The effect of VEGF-targeted therapy on biomarker expression in sequential tissue from patients with metastatic clear cell renal cancer

Randomized, Double-Blind Phase III Study of Pazopanib Versus Placebo in Patients With Metastatic Renal Cell Carcinoma Who Have No Evidence of Disease After Metastasectomy: ECOG-ACRIN E2810

PURPOSE

Patients with no evidence of disease (NED) after metastasectomy for renal cell carcinoma are at high risk of recurrence. Pazopanib is an inhibitor of vascular endothelial growth factor receptor and other kinases that improves progression-free survival in patients with metastatic RCC (mRCC). We conducted a randomized, double-blind, placebo-controlled multicenter study to test whether pazopanib would improve disease-free survival (DFS) in patients with mRCC rendered NED after metastasectomy.

PATIENTS AND METHODS

Patients with NED after metastasectomy were randomly assigned 1:1 to receive pazopanib 800 mg once daily versus placebo for 52 weeks. The study was designed to observe an improvement in DFS from 25% to 45% with pazopanib at 3 years, corresponding to 42% reduction in the DFS event rate.

RESULTS

From August 2012 to July 2017, 129 patients were enrolled. The study was unblinded after 83 DFS events (92% information). The study did not meet its primary end point. An updated analysis at 60.5-month median follow-up from random assignment (95% CI, 59.3 to 71.0) showed that the 3-year DFS was 27.4% (95% CI, 17.9 to 41.7) for pazopanib and 21.9% (95% CI, 13.3 to 36.2) for placebo. Hazard ratio (HR) for DFS was 0.90 ([95% CI, 0.60 to 1.34]; Pone-sided = .29) in favor of pazopanib. Three-year overall survival (OS) was 81.9% (95% CI, 72.7 to 92.2) for pazopanib and 91.4% (95% CI, 84.4 to 98.9) for placebo. The HR for OS was 2.55 (95% CI, 1.23 to 5.27) in favor of placebo (Ptwo-sided = .012). Health-related quality-of-life measures deteriorated in the pazopanib group during the treatment period.

CONCLUSION

Pazopanib did not improve DFS as the primary end point compared with blinded placebo in patients with mRCC with NED after metastasectomy. In addition, there was a concerning trend favoring placebo in OS.

Accurate detection of benign and malignant renal tumor subtypes with MethylBoostER: An epigenetic marker-driven learning framework

Current gold standard diagnostic strategies are unable to accurately differentiate malignant from benign small renal masses preoperatively; consequently, 20% of patients undergo unnecessary surgery. Devising a more confident presurgical diagnosis is key to improving treatment decision-making. We therefore developed MethylBoostER, a machine learning model leveraging DNA methylation data from 1228 tissue samples, to classify pathological subtypes of renal tumors (benign oncocytoma, clear cell, papillary, and chromophobe RCC) and normal kidney. The prediction accuracy in the testing set was 0.960, with class-wise ROC AUCs >0.988 for all classes. External validation was performed on >500 samples from four independent datasets, achieving AUCs >0.89 for all classes and average accuracies of 0.824, 0.703, 0.875, and 0.894 for the four datasets. Furthermore, consistent classification of multiregion samples (N = 185) from the same patient demonstrates that methylation heterogeneity does not limit model applicability. Following further clinical studies, MethylBoostER could facilitate a more confident presurgical diagnosis to guide treatment decision-making in the future.

The Role of Circulating Biomarkers in the Oncological Management of Metastatic Renal Cell Carcinoma: Where Do We Stand Now?

Renal cell carcinoma (RCC) is an increasingly common malignancy that can progress to metastatic renal cell carcinoma (mRCC) in approximately one-third of RCC patients. The 5-year survival rate for mRCC is abysmally low, and, at the present time, there are sparingly few if any effective treatments. Current surgical and pharmacological treatments can have a long-lasting impact on renal function, as well. Thus, there is a compelling unmet need to discover novel biomarkers and surveillance methods to improve patient outcomes with more targeted therapies earlier in the course of the disease. Circulating biomarkers, such as circulating tumor DNA, noncoding RNA, proteins, extracellular vesicles, or cancer cells themselves potentially represent a minimally invasive tool to fill this gap and accelerate both diagnosis and treatment. Here, we discuss the clinical relevance of different circulating biomarkers in metastatic renal cell carcinoma by clarifying their potential role as novel biomarkers of response or resistance to treatments but also by guiding clinicians in novel therapeutic approaches.

Multicenter Phase I/II Study of Nivolumab Combined with Paclitaxel Plus Ramucirumab as Second-line Treatment in Patients with Advanced Gastric Cancer

PURPOSE

We conducted a phase I/II study to investigate the safety and efficacy of nivolumab with paclitaxel plus ramucirumab.

PATIENTS AND METHODS

Patients with advanced gastric cancer (AGC) refractory to first-line chemotherapy were included. Patients received nivolumab (3 mg/kg on days 1 and 15) combined with paclitaxel (80 mg/m2 on days 1, 8, and 15) and ramucirumab (8 mg/kg on days 1 and 15) every 4 weeks. After feasibility evaluation in six patients (phase I), 37 additional patients were enrolled in the phase II part with the primary endpoint of 6-month progression-free survival (PFS) rate with two-sided 80% confidence interval (CI). The combined positive score (CPS) was defined as the number of programmed death-ligand 1-positive cells divided by the total number of viable tumor cells multiplied by 100.

RESULTS

Forty-three patients were enrolled. Of these, 60.5% had CPS ≥ 1. Dose-limiting toxicities were observed in two patients, and the recommended dose was determined as level 1. Thirty-nine (90.7%) patients experienced treatment-related adverse events (AEs) grade ≥3 and 14 (32.6%) patients experienced immune-related AEs grade ≥3. The overall response rate was 37.2% (95% CI, 23.0%-53.5%) and the 6-month PFS rate was 46.5% (80% CI, 36.4%-55.8%; P = 0.067). Median survival time was 13.1 months (95% CI, 8.0-16.6 months): 13.8 months (95% CI, 8.0-19.5 months) in patients with CPS ≥ 1 and 8.0 months (95% CI, 4.8-24.1 months) in patients with CPS < 1.

CONCLUSIONS

Nivolumab with paclitaxel plus ramucirumab demonstrated promising antitumor activity with manageable toxicities as second-line treatment for AGC.

Activation-Induced Cytidine Deaminase Expression Facilitates the Malignant Phenotype and Epithelial-to-Mesenchymal Transition in Clear Cell Renal Cell Carcinoma

Although advances have been made in the development of antiangiogenesis targeted therapy and surgery, metastatic clear cell renal cell carcinoma (ccRCC) is still incurable. Activation-induced cytidine deaminase (AID) is mainly expressed in a variety of germ and somatic cells, and induces somatic hypermutation and class-switch recombination, playing a vital role in antibody diversification. We confirmed that AID was expressed at a higher level in ccRCC tissues than in the corresponding nontumor renal tissues. We explored the impact of AID on ccRCC proliferation, invasion, and migration. In 769-p and 786-0 cells, expression of an AID-specific short hairpin RNA significantly reduced AID expression, which markedly inhibited tumor cell invasion, proliferation, and migration. Previous studies showed that AID is associated with Wnt ligand secretion mediator (WLS/GPR177), cyclin-dependent kinase 4 (CDK4), and stromal cell-derived factor-1 (SDF-1/CXCL12) regulation, which was further confirmed in human ccRCC tissues. Therefore, we studied the relationship between AID and these three molecules, and the impact of AID on epithelial-to-mesenchymal transition in ccRCC. WLS/GPR177, SDF-1/CXCL12, and CDK4 were sensitive to 5-azacytidine (a DNA demethylation agent), which reverted the inhibition of carcinogenesis caused by AID repression. In summary, AID is an oncogene that might induce tumorigenesis through DNA demethylation. Targeting AID may represent a novel therapeutic approach to treat metastatic ccRCC.

Targeting PD-1 or PD-L1 in Metastatic Kidney Cancer: Combination Therapy in the First-Line Setting

Recent FDA approvals of regimens targeting programmed death 1 (PD-1) in combination with anti-CTLA-4 or with VEGF tyrosine kinase inhibitors are reshaping front-line therapy for metastatic kidney cancer. In parallel, therapeutics specific for programmed death ligand 1 (PD-L1), one of the two major ligands for PD-1, are under continued investigation. Surprisingly, not all PD-1 and PD-L1 agents lead to similar clinical outcomes, potentially due to biological differences in the cellular expression and regulation of these targets. Here, we review current clinical data on combination immune checkpoint inhibitor therapy in metastatic kidney cancer and discuss the relevant biology of PD-1 and PD-L1. The design of future rational combination therapy trials in metastatic renal cell carcinoma will rely upon an understanding of this biology, along with an evolving understanding of immune cell populations and their functional states in the tumor microenvironment.

Immunoscore System for Predicting Clinical Outcome of Metastatic Renal Cell Carcinoma Patients Treated with Tyrosine Kinase Inhibitors

We conducted this study to determine whether immunoscore system (IS) predicts survival in patients with metastatic renal cell carcinoma (mRCC). A total of 218 mRCC patients treated with sunitinib or sorafenib in Zhongshan Hospital, Fudan University were recruited during 2007-2017, retrospectively. CD8, CD4, Treg, PD-1 and PD-L1 expression were evaluated by immunohistochemical staining of paraffin embedded slide. Kaplan-Meier method and COX regression model were used in survival analyses. Multivariate analyses demonstrated that expressions of CD8, Treg, PD-1 and stromal PD-L1 (sPD-L1) expressions were independent predictive factors for OS, thus IS was established containing these four immunological factors. Subsequent analysis revealed that performance of IS provided good differentiation of OS and PFS. Besides, multivariate analysis identified IS as an independent prognostic factor for OS (p<0.001) and PFS (p=0.002). IS, compared with International mRCC Database Consortium (IMDC) risk model, and provided better prediction ability for OS. Results suggested that IS was a powerful prognostic factor for OS and PFS in patients with mRCC treated with tyrosine kinase inhibitors. And IS can be used as essential supplement to IMDC for outcome prediction in mRCC patients.

Prediction of response to targeted and immune checkpoint therapies

Targeted therapies continue to be key components of cancer treatment. New approaches to detection of acquired resistance at the genomic level, in combination with new therapies, help to overcome the challenges that are seen frequently, rapidly and broadly across tumor pathologies, and provide opportunities for cancer management. In the last several years, a new breed of modalities called immune checkpoint inhibitors have come to the forefront of clinically effective treatments. A plethora of rapid approvals and early access initiatives have seen anti-cytotoxic T-lymphocyte-associated antigen-4, and particularly anti-programmed death receptor-1 therapies, deployed in a number of tumor indications of high unmet need. With the rise of immune checkpoint inhibition, and the broader resurgence in the immuno-oncology field, we are facing challenges in the prediction of response.

Crosstalk between VEGFR and other receptor tyrosine kinases for TKI therapy of metastatic renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma (RCC), and is frequently accompanied by the genetic features of von Hippel–Lindau (VHL) loss. VHL loss increases the expression of hypoxia-inducible factors (HIFs) and their targets, including epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF). The primary treatment for metastatic RCC (mRCC) is molecular-targeted therapy, especially anti-angiogenic therapy. VEGF monoclonal antibodies and VEGF receptor (VEGFR) tyrosine kinase inhibitors (TKIs) are the main drugs used in anti-angiogenic therapy. However, crosstalk between VEGFR and other tyrosine kinase or downstream pathways produce resistance to TKI treatment, and the multi-target inhibitors, HIF inhibitors or combination strategies are promising strategies for mRCC. HIFs are upstream of the crosstalk between the growth factors, and these factors may regulate the expression of VEGR, EGF, PDGF and other growth factors. The frequent VHL loss in ccRCC increases HIF expression, and HIFs may be an ideal candidate to overcome the TKI resistance. The combination of HIF inhibitors and immune checkpoint inhibitors is also anticipated. Various clinical trials of programmed cell death protein 1 inhibitors are planned. The present study reviews the effects of current and potential TKIs on mRCC, with a focus on VEGF/VEGFR and other targets for mRCC therapy.

Dynamic epigenetic changes to VHL occur with sunitinib in metastatic clear cell renal cancer

Background

Genetic intratumoral heterogeneity (ITH) hinders biomarker development in metastatic clear cell renal cancer (mccRCC). Epigenetic relative to genetic ITH or the presence of consistent epigenetic changes following targeted therapy in mccRCC have not been evaluated. The aim of this study was to determine methylome/genetic ITH and to evaluate specific epigenetic and genetic changes associated with sunitinib therapy.

Patients and methods

Multi-region DNA sampling performed on sequential frozen pairs of primary tumor tissue from 14 metastatic ccRCC patients, in the Upfront Sunitinib (SU011248) Therapy Followed by Surgery in Patients with Metastatic Renal Cancer: a Pilot Phase II Study (SuMR; ClinicalTrials.gov identifier: NCT01024205), at presentation (biopsy) and after 3-cycles of 50mg sunitinib (nephrectomy). Untreated biopsy and nephrectomy samples before and after renal artery ligation were controls. Ion Proton sequencing of 48 key ccRCC genes, and MethylCap-seq DNA methylation analysis was performed, data was analysed using the statistical computing environment R.

Results

Unsupervised hierarchical clustering revealed complete methylome clustering of biopsy and three nephrectomy samples for each patient (14/14 patients). For mutational status, untreated biopsy and all treated nephrectomy samples clustered together in 8/13 (61.5%) patients. The only methylation target significantly altered following sunitinib therapy was VHL promoter region 7896829 which was hypermethylated with treatment (FDR=0.077, P<0.001) and consistent for all patients (pre-treatment 50% patients had VHL mutations, 14% patients VHL hypermethylation). Renal artery ligation did not affect this result. No significant differences in driver or private mutation count was found with sunitinib treatment.

Conclusions

Demonstration of relative methylome homogeneity and consistent VHL hypermethylation, after sunitinib, may overcome the hurdle of ITH present at other molecular levels for biomarker research.

Neutrophil-to-lymphocyte ratio after pazopanib treatment predicts response in patients with advanced soft-tissue sarcoma

BACKGROUND

Pazopanib is a multi-tyrosine kinase inhibitor that is used to treat advanced soft-tissue sarcoma, and its efficacy has been confirmed in several clinical trials, although no clinically useful biomarkers have been identified. In other cancers, the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), and the lymphocyte-to-monocyte ratio (LMR) are associated with chemotherapy response and prognosis. Therefore, we aimed to evaluate the associations of pazopanib response with NLR, PLR, and LMR among patients with advanced soft-tissue sarcoma.

METHODS

Data regarding NLR, PLR, and LMR were obtained for 25 patients who received pazopanib for soft-tissue sarcoma. The patients were categorized according to their values for NLR (≥3.8 vs. <3.8), PLR (≥230 vs. <230), and LMR (≥2.4 vs. <2.4), and we evaluated the associations of these markers with progression-free survival and overall survival using Kaplan-Meier curves and Cox proportional models.

RESULTS

No significant differences in progression-free survival or overall survival were observed based on the pre-treatment NLR, PLR, and LMR values. However, decreased NLR values after treatment using pazopanib were independently associated with significantly prolonged progression-free survival (hazard ratio: 0.07, p = 0.001) and overall survival (hazard ratio: 0.17, p = 0.0006).

CONCLUSIONS

Decreased NLR values after treatment using pazopanib may predict high efficacy and favorable outcomes among patients with advanced soft-tissue sarcoma.

Systematic Review: Perioperative Systemic Therapy for Metastatic Renal Cell Carcinoma

Background: Approximately 16% of patients with renal cell carcinomas (RCC) present with stage IV disease at time of diagnosis. Treatment options for metastatic clear cell RCC, the most common histologic subtype, have proliferated over the past decade and include a combination of surgery and systemic therapy. The selection of systemic agent and best timing of systemic therapy in relation to nephrectomy is an area of active research. Objective: To evaluate the evidence for perioperative systemic therapy, including presurgical and postsurgical, for metastatic RCC. Methods: A systematic literature search using PubMed and MEDLINE databases was performed in January 2017 for articles related to perioperative systemic therapy in metastatic RCC using key word search terms. The authors screened the search results and identified selected publications by predetermined inclusion criteria and consensus. Expert opinion was obtained to assess for publications missed by search. Results: Early phase clinical trials of antiangiogenic tyrosine kinase inhibitors prior to cytoreductive nephrectomy in select patients show that these systemic agents are safe and effective in the presurgical setting. There are no randomized data evaluating pre- or post-surgical systemic therapy in metastatic RCC. Conclusions: Retrospective and early-phase prospective studies on the use and timing of systemic therapy in relation to cytoreductive nephrectomy in metastatic RCC show that standard of care antiangiogenic agents are safe and effective in the perioperative setting, though randomized data are still lacking. Pre-surgical immune checkpoint therapy for metastatic RCC has strong biologic rationale and holds promise. Sequential tumor sampling in neoadjuvant and presurgical trials is necessary to determine biomarkers of response and resistance.

Differential intratumoral distributions of CD8 and CD163 immune cells as prognostic biomarkers in breast cancer

Background

Tumor immune cell infiltrates are essential in hindering cancer progression and may complement the TNM classification. CD8+ and CD163+ cells have prognostic impact in breast cancer but their spatial heterogeneity has not been extensively explored in this type of cancer. Here, their potential as prognostic biomarkers was evaluated, depending on their combined densities in the tumor center (TC) and the tumor invasive margin (IM).

Methods

CD8+ and CD163+ cells were quantified by immunohistochemistry of formalin-fixed, paraffin-embedded (FFPE) tumor tissue samples from a cohort totaling 162 patients with histologically-confirmed primary invasive non-metastatic ductal breast cancer diagnosed between 2000 and 2015. Clinical follow-up (median 6.9 years) was available for 97 of these patients.

Results

Differential densities of CD8+ and CD163+ cells in the combined TC and IM compartments (i.e., high(H)/low(L), respectively for CD8+ cells and the reverse L/H combination for CD163+ cells) were found to have significant prognostic value for survival, and allowed better patient stratification than TNM stage, tumor size, lymph node invasion and histological grade. The combined evaluation of CD8+ and CD163+ cell densities jointly in TC and IM further improves prediction of clinical outcomes based on disease-free and overall survival. Patients having the favorable immune signatures had favorable clinical outcomes despite poor clinicopathological parameters.

Conclusions

Given the important roles of CD8+ and CD163+ cells in regulating opposing immune circuits, adding an assessment of their differential densities to the prognostic biomarker armamentarium in breast cancer would be valuable. Larger validation studies are necessary to confirm these findings.

Trial registrations

Study code: IRB-ID 6079/448/10-6-13

Date of approval: 10/06/2013

Retrospective study (2000–2010)

First patient prospectively enrolled 14/2/2014

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-017-0240-7) contains supplementary material, which is available to authorized users.

[Immunotherapy in uropathology]

The algorithms for treatment of metastatic cancers are evolving due to positive results obtained with immunotherapy. Therapeutics approaches to stimulate the immune system have already been used in the treatment of kidney and bladder cancer, such as the administration of cytokines and BCG therapy, confirming the immunogenicity of these tumors. The aim of immunotherapies is not only to activate the immune system against tumor cells, but also to take into account the tumor-induced suppressive microenvironment, in particular by removing the anergy of T-cell lymphocytes, and by targeting the co-stimulation inhibitors molecules. Among the genito-urinary cancers, second-line clinical trials have clearly shown that kidney and bladder cancers are sensitive to the inhibition of PD-1/PD-L1 axis and have already achieved FDA approvals for some molecules. Numerous other clinical trials are underway, particularly in first-line treatment in bladder and renal cancers. Refractory testicular cancer could also benefit from these treatments. Other approaches using vaccine therapy especially in castration-resistant prostate cancer are also of interest. We will see, in this chapter dedicated to the urogenital cancers, the benefit of the immunotherapy by resituating it in the genetic and immunological context of each organ. We will also present briefly the therapeutic outlines and the place of biomarkers.

Epigenetic sampling effects: nephrectomy modifies the clear cell renal cell cancer methylome

PURPOSE

Currently, it is unclear to what extent sampling procedures affect the epigenome. Here, this phenomenon was evaluated by studying the impact of artery ligation on DNA methylation in clear cell renal cancer.

METHODS

DNA methylation profiles between vascularised tumour biopsy samples and devascularised nephrectomy samples from two individuals were compared. The relevance of significantly altered methylation profiles was validated in an independent clinical trial cohort.

RESULTS

We found that six genes were differentially methylated in the test samples, of which four were linked to ischaemia or hypoxia (REXO1L1, TLR4, hsa-mir-1299, ANKRD2). Three of these genes were also found to be significantly differentially methylated in the validation cohort, indicating that the observed effects are genuine.

CONCLUSION

Tissue ischaemia during normal surgical removal of tumour can cause epigenetic changes. Based on these results, we conclude that the impact of sampling procedures in clinical epigenetic studies should be considered and discussed, particularly after inducing hypoxia/ischaemia, which occurs in most oncological surgery procedures through which tissues are collected for translational research.

Anti-angiogenic Therapy in Cancer: Downsides and New Pivots for Precision Medicine

Primary solid tumors originate close to pre-existing tissue vasculature, initially growing along such tissue blood vessels, and this phenomenon is important for the metastatic potential which frequently occurs in highly vascularized tissues. Unfortunately, preclinic and clinic anti-angiogenic approaches have not been very successful, and multiple factors have been found to contribute to toxicity and tumor resistance. Moreover, tumors can highlight intrinsic or acquired resistances, or show adaptation to the VEGF-targeted therapies. Furthermore, different mechanisms of vascularization, activation of alternative signaling pathways, and increased tumor aggressiveness make this context even more complex. On the other hand, it has to be considered that the transitional restoration of normal, not fenestrated, microvessels allows the drug to reach the tumor and act with the maximum efficiency. However, these effects are time-limited and different, depending on the various types of cancer, and clearly define a specific “normalization window.” So, new horizons in the therapeutic approaches consist on the treatment of the tumor with pro- (instead of anti-) angiogenic therapies, which could strengthen a network of well-structured blood vessels that facilitate the transport of the drug.

Effective downsizing but enhanced intratumoral heterogeneity following neoadjuvant sorafenib in patients with non-metastatic renal cell carcinoma

OBJECTIVES

To evaluate the safety and feasibility of sorafenib prior to surgery for downsizing tumors in patients with non-metastatic cT1-3 renal tumors together with a characterization of functional intratumoral heterogeneity (ITH).

MATERIALS AND METHODS

The effects of 4-week sorafenib prior to curative surgery were assessed in a prospective, single-center, randomized, placebo-controlled, double-blinded, pilot trial in patients with T1-3N0M0 renal cell carcinoma (RCC). Patients received sorafenib or placebo for 28 days prior to surgery. MRI was performed at baseline and prior to surgery to calculate tumor volume. The clinical responses were further characterized on the molecular level by immunohistochemical stainings for Ki-67, cleaved caspase-3, and CD31.

RESULTS

After enrolling 20 patients into the study, 14 patients were randomized, of which 12 patients were available for analysis. While no significant change in tumor volume was seen for placebo (range = -24.2-0.2%) a reduction of 29.0% (range = -4.9-61.1%) was detected for sorafenib (p < 0.05). Primary renal tumor diameter changed from 10.6 cm (range = 6.5-10.8) to 10.7 cm (range = 6.7-11.1) in the placebo group, and from 5.4 cm (range = 4.3-7.3) to 4.4 cm (range = 3.5-6.8) for the sorafenib group, at baseline vs. 28 days of treatment. Correlative assessment of proliferation, apoptosis, and microvessel density revealed an enhanced degree of functional ITH in treated patients suggesting adaptive and/or regenerative processes with potential relevance for the development of drug resistance.

CONCLUSIONS

Sorafenib in standard dosage, given preoperatively for 28 days, was clinically active in downsizing tumors in patients with locally confined, non-metastatic RCC together but led to an enhanced functional ITH in the residual tumor tissue.

Tertiary lymphoid structures, drivers of the anti-tumor responses in human cancers

The characterization of the microenvironment of human tumors led to the description of tertiary lymphoid structures (TLS) characterized by mature dendritic cells in a T-cell zone adjacent to B-cell follicle including a germinal center. TLS represent sites of lymphoid neogenesis that develop in most solid cancers. Analysis of the current literature shows that the TLS presence is associated with a favorable clinical outcome for cancer patients, regardless of the approach used to quantify TLS and the stage of the disease. Using several approaches that combine immunohistochemistry, gene expression assays, and flow cytometry on large series of lung tumors, our work demonstrated that TLS are important sites for the initiation and/or maintenance of the local and systemic T- and B-cell responses against tumors. Surrounded by high endothelial venules, they represent a privileged area for the recruitment of lymphocytes into tumors and generation of central-memory T and B cells that circulate and limit cancer progression. TLS can be considered as a novel biomarker to stratify the overall survival risk of untreated cancer patients and as a marker of efficient immunotherapies. The induction and manipulation of cancer-associated TLS using drug agonists and/or biotherapies should open new avenues to treat cancer patients.

Long-term Response to Nivolumab and Acute Renal Failure in a Patient with Metastatic Papillary Renal Cell Carcinoma and a PD-L1 Tumor Expression Increased with Sunitinib Therapy: A Case Report

INTRODUCTION

Papillary renal cell carcinoma (PRCC), which represents around 20% of renal cell carcinomas, is a heterogeneous disease that includes different tumor types with several clinical and molecular phenotypes. Nivolumab, a fully human IgG4 programed cell death protein 1 immune checkpoint inhibitor antibody, has shown not only an overall survival advantage when compared to everolimus but also a relatively good side-effect profile among patients with previously treated advanced or metastatic renal cell carcinoma.

CASE REPORT

We describe a case of a young man diagnosed with PRCC that achieved a durable response to nivolumab despite a temporary suspension of the treatment due to a renal function side effect. To the best of our knowledge, it is the first renal failure secondary to nivolumab in a metastatic renal cell carcinoma patient.

CONCLUDING REMARKS

Nivolumab is a promising drug in patients with metastatic PRCC and long-term responses can be achieved. In case of acute renal failure secondary to this treatment, temporary therapy suspension and a low dose of systemic corticosteroids can recover renal function without a negative impact on treatment efficacy.

High fidelity of driver chromosomal alterations among primary and metastatic renal cell carcinomas: implications for tumor clonal evolution and treatment

Recent studies have demonstrated considerable genomic heterogeneity in both primary and metastatic renal cell carcinoma (RCC). This mutational diversity has serious implications for the development and implementation of targeted molecular therapies. We evaluated 39 cases of primary RCC tumors with their matched metastatic tumors to determine if the hallmark chromosomal anomalies of these tumors are preserved over the course of disease progression. Thirty-nine matched pairs of primary and metastatic RCCs (20 clear cell RCC, 16 papillary RCC, and 3 chromophobe RCC) were analyzed. All clear cell RCC and papillary RCC tumors were evaluated for chromosome 3p deletion, trisomy 7 and 17 using fluorescence in situ hybridization. Chromophobe RCC tumors were evaluated for genetic alterations in chromosomes 1, 2, 6, 10, and 17. Of the 20 clear cell RCC tumors, 18 primary tumors (90%) showed a deletion of chromosome 3p and were disomic for chromosomes 7 and 17. All molecular aberrations were conserved within the matched metastatic tumor. Of the 16 papillary RCC tumors, 10 primary tumors (62%) showed trisomy for both chromosomes 7 and 17 without 3p deletion. These molecular aberrations and others were conserved in the paired metastatic tumors. Of the three chromophobe RCC tumors, multiple genetic anomalies were identified in chromosomes 1, 2, 6, 10, and 17. These chromosomal aberrations were conserved in the matched metastatic tumors. Our results demonstrated genomic fidelity among the primary and metastatic lesions in RCCs. These findings may have important clinical and diagnostic implications.

Myopodin methylation is a prognostic biomarker and predicts antiangiogenic response in advanced kidney cancer

Myopodin is a cytoskeleton protein that shuttles to the nucleus depending on the cellular differentiation and stress. It has shown tumor suppressor functions. Myopodin methylation status was useful for staging bladder and colon tumors and predicting clinical outcome. To our knowledge, myopodin has not been tested in kidney cancer to date. The purpose of this study was to evaluate whether myopodin methylation status could be clinically useful in renal cancer (1) as a prognostic biomarker and 2) as a predictive factor of response to antiangiogenic therapy in patients with metastatic disease. Methylation-specific polymerase chain reactions (MS-PCR) were used to evaluate myopodin methylation in 88 kidney tumors. These belonged to patients with localized disease and no evidence of disease during follow-up (n = 25) (group 1), and 63 patients under antiangiogenic therapy (sunitinib, sorafenib, pazopanib, and temsirolimus), from which group 2 had non-metastatic disease at diagnosis (n = 32), and group 3 showed metastatic disease at diagnosis (n = 31). Univariate and multivariate Cox analyses were utilized to assess outcome and response to antiangiogenic agents taking progression, disease-specific survival, and overall survival as clinical endpoints. Myopodin was methylated in 50 out of the 88 kidney tumors (56.8 %). Among the 88 cases analyzed, 10 of them recurred (11.4 %), 51 progressed (57.9 %), and 40 died of disease (45.4 %). Myopodin methylation status correlated to MSKCC Risk score (p = 0.050) and the presence of distant metastasis (p = 0.039). Taking all patients, an unmethylated myopodin identified patients with shorter progression-free survival, disease-specific survival, and overall survival. Using also in univariate and multivariate models, an unmethylated myopodin predicted response to antiangiogenic therapy (groups 2 and 3) using progression-free survival, disease-specific, and overall survival as clinical endpoints. Myopodin was revealed hypermethylated in kidney cancer. Myopodin methylation status identified which patients showed a more aggressive clinical behavior and predicted antiangiogenic response. These observations support the clinical utility of an unmethylated myopodin as a prognostic and predictive biomarker in kidney cancer.

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.

The Role of Cytoreductive Nephrectomy: European Association of Urology Recommendations in 2016

PATIENT SUMMARY

After the introduction of systemic targeted therapies, the use of nephrectomy in patients with metastatic renal cell carcinoma has declined. Currently, systemic therapy is offered to more patients first as a means to select those candidates that will likely benefit from removal of their primary tumour. Although studies consistently demonstrate a survival benefit after nephrectomy, most patients with poor risk metastatic disease are unlikely to benefit from surgery. Soon studies will report on the effect of nephrectomy in patients with metastatic disease at diagnosis.

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

The Angiopoietin-2 (Ang2, Angpt2) growth factor is a context-dependent antagonist/agonist ligand of the endothelial Tie2 receptor tyrosine kinase and known to promote tumour angiogenesis and metastasis. Angiopoietin antagonists have been tested in clinical cancer trials in combination with VEGF-based anti-angiogenic therapy, including sunitinib, which is widely used as a first-line therapy for metastatic renal cell carcinoma (mRCC). However, little is known about Ang2 protein expression in human tumours and the correlation of tumour Ang2 expression with tumour vascularization, tumour cell proliferation and response to anti-angiogenic therapies. Here, we evaluated, using immunohistochemistry, the expression of Ang2, CD31 and the cell proliferation marker Ki-67 in the primary kidney cancer from 136 mRCC patients, who received first-line sunitinib after nephrectomy. Ang2 protein expression was restrained to RCC tumour vessels, and correlated with tumour vascularization and response to sunitinib. High pre-therapeutic Ang2 expression, and more strongly, combined high expression of both Ang2 and CD31, were associated with a high clinical benefit rate (CBR). Low cancer Ki-67 expression, but not Ang2 or CD31 expression, was associated with favourable progression-free (PFS) and overall survival (OS) as compared to patients with high Ki-67 expression (PFS 6.5 vs. 10.6 months, P = 0.009; OS, 15.7 vs. 28.5 months, P = 0.015). In summary, in this study to investigate endothelial Ang2 in mRCC patients treated with first-line sunitinib, high cancer Ang2 expression was associated with the CBR, but not PFS or OS, whereas low Ki-67 expression was significantly associated with long PFS and OS.

FAK regulates platelet extravasation and tumor growth after antiangiogenic therapy withdrawal

Recent studies in patients with ovarian cancer suggest that tumor growth may be accelerated following cessation of antiangiogenesis therapy; however, the underlying mechanisms are not well understood. In this study, we aimed to compare the effects of therapy withdrawal to those of continuous treatment with various antiangiogenic agents. Cessation of therapy with pazopanib, bevacizumab, and the human and murine anti-VEGF antibody B20 was associated with substantial tumor growth in mouse models of ovarian cancer. Increased tumor growth was accompanied by tumor hypoxia, increased tumor angiogenesis, and vascular leakage. Moreover, we found hypoxia-induced ADP production and platelet infiltration into tumors after withdrawal of antiangiogenic therapy, and lowering platelet counts markedly inhibited tumor rebound after withdrawal of antiangiogenic therapy. Focal adhesion kinase (FAK) in platelets regulated their migration into the tumor microenvironment, and FAK-deficient platelets completely prevented the rebound tumor growth. Additionally, combined therapy with a FAK inhibitor and the antiangiogenic agents pazopanib and bevacizumab reduced tumor growth and inhibited negative effects following withdrawal of antiangiogenic therapy. In summary, these results suggest that FAK may be a unique target in situations in which antiangiogenic agents are withdrawn, and dual targeting of FAK and VEGF could have therapeutic implications for ovarian cancer management.

A decade of pharmacogenomics research on tyrosine kinase inhibitors in metastatic renal cell cancer: a systematic review

OBJECTIVE

The individual response to targeted tyrosine kinase inhibitors (TKIs) in the treatment of metastatic renal cell cancer (mRCC) is highly variable. Outlined in this article are findings on potential biomarkers for TKI treatment outcome in mRCC and an evaluation of the status of clinical implementation.

METHODS

Articles were selected by two independent reviewers using a systematic search in five medical databases on renal cell carcinoma, TKIs, and pharmacogenetics.

RESULTS

Many researchers have focused on predictive biomarkers for treatment outcome of targeted therapies in mRCC patients. Attempts to explain differences in efficacy and toxicity of TKIs by use of genetic variants in genes related to the pharmacokinetics and pharmacodynamics of the drug have been successful.

CONCLUSION

Most findings on potential biomarkers have not been validated and therefore biomarker testing to guide choice of therapy and dose in mRCC is not yet feasible.

Quantification of a Non-conventional Protein Secretion: The Low-Molecular-Weight FGF-2 Example

Quantification of secreted factors is most often measured with enzyme-linked immunosorbent assay (ELISA), Western Blot, or more recently with antibody arrays. However, some of these, like low-molecular-weight fibroblast growth factor-2 (LMW FGF-2; the 18 kDa form), exemplify a set of secreted but almost non-diffusible molecular actors. It has been proposed that phosphorylated FGF-2 is secreted via a non-vesicular mechanism and that heparan sulfate proteoglycans function as extracellular reservoir but also as actors for its secretion. Heparan sulfate is a linear sulfated polysaccharide present on proteoglycans found in the extracellular matrix or anchored in the plasma membrane (syndecan). Moreover the LMW FGF-2 secretion appears to be activated upon FGF-1 treatment. In order to estimate quantification of such factor export across the plasma membrane, technical approaches are presented (evaluation of LMW FGF-2: (1) secretion, (2) extracellular matrix reservoir, and (3) secretion modulation by surrounding factors) and the importance of such procedures in the comprehension of the biology of these growth factors is underlined.

Diagnosis of Renal Cell Carcinoma: A Clinician's Perspective

Renal cell carcinoma (RCC) is a heterogeneous disease. A rigorous diagnostic assessment by a pathologist with close communication with the clinician provides more accurate prognostication and informed treatment decisions. In the localized setting, an accurate prognostic assessment directs patients to potential adjuvant clinical trials. For patients with advanced disease, the pathologic assessment may have a direct impact on the systemic therapy algorithm. Additionally, it provides the basis for continuous efforts in biomarker development. In rare histologic subtypes, the interaction between clinicians and pathologists provides an opportunity to offer patients specific clinical trials. Molecular characterization platforms may identify targets for therapeutic intervention.

Preclinical Evidence That Trametinib Enhances the Response to Antiangiogenic Tyrosine Kinase Inhibitors in Renal Cell Carcinoma

Sunitinib and pazopanib are antiangiogenic tyrosine kinase inhibitors (TKI) used to treat metastatic renal cell carcinoma (RCC). However, the ability of these drugs to extend progression-free and overall survival in this patient population is limited by drug resistance. It is possible that treatment outcomes in RCC patients could be improved by rationally combining TKIs with other agents. Here, we address whether inhibition of the Ras-Raf-MEK-ERK1/2 pathway is a rational means to improve the response to TKIs in RCC. Using a xenograft model of RCC, we found that tumors that are resistant to sunitinib have a significantly increased angiogenic response compared with tumors that are sensitive to sunitinib in vivo. We also observed significantly increased levels of phosphorylated ERK1/2 in the vasculature of resistant tumors, when compared with sensitive tumors. These data suggested that the Ras-Raf-MEK-ERK1/2 pathway, an important driver of angiogenesis in endothelial cells, remains active in the vasculature of TKI-resistant tumors. Using an in vitro angiogenesis assay, we identified that the MEK inhibitor (MEKI) trametinib has potent antiangiogenic activity. We then show that, when trametinib is combined with a TKI in vivo, more effective suppression of tumor growth and tumor angiogenesis is achieved than when either drug is utilized alone. In conclusion, we provide preclinical evidence that combining a TKI, such as sunitinib or pazopanib, with a MEKI, such as trametinib, is a rational and efficacious treatment regimen for RCC.

Harnessing the PD-1 pathway in renal cell carcinoma: current evidence and future directions

Programmed cell death-1 (PD-1) is a recognized immune checkpoint. It is frequently upregulated on the T cells that infiltrate tumors, providing an inhibitory signal, which may facilitate immune escape. Blocking antibodies have been developed to interrupt the interaction of PD-1 with its ligands PD-L1/PD-L2, with the goal of increasing the host antitumor immune response. Initial results have been encouraging, with durable responses in both treatment-naive and pretreated patients, along with an acceptable toxicity profile. This tolerability makes PD-1 blockade an excellent potential partner for combination strategies with the approved targeted agents, such as tyrosine kinase inhibitors (TKIs) and anti-vascular endothelial growth factor (anti-VEGF) antibodies, as well as other investigational immune checkpoint inhibitors or agonist antibodies that may costimulate an immune response. PD-L1 expression on tumor cells and tumor-infiltrating immune cells is also being evaluated as a predictive biomarker of response to treatment. This review summarizes the biological basis, preclinical studies, ongoing trials, and future challenges associated with targeting the PD-1 pathway in renal cell carcinoma.

Translational research will fail without surgical leadership: SCOTRRCC a successful surgeon-led Nationwide translational research infrastructure in renal cancer

BACKGROUND

High quality human biosamples with associated high quality clinical data are essential for successful translational research. Despite this, the traditional approach is for the surgeon to act as a technician in the tissue collection act. Biomarker research presents multiple challenges and the field is littered with failures. Tissue quality, poor clinical information, small sample numbers and lack of validation cohorts are just a few reasons for failure. It is clear that the surgeon involved in tissue acquisition must be fully engaged in the process of biosampling for a specific condition, as this will negate many of the issues for translational research failure due to an inadequate bioresource.

APPROACH

In this Matter for Debate paper, the Scottish Collaboration On Translational Research into Renal Cell Cancer (SCOTRRCC) is discussed as an example of a urological surgery lead bioresource which has resulted in a National collection of renal cancer tissue and blood (from over 900 patients to date), negating all of the traditional issues with biobanks because of close enagagement and acknowledgement of urologists and uropathologists from seven centres around Scotland. SCOTRRCC has leveraged renal cancer research in Scotland resulting in several high impact publications and providing a springboard for future research in this disease in Scotland and beyond.

CONCLUSIONS

The SCOTRRCC model presented here can be transferred to other surgical disciplines for success in translational research.

The impact of FGFR1 and FRS2α expression on sorafenib treatment in metastatic renal cell carcinoma

Background

Angiogenesis plays a role in tumor growth and is partly mediated by factors in both the fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) pathways. Durable clinical responses with VEGF tyrosine kinase inhibitors (TKIs) may be limited by intrinsic tumor resistance. We hypothesized that FGF signaling may impact clinical responses to sorafenib.

Methods

Nephrectomy material was available from 40 patients with metastatic renal cell carcinoma (RCC) enrolled in a phase II clinical trial of sorafenib ± interferon (ClinicalTrials.gov Identifier NCT00126594). Fibroblast growth factor receptor 1 (FGFR1) and fibroblast growth factor receptor substrate 2 alpha (FRS2α) expression was assessed by in situ hybridization and immunofluorescence, respectively. The relationship between fibroblast growth factor pathway marker levels and progression-free survival (PFS) was analyzed using Kaplan-Meier and Cox proportional hazards regression methods.

Results

Univariate analysis indicated that more intense FGFR1 staining was associated with shorter PFS (log-rank P = 0.0452), but FRS2α staining was not significantly associated with PFS (log-rank P = 0.2610). Multivariate Cox proportional hazards regression models were constructed for FGFR1 and FRS2α individually, adjusting for baseline Eastern Cooperative Oncology Group performance status, treatment arm and anemia status. When adjusted for each of these variables, the highest intensity level of FGFR1 (level 3 or 4) had increased progression risk relative to the lowest intensity level of FGFR1 (level 1) (P = 0.0115). The highest intensity level of FRS2α (level 3 or 4) had increased progression risk relative to the lowest intensity level of FRS2α (level 1) (P = 0.0126).

Conclusions

Increased expression of FGFR1 and FRS2α was associated with decreased PFS among patients with metastatic RCC treated with sorafenib. The results suggest that FGF pathway activation may impact intrinsic resistance to VEGF receptor inhibition.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1302-1) contains supplementary material, which is available to authorized users.

Predictive molecular biomarkers to guide clinical decision making in kidney cancer: current progress and future challenges

Although the past decade has seen a surfeit of new targeted therapies for renal cell carcinoma (RCC), no predictive molecular biomarker is currently used in routine clinical practice to guide personalized therapy as a companion diagnostic. Many putative biomarkers have been suggested, but none have undergone rigorous validation. There have been considerable advances in the biological understanding of RCC in recent years, with the development of accompanying molecular diagnostics that with additional validation, may be helpful for routine clinical decision making. In this review, we summarize the current understanding of predictive biomarkers in RCC management and also highlight upcoming developments of interest in biomarker research for personalizing RCC diagnostics and therapeutics.

Emerging technologies for studying DNA methylation for the molecular diagnosis of cancer

DNA methylation is an epigenetic mechanism that plays a key role in regulating gene expression and other functions. Although this modification is seen in different sequence contexts, the most frequently detected DNA methylation in mammals involves cytosine-guanine dinucleotides. Pathological alterations in DNA methylation patterns are described in a variety of human diseases, including cancer. Unlike genetic changes, DNA methylation is heavily influenced by subtle modifications in the cellular microenvironment. In all cancers, aberrant DNA methylation is involved in the alteration of a large number of oncological pathways with relevant theranostic utility. Several technologies for DNA methylation mapping have been developed recently and successfully applied in cancer studies. The scope of these technologies varies from assessing a single cytosine-guanine locus to genome-wide distribution of DNA methylation. Here, we review the strengths and weaknesses of these approaches in the context of clinical utility for the molecular diagnosis of human cancers.

Correlation of PD-L1 tumor expression and treatment outcomes in patients with renal cell carcinoma receiving sunitinib or pazopanib: results from COMPARZ, a randomized controlled trial

PURPOSE

The interaction of programmed death-1 ligand (PD-L1) with its receptor (PD-1) on T cells inactivates antitumor immune responses. PD-L1 expression has been associated with poor outcomes in renal cell carcinoma (RCC) but has not been investigated in advanced RCC patients receiving VEGF-targeted therapy.

EXPERIMENTAL DESIGN

Formalin-fixed paraffin-embedded specimens were collected at baseline from patients in the COMPARZ trial. Tumor cell PD-L1 expression by IHC was evaluated using H-score (HS). Dual PD-L1/CD68 staining was used to differentiate PD-L1 tumor expression from tumor-associated macrophages. Intratumor CD8-positive T cells were quantified morphometrically. Associations between biomarkers and survival were investigated using the log-rank test.

RESULTS

HS data were available from 453 of 1,110 patients. Sixty-four percent of patients had negative PD-L1 expression (HS = 0). Patients with HS > 55 (n = 59, 13%) had significantly shorter overall survival (OS) than those with HS ≤ 55 in both pazopanib and sunitinib arms (median 15.1 vs. 35.6 and 15.3 vs. 27.8 months, respectively, P = 0.03). In both arms, median OS was shortest in patients with HS > 55 and intratumor CD8-positive T-cell counts > 300 (9.6 and 11.9 months with pazopanib and sunitinib, respectively). Median OS in patients with HS ≤ 55 and CD8-positive T-cell counts ≤ 300 was 36.8 and 28.0 months with pazopanib and sunitinib, respectively. Progression-free survival results were similar to OS results.

CONCLUSIONS

Increased tumor cell PD-L1, or PD-L1 plus tumor CD8-positive T-cell counts, were associated with shorter survival in patients with metastatic RCC receiving VEGF-targeted agents. These findings may have implications for future design of randomized clinical trials in advanced RCC.

PD-1 blockade in renal cell carcinoma: to equilibrium and beyond

The past several years have witnessed a resurgence of interest in cancer immunotherapy. The development of blocking antibodies against the inhibitory programmed death-1 (PD-1) pathway represents a clinical breakthrough in the treatment of solid tumors such as melanoma, and these agents show great promise in renal cell carcinoma (RCC). The early data have been surprising in that they demonstrate that blockade of a single immune checkpoint can elicit objective responses in patients with RCC, despite the recognized complexity of the immunosuppressive tumor microenvironment. Reinvigorating the patient's own immune cells to reactivate and to target the tumor has the potential advantages of more selective killing and thus decreased toxicity. In addition, checkpoint blockade immunotherapy has the advantage of inducing a memory response that is unattainable with our current cytotoxic and targeted therapies. This Crossroads overview will highlight the emerging investigation of PD-1 blockade in RCC and how this T cell-targeted strategy may thwart the tumor's escape mechanisms and shift the immune system/tumor balance back to a state of equilibrium and even to tumor elimination.

Predictive biomarkers in renal cell cancer: insights in drug resistance mechanisms

INTRODUCTION

VEGF-targeted therapy is currently the first line treatment for patients with metastatic clear cell renal cell carcinoma (ccRCC), but most patients either display primary (intrinsic) resistance or acquire drug resistance. In recent years multiple mechanisms of resistance to VEGF-targeted therapy emerged from preclinical research, but it is currently unknown to what extent these drug resistance modalities play a role in the clinic. Here we reviewed the current literature on biomarkers that predict treatment outcome in patients with ccRCC to gain insight in clinical drug resistance mechanisms.

METHODS

A search syntax was compiled by combining different synonyms of "biomarker" AND "renal" AND "cancer". MEDLINE was accessed through PubMed, where this syntax was entered and used to search titles and abstracts of publications. Articles were selected based on three criteria: (1) description of patients with clear cell RCC, (2) treatment with VEGF targeted therapy and (3) discussion of biomarkers that were studied for potential association with treatment response.

RESULTS

The literature search was performed on March 4th 2014 and yielded 1882 articles. After carefully reading the titles and abstracts based on the three previously mentioned criteria, 103 publications were evaluated. Backward citation screening was performed on all eligible studies and revealed another 24 articles. This search revealed that (1) High glucose uptake and low contrast enhancement on PET- and CT-imaging before start of treatment may correlate with poor response to therapy, (2) Low dose intensity due to treatment intolerance is related to shorter progression free survival. (3) Acquired resistance appears to be associated with rebound vascularization based on both longitudinal monitoring of contrast enhancement by CT and blood vessel counts in tumor tissue, and (4) Based on plasma cytokine and single nucleotide polymorphism (SNP) studies, interleukin-8, VEGFR-3, FGFR2 and HGF/MET emerged as potential clinical markers for chemoresistance.

CONCLUSION

Low dose intensity, specific tumor-imaging techniques and potential biological biomarkers may be predictive for response to VEGF-targeted therapy in ccRCC. Some of these plausible biomarkers may also provide more insight into the underlying mechanisms of resistance such as altered glucose metabolism and rapid rebound vascularization.

Relationships between the Effect of Sunitinib and Immature Blood Vessels in Metastatic Renal Cell Cancer

Introduction: This study was conducted to investigate the relationships between the effect of sunitinib and immature microvessels which are not covered by pericytes. Materials and Methods: This study involved 29 patients with clear-cell renal cell carcinoma (RCC) who took sunitinib after radical nephrectomy or biopsy due to metastatic RCC. Associations among clinicopathological factors, responses to sunitinib, and patient survival were reviewed. CD31 was used to stain endothelial cells, and anti-α-smooth muscle actin was used to stain pericytes. Immature vessels were defined as vessels that were positive only for CD31 staining. A high pericyte coverage was defined as a rate of pericyte coverage above 40%. Results: Partial responses, disease stabilization, and disease progression constituted 51.7, 10.4, and 37.9% of cases, respectively. Nine cases had a low pericyte coverage (31.0%). In the high-pericyte-coverage group, the number of metastatic sites was smaller (p = 0.003). The overall response rate to sunitinib was greater in the high-pericyte-coverage group than in the low-pericyte-coverage group (p = 0.027). The median overall survival and the median progression-free survival were not significantly different between the high- and low-pericyte-coverage groups. Conclusion: In the high-pericyte-coverage group, the overall response rates to sunitinib were higher, and the numbers of metastatic sites were smaller.