Predicting outcome to VEGF-targeted therapy in metastatic clear-cell renal cell carcinoma: data from recent studies

HEYL Regulates Neoangiogenesis Through Overexpression in Both Breast Tumor Epithelium and Endothelium

Blocking tumor angiogenesis is an appealing therapeutic strategy, but to date, success has been elusive. We previously identified HEYL, a downstream target of Notch signaling, as an overexpressed gene in both breast cancer cells and as a tumor endothelial marker, suggesting that HEYL overexpression in both compartments may contribute to neoangiogenesis. Carcinomas arising in double transgenic Her2-neu/HeyL mice showed higher tumor vessel density and significantly faster growth than tumors in parental Her2/neu mice. Providing mechanistic insight, microarray-based mRNA profiling of HS578T-tet-off-HEYL human breast cancer cells revealed upregulation of several angiogenic factors including CXCL1/2/3 upon HEYL expression, which was validated by RT-qPCR and protein array analysis. Upregulation of the cytokines CXCL1/2/3 occurred through direct binding of HEYL to their promoter sequences. We found that vessel growth and migration of human vascular endothelial cells (HUVECs) was promoted by conditioned medium from HS578T-tet-off-HEYL carcinoma cells, but was blocked by neutralizing antibodies against CXCL1/2/3. Supporting these findings, suppressing HEYL expression using shRNA in MDA-MB-231 cells significantly reduced tumor growth. In addition, suppressing the action of proangiogenic cytokines induced by HEYL using a small molecule inhibitor of the CXCl1/2/3 receptor, CXCR2, in combination with the anti-VEGF monoclonal antibody, bevacizumab, significantly reduced tumor growth of MDA-MB-231 xenografts. Thus, HEYL expression in tumor epithelium has a profound effect on the vascular microenvironment in promoting neoangiogenesis. Furthermore, we show that lack of HEYL expression in endothelial cells leads to defects in neoangiogenesis, both under normal physiological conditions and in cancer. Thus, HeyL-/- mice showed impaired vessel outgrowth in the neonatal retina, while the growth of mammary tumor cells E0771 was retarded in syngeneic HeyL-/- mice compared to wild type C57/Bl6 mice. Blocking HEYL's angiogenesis-promoting function in both tumor cells and tumor-associated endothelium may enhance efficacy of therapy targeting the tumor vasculature in breast cancer.

Diagnostic and prognostic role of matrix metalloproteases in cancer

BACKGROUND

Matrix metalloproteases (MMPs) are key players in the progression and metastasis of cancer. MMPs cleave extracellular matrix components and in this way promote tumor growth, invasion and vascularization. MMPs also affect tumor progression by regulating availability and activity of growth factors, inflammatory cytokines and chemokines. Accordingly, several MMPs have been found to serve as prognostic indicators in solid tumors. Usually the increased levels of MMPs in patients' tumor tissue or serum/plasma are associated with poor outcome. Interestingly, recent results show that certain MMPs also serve as tumor suppressors.

OBJECTIVE

This review discusses the latest view on MMPs as diagnostic and prognostic indicators in cancer patients.

METHODS

Studies with clinical samples of 70 or more patients are included in particular. In addition, the possible roles of MMPs in future molecular diagnostics and in the evaluation of therapeutic responses are discussed.

CONCLUSION

MMP-9 in particular has shown prognostic value in various types of tumor, and its measurement in circulation, urine or tumor tissue might help in clinical surveillance of otherwise problematic patient cases. There is upcoming new knowledge on MMPs in therapy response evaluation, in which MMPs might be useful together with CT scans and other clinically more established prognostic factors. Certain MMPs have a dual role in terms of cancer-modulating properties and thus it is essential to evaluate their expression and function in tumor cells and host environment to select validated therapy targets but spare MMP antitargets.

Evaluation of patients with metastatic renal cell carcinoma after failure of first-line treatment

The approval and use of molecular targeted agents for the first-line treatment of metastatic renal cell carcinoma (mRCC) has substantially improved the clinical outcome of patients. Although eventually all patients progress, hopes have been renewed with the approval of everolimus for patients who progress on or after treatment with tyrosine kinase inhibitors. In order to improve the prognosis for these patients, it is imperative to understand the reasons why patients with mRCC fail on first-line treatment. Currently, progression is assessed on the basis of the Response Evaluation Criteria in Solid Tumors, but it is known that targeted agents tend to cause disease stabilization rather than a significant decrease in tumor mass. Therefore, it may be time to evaluate the need to incorporate additional diagnostic methods in the assessment of disease response. Equally important is the study of the factors that determine the success or failure of second-line therapy in order to increase the chances of delivering the most effective and personalized therapy possible. In this article, we review the evidence related to the evaluation of patients with mRCC who fail on first-line treatment with targeted agents, including the systems to assess response and progression, the prognostic factors, the prognostic models that have been created based on these factors, and what is known about predictive biomarkers of disease outcome.

Evaluation of plasma and tissue S100A4 protein and mRNA levels as potential markers of metastasis and prognosis in clear cell renal cell carcinoma

OBJECTIVES

To investigate levels of S100A4 protein in plasma and S100A4 mRNA in tumours from patients with clear cell renal cell carcinoma (CCRCC), and correlate these with metastasis, survival and levels of vascular endothelial growth factor (VEGF).

METHODS

Plasma S100A4 and VEGF protein concentrations were measured using enzyme-linked immuno sorbent assays in 39 healthy subjects and 68 consecutive patients with untreated CCRCC. Levels of S100A4 and VEGF mRNA in tumour and matched control (healthy) tissue samples were measured using realtime quantitative reverse transcription- polymerase chain reaction. Findings were analysed with respect to clinico pathological characteristics.

RESULTS

Plasma VEGF concentrations were higher in patients with CCRCC than in healthy subjects. S100A4 and VEGF mRNA levels were up-regulated in CCRCC tumour tissue compared with control tissue samples. Logistic regression analysis revealed that up-regulated tumour S100A4 and VEGF mRNA levels were independent risk factors for the presence of invasion and/or metastasis.

CONCLUSIONS

S100A4 and VEGF are associated with tumour invasion and metastasis, and may be useful prognostic markers in patients with CCRCC. S100A4 and VEGF may represent potential targets for therapeutic intervention.

Prognostic factors in patients with advanced renal cell carcinoma

BACKGROUND

The purpose of this study was to evaluate prognostic factors in patients with RCC.

MATERIALS AND METHODS

The expression of several biomarkers were measured by immunohistochemistry (IHC), together with 2 analytic factors (thrombocytosis and neutrophilia), in 135 patients with advanced RCC treated with new targeted drugs (NTDs) (n = 67) and/or cytokines (CKs) (n = 68)-with 23 of the patients who received CKs also receiving NTDs-between July 1996 and February 2010. Relationships with overall survival (OS) and progression-free survival (PFS) were searched for.

RESULTS

Univariate statistical analysis revealed that high expression of hypoxia-inducible factor-1α (HIF-1α) correlated with poor prognosis in NTD treatment (PFS, 5.4 vs. 13.5, low expression months; P = .033) and CK treatment (PFS, 3.3 vs. 5.7, low expression; P = .003). Overexpression of carbonic anhydrase IX (CAIX) was associated with better prognosis with NTD treatment (OS, 32.1 vs. 7.8 months; P < .001) and CK treatment (OS, 32.9 vs. 5.9 months; P = .001). Positive PTEN was related to good prognosis with sunitinib (PFS, 15.1 vs. 6.5 months; P = .003) and CKs (OS, 13.7 vs. 7.9 months; P = .039). Increased expression of p21 was related to poor prognosis with NTD treatment (PFS, 5.9 vs. 16.8 months; P = .024) and CK treatment (PFS, 3.9 vs. 7.5 months; P < .001) Thrombocytosis was related to poor prognosis with NTDs (OS, 15.9 vs. 26.7 months; P = .007) and CKs (OS, 5.9 vs. 14.3 months; P = .010). Neutrophilia was related to poor prognosis with NTDs (OS, 17.6 vs. 25.4 months; P = .063) and CKs (OS, 5.9 vs. 12.8 months; P = .035). Multivariate analysis revealed that overexpression of CAIX was a favorable prognostic factor independent of PFS (hazard ratio [HR], 0.107; P < .001) and OS (HR, 0.055; P < .001).

CONCLUSIONS

HIF-1α, PTEN, p21, thrombocytosis, neutrophilia, and CAIX in particular are useful prognostic factors in patients with advanced RCC.

Genomic copy number alterations in clear cell renal carcinoma: associations with case characteristics and mechanisms of VHL gene inactivation

Array comparative genomic hybridization was used to identify copy number alterations in clear cell renal cell carcinoma (ccRCC) patient tumors to identify associations with patient/clinical characteristics. Of 763 ccRCC patients, 412 (54%) provided frozen biopsies. Clones were analyzed for significant copy number differences, adjusting for multiple comparisons and covariates in multivariate analyses. Frequent alterations included losses on: 3p (92.2%), 14q (46.8%), 8p (38.1%), 4q (35.4%), 9p (32.3%), 9q (31.8%), 6q (30.8%), 3q (29.4%), 10q (25.7%), 13q (24.5%), 1p (23.5%) and gains on 5q (60.2%), 7q (39.6%), 7p (30.6%), 5p (26.5%), 20q (25.5%), 12q (24.8%), 12p (22.8%). Stage and grade were associated with 1p, 9p, 9q, 13q and 14q loss and 12q gain. Males had more alterations compared with females, independent of stage and grade. Significant differences in the number/types of alterations were observed by family cancer history, age at diagnosis and smoking status. Von Hippel–Lindau (VHL) gene inactivation was associated with 3p loss (P<E-05), and these cases had fewer alterations than wild-type cases. The fragile site flanking the FHIT locus (3p14.2) represented a unique breakpoint among VHL hypermethylated cases, compared with wild-type cases and those with sequence changes. This is the first study of its size to investigate copy number alterations among cases with extensive patient, clinical/risk factor information. Patients characterized by VHL wild-type gene status (vs sequence alterations) and male (vs female) cases had more copy number alterations regardless of diagnostic stage and grade, which could relate to poor prognosis.

Von Hippel-Lindau (VHL) inactivation in sporadic clear cell renal cancer: associations with germline VHL polymorphisms and etiologic risk factors

Renal tumor heterogeneity studies have utilized the von Hippel-Lindau VHL gene to classify disease into molecularly defined subtypes to examine associations with etiologic risk factors and prognosis. The aim of this study was to provide a comprehensive analysis of VHL inactivation in clear cell renal tumors (ccRCC) and to evaluate relationships between VHL inactivation subgroups with renal cancer risk factors and VHL germline single nucleotide polymorphisms (SNPs). VHL genetic and epigenetic inactivation was examined among 507 sporadic RCC/470 ccRCC cases using endonuclease scanning and using bisulfite treatment and Sanger sequencing across 11 CpG sites within the VHL promoter. Case-only multivariate analyses were conducted to identify associations between alteration subtypes and risk factors. VHL inactivation, either through sequence alterations or promoter methylation in tumor DNA, was observed among 86.6% of ccRCC cases. Germline VHL SNPs and a haplotype were associated with promoter hypermethylation in tumor tissue (OR = 6.10; 95% CI: 2.28-16.35, p = 3.76E-4, p-global = 8E-5). Risk of having genetic VHL inactivation was inversely associated with smoking due to a higher proportion of wild-type ccRCC tumors [former: OR = 0.70 (0.20-1.31) and current: OR = 0.56 (0.32-0.99); P-trend = 0.04]. Alteration prevalence did not differ by histopathologic characteristics or occupational exposure to trichloroethylene. ccRCC cases with particular VHL germline polymorphisms were more likely to have VHL inactivation through promoter hypermethylation than through sequence alterations in tumor DNA, suggesting that the presence of these SNPs may represent an example of facilitated epigenetic variation (an inherited propensity towards epigenetic variation) in renal tissue. A proportion of tumors from current smokers lacked VHL alterations and may represent a biologically distinct clinical entity from inactivated cases.

Correlation of percentage changes in platelet counts with recurrence rate following radical nephrectomy

Objectives:

To categorize and correlate percentage changes in platelets counts - an objective approach with recurrence rate following radical nephrectomy.

Materials and Methods:

All consecutive patients who had radical nephrectomy for localized renal tumor in the period from January 1997 to December 2005 have been included in this study. The data was collected retrospectively. The primary outcome of this study was over all and cancer- specific survival and its correlation with percentage change in platelet count from pre-surgical level. Change in platelets counts was categorized as less than or more than 0-10%, 10-20% and more than 20% from base line (pre-surgery). This was correlated with the follow-up recurrence and disease free survival. Survival distribution were estimated using Kaplan-Meier method, univariate and multivariate regression analyses were performed using Cox proportional hazards models to address the impact of different prognostic factors on survival.

Results:

Of the 237 patients treated with radical nephrectomy, pT1, pT2, pT3, and pT4 accounted for 116 (49%), 44 (18.5%), 68(28.7%), and nine (3.8%) cases respectively. The mean tumor size was 6.3 cm (Range: 4-17 cm; SD: 3). The pre-operative platelet count ranged from 82 to 1573 (Mean: 327.5; SD: 171.7). The overall follow-up time ranged from 1-102 months (Mean: 39 months; SD: 27months). There was significant correlation between the recurrence rate and increase in platelets count of more than 20% following radical nephrectomy (P value- 0.0001).

Conclusions:

Categorization of platelets changes following radical nephrectomy for localized renal cell carcinoma, in particular, a change in more than 20% can accurately predict recurrence and cancer specific survival following radical nephrectomy for localized renal cell carcinoma.

Emerging molecular classification in renal cell carcinoma: implications for drug development

In the past decade, progress has been made in the development of targeted therapies for advanced renal cell carcinoma (RCC). However, as multiple therapeutic choices become available to clinicians, we currently lack effective indicators that allow physicians to choose the best treatment option for specific patients. For approved targeted therapies, potential molecules that could indicate drug effectiveness in a specific tumor follow naturally from both the therapeutic mechanism and the previously elucidated tumor biology. However, in advanced RCC, the use of these molecules as biomarkers for treatment selection has shown equivocal results and requires further investigation. In addition to looking at specific molecular targets, subclassification of tumors based on their molecular characteristics may also allow stratification of patients based on therapeutic benefits, providing information for treatment selection. Furthermore, the continued development of such tumor classification schemes will hopefully uncover other molecular targets that warrant development as future RCC therapies. The use of molecular classification of patients' tumors for treatment selection will provide the opportunity to increase the effectiveness of currently available therapies for advanced RCC and to judiciously pursue promising options for future RCC therapies.

Updates on novel therapies for metastatic renal cell carcinoma

Metastatic renal cell carcinoma (RCC) poses one of the great therapeutic challenges in oncology. RCC is predominantly refractory to treatment with traditional cytotoxic chemotherapies, and until recently management options were limited to immunotherapy or palliative care. However, in the past few years we have experienced a sea change in the treatment of advanced RCC with the introduction of targeted therapies that derive their efficacy at least in part through alterations in tumor angiogenesis. The tyrosine kinase inhibitors sunitinib, pazopanib, and sorafenib, the monoclonal antibody bevacizumab (in combination with interferon-α), and the rapamycin analogs, temsirolimus and everolimus, are now approved agents in the United States for the treatment of metastatic RCC. Efforts to expand upon these successes include developing novel antiangiogenic agents, optimizing concomitant and sequential regimens, identifying predictors of response to specific treatments, and further dissecting the underlying molecular pathogenesis of RCC to reveal novel therapeutic targets.

Vandetanib, designed to inhibit VEGFR2 and EGFR signaling, had no clinical activity as monotherapy for recurrent ovarian cancer and no detectable modulation of VEGFR2

PURPOSE

To evaluate clinical activity and target modulation of vandetanib in women with recurrent ovarian cancer.

EXPERIMENTAL DESIGN

A phase II trial of orally administered vandetanib 300 mg daily was designed to include analyses of target inhibition through paired biopsies and dynamic imaging. Core 18-gauge needle biopsies and dynamic contrast-enhanced magnetic resonance imaging were obtained before initiation of therapy and 6 weeks into therapy. Biopsy samples were subjected to reverse-phase protein lysate array endpoint analysis. Cytokine concentrations were measured by enzyme-linked immunosorbent assay in serially collected plasma samples.

RESULTS

Twelve patients entered the study, and accrual was terminated in the first stage because of lack of response or disease stabilization beyond 6 months. Adverse events included rash, diarrhea, and prolonged QT interval corrected for heart rate, but not hypertension. Exploratory analyses showed that epidermal growth factor receptor (EGFR) phosphorylation was reduced in the eight paired biopsy sets obtained; vascular endothelial growth factor (VEGF) receptor-2 phosphorylation was not consistently affected nor were dynamic contrast-enhanced MRI permeability and flow parameters. Serial plasma VEGF concentrations were variable and did not significantly change in the 11 patients assessed.

CONCLUSIONS

Vandetanib 300 mg daily monotherapy had no significant clinical benefit in this disease setting. Proteomic analysis of paired biopsies detected both phosphorylated-EGFR and phosphorylated-VEGF receptor-2 in ovarian tumor tissue, but only phosphorylated-EGFR was measurably inhibited by vandetanib.

Absence of VHL gene alteration and high VEGF expression are associated with tumour aggressiveness and poor survival of renal-cell carcinoma

Background:

The von Hippel–Lindau gene (VHL) alteration, a common event in sporadic clear-cell renal-cell carcinoma (CCRCC), leads to highly vascularised tumours. Vascular endothelial growth factor (VEGF) is the major factor involved in angiogenesis, but the prognostic significance of both VHL inactivation and VEGF expression remain controversial. The aims of this study were to analyse the relationship between VHL genetic and epigenetic alterations, VHL expression and VEGF tumour or plasma expression, and to analyse their respective prognostic value in patients with CCRCC.

Methods:

A total of 102 patients with CCRCC were prospectively analysed. Alterations in VHL were determined by sequencing, Multiplex Ligation-dependent Probe Amplification (MLPA) and methylation-specific MLPA. Expression of pVHL and VEGF was determined by immunohistochemistry. Plasma VEGF was measured by enzyme-linked immunosorbent assay (ELISA).

Results:

VHL mutation, deletion and promoter methylation were identified in 70, 76 and 14 cases, respectively. Overall, at least one VHL-gene alteration occurred in 91 cases (89.2%). Both VEGF tumour and plasma expression appeared to be decreased in case of VHL alteration. Median progression-free survival and CCRCC-specific survival were significantly reduced in patients with wild-type VHL or altered VHL and high VEGF expression, which, therefore, represent two markers of tumour aggressiveness in CCRCC.

Conclusion:

Stratifying CCRCCs according to VHL and VEGF status may help tailor therapeutic strategy.

Influence of the VEGF-A 936C>T germinal polymorphism on tumoral VEGF expression in head and neck cancer

Aims: Elevated tumoral vascular endothelial growth factor A (VEGF-A) expression is linked to poor survival in head and neck cancer patients. The aim of the present study was to analyze the influence of VEGF-A gene polymorphisms on tumoral VEGF-A expression and to test their prognostic value in head and neck cancer patients. Materials & methods: VEGF-A polymorphisms at position -2578C>A, -1498T>C, -1154G>A, -634G>C and 936C>T were analyzed (PCR-RFLP) in tumoral DNA, along with tumoral VEGF-A expression (ELISA), in 49 Caucasian head and neck cancer patients. Results: A trend towards a difference in tumoral VEGF-A expression depending on 936C>T polymorphism was observed, with a median at 540 pg/mg prot in CT + TT patients (n = 5) versus 940 pg/mg prot in CC patients (n = 44) (p = 0.064). VEGF-A expression was not related to any other polymorphism. Unlike tumoral VEGF-A expression, the analyzed genotypes were not related to patient survival. Conclusion: As opposed to tumoral VEGF-A expression, VEGF-A gene polymorphisms are not of prognostic value in head and neck cancer patients. Further studies aimed at confirming the influence of VEGF-A 936C>T germinal polymorphism on tumoral VEGF-A expression are needed.