14 days after bevacizumab therapy (treatment group) or saline infusion (control group). Perfusion CT was analyzed to calculate blood flow (BF), blood volume (BV), and permeability surface area product (PS); FDG-PET was analyzed to calculate SUVmax, SUVmean, total lesion glycolysis (TLG), entropy, and homogeneity. The flow-metabolic ratio (FMR) was also calculated and immunohistochemical analysis of microvessel density (MVD) was performed.

RESULTS

On day 14, BF and BV in the treatment group were significantly lower than in the control group. There were no significant differences in all FDG-PET-derived parameters between both groups. In the treatment group, FMR prominently decreased after therapy and was positively correlated with MVD.

CONCLUSIONS

In VX2 tumors, FMR could provide further insight into the early antiangiogenic effect reflecting a mismatch in intratumor blood flow and metabolism.

Association of the vascular endothelial growth factor -2578C/A polymorphism with cancer risk: A meta-analysis update

The vascular endothelial growth factor (VEGF) -2578C/A polymorphism has been previously reported to be associated with cancer risk; however, the results have been controversial. Therefore, the aim of the present study was to explore the association between the VEGF -2578C/A polymorphism with the cancer risk. A total of 37 case-control studies were identified. The pooled analysis showed that there was no association between VEGF -2578C/A and the risk of cancer, and the odds ratios (ORs) [with the corresponding 95% confidence intervals (95% CIs)] were 0.97 (0.91-1.04) for C vs. A, 0.94 (0.86-1.02) for CC vs. AA, 0.92 (0.80-1.06) for CA vs. AA, 0.96 (0.89-1.03) for CC/CA vs. AA and 0.97 (0.88-1.08) for CC vs. CA/AA. Subgroup analyses according to ethnicity, source of control and type of cancer showed that the VEGF -2578C/A polymorphism is associated with colorectal and lung cancers. Additionally, the polymorphism may decrease the risk of cancer in the Asian population. This VEGF polymorphism was not associated with a risk of cancer for the Caucasian [0.92 (0.76-1.11) for CC vs. AA] and African populations [1.31 (0.67-2.58) for CC vs. AA], and it was not associated with bladder [1.06 (0.74-1.53) for CC/AA] and breast cancers [1.01 (0.90-1.15) for CC/AA]. Therefore, the present meta-analysis indicates that VEGF -2578C/A may only be associated with the risk of colorectal cancer, lung cancer and the Asian population. More studies with larger sample sizes are required to provide more conclusive evidence.

VEGF pathway polymorphisms as prognostic and pharmacogenetic factors in cancer: a 2013 update

With the recent advances in genomic medicine and the development of targeted antiangiogenic therapy for cancer patients, there has been an increased interest in the role of predictive and prognostic markers for antiangiogenic therapy. Here, we provide a summary of the angiogenesis pathway, the role of predictive and prognostic markers in cancer and a summary of the current literature and studies on predictive and prognostic markers for antiangiogenic therapy. Our aim is to summarize those studies that are currently in the literature with an emphasis on the future directions of the field from 2013 and beyond. We conclude by providing our perspective on the future directions of this growing field, as well as possible challenges and pitfalls along the way.

Polymorphisms in the genes related to angiogenesis are associated with uterine cervical cancer

INTRODUCTION

The expression of plasminogen activator inhibitor type 1 (PAI-1), vascular endothelial growth factor (VEGF), and transforming growth factor β1 (TGF-β1) participates in the angiogenesis of several cancer types. The goal of this study was to investigate polymorphisms in genes related to angiogenesis (PAI-1-675 4G/5G, VEGF C936T, and TGF-β1 G-800A) to evaluate the risk for developing uterine cervical cancer (UCC).

METHODS

In a case-control study, 100 healthy subjects and 100 patients with UCC from Mexico were included. We determined the genetic profile of the polymorphic markers, which were evaluated by polymerase chain reaction using a sequence-specific primer.

RESULTS

There was no statistical difference in the allele distribution from the intergroup comparisons of PAI-1 675 4G/5G and VEGF C936T data; however, a significant difference was observed within TGF-β1 G-800A. The linkage disequilibrium analysis revealed that PAI-1 -675 4G and TGF-β1 -800A pair-haplotype was in strong linkage disequilibrium with a significantly increased risk (odds ratio, 3.44; 95% confidence interval, 1.66-7.25) to UCC.

CONCLUSIONS

The polymorphisms in the genes related to angiogenesis -675 4G/5G PAI-1 and G-800A TGF-β1, segregated solely or combined, might contribute to the increased susceptibility to UCC in a Mexican population.

Importance of adrenergic pathways in women's cancers

The importance of adrenergic pathways in cancer has long been suspected, but now there is mounting epidemiological, preclinical, and clinical evidence of its importance in gynecologic cancers. To date, most of these effects are mediated primarily through the beta 2 adrenergic receptor activation of the tumor cell cyclic AMP-protein kinase A signaling pathway. This review will discuss the current knowledge about the neuroendocrine stress response in gynecologic tumor biology.

Positive association of the vascular endothelial growth factor-A +405 GG genotype and poor survival in stage I-II gastric cancer in the Northern Chinese population

The vascular endothelial growth factor-A (VEGF-A) plays an important role in the angiogenesis and prognosis for gastric cancer. In addition, several single-nucleotide polymorphisms (SNPs) in VEGF-A have been shown to affect gene expression and process of angiogenesis. The present study evaluated the correlations between SNPs in VEGF-A and gastric cancer survival. Formalin-fixed paraffin-embedded tissues of 404 gastric cancer patients and blood samples from 404 controls were included in the study. The SNPs -460T/C (rs833061), +405G/C (rs2101963), -7C/T (rs25648) and +936C/T (rs3025039) were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. We showed patients carrying the +405GG genotype had significantly worse survival in the N0 (lymph-node negative), N0L0 (lymph-node negative and lymphovascular-invasion negative) and TNM stage I-II subgroups (P = 0.021, P = 0.007 and P = 0.017, respectively). In addition, haplotype -460T/+405G/-7C and -460C/+405G/-7C carriers showed poor survival in the N0, N0L0 and TNM stage I-II subgroups (P = 0.004, P = 0.030 and P = 0.009 for TGC; P = 0.033, P = 0.049 and P = 0.011 for CGC). Overall, the +405 GG genotype or TGC and CGC haplotypes were correlated with poor survival in TNM stage I-II gastric cancer patients. The +405G/C polymorphism of VEGF-A could be used as a biomarker for molecular staging in stage I-II gastric cancer in Northern China.

Tissue biomarkers as prognostic variables of cervical cancer

The most important prognostic variables of cervical carcinoma are FIGO stage, lymph node status and clinical-pathological features of primary tumor. Recently, there has been increasing interest in the identification of biomarkers able to predict both response to treatment and survival. The aim of this review is to critically evaluate current published evidence on the ability of various tissue biomarkers to predict the clinical outcome of patients with cervical carcinoma. In particular, the paper takes into account DNA content, cell-cycle and apoptosis-regulatory proteins, epidermal growth factor receptor [EGFR], vascular endothelial growth factor [VEGF], cyclooxygenase [COX]-2, signal transducer and activator of transcription [Stat]3, human papilloma virus [HPV] status, tumor hypoxia, tumor infiltrating lymphocytes [TIL], microarray technology and microRNA (miRNA). The presence of HPV-18 genotype and an elevated VEGF expression appear to be poor prognostic factors in women with early disease treated with primary surgery, whereas the expression of EGFR, VEGF, COX-2 and tumor hypoxia may have a major impact on the survival of patients treated with definitive radiotherapy or chemoradiation. The data supporting the reliability of ΔNp73 and TAp73α as novel biomarkers of response to radiotherapy are interesting but still limited. DNA microarray technology could offer new laboratory tools for a rationale planning of treatment strategy, and miRNAs might represent new candidate targets to be investigated for both prognostic and therapeutic purposes. Moreover, the assessment of different types of TIL and their ligands in tumor biopsies could enable the identification of a subset of high-risk patients, paving the way to novel immune therapies aimed at blocking T-reg cell activity.

Current Evidence on VEGF+405G/C Polymorphism and Malignancy Susceptibility: A Meta-Analysis Involving 30 Studies

The association of VEGF+405G/C (where VEGF is vascular endothelial growth factor) polymorphism and malignancy susceptibility attracts considerable attention because VEGF is one of the most potent angiogenic factors and plays a critical role in the onset and development of malignancy. However, the published findings remain inconclusive. In order to derive a more precise assessment of the association, we performed a meta-analysis including 30 published case-control studies from PubMed, Embase, and Ovid databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. In the pooled analyses, no significant association was found between VEGF+405G/C polymorphism and malignancy susceptibility in different genetic models (G-allele vs. C-allele: OR = 1.00, 95% CI: 0.93–1.07; CC vs. GG: OR = 1.01, 95% CI: 0.88–1.15; GC+CC vs. GG: OR = 1.00, 95% CI: 0.91–1.10; CC vs. GC+GG: OR = 1.01, 95% CI: 0.90–1.13). When stratified by ethnicity, a weak association between this polymorphism and malignancy susceptibility was found in African under allelic frequency comparison (OR = 0.65, 95% CI: 0.43–0.98) and dominant genetic model comparison (OR = 1.95, 95% CI: 1.09–3.50). In summary, although our meta-analysis indicated a weak association of VEGF+405G/C polymorphism with malignancy susceptibility in African, no persuasive evidence of association between the polymorphism and malignancy susceptibility was detected in the pooled analyses. Therefore, more studies with larger scale of participants, especially Africans, are required to further evaluate gene-environment interaction on this polymorphism and malignancy susceptibility.

Vascular endothelial growth factor pathway polymorphisms as prognostic and pharmacogenetic factors in cancer: a systematic review and meta-analysis

Angiogenesis is an important host process that interacts with cancer cells to promote growth, invasion, and metastasis. Numerous therapeutic agents targeting the VEGF pathway have been developed. Host variability in VEGF pathway can influence angiogenesis-dependent signaling, altering sensitivity to antiangiogenic drugs and prognosis. A systematic review and meta-analysis was conducted (May 1990-July 2011). Eligible studies involved cancer patients and compared polymorphisms in the VEGF pathway [VEGF and molecules directly interacting with VEGF: KDR, FLT1, FGF, FGF2, FGFR, NRP1, endostatin (encoded by COL18A1)], and reported one of the following outcomes: overall survival, progression-free survival, time to recurrence, disease-free survival, response rate, or drug toxicity. We identified 48 cancer studies assessing prognosis and 12 cancer studies exploring pharmacogenetics of anti-VEGF therapy across various VEGF pathway polymorphisms. There was marked inter- and intradisease site heterogeneity in the effect of polymorphisms on both outcome and response to therapy. Meta-analyses of 5 VEGF polymorphisms (+936C>T, -460T>C, +405G>C, -1154G>A, and -2578C>A) identified a significant prognostic relationship: VEGF +405G>C variants showed a highly statistically significant improvement in overall survival [HR, 0.74; 95% confidence interval, 0.60-0.91; P = 0.004]. Variants (heterozygotes and/or homozygotes) of VEGF +405G>C were significantly associated with improved survival in a meta-analysis of multiple cancer sites.

Genetic polymorphisms as predictive and prognostic biomarkers in gynecological cancers: a systematic review

PURPOSE

Numerous studies have explored the potential role of genetic polymorphisms as predictive or prognostic biomarkers in gynecologic malignancies. A systematic review for all eligible polymorphisms has not yet been reported. The aim of this study was to summarize the current status of the field and provide direction for future research.

DESIGN

We searched literature databases (MEDLINE, EMBASE, Cochrane) from 2006 to April 2011 to identify studies evaluating the association between gene polymorphisms and clinical outcome in ovarian, endometrial, cervical, or vulvar cancer. The main outcome measures were overall survival (OS) and progression-free survival (PFS). Studies reporting relationships between polymorphisms and toxicity were also included.

RESULTS

Sixty two studies met the inclusion criteria. The median sample size was 140. Most of the included studies (n=50, 81%) were conducted in ovarian cancer patients. Almost a third assessed potential predictive associations between gene polymorphism and outcome in ovarian cancer. The most commonly evaluated genes were ERCC1, VEGF, ABCB1 (MDR), and GSTP1. Most studies (n=44, 71%) were observational case-series. Only four studies (6%) included a validation arm and patient population ethnicity was explicitly stated only in 27% of included studies.

CONCLUSION

No consistent association between any gene polymorphism and clinical outcome in gynecological cancers has been found across studies. There is incomplete adherence to the REMARK guidelines and inadequate methodology reporting in most studies. Moving forward, analysis of large trial-based clinical samples; adherence to the highest methodological standards, and focus on validation analyses are necessary to identify clinically useful pharmacogenomic biomarkers of outcome.

Vascular Endothelial Growth Factor Gene Polymorphisms and Risk of Cervical Intraepithelial Neoplasia

Objective:

To evaluate the association between 3 vascular endothelial growth factor (VEGF) gene polymorphisms and susceptibility of cervical intraepithelial neoplasia (CIN).

Materials and Methods:

This prospectively collected case-control study investigates three common VEGF gene polymorphisms (ie, VEGF −460 [rs833061], VEGF +405 [rs2010963], and VEGF +936 [rs3025039]) in 203 women with CIN and 209 healthy women by DNA pyrosequencing. Associations between polymorphisms and CIN risk are evaluated with univariate and multivariable models and haplotype analysis.

Results:

In a multivariable regression model, the variant VEGF +405C allele was associated (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.2-5.1], P = 0.02) with increased susceptibility of CIN independent of number of sexual partners (OR, 2.2; 95% CI, 1.1-4.6; P = 0.03) and smoking (OR, 3.3; 95% CI, 1.6-6.6; P = 0.001). The haplotype VEGF −460C - +405C - +936C was associated with an OR of 5.2 (95% CI, 1.2-52.7) for the susceptibility of CIN.

Conclusions:

The presence of the variant VEGF +405C allele and the haplotype VEGF −460C - +405C - +936C are independently associated with higher susceptibility of CIN.

Meta-analysis of the association between VEGF-634 G>C and risk of malignancy based on 23 case-control studies

PURPOSE

The association between polymorphism of vascular endothelial growth factor (VEGF)-634 G>C and malignancy risk has been widely studied, and no conclusive result was available up to now.

METHODS

Twenty-three case-control studies with 21,917 individuals were included in this meta-analysis through searching the databases of Medline, Embase, and CNKI (up to October 1st, 2010). The odds ratio (OR) and 95% confidence interval (95%CI) were used to investigate the strength of the association.

RESULTS

Overall, the pooled analysis showed that there was no association between VEGF-634 G>C and risk of malignancy, and the ORs (95%CIs) were 0.98 (0.85-1.12) for GG versus CC, 1.03 (0.90-1.17) for GC versus CC, 1.00 (0.89-1.13) for G carrier versus CC, and 1.08 (0.94-1.23) for C carrier versus GG. Subgroup analyses according to ethnicity, source of control, type of cancer, and sample size were also performed, and results indicated that VEGF-634 G>C was not associated with risk of malignancy for neither Asians [1.06 (0.81-1.38) for GG vs. CC and 1.08 (0.84-1.39) for GC vs. CC] nor Caucasians [0.93 (0.83-1.05) for GG vs. CC and 0.98 (0.87-1.10) for GC vs. CC]. It was also not associated with risk of breast cancer [0.95 (0.81-1.12) for GG vs. CC], gastric cancer [0.93 (0.47-1.84) for GG vs. CC], and colorectal cancer [1.17 (0.93-1.47) for GG vs. CC].

CONCLUSIONS

This meta-analysis suggests that VEGF-634 G>C may be not associated with risk of malignancy. More studies with larger sample size were needed to provide more precise evidence.