Epidemiologic and socioeconomic burden of metastatic renal cell carcinoma (mRCC): a literature review

Prognostic effect of preoperative serum albumin to globulin ratio in patients treated with cytoreductive nephrectomy for metastatic renal cell carcinoma

Background

Accurate identification of ideal candidates for cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) is an unmet need. We tested the association between preoperative value of systemic albumin to globulin ratio (AGR) and overall survival (OS) as well as cancer-specific survival (CSS) in mRCC patients treated with CN.

Methods

mRCC patients treated with CN were included. The overall population was therefore divided into two AGR groups using cut-off of 1.43 (low, <1.43 vs. high, ≥1.43). Univariable and multivariable Cox regression analyses tested the association between AGR and OS as well as CSS. The discrimination of the model was evaluated with the Harrel’s concordance index (C-index). The clinical value of the AGR was evaluated with decision curve analysis (DCA).

Results

Among 613 mRCC patients, 159 (26%) patients had an AGR <1.43. Median follow-up was 31 (IQR: 16–58) months. On univariable analysis, low preoperative serum AGR was significantly associated with both OS (HR: 1.55, 95% CI: 1.26–1.89, P<0.001) and CSS (HR: 1.55, 95% CI: 1.27–1.90, P<0.001). On multivariable analysis, AGR <1.43 was associated with worse OS (HR: 1.51, 95% CI: 1.23–1.85, P<0.001) and CSS (HR: 1.52, 95% CI: 1.24–1.86, P<0.001). The addition of AGR only minimally improved the discrimination of a base model that included established clinicopathologic features (C-index=0.640 vs. C-index=0.629). On DCA, the inclusion of AGR marginally improved the net benefit of the prognostic model. Low AGR remained independently associated with OS and CSS in the IMDC intermediate risk group (HR: 1.52, 95% CI: 1.16–1.99, P=0.002).

Conclusions

In our study, low AGR before CN was associated with worse OS and CSS, particularly in intermediate risk patients.

A Global Trend Analysis of Kidney Cancer Incidence and Mortality and Their Associations with Smoking, Alcohol Consumption, and Metabolic Syndrome

BACKGROUND

Kidney cancer is a major urological disease globally, with more than 400 000 new cases diagnosed every year.

OBJECTIVE

To investigate incidence and mortality trends for kidney cancer and their associations with modifiable risk factors for kidney cancer.

DESIGN, SETTING, AND PARTICIPANTS

The most up-to-date figures on kidney cancer incidence and mortality were collected from the GLOBOCAN database and the Cancer Incidence in Five Continents (CI5). Data on total alcohol consumption and the prevalence of smoking, overweight, diabetes, and hypertension were extracted from the World Health Organization Global Health Observatory data repository.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Age-standardized rates (ASRs) for incidence and mortality and their correlations with potential risk factors for kidney cancer were investigated. Multivariable linear regression analysis was also conducted. The 10-yr temporal patterns for incidence are presented as the average annual percent change with 95% confidence interval using joinpoint regression analysis.

RESULTS AND LIMITATIONS

Globally, there is wide variation in kidney cancer incidence and mortality. There were positive correlations between rates of smoking, alcohol consumption, and overweight and ASRs of kidney cancer incidence and mortality. Multivariable regression analysis revealed that alcohol consumption and overweight were significant risk factors for kidney cancer incidence, while smoking and alcohol consumption were significant risk factors for kidney cancer mortality. There was an increasing trend for the incidence of kidney cancer globally, with a particularly prominent trend for European countries. Of note, increasing incidence of kidney cancer is evident even for younger individuals aged <50 yr. However, cancer registries vary by country and period and there is a lack of data regarding the severity of risk factors and disease characteristics such as the distribution of histological groups, tumor grading, and staging.

CONCLUSIONS

There is an increasing trend for kidney cancer incidence globally, particularly in European countries and the younger population. Modifiable risk factors for kidney cancer incidence and mortality have been identified. The increasing incidence of kidney cancer among younger individuals is worrying and warrants early action on possible preventive measures.

PATIENT SUMMARY

The incidence of kidney cancer has been increasing globally, particularly in European countries and the younger population. Risk factors include smoking, alcohol consumption, overweight, and hypertension, and these factors are all modifiable.

Development and internal validation of nomograms for the prediction of postoperative survival of patients with grade 4 renal cell carcinoma (RCC)

Background

To develop successful prognostic models for grade 4 renal cell carcinoma (RCC) following partial nephrectomy and radical nephrectomy.

Methods

The nomograms were established based on a retrospective study of 135 patients who underwent partial and radical nephrectomy for grade 4 RCC at the Department of Urology, Peking University First Hospital from January 2013 to October 2018. The predictive performance of the nomograms was assessed by the calibration plot and C-index. The results were validated using bootstrap resampling.

Results

Aspartate transaminase (AST), the maximum diameter of tumor (cutoff value =7 cm), lymph node metastasis, and the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk group were independent factors for determining the overall survival (OS) and cancer-specific survival (CSS) in multivariate analysis. AST, the maximum diameter of the tumor (cutoff value =7 cm), and lymph node metastasis were found to be independent variables for progression-free survival (PFS) in multivariate analysis. These variables were used for the studies to establish nomograms. All calibration plots revealed excellent predictive accuracy of the models. The C-indexes of the nomograms for predicting OS, CSS and PFS were 0.729 (95% CI, 0.659-0.799), 0.725 (95% CI, 0.654-0.796) and 0.702 (95% CI, 0.626-0.778), respectively. Moreover, the recurrence rate was not associated with open or laparoscopic radical nephrectomy in our cohort (P=0.126).

Conclusions

We have developed easy-to-use models that are internally validated to predict postoperative 1-, 3-, and 5-year OS, CSS, and PFS rates of grade 4 RCC patients. The new models could aid in identifying high-risk patients, making postoperative therapeutic and follow-up strategies as well as predicting patients' survival after externally validated. Besides, our study shows that the recurrence rate is not associated with open or laparoscopic radical nephrectomy.

Oncometabolite L-2-hydroxyglurate directly induces vasculogenic mimicry through PHLDB2 in renal cell carcinoma

Metabolism reprograming is a hallmark of cancer and plays an important role in tumor progression. The aberrant metabolism in renal cell carcinoma (RCC) leads to accumulation of the oncometabolite l‐2‐hydroxyglurate (L‐2HG). L‐2HG has been reported to inhibit the activity of some α‐ketoglutarate‐dependent dioxygenases such as TET enzymes, which mediate epigenetic alteration, including DNA and histone demethylation. However, the detailed functions of L‐2HG in renal cell carcinoma have not been investigated thoroughly. In our study, we found that L‐2HG was significantly elevated in tumor tissues compared to adjacent tissues. Furthermore, we demonstrated that L‐2HG promoted vasculogenic mimicry (VM) in renal cancer cell lines through reducing the expression of PHLDB2. A mechanism study revealed that activation of the ERK1/2 pathway was involved in L‐2HG‐induced VM formation. In conclusion, these findings highlighted the pathogenic link between L‐2HG and VM and suggested a novel therapeutic target for RCC.

What's new?

Metabolic reprograming, a hallmark of cancer, influences tumor progression. In the case of renal cell carcinoma (RCC) specifically, progression appears to be facilitated by the oncometabolite L‐2‐hydroxyglurate (L‐2HG), though underlying mechanisms remain enigmatic. Here, the authors investigated the ability of L‐2HG in RCC to promote vasculogenic mimicry (VM), in which aggressive cancer cells form vessel‐like networks that support tumor growth. Analyses of RCC patient tissues revealed elevated L‐2HG levels, wherein tumor cells with greater L‐2HG levels exhibited more VM structures. TCGA data and high‐throughput sequencing analyses further show that L‐2HG contributes to VM formation via reduction of PHLDB2 levels.

Establishment of a Risk Signature Based on m6A RNA Methylation Regulators That Predicts Poor Prognosis in Renal Cell Carcinoma

Purpose

N6-methyladenosine (m6A) modifications represent one of the most common methylation modifications, and they are mediated by m6A RNA methylation regulators. However, their functions in renal cell carcinoma (RCC) are not completely understood. The aim of this study was to investigate the effects of the regulators in RCC.

Materials and Methods

The expression levels of the 13 main m6A RNA methylation regulators in RCC were detected and consensus clustering was performed to explore their relationships with RCC. Thereafter, a risk signature based on the regulators was established. This risk model was fully verified by conducting prognostic analyses using two datasets (The Cancer Genome Atlas [TCGA] and Gene Expression Omnibus [GEO] datasets) and a ROC curve analysis.

Results

Of the 13 main m6A regulators, six were significantly upregulated and four were significantly downregulated in 893 RCC cases compared to 128 normal controls in the TCGA database. Consensus clustering based on the regulators identified two clusters of RCC cases, which were significantly associated with a pathological characteristic (T status). Thus, these results indicated that m6A RNA methylation regulators were associated with RCC. Thereafter, a risk model involving two of the regulators (METTL14 and WTAP) was established. The alterations in the mRNA and protein expression levels of these two regulators were further confirmed based on Human Protein Atlas data and real-time PCR in RCC and normal cell lines. The results indicated that the risk model may serve as an independent prognostic marker of overall survival, and it was also associated with clinicopathological characteristics (T status, M status, pathological stage, and gender) in RCC.

Conclusion

Collectively, the results of this study indicated that the risk model (based on two m6A RNA methylation regulators) may serve as an independent prognostic indicator of RCC, which may aid further investigation into m6A RNA modification in RCC.

Cadmium induces epithelial-mesenchymal transition and migration of renal cancer cells by increasing PGE2 through a cAMP/PKA-COX2 dependent mechanism

Environmental or occupational exposure of Cadmium (Cd) is concerned to be a threat to human health. The kidney is main target of Cd accumulation, which increases the risk of renal cell carcinoma (RCC). In addition, low content of Cd had been determined in kidney cancer, however, the roles of presence of Cd in renal tumors progression are still unclear. The present study is proposed to determine the effect of low-dose Cd exposure on the renal cancer cells and aimed to clarify the underlying mechanisms. The cell viability, cytotoxicity, and the migratory effect of low-dose Cd on the renal cancer cells were detected. Moreover, the roles of reactive oxygen species (ROS), Ca²⁺, and cyclic AMP (cAMP)/protein kinase A (PKA)-cyclooxygenase2 (COX2) signaling, as well as COX2 catalytic product prostaglandin E2 (PGE2) on cell migration and invasion were identified. Our results suggested that low dose Cd exposure promoted migration of renal cancer Caki-1 cells, which was not dependent on Cd-induced ROS and intracellular Ca²⁺ levels. Cd exposure induced cAMP/PKA-COX2, which mediated cell migration and invasion, and decreased expressions of epithelial-mesenchymal transition (EMT) marker, E-cadherin, but increased expressions of N-cadherin and Vimentin. Moreover, Cd-induced secretion of PGE2 feedback on activation of cAMP/PKA-COX2 signaling, also promoted EMT, migration and invasion of renal cancer Caki-1 cells. This study might contribute to understanding of the mechanism of Cd-induce progression of renal cancer and future studies on the prevention and therapy of renal cell carcinomas.

Identification of fenoldopam as a novel LSD1 inhibitor to abrogate the proliferation of renal cell carcinoma using drug repurposing strategy

Although targeted therapy for renal cell carcinoma (RCC) has achieved good therapeutic effects in clinic, a considerable number of patients develop drug resistance over time. So, there is still an urgent need to develop new drugs for RCC treatment. As LSD1 is considered as a promising drug target in diverse cancers, including RCC, we tried to find new LSD1 inhibitor using drug repurposing strategy from a compound library, and fenoldopam, an FDA-approved drug, was identified as a potent LSD1 inhibitor with IC₅₀ = 0.8974 μM in a reversible manner. Molecular docking predicted that fenoldopam occupied the FAD cavity of LSD1, forming hydrogen bonds with surrounding residues. Moreover, fenoldopam inactivated LSD1 and performed antiproliferative activity against ACHN cells and promoted cells apoptosis in vitro. Taken together, fenoldopam was identified as a novel LSD1 inhibitor firstly, and may serve as a new skeleton for RCC therapy.

Circulating tumor DNA analysis of metastatic renal cell carcinoma

The genomic landscape of metastatic renal cell carcinoma (RCC) is not well understood, and currently available data suggest that it is functionally distinct from that of localized tumors. Additionally, the large number of approved and trial agents used to treat metastatic RCC likely cause selective adaptations in the tumors. Circulating tumor DNA (ctDNA) is a platform to non-invasively determine the genomic profiles of these tumors. The objectives of the present study were to corroborate previous ctDNA studies in metastatic RCC, to identify novel mutations in metastatic RCC, and to compare ctDNA profiles obtained from plasma and urine in patients with metastatic RCC. ctDNA sequencing using the plasma and urine of 50 patients with metastatic RCC who received ctDNA profiling as part of routine clinical care at a single institution was performed using an investigational 120-gene panel. Genomic alterations (GAs) were identified in all 50 patients. The genes with the most GAs were GNAS, PTEN, MYC, MET and HNF1A and novel mutations in additional genes were identified. A significant correlation between the number of GAs detected in matched urine and plasma samples was also identified, but only 28.1% of GAs detected in plasma samples were also detected in matched urine samples. The results of the present study were consistent with those of the largest previous study of ctDNA from patients with metastatic RCC and may help identify additional potential targets for the treatment of such patients.

RNA-binding protein SORBS2 suppresses clear cell renal cell carcinoma metastasis by enhancing MTUS1 mRNA stability

RNA-binding proteins (RBPs) predominantly contribute to abnormal posttranscriptional gene modulation and disease progression in cancer. Sorbin and SH3 domain-containing 2 (SORBS2), an RBP, has been reported to be a potent tumor suppressor in several cancer types. Through integrative analysis of clinical specimens, we disclosed that the expression level of SORBS2 was saliently decreased in metastatic tissues and positively correlated with overall survival. We observed that overexpression of SORBS2 brought about decreased metastatic capacity in ccRCC cell lines. Transcriptome-wide analysis revealed that SORBS2 notably increased microtubule-associated tumor-suppressor 1 gene (MTUS1) expression. In-depth mechanistic exploring discovered that the Cys2-His2 zinc finger (C2H2-ZnF) domain of SORBS2 directly bound to the 3′ untranslated region (3′UTR) of MTUS1 mRNA, which increased MTUS1 mRNA stability. In addition, we identified that MTUS1 regulated microtubule dynamics via promoting KIF2C^S192 phosphorylation by Aurora B. Together, our research identified SORBS2 as a suppressor of ccRCC metastasis by enhancing MTUS1 mRNA stability, providing a novel understanding of RBPs during ccRCC progression.

Screening of Urinary Renal Cancer Metabolic Biomarkers with Gold Nanoparticles-assisted Laser Desorption/Ionization Mass Spectrometry

Renal cell carcinoma is a very aggressive and often fatal disease for which there are no specific biomarkers found to date. The purpose of this work was to find features that differentiate urine metabolic profiles of healthy people and cancer patients. Laser desorption/ionization mass spectrometry on gold nanostructures-based techniques were used for the metabolic analysis of urine of 50 patients with kidney cancer. Comparison with data from 50 healthy volunteers led to the discovery of several compounds that may be considered potential renal cell carcinoma (RCC) biomarkers. Statistical analysis of data allowed for the discovery of m/z values that had the greatest impact on group differentiation. A database search enabled the assignment of signals for the most promising 15 features among them: serine, heptanol, 3-methylene-indolenine, 2-methyl-3-hydroxy-5-formylpyridine-4-carboxylate, phosphodimethylethanolamine, 4-methoxyphenylacetic acid, N-acetylglutamine, 3,5-dihydroxyphenylvaleric acid, hydroxyhexanoylglycine, valyl-leucine, leucyl-histidine, oleamide, 9,12,13-trihydroxyoctadecenoic acid, stearidonyl carnitine and squalene. Differences of metabolite profiles of human urine could be identified by gold nanoparticle-enhanced target (AuNPET) LDI MS method and used for the detection of renal cancer.

The effect of a novel glycolysis-related gene signature on progression, prognosis and immune microenvironment of renal cell carcinoma

Background

Glycolysis is a central metabolic pathway for tumor cells. However, the potential roles of glycolysis-related genes in renal cell carcinoma (RCC) have not been investigated.

Methods

Seven glycolysis-related gene sets were selected from MSigDB and were analyzed through GSEA. Using TCGA database, the glycolysis-related gene signature was constructed. Prognostic analyses were based on the Kaplan–Meier method. The cBioPortal database was employed to perform the mutation analyses. The CIBERSORT algorithm and TIMER database were used to determine the immunological effect of glycolytic gene signature. The expressions in protein level of eight glycolytic risk genes were determined by HPA database. Finally, qPCR, MTT and Transwell invasion assays were conducted to validate the roles of core glycolytic risk genes (CD44, PLOD1 and PLOD2) in RCC.

Results

Four glycolysis-related gene sets were significantly enriched in RCC samples. The glycolytic risk signature was constructed (including CD44, PLOD2, KIF20A, IDUA, PLOD1, HMMR, DEPDC1 and ANKZF1) and identified as an independent RCC prognostic factor (HR = 1.204). Moreover, genetic alterations of glycolytic risk genes were uncommon in RCC (10.5%) and glycolytic risk signature can partially affect immune microenvironment of RCC. Six glycolytic risk genes (except for IDUA and HMMR) were over-expression in A498 and 786-O renal cancer cells through qPCR test. MTT and Transwell assays revealed that silencing of CD44, PLOD1 and PLOD2 suppressed the proliferation and invasion of renal cancer cells.

Conclusions

The glycolysis-related risk signature is closely associated with RCC prognosis, progression and immune microenvironment. CD44, PLOD1 and PLOD2 may serve as RCC oncogenes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07702-7.

Visceral Adiposity as a Significant Predictor of Sunitinib-Induced Dose-Limiting Toxicities and Survival in Patients with Metastatic Clear Cell Renal Cell Carcinoma

Sunitinib is a first-line treatment for metastatic renal cell carcinoma (mRCC). Little is known about the predictive factors of sunitinib-induced dose-limiting toxicity (DLT) in Asian populations. We investigated whether body composition predicts sunitinib-induced DLT. We retrospectively reviewed sunitinib-treated Korean patients with clear cell mRCC from eight institutions. Body composition was measured using computed tomography. DLT was defined as any adverse event leading to dose reduction or treatment discontinuation. Univariate analysis was used to compare body composition indices, and logistic regression analyses were performed for factors predicting early DLT. Overall, 111/311 (32.5%) of patients experienced DLT. Significant differences were observed in the subcutaneous adipose tissue index (SATI; p = 0.001) and visceral adipose tissue index (VATI; p < 0.001) between patients with and without DLT. Multivariate analyses revealed that VATI (odds ratio: 1.013; p = 0.029) was significantly associated with early DLT. Additionally, 20% of patients who had a body mass index (BMI) greater than 23 kg/m² and a low VATI experienced DLT, whereas 34.3% of the remaining groups had DLT (p = 0.034). Significant differences were observed for median progression-free survival (13.0 vs. 26.0 months, respectively; p = 0.006) between patients with low and high VATI. Visceral adiposity was a significant predictor of sunitinib-associated DLT and survival. Patients with a low VATI and a BMI greater than 23 kg/m² experienced lower DLTs.

C3, C3AR1, HLA-DRA, and HLA-E as potential prognostic biomarkers for renal clear cell carcinoma

Background

Prognostic biomarkers play a vital role in the early detection of the cancer and assessment of prognosis. With advances in technology, a large number of biomarkers of kidney renal clear cell carcinoma (KIRC) have been discovered, but their prognostic value has not been fully investigated, and thus have not been widely used in clinical practice. We aimed to identify the reliable markers associated with the prognosis of KIRC patients.

Methods

We obtained 72 normal samples and 539 tumor samples from The Cancer Genome Atlas (TCGA), and 23 normal samples and 32 tumor samples from the Gene Expression Omnibus (GEO). Overlapping differentially expressed genes (ODEGs) were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, followed by construction of a protein-protein interaction (PPI) network to screen hub genes. Kaplan-Meier analysis, univariate Cox analysis, multivariate Cox analysis, Wilcoxon signed-rank test, Kruskal-Wallis test, and gene set enrichment analysis (GSEA) were performed to verify the prognostic value and function of the markers we selected. The relationships among gene expression level, tumor immune cell infiltration, and immune-checkpoints were also analyzed.

Results

A total of 910 genes were screened out, and C3, C3AR1, HLA-DRA, and HLA-E were identified as potential tumor markers. The expression of each gene was closely associated with tumor immune cell infiltration, survival rate, and the patients’ clinical characteristics (P<0.05). C3AR1, HLA-DRA, and HLA-E were also verified as independent prognostic factors of KIRC (P<0.05), and all these potential biomarkers had a close correlation with immune checkpoints.

Conclusions

C3, C3AR1, HLA-DRA, and HLA-E could be reliable biomarkers of KIRC and may have a significant contribution to make in immunotherapy, thus playing an important role in the improvement of prognosis.

Real-world evidence of cabozantinib in patients with metastatic renal cell carcinoma: Results from the CABOREAL Early Access Program

BACKGROUND

Real-world data on cabozantinib in metastatic renal cell carcinoma (mRCC) is limited. This study (CABOREAL) reports treatment patterns and outcomes for patients treated with cabozantinib through the French Early Access Program.

PATIENTS AND METHODS

This multicentre (n = 26), observational, retrospective study enrolled patients with mRCC who had received ≥1 dose of cabozantinib. Overall survival (OS) was estimated using the Kaplan-Meier method; subgroups were compared using the log-rank test. A multiple Cox regression model assessed predictive factors of OS after cabozantinib initiation.

RESULTS

Four hundred and ten recruited patients started treatment between September 2016 and February 2018: the Eastern Cooperative Oncology Group Performance Status ≥2, 39.3%; poor International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk, 31.7%; 0-1, 2 and ≥3 previous treatment lines, 25.3%, 33.4% and 41.2%, respectively; bone metastases, 55.9%; brain metastases, 16.8%. Median (min-max) follow-up was 14.4 (0-30) months. Overall, 57.0% of patients had a dose reduction, 15.6% an alternative dose schedule. The median average daily dose was 40.0 mg. Median (quartile [Q]1-Q3) treatment duration was 7.6 (0.1-29.1) months, median OS was 14.4 months, and the 12-month OS rate was 56.5% (95% confidence interval: 51.5-61.2). Most patients (54.4%) received subsequent treatment. Predictive factors associated with longer OS were body mass index ≥25 kg/m² (p = 0.0021), prior nephrectomy (p = 0.0109), favourable or intermediate IMDC risk (p < 0.0001) and cabozantinib initiation at 60 mg/day (p = 0.0486).

CONCLUSIONS

In the largest real-world study to date, cabozantinib was effective in unselected, heavily pretreated patients with mRCC. Initiation at 60 mg/day was associated with improved outcomes. CLINICALTRIALS.

GOV IDENTIFIER

NCT03744585.

Targeting Strategies for Renal Cancer Stem Cell Therapy

Renal cell carcinoma (RCC) is an intractable genitourinary malignancy that accounts for approximately 4% of adult malignancies. Currently, there is no approved targeted therapy for RCC that has yielded durable remissions, and they remain palliative in intent. Emerging evidence has indicated that renal tumorigenesis and RCC treatment-resistance may originate from renal cancer stem cells (CSCs) with tumor-initiating capacity (CSC hypothesis). A better understanding of the mechanism underlying renal CSCs will help to dissect RCC heterogeneity and drug treatment efficiency, to promote more personalized and targeted therapies. In this review, we summarized the stem cell characteristics of renal CSCs. We outlined the targeting strategies and challenges associated with developing therapies that target renal CSCs angiogenesis, immunosuppression, signaling pathways, surface biomarkers, microRNAs and nanomedicine. In conclusion, CSCs are an important role in renal carcinogenesis and represent a valid target for treatment of RCC patients.

Construction and Validation of a Convenient Clinical Nomogram to Predict the Risk of Brain Metastasis in Renal Cell Carcinoma Patients

Brain metastasis (BM) is a typical type of metastasis in renal cell carcinoma (RCC) patients. The early detection of BM is likely a crucial step for RCC patients to receive appropriate treatment and prolong their overall survival. The aim of this study was to identify the independent predictors of BM and construct a nomogram to predict the risk of BM. Demographic and clinicopathological data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database for RCC patients between 2010 and 2015. Univariate and multivariate logistic regression analyses were performed to identify the independent risk factors, and then, a visual nomogram was constructed. Multiple parameters were used to evaluate the discrimination and clinical value. We finally included 42577 RCC patients. Multivariate logistic regression analysis showed that histological type, tumor size, bone metastatic status, and lung metastatic status were independent BM-associated risk factors for RCC. We developed a nomogram to predict the risk of BM in patients with RCC, which showed favorable calibration with a C-index of 0.924 (0.903-0.945) in the training cohort and 0.911 (0.871-0.952) in the validation cohort. The calibration curves and decision curve analysis (DCA) also demonstrated the reliability and accuracy of the clinical prediction model. The nomogram was shown to be a practical, precise, and personalized clinical tool for identifying the RCC patients with a high risk of BM, which not only will contribute to the more reasonable allocation of medical resources but will also enable a further improvements in the prognosis and quality of life of RCC patients.

Upregulated circPDK1 Promotes RCC Cell Migration and Invasion by Regulating the miR-377-3P-NOTCH1 Axis in Renal Cell Carcinoma

Background

Circular RNAs (circRNAs) are novel clusters of endogenous noncoding RNAs (ncRNAs) that are involved in the regulation of multiple biological processes in diverse types of cancers. However, the roles and precise mechanisms of circRNAs in renal cell carcinoma (RCC) occurrence and progression have not been clearly elucidated.

Methods

We identified the aberrantly expressed circRNAs in RCC by high-throughput RNA-seq assay and used qRT-PCR to test the expression level of circRNAs in RCC tissues. Loss-of-function experiments were executed to detect the biological roles of circPDK1 in the RCC cells both in vivo and in vitro. RNA Fish, luciferase reporter assays and Western blotting were used to explore the molecular mechanism of circPDK1 function. All data were expressed as the means ± standard error of the mean (SEM). Student’s t-test, one-way ANOVA, Cox regression, an LSD-t-test, Pearson’s chi-squared test, a Log-rank test, and linear regression analyses were used to evaluate the group differences. P < 0.05 was considered significant.

Results

CircPDK1 was overexpressed in RCC tissues and positively associated with patient tumor metastasis and renal cell invasion. The in vivo functional assays also revealed that circPDK1 drove RCC xenograft metastasis. CircPDK1 was mainly located in the cytoplasm, serving as a sponge of miR-377-3P to regulate RCC invasion and metastasis through NOTCH1 (Notch Homolog 1). Ectopic express of NOTCH1 in RCC cell lines will block the metastasis inhibition effect after circPDK1 knockdown.

Conclusion

CircPDK1 is aberrantly expressed in RCC and promotes the metastasis of RCC cells mainly through sponging miR-377-3P and reducing its negative regulation of NOTCH1. Thus, circPDK1 may act as a therapeutic target and biomarker for RCC.

Role of Tissue Transglutaminase Catalytic and Guanosine Triphosphate-Binding Domains in Renal Cell Carcinoma Progression

Tissue transglutaminase (TG2) is a multifunctional protein that can act as a cross-linking enzyme, GTPase/ATPase, protein kinase, and protein disulfide isomerase. TG2 is involved in cell adhesion, migration, invasion, and growth, as well as epithelial-mesenchymal transition (EMT). Our previous findings indicate that the increased expression of TG2 in renal cell carcinoma (RCC) results in tumor metastasis with a significant decrease in disease- and cancer-specific survival outcome. Given the importance of the prometastatic activity of TG2 in RCC, in the present study, we aim to investigate the relative contribution of TG2's transamidase and guanosine triphosphate (GTP)-binding/GTPase activity in the cell migration, invasion, EMT, and cancer stemness of RCC. For this purpose, the mouse RCC cell line RenCa was transduced with wild-type-TG2 (wt-TG2), GTP-binding deficient-form TG2-R580A, transamidase-deficient form with low GTP-binding affinity TG2-C277S, and transamidase-inactive form TG2-W241A. Our results suggested that predominantly, GTP-binding activity of TG2 is responsible for cell migration and invasion. In addition, CD marker analysis and spheroid assay confirmed that GTP binding/GTPase activity of TG2 is important in the maintenance of mesenchymal character and the cancer stem cell profile. These findings support a prometastatic role for TG2 in RCC that is dependent on the GTP binding/GTPase activity of the enzyme.

Surgical Management of Genitourinary Cancer Liver Metastases

Genitourinary cancers are common. Liver metastases from genitourinary cancers are uncommon; isolated liver metastasis is rare. Liver resection in select patients with metastatic renal cell carcinoma can lead to prolonged survival. Patients with metachronous and low-burden disease are most likely to benefit. Chemotherapy is first-line treatment of metastatic germ cell tumors. Liver resection is dependent on germ cell lineage and initial response to chemotherapy. Prognosis with liver metastases from prostate cancer is poor; liver-only lesions are rare. Liver resection generally is not indicated. Cumulative experience with liver resection for metastatic bladder cancer is limited. Liver metastases are poor prognostic indicators for metastasectomy.

Identification of RNA Transcript Makers Associated With Prognosis of Kidney Renal Clear Cell Carcinoma by a Competing Endogenous RNA Network Analysis

Objective

This study aims to identify several RNA transcripts associated with the prognosis of kidney renal clear cell carcinoma (KIRC).

Methods

The differentially expressed mRNAs, lncRNAs, and miRNAs (DEmRNAs, DElncRNAs, and DEmiRNAs) between KIRC cases and controls were screened based on an RNA-seq dataset from The Cancer Genome Atlas (TCGA) database. Subsequently, miRcode, miRDB, and TargetScan database were used to predict interactions between lncRNAs, miRNAs and target mRNAs. Then, a ceRNA network was built using miRNAs-mRNAs and lncRNAs-miRNAs pairs. Functional analysis of mRNAs in ceRNA was performed. Finally, the survival analysis of RNA transcripts in ceRNA network and correlation analysis for key RNA regulators were carried out.

Results

There were 1527 DElncRNAs, 54 DEmiRNAs, and 2321 DEmRNAs. A ceRNA network was constructed among 81 lncRNAs, 9 miRNAs, and 197 mRNAs. Functional analysis showed that numerous mRNAs were significantly associated with regulation of cellular glucuronidation. In addition, 35 lncRNAs, 84 mRNAs and two miRNAs were significantly corelated to the survival of patients with KIRC (P < 0.05). Among them, miRNA-21 and miRNA-155 were negatively related to three lncRNAs (LINC00472, SLC25A5.AS1, and TCL6). Seven mRNA targets of miRNA-21 (FASLG, FGF1, TGFBI, ALX1, SLC30A10, ADCY2, and ABAT) and 12 mRNAs targets of miRNA-155 (STXBP5L, SCG2, SPI1, C12orf40, TYRP1, CTHRC1, TDO2, PTPRQ, TRPM8, ERMP1, CD36, and ST9SIA4) also acted as prognostic biomarkers for KIRC patients.

Conclusion

We screened numerous novel prognosis-related RNA markers for KIRC patients by a ceRNA network analysis, providing deeper understandings of prognostic values of RNA transcripts for KIRC.

Kidney Cancer: An Overview of Current Therapeutic Approaches

The management of metastatic renal cell carcinoma (RCC) has evolved rapidly in recent years with several immunotherapy-based combinations of strategies approved as first-line therapies. Targeted strategies, including systemic antiangiogenesis agents and immune checkpoint blockade, form the basis of a therapeutic approach. With rising rates of recurrence after first-line treatment, it is increasingly important to not only adopt a personalized treatment plan with minimal adverse events but also develop predictive biomarkers for response. This review discusses currently available first-line and second-line therapies in RCC and their pivotal data, with specific focus on ongoing clinical trials in the adjuvant setting, including those involving novel agents.

Profiles of overall survival-related gene expression-based risk signature and their prognostic implications in clear cell renal cell carcinoma

The present work aimed to evaluate the prognostic value of overall survival (OS)-related genes in clear cell renal cell carcinoma (ccRCC) and to develop a nomogram for clinical use. Transcriptome data from The Cancer Genome Atlas (TCGA) were collected to screen differentially expressed genes (DEGs) between ccRCC patients with OS > 5 years (149 patients) and those with <1 year (52 patients). In TCGA training set (265 patients), seven DEGs (cytochrome P450 family 3 subfamily A member 7 (CYP3A7), contactin-associated protein family member 5 (CNTNAP5), adenylate cyclase 2 (ADCY2), TOX high mobility group box family member 3 (TOX3), plasminogen (PLG), enamelin (ENAM), and collagen type VII α 1 chain (COL7A1)) were further selected to build a prognostic risk signature by the least absolute shrinkage and selection operator (LASSO) Cox regression model. Survival analysis confirmed that the OS in the high-risk group was dramatically shorter than their low-risk counterparts. Next, univariate and multivariate Cox regression revealed the seven genes-based risk score, age, and Tumor, lymph Node, and Metastasis staging system (TNM) stage were independent prognostic factors to OS, based on which a novel nomogram was constructed and validated in both TCGA validation set (265 patients) and the International Cancer Genome Consortium cohort (ICGC, 84 patients). A decent predictive performance of the nomogram was observed, the C-indices and corresponding 95% confidence intervals of TCGA training set, validation set, and ICGC cohort were 0.78 (0.74–0.82), 0.75 (0.70–0.80), and 0.70 (0.60–0.80), respectively. Moreover, the calibration plots of 3- and 5 years survival probability indicated favorable curve-fitting performance in the above three groups. In conclusion, the proposed seven genes signature-based nomogram is a promising and robust tool for predicting the OS of ccRCC, which may help tailor individualized therapeutic strategies.

Enhanced Computed Tomography-Based Radiomics Signature Combined With Clinical Features in Evaluating Nuclear Grading of Renal Clear Cell Carcinoma

OBJECTIVE

The aim of the study was to explore the value of enhanced computed tomography (CT)-based radiomics signature combined with clinical features in evaluating nuclear grading of clear cell renal cell carcinoma (ccRCC).

METHODS

One hundred one patients with ccRCC were classified into low- and high-grade group, and the data were divided into training set and verification set. Radiomics signatures were constructed in the training set in enhanced 3 stages and the combination of them. The predictive nomogram was constructed. The classification efficiency and the clinical practicability of the integrated radiomics model were evaluated.

RESULTS

The classification efficiency of enhanced 3-stage integrated histology model was higher than that of each single-phase model. The predictive nomogram incorporated the best radiomics signature, and the independent clinical risk factors showed good performance. A decision curve analysis curve shows that the net benefit of the combined model.

CONCLUSIONS

It is feasible to evaluate the nuclear grading of ccRCC based on enhanced CT radiomics signature combined with clinical features.

Radiographical efficacy of systemic treatment for bone metastasis from renal cell carcinoma

Enlarged bone metastasis from renal cell carcinoma (RCC) can cause skeletal-related events, and thus treatment to inhibit the growth of bone metastases is often required. Although radiotherapy for RCC bone metastases can achieve a certain degree of local control, evidence is lacking regarding the effects of systemic therapy to improve bone metastasis. The present study aimed to assess the treatment efficacy of targeted therapy and immune checkpoint inhibitors, and to determine whether systemic therapy without radiotherapy can shrink bone metastases of RCC. The present study retrospectively reviewed 44 patients with RCC with bone metastases treated via systemic therapy, including targeted therapy or immune checkpoint inhibitors. Patients were divided into two groups: Those who underwent systemic therapy with radiotherapy for bone lesions (n=29); and those who underwent systemic therapy without radiotherapy for bone lesions (n=15). The radiographical efficacy of systemic therapy and the time to progression of bone metastases were compared between groups. The overall response rate of systemic therapy with radiotherapy was 44%, and in total, 13 patients demonstrated a partial response. Only one patient (6%) had a partial response among those who were treated via systemic therapy without radiotherapy. The time to progression of bone metastasis was 9.5 and 2.1 months in patients treated with and without radiotherapy, respectively (P<0.0001). Collectively, the present results suggested that targeted therapy or immune checkpoint inhibitors without radiotherapy had only a slight effect on bone metastasis control.

Association of preoperative serum De Ritis ratio with oncological outcomes in patients treated with cytoreductive nephrectomy for metastatic renal cell carcinoma

PURPOSE

Identifying which patients are likely to benefit from cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) is important. We tested the association between preoperative serum De Ritis ratio (DRR, Aspartate Aminotransferase/Alanine Aminotransferase) and overall survival (OS) as well as cancer-specific survival (CSS) in mRCC patients treated with CN.

MATERIAL AND METHODS

mRCC patients treated with CN at different institutions were included. After assessing for the optimal pretreatment DRR cut-off value, we found 1.2 to have the maximum Youden index value. The overall population was therefore divided into 2 DRR groups using this cut-off (low, <1.2 vs. high, ≥1.2). Univariable and multivariable Cox regression analyses tested the association between DRR and OS as well as CSS. The discrimination of the model was evaluated with the Harrel's concordance index (C-index). The clinical value of the DRR was evaluated with decision curve analysis.

RESULTS

Among 613 mRCC patients, 239 (39%) patients had a DRR ≥1.2. Median follow-up was 31 (IQR 16-58) months. On univariable analysis, high DRR was significantly associated with OS (hazard ratios [HR]: 1.22, 95% confidence interval [CI]: 1.01-1.46, P = 0.04) and CSS (HR: 1.23, 95% CI: 1.02-1.47, P = 0.03). On multivariable analysis, which adjusted for the effect of established clinicopathologic features, high DRR remained significantly associated with both OS (HR: 1.26, 95% CI: 1.04-1.52, P = 0.02) and CSS (HR: 1.26, 95% CI: 1.05-1.53, P = 0.01). The addition of DRR only minimally improved the discrimination of a base model that included established clinicopathologic features (C-index = 0.633 vs. C-index = 0.629). On decision curve analysis, the inclusion of DRR did not improve the net-benefit beyond that obtained by established subgroup analyses stratified by IMDC risk groups, type of systemic therapy, body mass index and sarcomatoid features, did not reveal any prognostic value to DRR.

CONCLUSION

Despite the statistically significant association between DRR and OS as well as CSS in mRCC patients treated with CN, DRR does not seem to add any further prognostic value beyond that obtained by currently available features.

Prognostic Role of Prothrombin Time Activity, Prothrombin Time, Albumin/Globulin Ratio, Platelets, Sex, and Fibrinogen in Predicting Recurrence-Free Survival Time of Renal Cancer

Background

To help with the clinical practice of renal cancer patients, prognostic models are urgently warranted. We hunted and identified prognostic variables associated with recurrence-free survival (RFS) for renal cancer patients.

Patients and Methods

In this retrospective study, 187 renal cancer patients who had received curative radical/partial nephrectomy between November 2011 and January 2017 were enrolled in the current study. These patients were randomly split into the training (n = 95) and validation sets (n = 92) by the ratio of 1:1. Univariate and multivariable Cox regression analyses were used to establish the nomogram, which was then evaluated by receiver operating characteristic (ROC) and Kaplan-Meier (K-M) analyses.

Results

Patient characteristics and outcomes were well balanced between the training and validation sets; the median RFS values were 54.1 months and 58.9 months for the training and validation cohorts, respectively. The final nomogram included six independent prognostic variables (prothrombin time (%), prothrombin time (second), albumin/globulin ratio, platelets, sex and fibrinogen). The mean values of RFS for the low- and high-risk groups defined by a prognostic formula were 56.22 ± 18.50 months and 49.54 ± 23.57 months, respectively, in the training cohort and were 59.00 ± 19.50 months and 53.32 ± 19.95 months, respectively, in the validation cohort. The significance and stability of the model were tested by the time-dependent K-M model and ROC curves, respectively.

Conclusion

Our validated prognostic model incorporates variables routinely collected from renal cancer patients, identifying subsets of patients with different survival outcomes, which provides useful information for patient care and clinical trial design.

Identification of Key Genes of Prognostic Value in Clear Cell Renal Cell Carcinoma Microenvironment and a Risk Score Prognostic Model

Objective

We aimed at identifying the key genes of prognostic value in clear cell renal cell carcinoma (ccRCC) microenvironment and construct a risk score prognostic model.

Materials and Methods

Immune and stromal scores were calculated using the ESTIMATE algorithm. A total of 539 ccRCC cases were divided into high- and low-score groups. The differentially expressed genes in immune and stromal cells for the prognosis of ccRCC were screened. The relationship between survival outcome and gene expression was evaluated using univariate and multivariate Cox proportional hazard regression analyses. A risk score prognostic model was constructed based on the immune/stromal scores.

Results

The median survival time of the low immune score group was longer than that of the high immune score group (p = 0.044). Ten tumor microenvironment-related genes were selected by screening, and a predictive model was established, based on which patients were divided into high- and low-risk groups with markedly different overall survival (p < 0.0001). Multivariate Cox analyses showed that the risk score prognostic model was independently associated with overall survival, with a hazard ratio of 1.0437 (confidence interval: 1.0237-1.0641, p < 0.0001).

Conclusions

Low immune scores were associated with extended survival time compared to high immune scores. The novel risk predictive model based on tumor microenvironment-related genes may be an independent prognostic biomarker in ccRCC.

Metastatic renal cell carcinoma patients of T4 stage who are in status of N1 stage or older than 76 years cannot benefit from cytoreductive nephrectomy

Background

We aimed to identify which part of the patients with metastatic renal cell carcinoma (mRCC) is not suitable for cytoreductive nephrectomy (CN).

Methods

The data of mRCC patients was acquired from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate cox regression analysis and nomogram were performed for selecting factors independently associated with survival. Propensity score matching (PSM) was applied to reduce potential bias when comparing survival of mRCC patients treated by CN or non-surgery (NS). The survival analysis of subgroups was estimated by the Kaplan–Meier method and compared by log-rank testing. The summary of subgroup analysis was showed by forest plots.

Results

The records of 21,411 patients with mRCC were obtained from the SEER database. After screening, a total of 6532 patients were included for further analysis, of which 6043 underwent CN and 489 underwent NS. Age, T stage, N stage and tumor size were involved in subgroup analysis by PSM according to the result of multivariate cox regression analysis and clinical experience. Survival benefit was not found in T4 stage patients. Further analysis showed that T4&N1 and T4&age ≥ 76 yr subgroups could not obtain survival benefit from CN.

Conclusion

CN should not be performed in T4 stage mRCC patients who were in status of N1 stage or older than 76 years, because surgery cannot take significant survival benefit for them.

Cost-effectiveness of pembrolizumab with axitinib as first-line treatment for advanced renal cell carcinoma

OBJECTIVE

Pembrolizumab/axitinib significantly prolonged overall survival (OS) and progression-free survival (PFS), and increased objective response rate versus sunitinib in the phase III trial KEYNOTE-426 among previously untreated patients with advanced renal cell carcinoma (RCC). This study assessed the cost-effectiveness of pembrolizumab/axitinib versus other first-line treatments of advanced RCC from a US public healthcare payer perspective.

METHODS

A partitioned survival model with three states (progression-free, progressed, death) evaluated lifetime costs and quality-adjusted life-years (QALYs) for pembrolizumab/axitinib and other first-line regimens: sunitinib, pazopanib and avelumab/axitinib in the overall population; and sunitinib, cabozantinib and nivolumab/ipilimumab in the subgroup with intermediate/poor prognostic risk. Costs of treatments, adverse events and medical resources were estimated. OS, PFS and treatment duration were extrapolated using parametric models fitted to KEYNOTE-426 data and hazard ratios from network meta-analyses. Utilities were derived through mixed-effects regressions of KEYNOTE-426 EuroQol-5 Dimensions-3 Levels data.

RESULTS

In the overall population, pembrolizumab/axitinib was associated with incremental cost-effectiveness ratios (ICERs) of $95,725/QALY versus sunitinib and $128,210/QALY versus pazopanib, and was dominant (lower cost, higher effectiveness) versus avelumab/axitinib, with incremental QALY gains of 2.73, 2.40 and 1.80 versus these therapies, respectively. In the intermediate/poor-risk subgroup, base-case ICERs for pembrolizumab/axitinib were $101,030/QALY versus sunitinib, $6989/QALY versus cabozantinib, and $130,934/QALY versus nivolumab/ipilimumab, with incremental QALY gains of 2.62, 1.78 and 1.06 versus these therapies.

CONCLUSIONS

In this economic evaluation, pembrolizumab/axitinib was associated with higher life expectancy and QALYs and, based on typical willingness-to-pay thresholds of $150,000-$180,000/QALY, was found cost-effective versus other first-line treatments for advanced RCC in the US.

Characterization of solid renal neoplasms using MRI-based quantitative radiomics features

PURPOSE

To assess the diagnostic value of magnetic resonance imaging (MRI)-based radiomics features using machine learning (ML) models in characterizing solid renal neoplasms, in comparison/combination with qualitative radiologic evaluation.

METHODS

Retrospective analysis of 125 patients (mean age 59 years, 67% males) with solid renal neoplasms that underwent MRI before surgery. Qualitative (signal and enhancement characteristics) and quantitative radiomics analyses (histogram and texture features) were performed on T2-weighted imaging (WI), T1-WI pre- and post-contrast, and DWI. Mann-Whitney U test and receiver-operating characteristic analysis were used in a training set (n = 88) to evaluate diagnostic performance of qualitative and radiomics features for differentiation of renal cell carcinomas (RCCs) from benign lesions, and characterization of RCC subtypes (clear cell RCC [ccRCC] and papillary RCC [pRCC]). Random forest ML models were developed for discrimination between tumor types on the training set, and validated on an independent set (n = 37).

RESULTS

We assessed 104 RCCs (51 ccRCC, 29 pRCC, and 24 other subtypes) and 21 benign lesions in 125 patients. Significant qualitative and quantitative radiomics features (area under the curve [AUC] between 0.62 and 0.90) were included for ML analysis. Models with best diagnostic performance on validation sets showed AUC of 0.73 (confidence interval [CI] 0.5-0.96) for differentiating RCC from benign lesions (using combination of qualitative and radiomics features); AUC of 0.77 (CI 0.62-0.92) for diagnosing ccRCC (using radiomics features), and AUC of 0.74 (CI 0.53-0.95) for diagnosing pRCC (using qualitative features).

CONCLUSION

ML models incorporating MRI-based radiomics features and qualitative radiologic assessment can help characterize renal masses.

Cell Polarity Protein Pals1-Associated Tight Junction Expression Is a Favorable Prognostic Marker in Clear Cell Renal Cell Carcinoma

Introduction: The Pals1-associated tight junction (PATJ) is a Crumbs (CRB) complex component that regulates epithelial cell apico-basal polarity and directional migration. This study assessed PATJ expression in clear cell renal cell carcinoma (ccRCC) vs. normal tissues and associated with ccRCC progression and prognosis. Methods: The effects of PATJ knockdown were investigated on regulation of normal kidney epithelial cell viability and protein expression in vitro. The PATJ mRNA data in ccRCC were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and analyzed with UALCAN, LinkedOmics, Kaplan-Meier Plotter, GEPIA, and SurvExpress tools. Immunohistochemistry was performed for PATJ in tissue microarray sections (n = 150 ccRCC and 30 normal renal specimens). Normal human kidney tubular epithelial cell (HKC) cells were transfected with PATJ and negative control siRNA for cell viability CCK-8 assay, flow cytometry, and western blots. Results: The data showed that PATJ mRNA and protein were downregulated in ccRCC tissues and cell lines. Downregulation of PATJ mRNA was associated with male patients, advanced tumor stages, grades, and ccB subtypes as well as poorer overall and disease-free survival of patients. Furthermore, PATJ protein was also significantly downregulated in ccRCC tissues and associated with advanced tumor pathologic, TNM stages and poorer overall. In vitro, knockdown of PATJ expression promoted HKC proliferation and the activation of mitogen-activated protein kinases (MAPK) pathway proteins. Conclusions: This study revealed that a decrease of PATJ in ccRCC, which was associated with male patients, advanced tumor, and poorer survival, suggesting that PATJ may be a useful prognostic biomarker and therapeutic target for ccRCC.

Changes in health-related quality of life outcomes in older patients with kidney cancer: A longitudinal cohort analysis with matched controls

BACKGROUND

Current evidence regarding health-related quality of life (HRQoL) changes among patients with kidney cancer (KC) is limited. We characterized HRQoL changes from before (baseline) to after (follow-up) diagnosis of KC in older Americans relative to matched controls, and identified sociodemographic and clinical factors associated with HRQoL changes in older patients with KC.

MATERIALS AND METHODS

This longitudinal, population-based, retrospective cohort study used data from Surveillance, Epidemiology and End Results linked with Medicare Health Outcomes Survey, 1998-2013. Participants aged ≥65 years with baseline and follow-up survey data were identified. Those with primary KC (n = 186) were matched to adults without cancer (n = 558). HRQoL (physical component summary and mental component summary [MCS]) changes in KC patients were compared using generalized linear mixed-effects models to those of controls. Regression models were used to identify baseline factors associated with HRQoL changes.

RESULTS

The adjusted least squares mean (95% confidence interval) reduction in physical component summary from baseline to follow-up was greater in KC patients vs. controls (-4.1 [-5.6, -2.7] vs. -2.3 [-3.1, -1.4], P = 0.025). While the reduction in MCS was similar in both groups (-2.4 [-3.9, -0.8] vs. -1.5 [-2.4, -0.6], P = 0.338). Lower income and distant stage KC predicted greater declines in MCS among KC patients.

CONCLUSION

KC significantly affects overall general health in older patients, with sociodemographic factors and distant KC predicting greater reductions in HRQoL. Findings may help clinicians set patient expectations about their HRQoL post-diagnosis and increase clinician awareness of risk factors for HRQoL deterioration.

Long Non-Coding RNA Profile Study Identifies an Immune-Related lncRNA Prognostic Signature for Kidney Renal Clear Cell Carcinoma

Kidney renal clear cell carcinoma (KIRC) is the predominant pathological subtype of renal cell carcinoma (RCC) in adults. Long non-coding RNAs (lncRNAs) are an important class of gene expression regulators and serve fundamental roles in immune regulation. The intent of this study is to develop a novel immune-related lncRNA signature to accurately predict the prognosis for KIRC patients. Here, we performed genome-wide comparative analysis of lncRNA expression profiles in 537 KIRC patients from The Cancer Genome Atlas (TCGA) database. Cox regression model–identified immune-related lncRNAs were extracted for constructing a novel five immune-related lncRNA signature (AC008105.3, LINC02084, AC243960.1, AC093278.2, and AC108449.2) with the ability to predict the prognosis of KIRC patients. Univariate and multivariate Cox regression analyses demonstrated that the signature could act as an independent prognostic predictor for overall survival (OS). With the further investigation on different clinicopathological parameters, we found that the signature could divide KIRC samples into high-risk groups with shorter OS and low-risk groups with longer OS in different subgroups. Principal component analysis suggested that the five immune-related lncRNA signature drew a clear distinction between high- and low-risk groups based on the immune-related lncRNAs. The different immune status between the two groups was observed in gene set enrichment analysis and the ESTIMATE algorithm. Except for AC093278.2, the expressions of the other four lncRNAs expression were significantly upregulated in tumor tissues. In summary, the identified immune-lncRNA signature had important clinical implications in prognosis prediction and could be exploited as underlying immune therapeutic targets for KIRC patients.

Identification of KIF18B as a Hub Candidate Gene in the Metastasis of Clear Cell Renal Cell Carcinoma by Weighted Gene Co-expression Network Analysis

Background

Clear cell renal cell carcinoma (ccRCC) is a common type of fatal malignancy in the urinary system. As the therapeutic strategies of ccRCC are severely limited at present, the prognosis of patients with metastatic carcinoma is usually not promising. Revealing the pathogenesis and identifying hub candidate genes for prognosis prediction and precise treatment are urgently needed in metastatic ccRCC.

Methods

In the present study, we conducted a series of bioinformatics studies with the gene expression profiles of ccRCC samples from Gene Expression Omnibus (GEO) and the cancer genome atlas (TCGA) database for identifying and validating the hub gene of metastatic ccRCC. We constructed a co-expression network, divided genes into co-expression modules, and identified ccRCC-related modules by weighted gene co-expression network analysis (WGCNA) with data from GEO. Then, we investigated the functions of genes in the ccRCC-related modules by enrichment analyses and built a sub-network accordingly. A hub candidate gene of the metastatic ccRCC was identified by maximal clique centrality (MCC) method. We validate the hub gene by differentially expressed gene analysis, overall survival analysis, and correlation analysis with clinical traits with the external dataset (TCGA). Finally, we explored the function of the hub gene by correlation analysis with targets of precise therapies and single-gene gene set enrichment analysis.

Results

We conducted WGCNA with the expression profiles of GSE73731 from GEO and divided all genes into 8 meaningful co-expression modules. One module is proved to be positively correlated with pathological stage and tumor grade of ccRCC. Genes in the ccRCC-related module were mainly enriched in functions of mitotic cell division and several proverbial tumor related signal pathways. We then identified KIF18B as a hub gene of the metastasis of ccRCC. Validating analyses in external dataset observed the up-regulation of KIF18B in ccRCC and its correlation with worse outcomes. Further analyses found that the expression of KIF18B is related to that of targets of precise therapies.

Conclusion

Our study proposed KIF18B as a hub candidate gene of ccRCC for the first time. Our conclusion may provide a brand-new clue for prognosis evaluating and precise treatment for ccRCC in the future.

The burden of kidney cancer and its attributable risk factors in 195 countries and territories, 1990-2017

Kidney cancer globally accounts for more than 131,000 deaths each year and has been found to place a large economic burden on society. However, there are no recent articles on the burden of kidney cancer across the world. The aim of this study was to present a status report on the incidence, mortality and disability-adjusted life years (DALYs) associated with kidney cancer in 195 countries, from 1990 to 2017. Vital registration and cancer registry data (total of 23,660 site-years) were used to generate the estimates. Mortality was estimated first and the incidence and DALYs were calculated based on the estimated mortality values. All estimates were presented as counts and age-standardised rates per 100,000 population. The estimated rates were calculated by age, sex and according to the Socio-Demographic Index (SDI). In 2017, kidney cancer accounted for 393.0 thousand (95% UI: 371.0-404.6) incident cases, 138.5 thousand (95% UI: 128.7-142.5) deaths and 3.3 million (95% UI: 3.1-3.4) DALYs globally. The global age-standardised rates for the incidence, deaths and DALY were 4.9 (95% UI: 4.7-5.1), 1.7 (95% UI: 1.6-1.8) and 41.1 (95% UI: 38.7-42.5), respectively. Uruguay [15.8 (95% UI: 13.6-19.0)] and Bangladesh [1.5 (95% UI: 1.0-1.8)] had highest and lowest age-standardised incidence rates, respectively. The age-standardised death rates varied substantially from 0.47 (95% UI: 0.34-0.58) in Bangladesh to 5.6 (95% UI: 4.6-6.1) in the Czech Republic. Incidence and mortality rates were higher among males, than females, across all age groups, with the highest rates for both sexes being observed in the 95+ age group. Generally, positive associations were found between each country's age-standardised DALY rate and their corresponding SDI. The considerable burden of kidney cancer was attributable to high body mass index (18.5%) and smoking (16.6%) in both sexes. There are large inter-country differences in the burden of kidney cancer and it is generally higher in countries with a high SDI. The findings from this study provide much needed information for those in each country that are making health-related decisions about priority areas, resource allocation, and the effectiveness of prevention programmes. The results of our study also highlight the need for renewed efforts to reduce exposure to the kidney cancer risk factors and to improve the prevention and the early detection of this disease.

Embolization of an Exophytic Posterior Neck Mass Secondary to a Cutaneous Renal Cell Carcinoma Metastasis

Renal cell carcinoma (RCC) commonly metastasizes to the lung, liver, bones, and brain; however, cutaneous metastases remain rare with few reported cases. Since RCCs have the propensity to metastasize to highly vascular areas, the scalp and skin of the head and neck region are likely locations for cutaneous metastases. We report a rare case of a large, exophytic, cauliflower-like, hemorrhagic, metastatic mass of the posterior neck. This is the first reported case of a head and neck cutaneous RCC metastasis treated with endovascular embolization prior to surgical resection. Due to the increased vascularity of RCCs and risk of excessive hemorrhage during resection, adjunctive embolization of cutaneous head and neck metastasis may have a role. Essential characteristics to our treatment strategy are discussed with a review of pertinent literature.

Association between tyrosine-kinase inhibitor induced hypertension and treatment outcomes in metastatic renal cancer

BACKGROUND

Tyrosine-kinase inhibitor (TKI) drugs have been considered first line treatment for metastatic renal cell cancer (RCC) for over a decade. TKI-induced hypertension is a common adverse-event in patients treated for metastatic RCC.

AIM

This study was aimed at investigating an association between TKI-induced hypertension and treatment outcomes for metastatic RCC patients.

METHODS AND RESULTS

Retrospective data pertaining to patients with histologically or radiologically confirmed metastatic RCC treated with sunitinib, pazopanib, sorafenib, axitinib or cabozantinib between June 2012 and May 2019 were evaluated. Clinical information and serial blood pressure measurements were extracted from medical records for each patient. We compared objective response rate, progression-free survival (PFS), and 12-month survival between TKI-induced hypertension (TIH) and non-TIH groups using χ² and Mann-Whitney tests. Out of 72 patients screened, 52 met study eligibility criteria. The median age at diagnosis was 61 years (range: 42-85 years) with a clear male predominance. The majority of patients had a history of nephrectomy with clear cell pathology. Almost all patients were on first-line TKI therapy with sunitinib or pazopanib. Median follow-up was 11 months. About half of patients developed TKI-induced hypertension (grade 2-3). In the TIH group 82% were commenced on an antihypertensive agent. Median PFS measured 30.5 weeks for TIH group compared to 22.2 weeks for non-TIH (P = .05). The 6 month and 12 month survival rates for TIH were 82% and 56%, respectively, as compared to 76% and 44% for non-TIH.

CONCLUSION

The occurrence of TKI-induced hypertension was found to be a positive prognostic factor for progression in patients with metastatic RCC.

Real-world use of temsirolimus in Japanese patients with unresectable or metastatic renal cell carcinoma: recent consideration based on the results of a post-marketing, all-case surveillance study

OBJECTIVE

A prospective, observational, post-marketing surveillance was conducted to assess the safety and effectiveness of temsirolimus in patients with renal cell carcinoma in Japan.

METHODS

Patients prescribed temsirolimus for advanced renal cell carcinoma were registered and received temsirolimus (25 mg weekly, intravenous infusion for 30-60 minutes) in routine clinical settings (observation period: 96 weeks).

RESULTS

Among 1001 patients included in the safety analysis data set (median age, 65.0 years; men, 74.8%; Eastern Cooperative Oncology Group performance status 0 or 1, 69.6%), 778 (77.7%) reported adverse drug reactions. The most common (≥10%) all-grade adverse drug reactions were stomatitis (26.7%), interstitial lung disease (17.3%) and platelet count decreased (11.1%). The incidence rate of grade ≥3 interstitial lung disease was 4.5%. The onset of interstitial lung disease was more frequent after 4-8 weeks of treatment or in patients with lower Eastern Cooperative Oncology Group performance status (21.6% for score 0 vs 8.3% for score 4, P < 0.001). Among 654 patients in the effectiveness analysis data set, the response and clinical benefit rates were 6.7% (95% confidence interval 4.9-8.9) and 53.2% (95% confidence interval 49.3-57.1), respectively. The median progression-free survival was 18.3 weeks (95% confidence interval 16.9-21.1).

CONCLUSIONS

The safety and effectiveness profile of temsirolimus observed in this study was similar to that observed in the multinational phase 3 study. The results are generalizable to the real-world scenario at the time of this research, and safety and effectiveness of temsirolimus as a subsequent anticancer therapy for renal cell carcinoma warrants further investigation. (ClinicalTrials.gov identifier NCT01210482, NCT01420601).

Saliva proteomic analysis reveals possible biomarkers of renal cell carcinoma

Early diagnosis is a key to improve the prognosis of renal cell carcinoma (RCC); however, reliable RCC biomarkers are lacking in clinical practice. In this study, we used isobaric tags for relative and absolute quantification-based mass spectrometry to identify salivary proteins as biomarkers for the diagnosis of RCC. The objective of this study is to discover biomarkers from saliva by utilizing high-throughput quantitative proteomics approaches. Saliva proteins from 124 RCC patients and healthy individuals were identified and quantified. RCC putative biomarkers were verified by real-time polymerase chain reaction or enzyme-linked immunosorbent assay in a prevalidation sample set. Seventy-one differentially expressed salivary proteins were identified. Serotransferrin, haptoglobin, KRT9, and S100A9, which in previous studies were found to be most closely related to cancers, were selected as putative RCC biomarkers. Haptoglobin and S100A9 were significantly elevated in RCC compared with healthy control samples, although the expression of serotransferrin and KRT9 did not differ between the groups. Furthermore, receiver operating characteristic curves with a cut-off value of 75.49 ng/mL for S100A9 revealed a sensitivity of 87.10% and a specificity of 91.94% for discriminating RCC patients from healthy individuals. Salivary haptoglobin differentiated RCC patients from healthy controls with a sensitivity of 85.48% and specificity of 80.65% (cut-off value 43.02 µg/mL). These results provide experimental evidence to support S100A9 and haptoglobin as potential novel, noninvasive biomarkers for the diagnosis of RCC.

The impact of insurance status on the survival outcomes of patients with renal cell carcinoma

Background

The impact of insurance status on renal cell carcinoma (RCC) patient survival is unclear. In this study, we investigated the effects of insurance status on the survival outcomes of RCC patients in the United States of America.

Methods

Data of patients diagnosed with RCC between 2007 and 2014 were obtained from the Surveillance, Epidemiology and End Results (SEER) database, a large national database including statistics on cancer patients. The Kaplan-Meier method and Cox regression analysis were used to determine the influence of insurance status on cancer-specific survival (CSS).

Results

A total of 30,951 eligible RCC patients were identified. Of these patients, 25,493 (82.37%) were insured, 3,959 (12.79%) had any Medicaid coverage, and 1,499 (4.84%) were uninsured. Kaplan-Meier analysis revealed that insurance status was associated with better CCS (P<0.001). The 5-year CSS rates of patients with insurance, any Medicaid, and no insurance were 88.3%, 82.6%, and 82.7%, respectively. Multivariate Cox regression analysis showed that patients with any Medicaid had poorer CSS than insured patients [hazard ratio (HR), 1.222; 95% confidence interval (CI), 1.100–1.357]. Stratified analysis revealed that at localized tumor stage and at regional tumor stage or among white patients, any Medicaid insurance was an independent predictor of an unfavorable survival outcome.

Conclusions

Among the RCC patients in this study, individuals with insurance experienced improved CSS while individuals with any Medicaid tended to suffer worse survival outcomes.

Mechanism of Vascular Toxicity in Rats Subjected to Treatment with a Tyrosine Kinase Inhibitor

Sunitinib (Su) is a tyrosine kinase inhibitor with antiangiogenic and antineoplastic effects that is recommended therapy for renal cell carcinoma, gastrointestinal stromal tumors, and pancreatic neuroendocrine tumors. Arterial hypertension is one of the adverse effects observed in the treatment with Su. The aim of this work was to deepen our understanding of the underlying mechanisms involved in the development of this side effect. Studies on endothelial function, vascular remodeling and nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) system were carried out in thoracic aortas from rats treated with Su for three weeks. Animals subjected to Su treatment presented with increased blood pressure and reduced endothelium-dependent vasodilation, the latter being reverted by NADPH oxidase blockade. Furthermore, vascular remodeling and stronger Masson trichrome staining, together with enhanced immunofluorescence signal for collagen 1 alpha 1 (Col1α1), were observed in aortas from treated animals. These results were accompanied by a significant elevation in superoxide anion production and the activity/protein/gene expression of NADPH oxidase isoforms (NOX1, NOX2, and NOX4), which was also prevented by NOX inhibition. Furthermore, a decrease in nitric oxide (NO) levels and endothelial nitric oxide synthase (eNOS) activation was observed in aortas from Su-treated animals. All these results indicate that endothelial dysfunction secondary to changes in vascular remodeling and oxidative stress might be responsible for the typical arterial hypertension that develops following treatment with Su.

Targeting NPL4 via drug repositioning using disulfiram for the treatment of clear cell renal cell carcinoma

The alcohol-abuse drug disulfiram has antitumor effects against diverse cancer types via inhibition of the ubiquitin-proteasome protein nuclear protein localization protein 4 (NPL4). However, the antitumor effects of NPL4 and disulfiram in clear cell renal cell carcinoma (ccRCC) are unclear. Here, we evaluated the therapeutic potential of targeting the ubiquitin-proteasome pathway using disulfiram and RNA interference and investigated the mechanisms underlying disulfiram in ccRCC. According to data from The Cancer Genome Atlas, NPL4 mRNA expression was significantly upregulated in clinical ccRCC samples compared with that in normal kidney samples, and patients with high NPL4 expression had poor overall survival compared with patients with low NPL4 expression. Disulfiram and NPL4 siRNA inhibited ccRCC cell proliferation in vitro, and disulfiram inhibited ccRCC tumor growth in a xenograft model. Synergistic antiproliferative effects were observed for combination treatment with disulfiram and sunitinib in vitro and in vivo. In RCC cells from mice treated with disulfiram and/or sunitinib, several genes associated with serine biosynthesis and aldose reductase were downregulated in cells treated with disulfiram or sunitinib alone and further downregulated in cells treated with both disulfiram and sunitinib. These findings provided insights into the mechanisms of disulfiram and suggested novel therapeutic strategies for RCC treatment.

Expression and Prognostic Significance of Cadherin 4 (CDH4) in Renal Cell Carcinoma

Background

Aberrant expression of cadherin family members and their possible biological function have been widely studied in renal cell carcinoma (RCC). However, the expression of cadherin 4 (CDH4) and its value in RCC diagnosis and prognosis remains elusive.

Material/Methods

The TCGA database was used to analyze the expression of CDH4 and its clinical parameters and prognosis in 891 RCC patients. In addition, real-time PCR was used to verify the transcription of CDH4 in renal clear cell carcinoma tissue, and the distribution of protein was observed by immunohistochemical staining.

Results

We found that the mRNA level of CDH4 was elevated in primary RCC in contrast with normal kidney samples using bioinformatics analysis based on the TCGA database. Among the 3 main subtypes of RCC, transcriptional CDH4 was significantly increased in KIRC and KIRP, while it was downregulated in KICH. Interestingly, CDH4 mRNA gradually decreased with the progression of KIRC and KIRP. The transcription of CDH4 in the primary tumor of KIRP patients at T3–T4 stages and KIRC patients with lymph node and distant metastasis were decreased significantly. Overall survival (OS) showed that KIRC and KICH patients with lower expression of CDH4 had worse outcomes.

Conclusions

The transcriptional level of CDH4 may serve as an effective diagnostic and prognostic biomarker for RCC patients.

A Review of Prostate-Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) in Renal Cell Carcinoma (RCC)

Metastatic renal cell carcinoma (mRCC) is a disease that portends poor prognosis despite an increasing number of novel systemic treatment options including new targeted therapies and immunotherapy. Ablative intervention directed at oligometastatic RCC has demonstrated survival benefit. Consequently, developing techniques for improved staging of mRCC on contemporary imaging modalities including X-ray computed tomography (CT), magnetic resonance imaging (MRI) and/or bone scan (BS) is a clinical priority. This is relevant for metastatic deposits too small to characterize or lymph nodes within physiological normality. Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein highly expressed on prostate cancer epithelial cells. Recently, small molecules targeting the PSMA receptor, linked to radioactive isotopes have been developed for use with positron emission tomography (PET). Despite its nomenclature, PSMA has also been found to be expressed in the neovasculature of non-prostate cancers such as renal cell carcinoma (RCC) and hence PSMA PET/CT imaging has been proposed as an alternative staging modality. Preliminary small studies involving the use of PSMA PET/CT imaging in mRCC have been encouraging with evidence of improved staging sensitivity which has directly led to change in management in some cases. Given these early encouraging reports, we performed a comprehensive narrative review on the available evidence, including the scientific basis for PSMA expression in RCC, the role of PSMA PET/CT imaging with potential clinical implications in mRCC, its limitations and future opportunities.

Development and validation of an individualized DNA repair-related gene signature in localized clear cell renal cell carcinoma

BACKGROUND

To establish a robust, individualized DNA repair-related gene signature to estimate prognosis for patients with localized clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

We retrospectively analyzed gene expression profiles of 541 localized ccRCC patients from two public ccRCC cohorts. The DNA repair-related gene pair index (DRPI) was constructed with the least absolute shrinkage and selection operator (LASSO) regression model. The associations between DRPI, overall survival (OS), and disease-specific survival (DSS) were evaluated by Kaplan-Meier analysis, univariate analysis, and multivariate Cox regression survival analysis. We compared the predictive accuracy of different risk models with Harrel's C-index.

RESULTS

In the primary univariate analysis, patients in DRPI-high-risk group had significantly shorter OS [P < 0.001, HR (95% CI) 2.093 (1.431-3.061)] and DSS [P < 0.001, HR (95% CI) 3.567 (2.017-6.339)]. After adjusted for stage and grade, DRPI-high-risk group remained an independent adverse risk factor for both OS [P = 0.026, HR (95% CI) 1.629 (1.094-2.452)] and DSS [P = 0.010, HR (95% CI) 2.209 (1.217-4.010)]. DPRI showed comparable predictive accuracy with cell cycle proliferation (CCP) score and ccA/ccB signature. Copy number alterations and tumor mutation burden were enriched in DRPI-high tumors. There were elevated number of Treg cells and higher T cell exhaustion marker expression in DRPI-high-risk tumors. The combined DNA repair-clinical score outperformed other risk models in terms of C-index.

CONCLUSION

We validated the proposed DRPI as a predictor of clinical outcome in localized ccRCC patients. It provides an individualized and more accurate risk assessment beyond clinicopathological characteristics.

The prevalence and prognostic and clinicopathological value of PD-L1 and PD-L2 in renal cell carcinoma patients: a systematic review and meta-analysis involving 3,389 patients

Background

The research of the prognostic and clinicopathologic values of programmed cell death ligand 1/2 (PD-L1/2) in renal cell carcinoma (RCC) patients has been mired by a dearth of studies and considerable controversy. We thus conducted a systematic review and meta-analysis to report the prevalence and prognostic and clinicopathological value of programmed cell death ligand 1 (PD-L1) and programmed cell death-legend 2 (PD-L2) in RCC patients.

Methods

The PubMed, Cochrane Library, EMBASE databases were searched to find human studies limited to English language literature published through October 1, 2019. Using random or fixed effects models, hazard ratios (HRs) and 95% confidence intervals (CIs) were evaluated to explore the prognostic value of PD-Ls expression, while odds ratios (ORs) and 95% CIs were evaluated to investigate clinicopathological parameters. The protocol of the study was registered in PROSPERO (CRD42019135199).

Results

After pooling all 16 eligible studies comprising 3,389 patients, we found that the overall prevalence of PD-L1 and PD-L2 in RCC patients was 27% and 39%, respectively. Furthermore, PD-L1 over-expression was a strong negative predictor for overall survival (OS), disease-free survival/progression-free survival (DFS/PFS), and cancer-specific survival (CSS) in renal cell carcinoma patients (HR =2.86, 95% CI: 1.83–4.47, P<0.001; HR =2.64, 95% CI: 1.99–3.52, P<0.001; HR =2.78, 95% CI: 2.17–3.56, P<0.001). Meanwhile, PD-L2 over-expression was only a weak negative predictor for CSS (HR =1.66, 95% CI: 1.05–2.65, P<0.05). Subgroup analysis showed that Caucasians had worse OS (HR =3.60, 95% CI: 1.77–7.33, P<0.001), PFS (HR =3.56, 95% CI: 2.44–5.18, P<0.001), and CSS (HR =3.13, 95% CI: 2.37–4.14, P<0.001) than Asians. PD-L1 was a strong indicator for worse prognosis (P<0.05 for all), while PD-L2 over-expression was only associated with sarcomatoid features (presence vs. absence, OR =1.80, 95% CI: 1.13–2.86, P=0.014). Notably, PD-L1 overexpression was more prevalent in women (male vs. female, OR =0.68, 95% CI: 0.51–0.90, P=0.006).

Conclusions

Higher PD-L1 expression is more closely associated with poor prognosis and more advanced clinicopathological features in RCC patients than PD-L2, especially in women and Caucasian patients. PD-L2 was a weak negative predictor of poor CSS of RCC and was not a prompt for the metastasis of RCC.

Simultaneous versus staged partial nephrectomies for bilateral synchronous solid renal masses

OBJECTIVES

The optimal management approach for synchronous bilateral renal masses is unknown, particularly regarding surgical sequencing of bilateral partial nephrectomy (PN). We evaluated the impact of simultaneous vs. staged bilateral PN on renal functional, perioperative, and oncologic outcomes.

PATIENTS AND METHODS

We reviewed our institutional nephrectomy registry to identify patients who underwent simultaneous or staged (within 6 months) bilateral PN for nonmetastatic bilateral synchronous solid renal masses between 1980 and 2015. Short-term and long-term renal function changes were assessed at 3 and 12 months, respectively. Perioperative outcomes were pooled across staged surgeries by taking the sum of each outcome. Local recurrence-free, distant metastases-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier method. Outcomes were compared by surgical sequencing approach. A sensitivity analysis was performed that grouped approaches by preoperative intent.

RESULTS

Among the 107 patients studied, 77 (72%) underwent simultaneous and 30 (28%) underwent staged PN. The majority of PN were performed by open approach. Clinicopathologic features were similar between groups. Patients who underwent simultaneous PN had lower mean short-term (-6% vs. -24%, P = 0.015) and median long-term (-4% vs. -22%, P < 0.001) reduction in eGFR vs. staged PN, respectively. Furthermore, patients with simultaneous PN had lower pooled length of stay (median 6 vs. 8 days, P < 0.001), rate of urine leak (3% vs. 17%, P = 0.018), and rate of high-grade complications (8% vs. 23%, P = 0.044), relative to staged PN, respectively. However, on sensitivity analysis, only differences in long term reduction in estimated glomerular filtration rate and length of stay remained. There were no significant differences in oncologic outcomes between groups.

CONCLUSIONS

Our results suggest that when technically feasible, simultaneous PN yields comparable outcomes vs. staged PN, offering a reasonable surgical sequencing approach for patients presenting with bilateral synchronous renal masses.

Oncogenic effects of RAB27B through exosome independent function in renal cell carcinoma including sunitinib-resistant

Exosomes are 40–100 nm nano-sized extracellular vesicles. They are released from many cell types and move into the extracellular space, thereby transferring their components to recipient cells. Exosomes are receiving increasing attention as novel structures participating in intracellular communication. RAB27B is one of the leading proteins involved in exosome secretion, and oncogenic effects have been reported in several cancers. In recent years, molecularly targeted agents typified by sunitinib are widely used for the treatment of metastatic or recurrent renal cell carcinoma (RCC). However, intrinsic or acquired resistance to sunitinib has become a major issue. The present study aimed to elucidate the role of RAB27B in RCC including sunitinib-resistant and its role in exosomes. Bioinformatic analyses revealed that high expression of RAB27B correlates with progression of RCC. The expression of RAB27B protein in RCC cell lines was significantly enhanced compared with that in normal kidney cell lines. Furthermore, RAB27B protein expression was enhanced in all of the tested sunitinib-resistant RCC cell lines compared to parental cells. Although no specific effect of RAB27B on exosomes was identified in RCC cells, loss-of-function studies demonstrated that knockdown of RAB27B suppressed cell proliferation, migration and invasive activities. Moreover, anti-tumor effects of RAB27B downregulation were also observed in sunitinib-resistant RCC cells. RNA sequence and pathway analysis suggested that the oncogenic effects of RAB27B might be associated with MAPK and VEGF signaling pathways. These results showed that RAB27B is a prognostic marker and a novel therapeutic target in sunitinib-sensitive and -resistant RCCs. Further analyses should improve our understanding of sunitinib resistance in RCC.