Association of Angiopoietin-2 and Ki-67 Expression with Vascular Density and Sunitinib Response in Metastatic Renal Cell Carcinoma

Molecular mechanisms and clinical relevance of endothelial cell cross-talk in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is the most common renal cancer in adults and stands out as one of the most vascularized and immune-infiltrated solid tumors. Overproduction of vascular endothelial growth factor A promotes uncontrolled growth of abnormal vessels and immunosuppression, and the tumor microenvironment (TME) has a prominent role in disease progression, drug targeting and drug response, and for patient outcome.

Methods

Studies of experimental models, large-scale omics approaches, and patient prognosis and therapy prediction, using gene expression signatures and tissue biomarker analysis, have been reviewed for enhanced understanding of the endothelium in ccRCC and the interplay with the surrounding TME.

Results

Preclinical and clinical studies have discovered molecular mechanisms of endothelial cross-talk of relevance for disease progression, patient prognosis, and therapy prediction. There is, however, a lack of representative ccRCC experimental models. Omics approaches have identified clinically relevant subsets of angiogenic and immune-infiltrated tumors with distinct molecular signatures and distinct endothelial cell and immune cell populations in patients.

Conclusions

Recent genetically engineered ccRCC mouse models together with emerging evidence from single cell RNA sequencing data open up for future validation studies, including multiplex imaging of ccRCC patient cohorts. These studies are of importance for therapy benefit and personalized treatment of ccRCC patients.

Durvalumab plus pazopanib combination in patients with advanced soft tissue sarcomas: a phase II trial

We aimed to determine the activity of the anti-VEGF receptor tyrosine-kinase inhibitor, pazopanib, combined with the anti-PD-L1 inhibitor, durvalumab, in metastatic and/or recurrent soft tissue sarcoma (STS). In this single-arm phase 2 trial (NCT03798106), treatment consisted of pazopanib 800 mg orally once a day and durvalumab 1500 mg once every 3 weeks. Primary outcome was overall response rate (ORR) and secondary outcomes included progression-free survival (PFS), overall survival, disease control rate, immune-related response criteria, and safety. The ORR was 30.4% and the trial met the pre-specified endpoint. The median PFS was 7.7 months (95% confidence interval: 5.7-10.4). The common treatment-related adverse events of grades 3-4 included neutropenia (9 [19.1%]), elevated aspartate aminotransferase (7 [14.9%]), alanine aminotransferase (5 [10.6%]), and thrombocytopenia (4 [8.5%]). In a prespecified transcriptomic analysis, the B lineage signature was a significant key determinant of overall response (P = 0.014). In situ analysis also showed that tumours with high CD20+ B cell infiltration and vessel density had a longer PFS (P = 6.5 × 10-4) than those with low B cell infiltration and vessel density, as well as better response (50% vs 12%, P = 0.019). CD20+ B cell infiltration was identified as the only independent predictor of PFS via multivariate analysis. Durvalumab combined with pazopanib demonstrated promising efficacy in an unselected STS cohort, with a manageable toxicity profile.

Immunohistochemical expression of cytochrome P4A11 (CYP4A11), carbonic anhydrase 9 (CAIX) and Ki67 in renal cell carcinoma; diagnostic relevance and relations to clinicopathological parameters

BACKGROUND

Cytochrome P4A11 (CYP4A11) is a member of cytochrome p450 family, which is involved in arachidonic acid metabolism that participates in promoting malignant cell proliferation, progression, and angiogenetic capacity. Carbonic Anhydrase 9 (CAIX) is a transmembrane protein that plays an integral part in regulating hypoxia which affects cancer cell metabolism, proliferation and promotes metastasis. The aim of this study was to evaluate the immunohistochemical expression of CYP4A11, CAIX and ki67 in RCC subtypes in relation to clinicopathological parameters and to evaluate the diagnostic significance of CYP4A11 and CAIX in differentiating renal cell carcinoma (RCC) subtypes.

MATERIALS AND METHODS

one hundred primary RCC cases, collected from Pathology Department, Faculty of Medicine, Tanta University and from private laboratories, were evaluated for immunohistochemical expression of CYP4A11, CAIX and ki67.

RESULTS

CYP4A11 was expressed in 59% of RCC; with 91.7% sensitivity and 90% specificity in differentiating clear cell and non-clear cell subtypes. CAIX was expressed in 50% of RCC; with 95% sensitivity, 80% specificity. High expression of CYP4A11 was statistically positively associated with higher tumor grade, high expression of CAIX was statistically positively associated with lower tumor grade and absence of necrosis and high ki67 labeling index was significantly associated with clear cell subtype, larger tumor sizes, higher tumor grade, advanced tumor stage, fat invasion and vascular invasion.

CONCLUSIONS

CYP4A11 and CAIX can be used as diagnostic markers to differentiate clear cell RCC from other subtypes. CYP4A11 is more diagnostically accurate and specific than CAIX. High expression of CYP4A11, low CAIX expression and high ki67 labeling index were related to features of aggressive tumor behavior.

Prognostic and predictive significance of VEGF, CD31, and Ang-1 in patients with metastatic clear cell renal cell carcinoma treated with first-line sunitinib

The most common type of renal cell carcinoma (RCC) is clear cell renal cell carcinoma (ccRCC), which has a high metastatic potential. Even though the International Metastatic RCC Database Consortium (IMDC) risk model is conventionally utilized for selection and stratification of patients with metastatic RCC (mRCC), there remains an unmet demand for novel prognostic and predictive markers. The goal of this study was to analyze the expression of Vascular endothelial growth factor (VEGF), Cluster of Differentiation 31 (CD31) to determine microvessel density, and Angiopoietin-1 (Ang-1) in primary kidney tumors, as well as their predictive and prognostic value in patients with metastatic ccRCC (mccRCC) who were treated with first-line sunitinib. The study included 35 mccRCC patients who were treated with first-line sunitinib in period between 2009 and 2019. Immunofluorescence was used to examine biomarker expression in tissue specimens of the primary tumor and surrounding normal kidney tissue. Median disease-free survival (DFS) was longer in patients with negative and low tumor VEGF score than in patients with medium tumor VEGF score (p=0.02). Those with low tumor CD31 expression had a longer median DFS than patients with high tumor CD31 expression (p=0.019). There was no correlation between Ang-1 expression and DFS. The expression of biomarkers in normal kidney tissue was significantly lower than in tumor tissue (p<0.001). In conclusion, higher VEGF scores and greater CD31 expression were associated with longer DFS, but neither of these biomarkers correlated with progression-free survival or overall survival.

Sodium Propionate Contributes to Tumor Cell Growth Inhibition through PPAR-γ Signaling

New therapeutic approaches are needed to improve the outcome of patients with glioblastoma (GBM). Propionate, a short-chain fatty acid (SCFA), has a potent antiproliferative effect on various tumor cell types. Peroxisome proliferator-activated receptor (PPAR) ligands possess anticancer properties. We aimed to investigate the PPAR-γ/SCFAs interaction in in vitro and in vivo models of GBM. The U87 cell line was used in the in vitro study and was treated with sodium propionate (SP). U87 cells were silenced by using PPAR-γ siRNA or Ctr siRNA. In the in vivo study, BALB/c nude mice were inoculated in the right flank with 3 × 10⁶ U-87 cells. SP (doses of 30 and 100 mg/kg) and GW9662 (1 mg/kg) were administered. In vitro exposure of GBM to SP resulted in prominent apoptosis activation while the autophagy pathway was promoted by SP treatments by influencing autophagy-related proteins. Knockdown of PPAR-γ sensitized GBM cells and blocked the SP effect. In vivo, SP was able to decrease tumor growth and to resolve GBM tissue features. SP promoted apoptosis and autophagy pathways and tumor cell proliferation leading to cell cycle arrest through a PPAR-γ-dependent mechanism suggesting that the PPAR-γ/SCFAs axis could be targeted for the management of GBM.

Renal Carcinoma and Angiogenesis: Therapeutic Target and Biomarkers of Response in Current Therapies

Due to the aberrant hypervascularization and the high immune infiltration of renal tumours, current therapeutic regimens of renal cell carcinoma (RCC) target angiogenic or immunosuppressive pathways or both. Tumour angiogenesis plays an essential role in tumour growth and immunosuppression. Indeed, the aberrant vasculature promotes hypoxia and can also exert immunosuppressive functions. In addition, pro-angiogenic factors, including VEGF-A, have an immunosuppressive action on immune cells. Despite the progress of treatments in RCC, there are still non responders or acquired resistance. Currently, no biomarkers are used in clinical practice to guide the choice between the different available treatments. Considering the role of angiogenesis in RCC, angiogenesis-related markers are interesting candidates. They have been studied in the response to antiangiogenic drugs (AA) and show interest in predicting the response. They have been less studied in immunotherapy alone or combined with AA. In this review, we will discuss the role of angiogenesis in tumour growth and immune escape and the place of angiogenesis-targeted biomarkers to predict response to current therapies in RCC.

First-line Immune Checkpoint Inhibitor Combinations in Metastatic Renal Cell Carcinoma: Where Are We Going, Where Have We Been?

The combination of targeted therapy and immunotherapy in the treatment of metastatic renal cell carcinoma (mRCC) has significantly improved outcomes for many patients. There are multiple FDA-approved regimens for the frontline setting based on numerous randomized Phase III trials. Despite these efforts, there remains a conundrum of identifying a biomarker-driven approach for these patients and it is unclear how to predict which patients are most likely to respond to these agents. This is due, in part, to an incomplete understanding of how these drug combinations work. The use of tyrosine kinase inhibitors that have multiple 'off-target' effects may lend themselves to the benefits observed when given in combination with immunotherapy. Further, targeting multiple clones within a patient's heterogenic tumor that are responsive to targeted therapy and others that are responsive to immunotherapy may also explain some level of improved response rates to the combination approaches compared to monotherapies. This review highlights the 5 FDA-approved regimens for mRCC in the frontline setting and offers insights into potential mechanisms for improved outcomes seen in these combination approaches.

KYP-2047, an Inhibitor of Prolyl-Oligopeptidase, Reduces GlioBlastoma Proliferation through Angiogenesis and Apoptosis Modulation

Simple Summary

Glioblastoma (GB) is the most aggressive brain tumor characterized by necrosis, excessive proliferation, and invasiveness. Despite relevant progress in conventional treatments, the survival rate for patients with GB remains low. The present study investigated the potential effect of KYP-2047, an inhibitor of the prolyl-oligopeptidase (POP or PREP), in an in vivo U87-xenograft model and in an in vitro study on human GB cells. This study demonstrated the abilities of KYP-2047 to counteract and reduce GB progression through angiogenesis and apoptosis modulation.

Abstract

Glioblastoma (GB) is the most aggressive tumor of the central nervous system (CNS), characterized by excessive proliferation, necrosis and invasiveness. The survival rate for patients with GB still remains low. Angiogenesis and apoptosis play a key role in the development of GB. Thus, the modulation of angiogenesis and apoptosis processes represent a possible strategy to counteract GB progression. This study aimed to investigate the potential effect of KYP-2047, an inhibitor of the prolyl-oligopeptidase (POP), known to modulate angiogenesis, in an in vivo U87-xenograft model and in an in vitro study on human GB cells. Our results showed that KYP-2047 at doses of 2.5 mg/kg and 5 mg/kg was able to reduce tumor burden in the xenograft-model. Moreover, KYP-2047 significantly reduced vascular endothelial-growth-factor (VEGF), angiopoietins (Ang) and endothelial-nitric-oxide synthase (eNOS) expression. In vitro study revealed that KYP-2047 at different concentrations reduced GB cells’ viability. Additionally, KYP-2047 at the concentrations of 50 µM and 100 µM was able to increase the pro-apoptotic protein Bax, p53 and caspase-3 expression whereas Bcl-2 expression was reduced. Thus, KYP-2047 could represent a potential therapeutic treatment to counteract or reduce GB progression, thanks its abilities to modulate angiogenesis and apoptosis pathways.

Spatial immunoprofiling of the intratumoral and peritumoral tissue of renal cell carcinoma patients

While the abundance and phenotype of tumor-infiltrating lymphocytes are linked with clinical survival, their spatial coordination and its clinical significance remain unclear. Here, we investigated the immune profile of intratumoral and peritumoral tissue of clear cell renal cell carcinoma patients (n = 64). We trained a cell classifier to detect lymphocytes from hematoxylin and eosin stained tissue slides. Using unsupervised classification, patients were further classified into immune cold, hot and excluded topographies reflecting lymphocyte abundance and localization. The immune topography distribution was further validated with The Cancer Genome Atlas digital image dataset. We showed association between PBRM1 mutation and immune cold topography, STAG1 mutation and immune hot topography and BAP1 mutation and immune excluded topography. With quantitative multiplex immunohistochemistry we analyzed the expression of 23 lymphocyte markers in intratumoral and peritumoral tissue regions. To study spatial interactions, we developed an algorithm quantifying the proportion of adjacent immune cell pairs and their immunophenotypes. Immune excluded tumors were associated with superior overall survival (HR 0.19, p = 0.02) and less extensive metastasis. Intratumoral T cells were characterized with pronounced expression of immunological activation and exhaustion markers such as granzyme B, PD1, and LAG3. Immune cell interaction occurred most frequently in the intratumoral region and correlated with CD45RO expression. Moreover, high proportion of peritumoral CD45RO+ T cells predicted poor overall survival. In summary, intratumoral and peritumoral tissue regions represent distinct immunospatial profiles and are associated with clinicopathologic characteristics.

Proliferative potential and response to nivolumab in clear cell renal cell carcinoma patients

Background

Biomarkers predicting immunotherapy response in metastatic renal cell cancer (mRCC) are lacking. PD-L1 immunohistochemistry is a complementary diagnostic for immune checkpoint inhibitors (ICIs) in mRCC, but has shown minimal clinical utility and is not used in routine clinical practice.

Methods

Tumor specimens from 56 patients with mRCC who received nivolumab were evaluated for PD-L1, cell proliferation (targeted RNA-seq), and outcome.

Results

For 56 patients treated with nivolumab as a standard of care, there were 2 complete responses and 8 partial responses for a response rate of 17.9%. Dividing cell proliferation into tertiles, derived from the mean expression of 10 proliferation-associated genes in a reference set of tumors, poorly proliferative tumors (62.5%) were more common than moderately (30.4%) or highly proliferative (8.9%) counterparts. Moderately proliferative tumors were enriched for PD-L1 positive (41.2%), compared to poorly proliferative counterparts (11.4%). Objective response for moderately proliferative (29.4%) tumors was higher than that of poorly (11.4%) proliferative counterparts, but not statistically significant (p = .11). When cell proliferation and negative PD-L1 tumor proportion scores were combined statistically significant results were achieved (p = .048), showing that patients with poorly proliferative and PD-L1 negative tumors have a very low response rate (6.5%) compared to moderately proliferative PD-L1 negative tumors (30%).

Conclusions

Cell proliferation has value in predicting response to nivolumab in clear cell mRCC patients, especially when combined with PD-L1 expression. Further studies which include the addition of progression-free survival (PFS) along with sufficiently powered subgroups are required to further support these findings.

Perivascular Neuropilin-1 expression is an independent marker of improved survival in renal cell carcinoma

Renal cell carcinoma (RCC) treatment has improved in the last decade with the introduction of drugs targeting tumor angiogenesis. However, the 5‐year survival of metastatic disease is still only 10–15%. Here, we explored the prognostic significance of compartment‐specific expression of Neuropilin 1 (NRP1), a co‐receptor for vascular endothelial growth factor (VEGF). NRP1 expression was analyzed in RCC tumor vessels, in perivascular tumor cells, and generally in the tumor cell compartment. Moreover, complex formation between NRP1 and the main VEGF receptor, VEGFR2, was determined. Two RCC tissue microarrays were used; a discovery cohort consisting of 64 patients and a validation cohort of 314 patients. VEGFR2/NRP1 complex formation in cis (on the same cell) and trans (between cells) configurations was determined by in situ proximity ligation assay (PLA), and NRP1 protein expression in three compartments (endothelial cells, perivascular tumor cells, and general tumor cell expression) was determined by immunofluorescent staining. Expression of NRP1 in perivascular tumor cells was explored as a marker for RCC survival in the two RCC cohorts. Results were further validated using a publicly available gene expression dataset of clear cell RCC (ccRCC). We found that VEGFR2/NRP1 trans complexes were detected in 75% of the patient samples. The presence of trans VEGFR2/NRP1 complexes or perivascular NRP1 expression was associated with a reduced tumor vessel density and size. When exploring NRP1 as a biomarker for RCC prognosis, perivascular NRP1 and general tumor cell NRP1 protein expression correlated with improved survival in the two independent cohorts, and significant results were obtained also at the mRNA level using the publicly available ccRCC gene expression dataset. Only perivascular NRP1 expression remained significant in multivariable analysis. Our work shows that perivascular NRP1 expression is an independent marker of improved survival in RCC patients, and reduces tumor vascularization by forming complexes in trans with VEGFR2 in the tumor endothelium. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Anti-angiogenic Targets: Angiopoietin and Angiopoietin Receptors

Tumor blood vessel formation (angiogenesis) is essential for tumor growth and metastasis. Two main endothelial ligand–receptor pathways regulating angiogenesis are vascular endothelial growth factor (VEGF) receptor and angiopoietin-TIE receptor pathways. The angiopoietin-TIE pathway is required for the remodeling and maturation of the blood and lymphatic vessels during embryonic development after VEGF and VEGF-C mediated development of the primary vascular plexus. Angiopoietin-1 (ANGPT1) stabilizes the vasculature after angiogenic processes, via tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (TIE2) activation. In contrast, ANGPT2 is upregulated at sites of vascular remodeling. ANGPT2 is secreted by activated endothelial cells in inflammation, promoting vascular destabilization. ANGPT2 has been found to be expressed in many human cancers. Intriguingly, in preclinical models inhibition of ANGPT2 has provided promising results in preventing tumor angiogenesis, tumor growth, and metastasis, making it an attractive candidate to target in tumors. However, until now the first ANGPT2 targeting therapies have been less effective in clinical trials than in experimental models. Additionally, in preclinical models combined therapy against ANGPT2 and VEGF or immune checkpoint inhibitors has been superior to monotherapies, and these pathways are also targeted in early clinical trials. In order to improve current anti-angiogenic therapies and successfully exploit ANGPT2 as a target for cancer treatment, the biology of the angiopoietin-TIE pathway needs to be profoundly clarified.

Potential suppressive effects of theophylline on human rectal cancer SW480 cells in vitro by inhibiting YKL-40 expression

Chitinase-3-like-1 protein (YKL-40), a member of the mammalian chitinase-like glycoproteins, serves a key role in the pathogenesis of rectal cancer. The present study examined the antitumor effect of theophylline, a pan-chitinase inhibitor, in rectal cancer in vitro and investigated the mechanism by which it acted. SW480 cell lines were treated with varying theophylline concentrations (10^-2, 10^-3, 10^-4 and 10^-5 mol/l). An MTT assay was used to observe cell proliferation and identify the optimal theophylline concentration. Western blotting was used to analyze YKL-40 expression. The cell cycle distribution of SW480 cell lines treated with theophylline was measured by flow cytometry. The angiopoietin-2 expression level was measured by ELISA. The expression levels of YKL-40 were evidently decreased in theophylline-treated SW480 cell lines. The proliferation of SW480 cells was inhibited following theophylline treatment, which was associated with G₁ phase cell cycle arrest and a decrease in the expression of angiopoietin-2. The mechanism of theophylline action may involve the downregulation of YKL-40 expression, arrest of the cell cycle at G₁ phase and inhibition of angiopoietin-2 expression. These results provide a rationale for the potential use of anti-YKL-40 and anti-angiogenic strategies in treating rectal cancer.

Prognostic and clinicopathological value of Ki-67/MIB-1 expression in renal cell carcinoma: a meta-analysis based on 4579 individuals

Background

Previous studies have investigated the prognostic significance of Ki-67/MIB-1 expression in renal cell carcinoma (RCC), however, the reports are controversial and inconsistent. This study aimed to investigate Ki-67/MIB-1 expression in RCC and its correlation with prognosis and clinicopathological features.

Methods

We searched relevant studies that reported associations between Ki-67/MIB-1 expression and prognosis in RCC from PubMed, Embase, Web of Science, and Cochrane Library studies published until April 14, 2017. Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted from eligible studies. Fixed and random effects models were used to calculate pooled HRs and 95% CIs according to heterogeneity.

Results

A total of 4579 participants from 23 eligible studies were included in this analysis. The results showed that Ki-67/MIB-1 expression was associated with poor overall survival (HR=2.06, 95% CI: 1.64-2.57) and cancer specific survival (HR=2.01, 95% CI: 1.66-2.44). In addition, Ki-67/MIB-1 expression was also correlated with TNM stage (III/IV vs I/II: OR=1.92, 95% CI: 1.61-2.28), pathological T stage (pT3/pT4 vs pT1/pT2: OR=1.56, 95% CI: 1.21-2.02), distant metastasis (M1 vs M0: OR=1.81, 95% CI: 1.34-2.43), and Fuhrman grade (III/IV vs I/II: OR=1.94, 95% CI: 1.21-3.10).

Conclusion

Our study demonstrates that the presence of high Ki-67/MIB-1 expression and advanced clinicopathological features were correlated with poor prognosis in RCC patients.

Therapeutic targeting of the angiopoietin-TIE pathway

The endothelial angiopoietin (ANG)-TIE growth factor receptor pathway regulates vascular permeability and pathological vascular remodelling during inflammation, tumour angiogenesis and metastasis. Drugs that target the ANG-TIE pathway are in clinical development for oncological and ophthalmological applications. The aim is to complement current vascular endothelial growth factor (VEGF)-based anti-angiogenic therapies in cancer, wet age-related macular degeneration and macular oedema. The unique function of the ANG-TIE pathway in vascular stabilization also renders this pathway an attractive target in sepsis, organ transplantation, atherosclerosis and vascular complications of diabetes. This Review covers key aspects of the function of the ANG-TIE pathway in vascular disease and describes the recent development of novel therapeutics that target this pathway.

Renal clear cell carcinoma: diffusion tensor imaging diagnostic accuracy and correlations with clinical and histopathological factors

AIM

To investigate whether diffusion tensor imaging (DTI) can be used to assess renal clinical histopathology, including the nuclear grade (NG), cell density (CD), and the presence of ki-67.

MATERIALS AND METHODS

Thirty patients were enrolled in the study and were confirmed at surgical histopathology to have clear cell renal cell carcinoma (CCRCC). For DTI, a coronal echo-planar imaging sequence was performed (1400 ms repetition time, 76 ms echo time, diffusion direction=6, number of excitations=4; b=0 and 800 s/mm², 6 mm section thickness with no intersection gap). CD and the presence of ki-67 were compared between the different NGs. Correlations between apparent diffusion coefficients (ADCs), E1, fractional anisotropy (FA), CD, and ki-67 were evaluated.

RESULTS

ADC, E1, and FA values are important tools used to identify NG. The cut-off values were 1.003×10^-3 mm²/s, 1.277×10^-3 mm²/s, and 0.218 mm²/s, respectively. The difference between high- and low-grade CD was significant (t=-4.50, p<0.05). Similarly, a significant difference between high and low grade was also found in ki-67 (t=-4.03, p<0.05). ADC, E1, and FA values were decreased with increased CD; a significant negative correlation was found (r=-0.796, -0.865, and -0.996, respectively). Significant negative correlations between ADC, E1, and FA values, and ki-67 were found (r=-0.739, -0.826, and -0.876, respectively).

CONCLUSIONS

DTI can be used to non-invasively assess CCRCC.

Novel Angiogenesis Markers as Long-Term Prognostic Factors in Patients With Renal Cell Cancer

OBJECTIVE

To evaluate Ang-2 expression alone and in combination with expression of cell proliferation and cell survival markers (MIB-1 and Bcl-2) and angiogenesis markers (VEGFR3 and CD31), and the associations of these markers with renal cell cancer (RCC) in long-term survival.

PATIENTS AND METHODS

Our study included 224 patients with RCC who were treated before the availability of antiangiogenic agents between 1985 and 1995, at the Pirkanmaa Hospital District in Finland. All tumor samples were reclassified and reevaluated by an experienced uropathologist, and parallel tissue microarrays (TMA) were performed for immunohistochemical analysis. Kaplan-Meier's survival estimation method and Cox proportional hazards models were used for survival analysis.

RESULTS

The percentage of Ang-2 expression in the tumor area varied from 0.07 to 25.65. Ang-2 expression was significantly associated with the tumor grade and stage, as well as the MIB-1, Bcl-2, and VEGFR3 expression (P = .042, P = .019, P = .039, P = .013, and P = .005, respectively). The highest Ang-2 expression predicted better survival, P < .05. High Bcl-2 and low MIB-1 expression combined with Ang-2 expression was associated with better survival. Multivariate analysis showed poorer survival in patients with low Ang-2 or high MIB-1 expressions: HR 1.89, 95% CI 1.16 to 3.08, P = .010 and HR 2.20, 95% CI 1.36 to 3.54, P = .001, respectively.

CONCLUSIONS

Very high Ang-2 expression was associated with better survival in patients with RCC. Ang-2 expression correlated with tumor stage and grade, but it was still an independent prognostic factor in a multivariate analysis.