Expression of vascular endothelial growth factor in renal cell carcinoma and the relation to angiogenesis and p53 protein expression

Expression of growth factors and their receptors in the primary renal cell carcinoma: new data and review

Introduction

The aim of our study was to investigate expression levels and the prognostic value of multiple growth factors and their receptors in the primary tumor cells of renal cell carcinoma (RCC).

Material and methods

Expression of vascular endothelial growth factor (VEGF)A, fibroblast growth factor (FGF)2, vascular endothelial growth factor receptor (VEGFR)1, VEGFR2, FGFR1, FGFR2, platelet-derived growth factor receptor (PDGFR)α, and PDGFRβ was investigated in 65 primary RCC specimens by immuhistochemical staining using the appropriate antibodies. Expression levels were evaluated by the semi-quantitative method. A search for correlations of expression levels of investigated growth factors and receptors with RCC features and patients outcomes was performed.

Results

Expression of all growth factors and their receptors was detected both on the surface and in the cytoplasm of the primary tumor cells in RCC patients. The expression of all analyzed factors was interconnected. FGFR2 expression correlated with the largest number of other growth factors and receptors. A strong correlation was revealed between high expression of the studied markers, high Fuhrman grade, and advanced RCC stages. In a univariate analysis overexpression of VEGFR2 (p <0.0001) and FGFR2 (p = 0.014) had negative influence on cancer-specific survival.

Conclusions

Expression of growth factors and tyrosine kinase receptors in the primary tumor cells is strongly interconnected and associated with unfavorable features of RCC.

18F-fluorodeoxyglucose uptake on PET/computed tomography in association with androgen receptor expression and other clinicopathologic factors in surgically resected triple-negative breast cancer

OBJECTIVE

To evaluate whether androgen receptor expression in triple-negative breast cancer (TNBC) is associated with F-fluorodeoxyglucose (FDG) uptake and to identify predictive factors of F-FDG uptake in TNBC.

METHODS

We retrospectively assessed data of 156 surgically resected primary TNBC in 156 consecutive patients who underwent F-FDG PET/computed tomography between July 2013 and May 2017. Clinicopathologic features, including androgen receptor expression, were categorized and the distribution of maximum standardized uptake value (SUVmax) was compared between the groups. We also evaluated the correlations between the predictive factors and SUVmax.

RESULTS

Median SUVmax was higher in the androgen receptor-negative group than in the androgen receptor-positive group (8.8 vs. 7.1, P = 0.026) with negative correlation between androgen receptor and SUVmax (P = 0.041, correlation coefficient (r) = -0.163). On multivariate regression analysis, tumor size (>20 mm), histological grade, Ki-67 (≥14%), and the presence of ductal carcinoma in situ (DCIS) were significantly associated with SUVmax (P < 0.001, P = 0.012, P = 0.017 and P = 0.021, respectively). Tumor size, histological grade and Ki-67 were positively correlated with SUVmax (P < 0.001, r = 0.450; P = 0.004, r = 0.228; P = 0.001, r = 0.269, respectively), while the presence of DCIS showed negative correlation with SUVmax (P < 0.001, r = -0.292).

CONCLUSION

Androgen receptor-positive TNBC showed lower F-FDG uptake than androgen receptor-negative triple-TNBC. Tumor size, histological grade, Ki-67 and the presence of DCIS significantly influenced F-FDG uptake in TNBC.

Lenvatinib for the treatment of renal cell carcinoma

INTRODUCTION

Renal cell carcinoma (RCC) accounts for 2-3% of all solid tumors. Expression of the receptor for the vascular endothelial growth factor (VEGF) is one of the most common features of RCC.

AREAS COVERED

Lenvatinib is a novel multi-kinase inhibitor that has been studied in several solid tumors. It has shown promising results in the treatment of RCC, especially when combined with everolimus, In this review, we summarize the available data of lenvatinib for the treatment of advanced/metastatic renal cell carcinoma.

EXPERT OPINION

Lenvatinib in combination with everolimus has provided encouraging results in both clinical and laboratory investigations showing that blocking angiogenesis and the mTOR signalling pathway could be a remarkable approach for treating RCC. As an additive to this type of approach it would be interesting in future clinical settings testing also the combination of lenvatinib and everolimus with immune-therapy.

Vascular endothelial growth factor gene polymorphisms and the risk of renal cell carcinoma: Evidence from eight case-control studies

Background

Vascular endothelial growth factor (VEGF) protein plays important role in renal cell carcinoma (RCC) development and progression. VEGF gene polymorphisms can alter the protein concentrations and might be associated with renal cell carcinoma risk. However, the results of studies investigating the association between VEGF polymorphisms and renal cell carcinoma risk are inconsistent. Thus, a meta-analysis was performed.

Methods

We selected eligible studies via electronic searches. Only high-quality studies were included based on specific inclusion criteria and the Newcastle-Ottawa Scale (NOS).

Results

Eight studies primarily focusing on seven polymorphisms were included in our meta-analysis. Our results showed dramatically high risks for renal cell carcinoma were found regarding most genetic models and alleles of the +936C/T polymorphism (except CT vs. CC). In addition, significant increased renal cell carcinoma risks were found regarding all genetic models and alleles of the -2578C/A polymorphism. However, no significant associations were found between renal cell carcinoma risk and the +1612G/A, -460T/C, -634G/C, -405G/C or -1154G/A polymorphisms.

Conclusions

Our meta-analysis indicates that the +936C/T and -2578C/A polymorphisms of VEGF are associated with an increased risk for renal cell carcinoma. Additional rigorous analytical studies are needed to confirm our results.

Prognostic and clinicopathological value of p53 expression in renal cell carcinoma: a meta-analysis

Background

The prognostic value of p53 expression in renal cell carcinoma (RCC) had been investigated in previous studies; however, the results remain inconsistent. This study was performed to investigate the prognostic and clinicopathological significance of p53 protein expression in RCC.

Materials and Methods

Literature was identified from PubMed, Embase, Web of Science, and Cochrane database, which investigated the relationships between p53 expression and outcomes. Hazard ratios (HRs) for survival outcomes and odds ratios (ORs) for clinical parameters associated with p53 were extracted from eligible studies. Heterogeneity was assessed using the I2 value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg's funnel plots and Egger's regression test.

Results

A total of 2,013 patients from 22 studies were included in the meta-analysis. The results showed that p53 positive expression is associated with poor overall survival (OS) (HR = 2.17, 95% confidence [CI]: 1.51–3.13) and cancer-specific survival (CSS) (HR = 1.59, 95% CI: 1.19–2.12) in RCC. In addition, p53 positive expression was closely correlated with TNM stage (III/IV vs. I/II: OR = 2.51, 95% CI: 1.05–6.00), Fuhrman grade (III/IV vs. I/II: OR = 1.80, 95% CI: 1.24–2.63), and distant metastasis (M1 vs. M0: OR = 1.70, 95% CI: 1.16–2.49), but not related to lymph node involvement (N1 vs. N0: OR = 1.32, 95% CI: 0.80–2.18), primary tumor stage (pT3/pT4 vs. pT1/pT2: OR = 1.16, 95% CI: 0.88–1.53), and sex (n = 2, male vs. female, OR = 1.09, 95% CI: 0.70–1.68).

Conclusions

This study suggests that p53 positive expression is correlated with poor prognosis and advanced clinicopathological features in patients with RCC, which indicates that p53 is a potentially effective therapeutic target.

The associations between five polymorphisms of vascular endothelial growth factor and renal cell carcinoma risk: an updated meta-analysis

Background

Vascular endothelial growth factor (VEGF) is a key mediator that plays an important role in angiogenesis, tumor growth, and tumor metastasis. The associations between five polymorphisms of VEGF (rs3025039, rs699947, rs10434, rs1570360, and rs2010963) and renal cell carcinoma (RCC) risk have been extensively investigated, but the currently available results are inconsistent and inconclusive. To obtain a more accurate assessment of the associations, we conducted a meta-analysis in this study.

Materials and methods

Relevant studies were collected systemically from the following three electronic databases: MEDLINE, Web of Science, and CNKI (Chinese National Knowledge Infrastructure). Statistical analyses were performed using Review Manager 5.2 in a fixed- or random-effects model. Pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to establish the strength of associations.

Results

A total of eight case–control studies with 1,936 RCC cases and 2,770 controls fulfilling the inclusion criteria were selected for this meta-analysis. The pooled OR indicated that rs699947 polymorphism was significantly associated with RCC risk in all genetic models. A significant association was also found between the rs3025039 polymorphism and RCC risk in a homozygous model (TT vs CC: OR =1.38, 95% CI =1.11–1.72, P=0.004), a dominant model (CT+TT vs CC: OR =1.21, 95% CI =1.05–1.39, P=0.01), and a recessive model (TT vs CC+CT: OR =1.28, 95% CI =1.04–1.57, P=0.02). After a subgroup analysis of ethnicity in the allele contrast model of rs3025039 polymorphism, we found a significant relationship in the allele contrast model (T vs C: OR =1.21, 95% CI =1.05–1.40, P=0.007) in the Asian population. With regard to rs10434 polymorphism, significant association was observed only in a homozygous model (GG vs AA: OR =0.75, 95% CI =0.57–0.98, P=0.03). As to rs1570360 or rs2010963, we did not observe any relationship between the two polymorphisms and RCC risk in our study.

Conclusion

Our meta-analysis confirmed the fact that rs699947, rs3025039, and rs10434 polymorphisms were significantly relevant to elevated RCC risk. In the meanwhile, this study also demonstrated that the allele contrast model of rs3025039 polymorphism was likely to be associated with risk of RCC in the Asian population.

Biological Features of a Renal Cell Carcinoma Cell Line Derived from Spinal Metastasis

The establishment of a metastatic renal cell carcinoma (mRCC) cell line can facilitate the search for molecular mechanisms involved in RCC metastasis. A novel human mRCC cell line, designated RCC96, was established from an mRCC of the spine from a 65-year-old Chinese man. Morphology, cell cycle phase, chromosome number, cell capability of migration, tumorigenicity in nude mice, and cytogenetic features of RCC96 were investigated. Cell growth curve was detected and the cell number doubling time was 52 h. Karyotype analysis showed that these cells were polyploidy. Transmission electron microscope showed that cells were with large atypical nuclei, well-developed rough endoplasmic reticulum, rich Golgi complex, and mitochondria, as well as visible microacinar in the cytoplasm. PCR and immunofluorescence staining demonstrated that the expression of some genes such as KISS-1, MMP2, and VEGF in RCC96 was not entirely consistent with that in other RCC cell lines, indicating the differences between primary and metastatic RCC cell lines. The RCC96 cell line may serve as a useful tool for studying the molecular pathogenesis and testing new therapeutic reagents for mRCC.

Tumor VEGF expression correlates with tumor stage and identifies prognostically different groups in patients with clear cell renal cell carcinoma

OBJECTIVES

Vascular endothelial growth factor (VEGF) is a potent inducer of tumor angiogenesis and represents the key element in the pathogenesis of clear cell renal cell carcinoma (ccRCC). The aim of this study was to investigate the use of tumor VEGF expression as a parameter to identify tumor stage and prognostically different patient groups.

METHODS AND MATERIALS

We retrospectively collected clinical data of 137 patients treated with partial or radical nephrectomy at our institutions for organ-confined, locally advanced, and metastatic ccRCCs between 1984 and 2013. Tumor cell VEGF immunohistochemical expression was compared with pathological and clinical features including age, sex, tumor stage, and Fuhrman grade. Comparison of VEGF expression levels between tumor stages was performed via Kruskal-Wallis nonparametric test. Survival analysis was conducted via Kaplan-Meier product-limit method, and Mantel-Haenszel log-rank test was employed to compare survival among groups.

RESULTS

Median age at diagnosis was 61 years (range: 33-85 y). Tumor stage was pT1N0M0 in 67 patients (49%), pT2N0M0 in 5 (4%), and pT3N0M0 in 25 (18%), while 40 patients (29%) had metastatic tumors at diagnosis. Fuhrman nuclear grade was G1 in 22 patients (16%), G2 in 60 (44%), G3 in 33 (24%), G4 in 13 patients (9%), and unknown in 9 patients. Tumor VEGF was differentially expressed among different stages (P<0.001) and in low (G1-2) and high (G3-4) Fuhrman grade tumors (P<0.001). No significant differences were found when stratifying by sex (P = 0.06) or age (P = 0.29). Median overall survival (OS) from partial or radical nephrectomy was 161 months (range: 1-366). We observed a significantly longer OS in patients with low (<25%) vs. high (>25%) VEGF expression levels (median OS 206 vs. 65 mo, P<0.001).

CONCLUSIONS

Our data show that tumor cell VEGF expression is significantly associated with tumor stage and Fuhrman grade and is able to predict patient outcome, suggesting a potential use of this parameter in identifying prognostically different patients with ccRCC.

Prognostic biomarkers in renal cell carcinoma

A hallmark of renal cell carcinoma is its variable prognosis. Surgical resection of primary renal cell carcinoma can be curative when the disease is localized. However, approximately 20% of patients with early stages of localized renal cell carcinomas subsequently develop metastasis after the primary tumor is removed. The median survival for patients with metastatic disease is approximately 13 months. Therefore, there is a great need for biomarkers to predict metastasis and prognosis. Many prognostic biomarkers were studied in the past decade. In recent years, several promising biomarkers, including CAIX, B7-H1 and IMP3, have also been identified by large retrospective studies. Further validation of these biomarkers is essential to transfer the research data into clinical practice. Eventually, an outcome prediction model with biomarkers, staging system and other risk factors will identify high-risk patients with likelihood of progression and formulate different follow-up protocols or systematic treatments for these patients.

Differential expression of prognostic proteomic markers in primary tumour, venous tumour thrombus and metastatic renal cell cancer tissue and correlation with patient outcome

Renal cell carcinoma (RCC) is the most deadly of urological malignancies. Metastatic disease affects one third of patients at diagnosis with a further third developing metastatic disease after extirpative surgery. Heterogeneity in the clinical course ensures predicting metastasis is notoriously difficult, despite the routine use of prognostic clinico-pathological parameters in risk stratification. With greater understanding of pathways involved in disease pathogenesis, a number of biomarkers have been shown to have prognostic significance, including Ki67, p53, vascular endothelial growth factor receptor 1 (VEGFR1) and ligand D (VEGFD), SNAIL and SLUG. Previous pathway analysis has been from study of the primary tumour, with little attention to the metastatic tumours which are the focus of targeted molecular therapies. As such, in this study a tissue microarray from 177 patients with primary renal tumour, renal vein tumour thrombus and/or RCC metastasis has been created and used with Automated Quantitative Analysis (AQUA) of immunofluorescence to study the prognostic significance of these markers in locally advanced and metastatic disease. Furthermore, this has allowed assessment of differential protein expression between the primary tumours, renal vein tumour thrombi and metastases. The results demonstrate that clinico-pathological parameters remain the most significant predictors of cancer specific survival; however, high VEGFR1 or VEGFD can predict poor cancer specific survival on univariate analysis for locally advanced and metastatic disease. There was significantly greater expression of Ki67, p53, VEGFR1, SLUG and SNAIL in the metastases compared with the primary tumours and renal vein tumour thrombi. With the exception of p53, these differences in protein expression have not been shown previously in RCC. This confirms the importance of proliferation, angiogenesis and epithelial to mesenchymal transition in the pathogenesis and metastasis of RCC. Importantly, this work highlights the need for further pathway analysis of metastatic tumours for overcoming drug resistance and developing new therapies.

VEGF polymorphisms are not associated with an increased risk of developing renal cell carcinoma in Spanish population

PURPOSE

Vascular endothelial growth factor (VEGF) plays a central role in promoting angiogenesis and is over-expressed in renal cell cancer (RCC). Published data on the association between polymorphisms of vascular endothelial growth factor (e.g., -2578C/A [rs699947], -460T/C [rs833061], +405C/G [rs2010963], and +936C/T [rs3025039]) and the risk of renal cell carcinoma are ambiguous and controversial. The aim of this investigation was to investigate this relationship in a series of Caucasian Spanish patients.

MATERIALS AND METHODS

A case-control study was performed with 216 cases and 280 controls, genotyping subjects for VEGF polymorphisms using the predesigned TaqMan single nucleotide polymorphism (SNP) genotyping assay (Applied Biosystems, Foster City, CA, USA). The combined effect of the four gene polymorphisms on overall survival was studied by haplotype analysis.

RESULTS

The overall results suggest that polymorphisms or haplotypes in the VEGF gene do not modify the risk of RCC. We were unable to replicate the association of the -460T/C (rs833061) polymorphism with renal cancer risk. Data were also gathered on clinical-pathological results, tumor size, clinical stage, histological grade, and survival.

CONCLUSIONS

According to our analysis of their contribution to prognostic factors, VEGF polymorphisms do not appear to exert a significant influence on RCC progression or prognosis. This finding might be explained by the tumor biology and pathogenesis of clear cell RCC. Additional studies with larger sample sizes are needed in different ethnic groups to further assess this association.

Immunohistochemical markers associated with brain metastases in patients with nonsmall cell lung carcinoma

BACKGROUND

To the authors' knowledge, there are no reliable markers able to identify patients with nonsmall cell lung cancer (NSCLC) that will develop metastases to the brain. The authors investigated associations between immunohistochemical markers and the development of brain metastases in patients with NSCLC.

METHODS

This was a hospital-based, case-control study of patients who were newly diagnosed with NSCLC between 1989 and 2003, developed brain metastases, and had pathology material available from both the primary NSCLC and the brain metastases. These patients were compared with a control group of patients who had NSCLC and no evidence of brain metastases. NSCLC was examined for expression levels of Ki-67, caspase-3, vascular endothelial growth factor A (VEGF-A), VEGF-C, E-cadherin, and epidermal growth factor receptor (EGFR) in 54 surgical pathology specimens using immunohistochemistry, and associations were evaluated between those markers and the development of brain metastases.

RESULTS

Brain metastases developed after a median of 12.5 months (range, 1.7-89.4 months) after the diagnosis of NSCLC. A significantly increased risk of developing brain metastases was associated with patients with NSCLC who had primary tumors with high Ki-67 levels (adjusted odds ratio [OR] of 12.2; 95% confidence interval [95% CI], 2.4-70.4 [P < .001]), low caspase-3 expression (adjusted OR of 43; 95% CI, 5.3 to >100 [P < .001]), high VEGF-C expression (adjusted OR of 14.6; 95% CI, 2.0 to >100 [P < .001]), and low E-cadherin (adjusted OR of 3.6; 95% CI, 0.9-16.4 [P = .05]). No significant risk was associated with VEGF-A or EGFR expression. High Ki-67 expression also was associated with a shorter overall survival (P = .04).

CONCLUSIONS

The results of the current study indicated that patients with NSCLC who had high Ki-67 expression, low caspase-3 expression, high VEGF-C expression, and low E-cadherin expression in their tumors may benefit from close surveillance because they may have an increased risk of developing brain metastases.

Targeting vasculature in urologic tumors: mechanistic and therapeutic significance

Recent advances toward understanding the molecular mechanisms regulating cancer initiation and progression provide new insights into the therapeutic value of targeting tumor vascularity by interfering with angiogenic signaling pathways. The functional contribution of key angiogenic factors toward increased vascularity characterizing metastatic tumors and their therapeutic exploitation is considered in three major urologic malignancies, renal, bladder, and prostate cancer. With the realization that the success of the therapeutic efficacy of the various anti-angiogenic approaches for the treatment of urologic tumors has yet to be proven clinically, the challenge remains to select critical angiogenesis pathways that can be targeted for an individual tumor. Here we discuss the major mechanisms that support formation of vasculature in renal, bladder, and prostate tumors and the current results of targeting of specific molecules/regulators for therapeutic intervention against metastastic disease.

Outcome prediction for renal cell carcinoma: evaluation of prognostic factors for tumours divided according to histological subtype

A wide variety of parameters have been investigated for their prognostic significance in mixed series of renal cell carcinoma (RCC). The classification of RCC into separate types with differing morphology, genotype and probable clinical outcome has led to a re-evaluation of many prognostic parameters with studies confined to a single RCC morphotype. Tumour stage remains the most important predictor of RCC outcome and recent investigations have focused upon tumour diameter and the prognostic significance of stromal, vascular and lymphatic invasion within the renal sinus. In large tumour series, morphotype has been correlated with patient survival, with clear cell RCC being associated with a less favourable outcome than chromophobe RCC and to a lesser extent papillary RCC, for organ confined tumours. The prognostic significance of nuclear grading remains controversial. Fuhrman grading has been shown to have prognostic utility for clear cell RCC in some series. Recent studies have shown that for papillary RCC, grading should be based upon nucleolar size and that Fuhrman grading is inappropriate for chromophobe RCC. Proliferative indices based upon a variety of markers have been correlated with outcome for clear cell RCC (Ki-67, AgNORs, p21(waf1/cip1) and p27(Kip1)) and papillary RCC (Ki-67, AgNORs), although in some series prognostic significance was lost on multivariate analysis. The presence of tumour necrosis has been shown to predict survival for clear cell and chromophobe RCC, and in clear cell RCC quantification of tumour vascular density has been correlated with outcome. Several molecular markers have been investigated for prognostic significance, mostly in clear cell RCC. Although some of these markers have been shown to be significantly associated with survival, these findings remain to be confirmed in large scale follow-up studies.

[Molecular biology of the clear cell renal cell carcinoma: principles for a selective treatment]

Renal cell carcinoma (RCC) and its most frequent subtype, the clear cell hystology type, has shown resistance to chemotherapy and radiotherapy treatment when disease was already spread in patients. Recently, a huge advance in the molecular biology of this tumor has been performed. This fact allowed a deeper and better knowledge of the disease and the development of new drugs that work against the growth factors involved in tumor origin. In this review article it is summarized the molecular milestones that are involved in the development of clear cell renal cell carcinomas.

Microvascular tumor invasion, tumor size and Fuhrman grade: a pathological triad for prognostic evaluation of renal cell carcinoma

PURPOSE

The biological behavior and clinical outcome of renal cell carcinoma are difficult to predict. We investigated the prognostic impact of clinicopathological variables to establish a risk stratification model to predict recurrence and survival rates.

MATERIALS AND METHODS

We studied 230 patients with renal cell carcinoma (stages T(1-4) N(x) M(0)) who underwent radical nephrectomy and/or nephron sparing surgery, and were followed for a median of 48 months (range 3 to 140). Univariate and multivariate analyses were performed, and the influence of clinical presentation, histological tumor size, tumor grade, lymph node involvement and microvascular tumor invasion on disease-free and cancer specific survival curves was determined. A composition model based on independent prognostic variables was then created to stratify tumors into low, intermediate and high risk of progression.

RESULTS

The tumor recurrence rate was 17% (39 of 230) and the cancer specific mortality rate was 13% (31 of 230). Multivariate analyses determined that microvascular tumor invasion, tumor grade and tumor size were the only independent prognostic factors. Disease-free survival rates for low, intermediate and high risk tumors were 94.7%, 56.8% and 13.1%, respectively. Cancer specific survival rates were 94.7%, 61.7% and 32.0%, respectively.

CONCLUSIONS

Tumor size, Fuhrman grade and microvascular tumor invasion are strong and independent predictors of survival of patients with renal cell carcinoma. Risk assessment and stratification based on this triad of pathological features may allow better individualization of followup schedules and trials of adjuvant treatment for patients with renal cell carcinoma.

A comparison of the vascular density of VEGF expression with microvascular density determined with CD34 and CD31 staining and conventional prognostic markers in renal cell carcinoma

AIM

The aim of this study was to compare the vascular density of Vascular endothelial growth factor (VEGF) expression with microvascular density determined by CD34 and CD31 with conventional prognostic parameters.

METHODS

The study involved 50 renal cell carcinoma (RCC) cases. VEGF, CD34, and CD31 were stained by immunohistochemistry, and then preparations were evaluated by two pathologists under light microscopy. The whole tumor area was scrutinized in all the sections. In the evaluation of VEGF, due to the lack of homogenous staining within the tumor, two parameters, distribution and intensity of expression, were evaluated semiquantitively. In the evaluation of microvascular density with CD34 and CD31 staining, three hot areas with the highest density were determined. In x200 magnification of these areas, on a single plane, the quantity of vascular structures with lumens was determined.

RESULTS

Intensity of VEGF Expression was higher in papillary type carcinoma of kidney parenchyma (P = 0.014) and it was significantly correlated with tumor stage (P = 0.013), survival time (P = 0.01), and tumor size (P = 0.035). Distribution of VEGF expression was also higher in papillary RCC (P = 0.055) and it was significantly correlated with tumor stage (P = 0.043) and tumor size (P = 0.039). Vascular density determined with CD34 staining was higher in conventional RCC (P < 0.05); in addition, it was significantly correlated with distribution and intensity of VEGF expression (P < 0.05) and tumor stage (P < 0.05). Vascular density determined with CD31 staining was not significantly correlated with tumor type, tumor stage, nuclear grade, and survival time.

CONCLUSIONS

Intensity and distribution of VEGF were higher in papillary RCC. Both parameters were significantly correlated with tumor size, stage, and vascular density determined with CD34 staining. Intensity of VEGF was also significantly correlated with capsule invasion. Vascular density determined with CD34 staining, however, was higher in conventional RCC, and it was correlated with tumor size and stage.

The prognostic significance of angiogenesis and the effect of vascular endothelial growth factor on angiogenic process in Wilms’ tumour

AIMS

There is a subgroup of patients with Wilms' tumour (WT) having favourable clinicopathological features but adverse outcome. We aimed to investigate the prognostic significance of angiogenesis and whether it can be used for predicting which patients will fall into this category, and the possible role of vascular endothelial growth factor (VEGF) on angiogenesis in WT.

METHODS

Tumours in nephrectomy specimens from 63 WT patients were investigated for neovascularisation and VEGF expression by immunohistochemistry. The endothelial cells were highlighted by anti-CD34 and anti-CD31, and the microvessels in the hot-spots were counted. Correlations between the microvessel density (MVD), VEGF expression, clinicopathological features and prognosis were studied.

RESULTS

Among 21 patients with follow-up data, favourable histology was detected in 17, seven of which died of disease. Patients with highly vascular tumours showed significantly poorer prognosis than those with low vascular tumours. There was no significant relationship between angiogenesis and VEGF expression. VEGF immunostaining revealed various patterns in different components of WT.

CONCLUSIONS

We suggest that high MVD can be used as an indicator of poor prognosis with WT patients displaying favourable histology and there might be some additional growth factors other than VEGF which may also be responsible for angiogenesis in WTs.

Clinical response to therapy targeted at vascular endothelial growth factor in metastatic renal cell carcinoma: impact of patient characteristics and Von Hippel-Lindau gene status

OBJECTIVE

To describe the relationship among patient characteristics, Von Hippel-Lindau (VHL) gene status and clinical outcome in metastatic renal cell carcinoma (RCC) in patients receiving vascular endothelial growth factor (VEGF)-targeted therapy.

PATIENTS AND METHODS

All patients with metastatic RCC who received therapy with interferon-alpha plus bevacizumab, SU11248 or AG013736 at the authors' institution were considered. Clinical features were collected and activation status of the VHL gene (VHL) was determined from baseline paraffin-embedded tumour samples. Tumour response, time to tumour progression (TTP) and overall survival were recorded.

RESULTS

Forty-three patients were evaluable for determination of VHL status and clinical response. There was an objective response in 18 patients (43%; 95% confidence interval 28-59%). The median TTP for the entire cohort was 8.1 months. There was an improved clinical outcome in patients with the following clinical features: male gender, lack of hepatic metastases, no previous radiation therapy and higher baseline haemoglobin level. Twenty-six patients (60%) had evidence of VHL mutation or promoter methylation; such patients had an objective response rate of 48%, vs 35% in patients with no VHL mutation or methylation. Patients with VHL methylation or a mutation predicted to truncate or shift the VHL reading frame had a median TTP of 13.3 months, vs 7.4 months in patients with none of these features (P = 0.06).

CONCLUSION

VEGF-targeted therapy is active in metastatic RCC and the response can be associated with certain clinical features. The TTP with VEGF-targeted therapy might be prolonged in patients with VHL methylation or mutations that truncate or shift the VHL reading frame. Further investigation of VHL pathway components is needed to understand the biology of the response to VEGF-targeted agents in metastatic RCC.

Mechanisms of Disease: angiogenesis in urologic malignancies

Angiogenesis is critical for growth of tumors and their metastasis. In this article we review the literature on studies of angiogenesis pathways and markers for renal cancer, prostate cancer and bladder cancer. Overall, there is clear evidence that markers of angiogenesis and expression of angiogenic factors are associated with adverse outcomes in each of these tumor types. Relatively few angiogenic pathways have been investigated so far, although over 50 factors are known to be involved, and little has been studied on the antiangiogenic pathways and their suppression. The failing in many of the studies is small size and lack of suitable statistical analysis. Nevertheless, this review demonstrates the importance of these pathways and the need to develop selection criteria for patients who are candidates for antiangiogenic therapies. On the basis of the expression profiles reported so far, therapies that target vascular endothelial growth factor should be considered for the treatment of renal, prostate and bladder cancers. As most tumors express factors that are involved in multiple angiogenic pathways, further research is needed to determine which are coregulated and what the most common patterns are.

Translation molekularer Zusammenhänge in die klinische Anwendung

For patients with metastatic renal cell cancer (RCC), therapeutic options after cytokine failure are rather limited. There is a considerable need to identify new substances for systemic therapy. Due to upregulation after the loss of a functional von Hippel Lindau gene product, the vascular endothelial growth factor (VEGF) pathway is a promising target for a molecular based therapy. Over the last few years, therapeutic agents have been developed which inhibit this pathway at various levels. Here, we provide an overview of the molecular background and currently used drugs which have entered clinical trials in the setting of metastatic RCC disease. Until now, the results from early clinical trials are very promising, however, the best schedule, dosage, potential combination regimens, as well as long time efficacy, are still to be determined.

Expression of cyclooxygenase-2 in epithelial ovarian tumors and its relation to vascular endothelial growth factor and p53 expression

The purpose of this study was to evaluate cyclooxygenase-2 (COX-2) expression in epithelial ovarian tumors and its correlation with vascular endothelial growth factor (VEGF) and p53 expression. Immunohistochemical studies with anti-COX-2, anti-VEGF, and anti-p53 antibodies were carried out in 54 malignant and 23 borderline epithelial ovarian tumors. Elevated COX-2 expression was detected in 77.8% of ovarian carcinomas, which was significantly higher than that of borderline tumors (26.1%) (P < 0.001). In ovarian carcinomas, there was no significant correlation between COX-2 expression and other clinicopathologic features. Elevated VEGF expression was detected in 74.1% of ovarian carcinomas, and p53 expression was found in 64.8% of ovarian carcinomas. COX-2 expression was statistically correlated with elevated VEGF expression (P < 0.001) and p53 positivity (P < 0.05). On a univariate analysis, FIGO stage (P < 0.0001), histologic type (P= 0.0104), and COX-2 expression (P= 0.0135) were significant prognostic factors for overall survival. In a multivariate analysis, FIGO stage (P < 0.0001) was the only independent prognostic factor for poor survival. These findings suggest that COX-2 may play a role in the progression of epithelial ovarian tumors and that COX-2 expression may contribute to ovarian tumor angiogenesis by stimulating VEGF expression. p53 may be responsible for the regulation of COX-2 expression.

Expression of p53 protein in esophageal squamous cell carcinoma: relation to hypoxia-inducible factor-1alpha, angiogenesis and apoptosis

OBJECTIVES

Hypoxia-inducible factor (HIF)-1 is important in the control of transcription of several genes related to angiogenesis. We have previously reported that expression of HIF-1alpha correlates with venous invasion and clinical outcome in esophageal squamous cell carcinoma. p53 has been reported to interact with HIF-1alpha and induce ubiquitin-mediated proteosomal degradation of HIF-1alpha. The purpose of this study was to clarify whether the expression of p53 is associated with that of HIF-1alpha.

METHODS

Expression of p53, HIF-1alpha and vascular endothelial growth factor (VEGF) was examined in 81 archival surgical specimens of human esophageal squamous cell carcinoma tissue. CD34 and single-stranded DNA were used to evaluate angiogenesis and apoptosis.

RESULTS

Forty-seven of the 81 (58.0%) tumor specimens showed high levels of nuclear p53 immunoreactivity. Overexpression of p53 was observed in the early clinical stage of tumor development. Expression of p53 was not correlated with HIF-1alpha or VEGF expression, angiogenesis or apoptosis in esophageal carcinoma.

CONCLUSIONS

These results suggest that mutations in p53 play a role in carcinogenesis but not in the progression of esophageal squamous cell carcinoma. HIF-1alpha may not only be regulated by p53 but also by other factors.

Renal cell carcinoma

PURPOSE OF REVIEW

This review focuses on recent developments in the biology and clinical therapeutics of renal cell carcinoma. Given historically limited advances in this disease, a more thorough understanding and testing of rationally targeted agents is needed.

RECENT FINDINGS

Von Hippel-Lindau gene inactivation is observed in most clear cell renal carcinoma, driving the malignant phenotype. The resulting vascular endothelial growth factor overexpression has been targeted though various approaches, with a clear signal of anti-tumor activity. In addition, immunotherapy remains a therapeutic standard in renal cell carcinoma and an area of ongoing investigation. Observation of small renal masses may represent a viable clinical option.

SUMMARY

Renal cell carcinoma has become a model disease for rationally targeted therapeutics based on significant understanding of the underlying biology. Recent advances have increased the potential for meaningful improvements in clinical outcomes for renal cell carcinoma patients.

VEGF‐Targeted Therapy in Metastatic Renal Cell Carcinoma

PURPOSE

To review the biology of renal cell carcinoma (RCC) and the clinical results of vascular endothelial growth factor (VEGF) blockade in metastatic RCC.

METHODS

A review of relevant published literature regarding VEGF, von Hippel-Lindau (VHL) gene inactivation, and VEGF overexpression in RCC was performed. Further, a review of the mechanism, toxicity, and clinical development of VEGF-targeted therapy in metastatic RCC was undertaken.

RESULTS

VHL tumor suppressor gene inactivation is observed in the majority of clear cell RCC cases, leading to VEGF overexpression. Therapy with agents directed against the VEGF protein or the VEGF receptor have demonstrated initial clinical activity in metastatic RCC.

CONCLUSIONS

Therapeutic targeting of VEGF in RCC has strong biologic rationale. Substantial clinical activity has been reported in initial clinical trials with VEGF-targeting agents. Further investigation is needed to optimally use these agents for maximal clinical benefit.

Biology and clinical development of vascular endothelial growth factor-targeted therapy in renal cell carcinoma

PURPOSE

To review the biology of renal cell carcinoma (RCC) leading to vascular endothelial growth factor (VEGF) overexpression and the clinical results of VEGF blockade in metastatic RCC.

METHODS

A review of relevant published literature regarding VEGF, von Hippel-Lindau (VHL) gene inactivation and VEGF overexpression in RCC was performed. Further, a review of the mechanism, toxicity, and clinical development of VEGF-targeted therapy in metastatic RCC was undertaken.

RESULTS

VEGF is the major proangiogenic protein that exerts a biologic effect through interaction with cellular receptors. The majority of sporadic clear-cell RCC tumors are characterized by VHL tumor suppressor gene inactivation. The resulting VHL gene silencing leads to VEGF overexpression. An antibody to VEGF (bevacizumab) has demonstrated a significant prolongation of time to disease progression compared with placebo in patients with metastatic RCC. Small molecules with inhibitory effects against the VEGF receptor have undergone initial clinical testing in metastatic RCC with substantial objective response rates.

CONCLUSION

Therapeutic targeting of VEGF in RCC has strong biologic rationale and preliminary clinical efficacy. Further investigation will determine the optimal timing, sequence, and utility of these agents in RCC.

Prognostic significance of CA 125, CD44, and epithelial membrane antigen in renal cell carcinoma

OBJECTIVES

To study retrospectively CA 125, CD44, and epithelial membrane antigen (EMA) expression in renal cell carcinoma and their role as prognostic factors. CD44 is a cell adhesion molecule, and CA 125 and EMA are tumor-associated antigens used in the diagnosis and monitoring of the outcome and response to treatment of various human malignancies. Their expression and prognostic significance after resection of renal cell carcinoma have not been adequately studied.

METHODS

The expression of CA 125, CD44, and EMA were studied immunohistochemically and correlated with the outcome of 92 patients who underwent nephrectomy for renal cell carcinoma.

RESULTS

Positive staining was found for CA 125 in 28 patients (30.43%), CD44 in 48 patients (52.17%), and EMA in 74 patients (80.43%). CA 125 expression was increased in those with higher T stage (P <0.001) and histologic grade (P = 0.007). An inverse relationship was found between EMA expression and grade (P <0.001). The median follow-up was 41.5 months (range 30 to 65). The median survival for positive and negative patients was 34.6 versus 54.3 months for CA 125 (P = 0.0044), 48.3 versus 51.5 months for CD44 (P = 0.4677), and 53.2 versus 34 months for EMA (P = 0.0046). Multivariate analysis showed that CA 125 and EMA expression were independent prognostic factors (P = 0.021 and P = 0.018, respectively). Subgroup analysis showed that CA 125 expression predicted a significantly higher probability of death (28.6% versus 8%, P =0.0413) in patients with T1 or T2 tumors.

CONCLUSIONS

CA 125 and EMA appear to be useful prognostic markers in renal cell carcinoma. Additional studies are needed to determine the value of these markers as a means of selection for postoperative management.

Thrombospondin-1, vascular endothelial growth factor expression and microvessel density in renal cell carcinoma and their relationship with multifocality

OBJECTIVE

To evaluate the relevance of microvessel density (MVD) and the angiogenic factors, vascular endothelial growth factor (VEGF, an important angiogenic factor in solid tumors) and thrombospondin-1 (TSP-1, a potent inhibitor of angiogenesis), to multifocality of renal cell carcinoma (RCC).

PATIENTS AND METHODS

Using immunohistochemistry the expression of CD34, TSP-1 and VEGF was assessed in 38 archival tissue specimens from 19 patients with unifocal RCC and 19 with multifocal RCC. Immunostaining results for VEGF was scored for the appropriate percentage of positive tumor cells and relative immunostaining intensity (score range 0-12). Only extracellular immunoreactivity was considered positive for TSP-1 and the same method was used to score the stromal staining. The microvessel density was measured by immunohistochemical staining with anti-CD34 monoclonal antibody.

RESULTS

VEGF immunoreactivity> or =1% was detectable in all unifocal and multifocal tumors. TSP-1 immunoreactivity was detected in 14 (73.7%) of 19 unifocal RCCs and in 16 (84.2%) of 19 multifocal RCC specimens (p=0.69). There were no statistically significant differences in the immunostaining intensity, percentage of immunopositive cells and the staining scores of VEGF and TSP-1 among the two groups. Additionally, there was no difference in MVD in multifocal and unifocal tumors.

CONCLUSION

As there is no difference in MVD count, and expression of angiogenic factors (VEGF and TSP-1) in multifocal and unifocal tumors, multifocality of RCC is not determined by VEGF/TSP-1 expression.

Prognostic factors of renal cell carcinoma

PURPOSE

Determination of prognostic factors is essential for the management of renal cell carcinoma. Stage, histological grade and type, and performance status are now well known and commonly used. During the last decade numerous predictors of patient outcome were tested. This review summarizes the most important studies, explores and compares the results, and tries to respond to the question, "Today, what do we expect of clinical, molecular and genetic factors concerning survival of patients with renal cell carcinoma?"

MATERIALS AND METHODS

Based on MEDLINE literature searches we comprehensively reviewed the literature on the prognostic factors associated with the tumor, the patient and the treatment.

RESULTS

During the last decades numerous factors have been studied but few of them maintained independent significance in terms of overall survival as assessed by multivariate analysis. Results are more often controversial from one series to another. No known molecular or cytogenetic tumor marker has been identified to help diagnose, manage or confirm renal cell carcinoma remission, progression or relapse.

CONCLUSIONS

The classical prognostic factors remain histological grade, histological type, performance status, patient age, number and location(s) of metastatic sites, time to appearance of metastases and prior nephrectomy. The only striking advancement during the last few years has been the proven contribution of radical nephrectomy for metastatic disease in patients with good performance status.

Wilms' tumor growth is suppressed by antiangiogenic pigment epithelium-derived factor in a xenograft model

BACKGROUND/PURPOSE

Pigment epithelium-derived factor (PEDF), a potent endogenous inhibitor of angiogenesis, is highly expressed in the kidney. The authors postulated that systemic administration of PEDF would decrease Wilms' tumor growth in a xenograft model, and increased renal vascularity would result in a mouse null for PEDF.

METHODS

Tumors were induced in athymic mice using human anaplastic Wilms' tumor cells. Purified PEDF protein or vehicle was administered for 7 days beginning 2 to 3 weeks after inoculation. Tumors were stained with anti-PEDF and anti-Factor VIII antibodies. Mitoses and microvascular density (MVD) were counted per high-power field (hpf). PEDF-null mice were generated on a SV129/C57Bl6 background. Wild-type and null kidneys were assessed for MVD.

RESULTS

Mean tumor weight in the 2-week group was 60% less than controls (P <.05). The MVD and mitotic count in treated tumors were significantly less than controls (P <.05). PEDF stained strongly in normal kidneys but was minimal to absent in Wilms' tumor. PEDF-null kidneys had increased MVD compared with wild-type (P <.05).

CONCLUSIONS

PEDF is expressed strongly in normal murine kidney, and loss of its angioinhibitory activity may contribute to pathologic angiogenesis in Wilms' tumor. Systemic PEDF suppresses WT growth by targeting both the tumor cells and its associated vasculature.

Expression of vascular endothelial growth factor in invasive ductal carcinoma of the breast and the relation to angiogenesis and p53 and HER-2/neu protein expression

The vascular endothelial growth factor (VEGF) appears to play an important role in tumor angiogenesis. The p53 and HER-2/neu genes have been thought to regulate VEGF expression. Although the most common genetic alterations described in human breast cancer are p53 gene mutations and HER-2/neu gene amplification, there is a paucity of reports concerning a possible association between VEGF expression and p53 and HER-2/neu expression. Ninety-nine invasive ductal carcinoma cases were examined by immunohistochemical studies with anti-VEGF, anti-p53, anti-HER-2/neu, and anti-CD34 antibodies. Computerized image analysis was used to evaluate the microvessel density (MVD). Eighty-eight tumors (88.9%) were classified as being VEGF positive. Twenty-five tumors (25.3%) showed p53 protein expression, while 36 tumors (35.4%) expressed the HER-2/neu protein. The MVD ranged from 22.0 to 197.0, with a median value of 58.5 (65.4 +/- 27.9). The tumors expressing VEGF had a significantly higher MVD than those that did not (P < 0.05). VEGF expression was significantly associated with p53 protein expression (P < 0.01). In double VEGF and p53 immunohistochemical stained sections, the two markers were generally expressed in the same tumor cells. The cancer stage was the only independent prognostic factor of disease-free and overall survival. The authors' results suggest that VEGF expression plays a role in promoting angiogenesis in invasive ductal carcinoma of the breast, and p53 is likely to be involved in regulating VEGF expression.

Angiogenesis, thrombospondin, and ductal carcinoma in situ of the breast

Angiogenesis, the growth of new vessels from existing vasculature, plays an essential role in tumour development. The process involves interaction between a variety of cells, growth factors, and components of the extracellular matrix, regulated by pro-angiogenic and anti-angiogenic factors. This review profiles these factors, outlines the available methods for measuring new vessel formation, and discusses the importance of angiogenesis in breast cancer, with emphasis on ductal carcinoma in situ.

Expression of vascular endothelial growth factor in adenocarcinomas of the uterine cervix and its relation to angiogenesis and p53 and c-erbB-2 protein expression

OBJECTIVE

The purpose of this study was to evaluate vascular endothelial growth factor (VEGF) expression in adenocarcinomas of the uterine cervix and its correlation with clinicopathologic features, angiogenesis, and expression of p53 and c-erbB-2 proteins.

METHODS

Thirty-seven cases of FIGO clinical stage I and II adenocarcinoma of the uterine cervix were examined by immunohistochemical studies with anti-VEGF, anti-CD34, anti-p53, and anti-c-erbB-2 antibodies. Computerized image analysis was used to evaluate microvessel density (MVD).

RESULTS

Thirty-one tumors (83.8%) were classified as VEGF positive. Six tumors (16.2%) showed p53 protein expression while 11 tumors (29.7%) expressed the c-erbB-2 protein. MVD ranged from 13.3 to 44.8, with a median value of 25.5 (26.9 +/- 7.5). Tumors expressing VEGF had a significantly higher MVD than those that did not express VEGF (P < 0.05). VEGF expression was significantly associated with c-erbB-2 protein expression (P < 0.05). The spatial distributions of both VEGF expression and c-erbB-2 expression were similar in tumor tissues. In univariate log-rank analysis, stage (P = 0.0250), lymphovascular space invasion (P = 0.0156), and MVD (P = 0.0360) were associated with shortened survival.

CONCLUSION

VEGF expression plays a role in promoting angiogenesis in cervical adenocarcinomas and c-erbB-2 is likely to be involved in the up-regulation of VEGF expression.