Comparisons of outcome and prognostic features among histologic subtypes of renal cell carcinoma

A cluster of long non-coding RNAs exhibit diagnostic and prognostic values in renal cell carcinoma

Kidney cancer ranked in the top 10 for both men and women in the estimated numbers of new cancer cases in the United States in 2018. Targeted therapies have recently been administered to patients with clear cell renal cell carcinoma (ccRCC), but the overall survival of patients at the terminal stage of the disease has not been as good as expected. It is therefore necessary to uncover efficient biomarkers for early diagnosis, and to clarify the molecular mechanisms underlying ccRCC progression and metastasis. Increased evidence has shown that long non-coding RNAs (lncRNAs) play important roles during tumor progression. In this study, 10 candidate lncRNAs with diagnostic and prognostic values in ccRCC were identified: IGFL2-AS1, AC023043.1, AP000439.2, AC124854.1, AL355102.4, TMEM246-AS1, AL133467.3, ZNF582-AS1, LINC01510 and PSMG3-AS1. Enrichment analysis revealed metabolic and functional pathways, which may be closely associated with kidney cancer tumorigenesis. Six representative processes were summarized, namely glycolysis, amino acid metabolism, lipid synthesis, reductive carboxylation, nucleotide metabolism, transmembrane transport and signal transduction. In combination, the present results provided prognostic and diagnostic biomarkers for ccRCC and might pave the way for targeted intervention and molecular therapies in the future.

Racial/ethnic disparities in renal cell carcinoma: Increased risk of early-onset and variation in histologic subtypes

BACKGROUND

Racial/ethnic minority groups have a higher burden of renal cell carcinoma (RCC), but RCC among Hispanic Americans (HAs) and American Indians and Alaska Natives (AIs/ANs) are clinically not well characterized. We explored variations in age at diagnosis and frequencies of RCC histologic subtypes across racial/ethnic groups and Hispanic subgroups using National Cancer Database (NCDB) and Arizona Cancer Registry Data.

METHODS

Adult RCC cases with known race/ethnicity were included. Logistic regression analysis was performed to estimate odds and 95% confidence interval (CI) of early-onset (age at diagnosis <50 years) and diagnosis with clear cell RCC (ccRCC) or papillary RCC.

RESULTS

A total of 405 073 RCC cases from NCDB and 9751 cases from ACR were identified and included. In both datasets, patients from racial/ethnic minority groups had a younger age at diagnosis than non-Hispanic White (NHW) patients. In the NCDB, AIs/ANs had twofold increased odds (OR, 2.21; 95% CI, 1.88-2.59) of early-onset RCC compared with NHWs. HAs also had twofold increased odds of early-onset RCC (OR, 2.14; 95% CI, 1.79-2.55) in the ACR. In NCDB, ccRCC was more prevalent in AIs (86.3%) and Mexican Americans (83.5%) than NHWs (72.5%). AIs/ANs had twofold increased odds of diagnosis with ccRCC (OR, 2.18; 95% CI, 1.85-2.58) in the NCDB, but the association was stronger in the ACR (OR, 2.83; 95% CI, 2.08-3.85). Similarly, Mexican Americans had significantly increased odds of diagnosis with ccRCC (OR, 2.00; 95% CI, 1.78-2.23) in the NCDB.

CONCLUSIONS

This study reports younger age at diagnosis and higher frequencies of ccRCC histologic subtype in AIs/ANs and Hispanic subgroups. These variations across racial/ethnic groups and Hispanic subgroups may have potential clinical implications.

LC-MS based metabolomic profiling for renal cell carcinoma histologic subtypes

Renal cell carcinomas (RCC) are classified according to their histological features. Accurate classification of RCC and comprehensive understanding of their metabolic dysregulation are of critical importance. Here we investigate the use of metabolomic analyses to classify the main RCC subtypes and to describe the metabolic variation for each subtype. To this end, we performed metabolomic profiling of 65 RCC frozen samples (40 clear cell, 14 papillary and 11 chromophobe) using liquid chromatography-mass spectrometry. OPLS-DA multivariate analysis based on metabolomic data showed clear discrimination of all three main subtypes of RCC (R² = 75.0%, Q² = 59.7%). The prognostic performance was evaluated using an independent cohort and showed an AUROC of 0.924, 0.991 and 1 for clear cell, papillary and chromophobe RCC, respectively. Further pathway analysis using the 21 top metabolites showed significant differences in amino acid and fatty acid metabolism between three RCC subtypes. In conclusion, this study shows that metabolomic profiling could serve as a tool that is complementary to histology for RCC subtype classification. An overview of metabolic dysregulation in RCC subtypes was established giving new insights into the understanding of their clinical behaviour and for the development of targeted therapeutic strategies.

Radiologic-Radiomic Machine Learning Models for Differentiation of Benign and Malignant Solid Renal Masses: Comparison With Expert-Level Radiologists

OBJECTIVE. The objective of our study was to compare the performance of radiologicradiomic machine learning (ML) models and expert-level radiologists for differentiation of benign and malignant solid renal masses using contrast-enhanced CT examinations. MATERIALS AND METHODS. This retrospective study included a cohort of 254 renal cell carcinomas (RCCs) (190 clear cell RCCs [ccRCCs], 38 chromophobe RCCs [chrRCCs], and 26 papillary RCCs [pRCCs]), 26 fat-poor angioleiomyolipomas, and 10 oncocytomas with preoperative CT examinations. Lesions identified by four expert-level radiologists (> 3000 genitourinary CT and MRI studies) were manually segmented for radiologicradiomic analysis. Disease-specific support vector machine radiologic-radiomic ML models for classification of renal masses were trained and validated using a 10-fold cross-validation. Performance values for the expert-level radiologists and radiologic-radiomic ML models were compared using the McNemar test. RESULTS. The performance values for the four radiologists were as follows: sensitivity of 73.7-96.8% (median, 84.5%; variance, 122.7%) and specificity of 48.4-71.9% (median, 61.8%; variance, 161.6%) for differentiating ccRCCs from pRCCs and chrRCCs; sensitivity of 73.7-96.8% (median, 84.5%; variance, 122.7%) and specificity of 52.8-88.9% for differentiating ccRCCs from fat-poor angioleiomyolipomas and oncocytomas (median, 80.6%; variance, 269.1%); and sensitivity of 28.1-60.9% (median, 84.5%; variance, 122.7%) and specificity of 75.0-88.9% for differentiating pRCCs and chrRCCs from fat-poor angioleiomyolipomas and oncocytomas (median, 50.0%; variance, 191.1%). After a 10-fold cross-validation, the radiologic-radiomic ML model yielded the following performance values for differentiating ccRCCs from pRCCs and chrRCCs, ccRCCs from fat-poor angioleiomyolipomas and oncocytomas, and pRCCs and chrRCCs from fat-poor angioleiomyolipomas and oncocytomas: a sensitivity of 90.0%, 86.3%, and 73.4% and a specificity of 89.1%, 83.3%, and 91.7%, respectively. CONCLUSION. Expert-level radiologists had obviously large variances in performance for differentiating benign from malignant solid renal masses. Radiologic-radiomic ML can be a potential way to improve interreader concordance and performance.

Molecular characterization and diagnostic criteria of renal cell carcinoma with emphasis on liquid biopsies

Introduction: Over the past 6 years, important genomic and transcriptomic studies performed on RCC reported a comprehensive molecular description of RCC pathogenic alterations. Such molecular findings pave the way for an integrated classification, based on histopathology aspects and molecular alterations in order to personalize the clinical management of RCC.Areas covered: The aim of this review is to evaluate the current knowledge and the potential value of liquid biopsy in RCC. Studies on presence and analysis of circulating tumor DNA (ctDNA), circulating RNA, specific microRNA, long non-coding RNA, and circulating tumor cells are reported for each phase of disease, from the diagnostic setting to the localized disease and, lastly, in the metastatic stage.Expert opinion: Advantages of liquid biopsies compared to serial tissue sampling are numerous. However, some limitations must be addressed before considering liquid biopsy as a noninvasive biomarker of clinical utility. The suboptimal sensitivity depends on the assessment technique and genetic platforms used, the tumor organ, the tumor stage, tumor heterogeneity, and clonality. The rate of discordance with tumor tissue genotyping may depends on temporal heterogeneity, spatial heterogeneity, and/or assay error (false-negative or false-positive genotyping).

Allele Loss and Reduced Expression of CYCLOPS Genes is a Characteristic Feature of Chromophobe Renal Cell Carcinoma

Copy-number alterations Yielding Cancer Liabilities Owing to Partial losS (CYCLOPS) genes have been recently identified as the most enriched class of copy-number associated gene dependencies in human cancer. These genes are cell essential and render tumor cells highly sensitive to the expression of the remaining copy. Chromophobe renal cell carcinoma (chRCC) is characterized by frequent chromosomal deletions, but the relevance of CYCLOPS genes in this tumor subtype is unclear. We found 39 (31%) of 124 recently published candidate CYCLOPS genes (B. Paolella et al., eLife 2017;6:e23268) located on 7 autosomes that are frequently lost in chRCC. GISTIC and RNA-seq data obtained from the TCGA-KICH database showed that 62% of these CYCLOPS genes had significantly lower expression levels in samples with deletion of the respective gene. As copy number (CN) loss of the CYCLOPS gene SF3B1 (Splicing factor 3B subunit 1) has been recently reported in 71% chRCC, we explored the relevance of SF3B1 CN alteration and SF3B1 expression in a set of chRCC and additional oncocytic renal neoplasms. The frequency of SF3B1 CN loss (65%) was similar to that obtained from the TCGA-KICH database and correlated significantly with both lower SF3B1 mRNA (P < .05) and protein expression (P < .001). Other tumor subtypes with oncocytic cytoplasm had normal SF3B1 CN and displayed strong SF3B1 protein expression. These results suggest that CN loss of CYCLOPS genes is a characteristic feature in chRCC. Since many CYCLOPS genes code for components of proteasomes and transcriptional regulation, their alteration could make chRCC vulnerable to targeted drugs.

Can MRI be used to diagnose histologic grade in T1a (< 4 cm) clear cell renal cell carcinomas?

OBJECTIVE

To assess whether MRI can differentiate low-grade from high-grade T1a cc-RCC.

MATERIALS AND METHODS

With IRB approval, 49 consecutive solid < 4 cm cc-RCC (low grade [Grade 1 or 2] N = 38, high grade [Grade 3] N = 11) with pre-operative MRI before nephrectomy were identified between 2013 and 2018. Tumor size, apparent diffusion coefficient (ADC) histogram analysis, enhancement wash-in and wash-out rates, and chemical shift signal intensity index (SI index) were assessed by a blinded radiologist. Subjectively, two blinded Radiologists also assessed for (1) microscopic fat, (2) homogeneity (5-point Likert scale), and (3) ADC signal (relative to renal cortex); discrepancies were resolved by consensus. Outcomes were studied using Chi square, multivariate analysis, logistic regression modeling, and ROC. Inter-observer agreement was assessed using Cohen's kappa.

RESULTS

Tumor size was 24 ± 7 (13-39) mm with no association to grade (p = 0.45). Among quantitative features studied, corticomedullary phase wash-in index (p = 0.015), SI index (p = 0.137), and tenth-centile ADC (p = 0.049) were higher in low-grade tumors. 36.8% (14/38) low-grade tumors versus zero high-grade tumors demonstrated microscopic fat (p = 0.015; Kappa = 0.67). Microscopic fat was specific for low-grade disease (100.0% [71.5-100.0]) with low sensitivity (36.8% [21.8-54.6]). Other subjective features did not differ between groups (p > 0.05). A logistic regression model combining microscopic fat + wash-in index + tenth-centile-ADC yielded area under ROC curve 0.98 (Confidence Intervals 0.94-1.0) with sensitivity/specificity 87.5%/100%.

CONCLUSION

The combination of microscopic fat, higher corticomedullary phase wash-in and higher tenth-centile ADC is highly accurate for diagnosis of low-grade disease among T1a clear cell RCC.

A long non-coding RNA signature to improve prognostic prediction in clear cell renal cell carcinoma

BACKGROUND

Accumulating research reports have indicated that long non-coding RNAs (lncRNAs) are abnormally expressed in many types of cancers. However, few lncRNA signatures for predicting cancer prognosis have been established. Our goal is to establish a lncRNA signature for predicting the prognosis of clear cell renal cell carcinoma (ccRCC).

METHODS

We downloaded KIRC lncRNA FPKM (Fragments Per Kilobase of transcript per Million Fragments) standardized expression data from The Cancer Genome Atlas (TCGA) by using the TANRIC tool. We established an 11-lncRNA signature that was clearly linked to the overall survival (OS) rates in the training and test sets.

RESULTS

The training set was divided into the high-risk and low-risk subgroups, between which the OS was disparate (HR = 1.51, 95%CI = 1.39-1.64, P < 0.0001). The accuracy of the 11-lncRNA signature for predicting prognosis was confirmed in the test set. Further analysis revealed that the prognostic value of this signature was independent of the neoplasm grade and TNM stage. Gene set enrichment analysis (GSEA) was performed, and a summary of 4 gene sets related to canonical pathway, biological process, molecular function and cellular component was obtained. We demonstrated the biological function of these lncRNAs in ccRCC cell lines and found that LINC00488 and HOTTIP promoted tumour proliferation and inhibited apoptosis. However, LINC-PINT had the opposite effect.

CONCLUSIONS

The establishment of the 11-lncRNA signature indicated the underlying biochemical functional roles of the selected lncRNAs in ccRCC. Our results may provide a reliable theoretical basis for clinical evaluation of ccRCC prognosis.

Dataset for the reporting of renal biopsy for tumour: recommendations from the International Collaboration on Cancer Reporting (ICCR)

The International Collaboration on Cancer Reporting (ICCR) has developed a suite of detailed datasets for international implementation. These datasets are based on the reporting protocols developed by the Royal College of Pathologists (UK), The Royal College of Pathologists of Australasia and the College of American Pathologists, with modifications undertaken by international expert groups appointed according to ICCR protocols. The dataset for the reporting of renal biopsy for tumour is designed to provide a structured reporting template containing minimum data recording key elements suitable for international use. In formulating the dataset, the ICCR panel incorporated recommendations from the 2012 Vancouver Consensus Conference of the International Society of Urological Pathology (ISUP) and the 2016 edition of the WHO Bluebook on tumours of the urinary and male genital systems. Reporting elements were divided into Required (Core) and Recommended (Non-core) components of the report. Required elements are as follows: specimen laterality, histological tumour type, WHO/ISUP histological tumour grade, sarcomatoid morphology, rhabdoid morphology, necrosis, lymphovascular invasion and coexisting pathology in non-neoplastic kidney. Recommended reporting elements are as follows: operative procedure, tumour site(s), histological tumour subtype and details of ancillary studies. In particular, it is noted that fluorescence in situ hybridisation studies may assist in diagnosing translocation renal cell carcinoma (RCC) and in distinguishing oncocytoma and eosinophilic chromophobe RCC. It is anticipated that the implementation of this dataset into routine clinical practice will facilitate uniformity of pathology reporting worldwide. This, in turn, should have a positive impact on patient treatment and the quality of demographic information held by cancer registries.

Diabetes and kidney cancer survival in patients undergoing nephrectomy: A Canadian multi-center, propensity score analysis

INTRODUCTION

Diabetes has been associated with worse survival outcomes in various malignancies; however, there are conflicting data in kidney cancer. Determining whether diabetes is associated with survival in kidney cancer may help guide treatment in a comorbid patient population.

METHODS

We used the Canadian Kidney Cancer information system database to identify patients undergoing partial or radical nephrectomy between 1989 and 2017 for localized renal cell carcinoma at 16 institutions across Canada. We derived inverse probability of treatment weights (IPTW) from a propensity score model based on various clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between diabetes and cancer-specific and overall survival, in the sample weighted by the IPTW.

RESULTS

4828 patients met inclusion criteria, of whom 948 (19.6%) were diabetic. Median follow-up in those without death was 26.6 months (interquartile range 9.7-53.8). Among the entire cohort, 901 deaths were from any cause, and 299 deaths from kidney cancer. Before propensity score methods, diabetics were older, more likely to have comorbidities and clear cell histopathology. After propensity score adjustment, all characteristics were balanced between groups (standardized difference <0.10). IPTW-adjusted Cox proportional hazard models demonstrated no significant association between diabetes and cancer-specific (hazard ratio 1.13, 95% confidence interval 0.78-1.62), or overall survival (hazard ratio 1.14, 95% confidence interval 0.94-1.38).

CONCLUSIONS

Our multi-centre study found that diabetes and nondiabetics have similar survival following nephrectomy for kidney cancer.

CT-based machine learning model to predict the Fuhrman nuclear grade of clear cell renal cell carcinoma

PURPOSE

To predict the Fuhrman grade of clear cell renal cell carcinoma (ccRCC) with a machine learning classifier based on single- or three-phase computed tomography (CT) images.

MATERIALS AND METHODS

Patients with pathologically proven ccRCC from February 1, 2009 to September 31, 2018 who were not treated were retrospectively collected for machine learning-based analysis. The texture features were extracted and ranked from precontrast phase (PCP), corticomedullary phase (CMP), nephrographic phase (NP) and three-phase CT images, and open-source gradient boosting from the decision tree library of CatBoost was used to establish a machine learning classifier to differentiate low- from high-grade ccRCC. The performances of machine learning classifiers based on features from single- and three-phase CT images were compared with each other.

RESULTS

A total of 231 patients with 232 pathologically proven ccRCC lesions were retrospectively collected. 35, 36, 41, and 22 Features were extracted and ranked from PCP, CMP, NP, and three-phase CT images, respectively. The machine learning model based on three-phase CT images [area under the ROC curve (AUC) = 0.87] achieved the best diagnostic performance for differentiating low- from high-grade ccRCC, followed by single-phase NP (AUC = 0.84), CMP (AUC = 0.80), and PCP images (AUC = 0.82).

CONCLUSION

Machine learning classifiers can be promising noninvasive techniques to differentiate low- and high-Fuhrman nuclear grade ccRCC, and classifiers based on three-phase CT images are superior to those based on features from each single phase.

Use of quantitative T2 mapping for the assessment of renal cell carcinomas: first results

Background

Correct staging and grading of patients with clear cell renal cell carcinoma (cRCC) is of clinical relevance for the prediction of operability and for individualized patient management. As partial or radial resection with postoperative tumor grading currently remain the methods of choice for the classification of cRCC, non-invasive preoperative alternatives to differentiate lower grade from higher grade cRCC would be beneficial.

Methods

This institutional-review-board approved cross-sectional study included twenty-seven patients (8 women, mean age ± SD, 61.3 ± 14.2) with histopathologically confirmed cRCC, graded according to the International Society of Urological Pathology (ISUP). A native, balanced steady-state free precession T2 mapping sequence (TrueFISP) was performed at 1.5 T. Quantitative T2 values were measured with circular 2D ROIs in the solid tumor portion and also in the normal renal parenchyma (cortex and medulla). To estimate the optimal cut-off T2 value for identifying lower grade cRCC, a Receiver Operating Characteristic Curve (ROC) analysis was performed and sensitivity and specificity were calculated. Students’ t-tests were used to evaluate the differences in mean values for continuous variables, while intergroup differences were tested for significance with two-tailed Mann-Whitney-U tests.

Results

There were significant differences between the T2 values for lower grade (ISUP 1–2) and higher grade (ISUP 3–4) cRCC (p < 0.001), with higher T2 values for lower grade cRCC compared to higher grade cRCC. The sensitivity and specificity for the differentiation of lower grade from higher grade tumors were 83.3% (95% CI: 0.59–0.96) and 88.9% (95% CI: 0.52–1.00), respectively, using a threshold value of ≥110 ms. Intraobserver/interobserver agreement for T2 measurements was excellent/substantial.

Conclusions

Native T2 mapping based on a balanced steady-state free precession MR sequence might support an image-based distinction between lower and higher grade cRCC in a two-tier-system and could be a helpful addition to multiparametric imaging.

Electronic supplementary material

The online version of this article (10.1186/s40644-019-0222-8) contains supplementary material, which is available to authorized users.

Clinicopathological and survival analysis of clinically advanced papillary and chromophobe renal cell carcinoma

INTRODUCTION

Clinically, the papillary (pRCC) and chromophobe (chRCC) histologic subtypes of renal cell carcinoma (RCC) are viewed as more indolent compared to the more-common clear cell histology (ccRCC). However, there remain advanced cases of these purportedly less-aggressive histologies that lead to significant mortality. We therefore sought to evaluate outcomes of advanced pRCC and chRCC compared to ccRCC utilizing the National Cancer Database's registry of RCC patients.

MATERIALS AND METHODS

A total of 115,365 ccRCC patients, 28,344 pRCC patients, and 11,942 chRCC patients met eligibility criteria. Overall survival (OS) was estimated using the Kaplan-Meier method (median follow-up 3.6 years). OS was compared between stage III and IV ccRCC, pRCC, and chRCC using multivariable Cox proportional hazards model adjusted for clinical and treatment characteristics.

RESULTS

A total of 25.7% of ccRCC patients, 14.1% of pRCC patients, and 14.8% of chRCC patients had stage III to IV disease. The 5-year OS for stage III ccRCC, pRCC, and chRCC was 66.9%, 63.6%, and 80.5%, respectively. The 5-year OS for stage IV ccRCC, pRCC and chRCC was 19.7%, 13.3%, and 22.0%, respectively. The hazard of death was significantly higher for stage IV pRCC vs. ccRCC (hazard ratio = 1.29; 95% confidence interval = 1.19, 1.39; P < 0.01) and similar for stage IV chRCC vs. ccRCC (hazard ratio = 1.01; 95% confidence interval = 0.85, 1.21; P = 0.885).

CONCLUSIONS

pRCC and chRCC are rare but similarly fatal compared to ccRCC when advanced or metastatic. With most clinical trials devoted toward ccRCC, greater efforts to identify aggressive variants and treatment strategies for metastatic pRCC and chRCC are necessary.

Gamma-Glutamyltransferase 1 Promotes Clear Cell Renal Cell Carcinoma Initiation and Progression

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. While the localized form of this disease can be treated surgically, advanced and metastatic stages are resistant to chemotherapies. Although more innovative treatments, such as targeted or immune-based therapies, exist, the need for new therapeutic options remains. ccRCC presents unique metabolic signatures and multiple studies have reported a significant increase in levels of reduced glutathione (GSH) and its precursors in ccRCC tumor samples compared with normal kidney tissues. These observations led us to investigate the effects of blocking the GSH pathway, particularly the gamma-glutamyltransferase 1 (GGT1) enzyme, in multiple ccRCC cell lines. In this study, we provide in vitro and in vivo evidence that GGT1/GSH pathway inhibition impacts ccRCC cell growth, through increased cell-cycle arrest. Of note, GGT1 inhibition also impairs ccRCC cell migration. Finally, pharmacologic GSH pathway inhibition decreases ccRCC cell proliferation and increases sensitivity to standard chemotherapy. Our results suggest that GGT1/GSH pathway inhibition represents a new strategy to overcome ccRCC chemoresistance. IMPLICATIONS: GGT1/GSH pathway inhibition represents a promising therapeutic strategy to overcome chemoresistance and inhibit progression of ccRCC tumors.

CT texture analysis in the differentiation of major renal cell carcinoma subtypes and correlation with Fuhrman grade

OBJECTIVE

CT texture analysis (CTTA) using filtration-histogram-based parameters has been associated with tumor biologic correlates such as glucose metabolism, hypoxia, and tumor angiogenesis. We investigated the utility of these parameters for differentiation of clear cell from papillary renal cancers and prediction of Fuhrman grade.

METHODS

A retrospective study was performed by applying CTTA to pretreatment contrast-enhanced CT scans in 290 patients with 298 histopathologically confirmed renal cell cancers of clear cell and papillary types. The largest cross section of the tumor on portal venous phase axial CT was chosen to draw a region of interest. CTTA comprised of an initial filtration step to extract features of different sizes (fine, medium, coarse spatial scales) followed by texture quantification using histogram analysis.

RESULTS

A significant increase in entropy with fine and medium spatial filters was demonstrated in clear cell RCC (p = 0.047 and 0.033, respectively). Area under the ROC curve of entropy at fine and medium spatial filters was 0.804 and 0.841, respectively. An increased entropy value at coarse filter correlated with high Fuhrman grade tumors (p = 0.01). The other texture parameters were not found to be useful.

CONCLUSION

Entropy, which is a quantitative measure of heterogeneity, is increased in clear cell renal cancers. High entropy is also associated with high-grade renal cancers. This parameter may be considered as a supplementary marker when determining aggressiveness of therapy.

KEY POINTS

• CT texture analysis is easy to perform on contrast-enhanced CT. • CT texture analysis may help to separate different types of renal cancers. • CT texture analysis may enhance individualized treatment of renal cancers.

Data set for the reporting of carcinoma of renal tubular origin: recommendations from the International Collaboration on Cancer Reporting (ICCR)

AIMS

The International Collaboration on Cancer Reporting (ICCR) has provided detailed data sets based upon the published reporting protocols of the Royal College of Pathologists, the Royal College of Pathologists of Australasia and the College of American Pathologists.

METHODS AND RESULTS

The data set for carcinomas of renal tubular origin treated by nephrectomy was developed to provide a minimum structured reporting template suitable for international use, and incorporated recommendations from the 2012 Vancouver Consensus Conference of the International Society of Urological Pathology (ISUP) and the fourth edition of the World Health Organisation Bluebook on tumours of the urinary and male genital systems published in 2016. Reporting elements were divided into those, which are required and recommended components of the report. Required elements are: specimen laterality, operative procedure, attached structures, tumour focality, tumour dimension, tumour type, WHO/ISUP grade, sarcomatoid/rhabdoid morphology, tumour necrosis, extent of invasion, lymph node status, surgical margin status, AJCC TNM staging and co-existing pathology. Recommended reporting elements are: pre-operative treatment, details of tissue removed for experimental purposes prior to submission, site of tumour(s) block identification key, extent of sarcomatoid and/or rhabdoid component, extent of necrosis, presence of tumour in renal vein wall, lymphovascular invasion and lymph node status (size of largest focus and extranodal extension).

CONCLUSIONS

It is anticipated that the implementation of this data set in routine clinical practice will inform patient treatment as well as provide standardised information relating to outcome prediction. The harmonisation of data reporting should also facilitate international research collaborations.

Mucinous Tubular and Spindle-Cell Carcinoma of the Kidney: Clinical Features, Genomic Profiles, and Treatment Outcomes

BACKGROUND

Mucinous tubular and spindle-cell carcinoma (MTSCC) is a rare kidney cancer subtype with limited cases reported in the literature. We report on outcomes of 25 patients with this variant who were managed at our institution.

MATERIALS AND METHODS

The institution database was queried, and clinical data extracted for patients with MTSCC. Molecular features examined included next-generation sequencing with Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets and allele-specific copy number analysis using the Fraction and Allele-Specific Copy Number Estimates from Tumor Sequencing (FACETS) algorithm in a subset of patients.

RESULTS

All patients underwent primary tumor-directed therapy (nephrectomy = 23, cryoablation = 2). Metastases were diagnosed in 6 patients (24%), 3 (12%) of whom had de novo metastatic disease. Five of 6 patients with metastatic disease had high-grade histological features compared with 0 of 19 nonmetastatic patients (83% vs. 0%; P < .001, Fisher exact test). Three-year overall survival from diagnosis was 84.8% (95% confidence interval, 59.6-94.9) with a median follow-up time of 3.9 years (range, 1 month to 10.3 years). Three deaths occurred, all from metastatic disease. Four patients received systemic therapy with time to treatment failure ≤6 months across different agents with the exception of 1 patient with prolonged response with sunitinib treatment (30.6 months). The most frequent molecular alterations were neurofibromin 2 mutations (n = 2; 40%), germline alterations (n = 2; 40%) including checkpoint kinase 2 and BRCA2 DNA repair associated mutations, multiple chromosomal copy number losses, and mismatch repair deficiency in 1 patient.

CONCLUSION

MTSCC is characterized by localized tumors treated successfully with primary tumor-directed therapy. However, patients with high-grade histological features were more likely to develop metastatic disease with limited responses to standard therapies.

Identification of a universal 6-lncRNA prognostic signature for three pathologic subtypes of renal cell carcinoma

Renal cell carcinoma (RCC) is the most common adult renal epithelial cancer susceptible to metastasis and patients with irresectable RCC always have a poor prognosis. Long noncoding RNAs (lncRNAs) have recently been documented as having critical roles in the etiology of RCC. Nevertheless, the prognostic significance of lncRNA-based signature for outcome prediction in patients with RCC has not been well investigated. Therefore, it is essential to identify a lncRNA-based signature for predicting RCC prognosis. In the current study, we comprehensively analyzed the RNA sequencing data of the three main pathological subtypes of RCC (kidney renal clear cell carcinoma [KIRC], kidney renal papillary cell carcinoma [KIRP], and kidney chromophobe carcinoma [KICH]) from The Cancer Genome Atlas (TCGA) database, and identified a 6-lncRNA prognostic signature with the help of a step-wise multivariate Cox regression model. The 6-lncRNA signature stratified the patients into low- and high-risk groups with significantly different prognosis. Multivariate Cox regression analysis showed that predictive value of the 6-lncRNA signature was independent of other clinical or pathological factors in the entire cohort and in each cohort of RCC subtypes. In addition, the three independent prognostic clinical factors (including age, pathologic stage III, and stage IV) was also stratified into low- and high-risk groups basis on the risk score, and the stratification analyses demonstrated that the high-risk score was a poor prognostic factor. In conclusion, these findings indicate that the 6-lncRNA signature is a novel prognostic biomarker for all three subtypes of RCC, and can increase the accuracy of predicting overall survival.

Evaluation of cytokeratin 19 as a prognostic tumoral and metastatic marker with focus on improved detection methods

In the last few years, there has been a growing interest in Cytokeratin 19 (CK19) studies in the cancer research field. CK19 belongs to the Type I CKs, serves as a useful research tool in prognosis, diagnosis, and management of the tumors. In this paper, we dissect the metastatic potential of CK19, its relation with cancer stem cells and retinal epithelial cells behavior, its application as a tumor marker and its role among 30 cancers such as thyroid, thoracic, lung, pancreatic, cervical, colorectal, and so forth. CK19 expressed in several cancer types because of its metastatic potential. This paper also presents modified detection methods of CK19 in disseminated tumor cells.

Chromophobe Renal Cell Carcinoma Presenting as a Cystic Renal Mass: Case Report and Review of the Literature

Patient: Male, 28

Final Diagnosis: Cystic chromophobe rcc

Symptoms: Flank pain

Medication: —

Clinical Procedure: Ct scan

Specialty: Radiology

Usefulness of rapid kV-switching dual energy CT in renal tumor characterization

PURPOSE

To investigate whether iodine content can discriminate between benign or malignant renal tumors, malign tumor subtypes, low-grade and high-grade tumors on rapid kv-switching dual-energy CT (rsDECT).

METHODS

This prospective study enrolled 95 patients with renal tumors who underwent rsDECT for tumor characterization between 2016 and 2018. Attenuation on true and virtual unenhanced images, absolute enhancement and enhancement ratio and iodine content of each lesion on nephrographic phase iodine density images were measured. Histopathological diagnosis was obtained following either surgery or core biopsy.

RESULTS

Eighty-five tumors were renal cell carcinoma (RCC) (56 clear cell, 20 papillary, 9 chromophobe) and 10 were benign (6 angiomyolipoma,4 oncocytoma). 46 tumors were low-grade and 23 high-grade. There was significant difference between iodine content of clear cell and non-clear cell (papillary + chromophobe) RCC (p < 0.001). However, no significant iodine content differences were found between papillary and chromophobe RCC, benign and malignant tumors, low-grade and high-grade tumors. The best cut-off iodine content for differentiating clear cell from non-clear cell RCC was 3.2 mg/ml and clear cell from papillary RCC was 2.9 mg/ml with a high sensitivity and specificity. Also, significant difference was found between attenuation values of true and virtual unenhanced images (p = 0.007). Mean iodine content, absolute enhancement and enhancement ratio were highly correlated.

CONCLUSION

rsDECT contributes to renal tumor characterization by showing higher iodine content in clear cell RCCs compared with non-clear cell RCCs.

Discrimination of oncocytoma and chromophobe renal cell carcinoma using MRI

PURPOSE

We aimed to evaluate magnetic resonance imaging (MRI) features, including signal intensities, enhancement patterns and T2 signal intensity ratios to differentiate oncocytoma from chromophobe renal cell carcinoma (RCC).

METHODS

This retrospective study included 17 patients with oncocytoma and 33 patients with chromophobe RCC who underwent dynamic MRI. Two radiologists independently reviewed images blinded to pathology. Morphologic characteristics, T1 and T2 signal intensities were reviewed. T2 signal intensities, wash-in, wash-out values, T2 signal intensity ratios were calculated. Sensitivity and specificity analyses were performed.

RESULTS

Mean ages of patients with oncocytoma and chromophobe RCC were 61.0±11.6 and 58.5±14.0 years, respectively. Mean tumor size was 60.6±47.3 mm for oncocytoma, 61.7±45.9 mm for chromophobe RCC. Qualitative imaging findings in conventional MRI have no distinctive feature in discrimination of two tumors. Regarding signal intensity ratios, oncocytomas were higher than chromophobe RCCs. Renal oncocytomas showed higher signal intensity ratios and wash-in values than chromophobe RCCs in all phases. Fast spin-echo T2 signal intensities were higher in oncocytomas than chromophobe RCCs.

CONCLUSION

Signal intensity ratios, fast spin-echo T2 signal intensities and wash-in values constitute diagnostic parameters for discriminating between oncoytomas and chromophobes. In the excretory phase of dynamic enhanced images, oncocytomas have higher signal intensity ratio than chromophobe RCC and high wash-in values strongly imply a diagnosis of renal oncocytoma.

LncRNA PVT1 promotes proliferation, invasion and epithelial-mesenchymal transition of renal cell carcinoma cells through downregulation of miR-16-5p

Background

LncRNAs have recently emerged as vital regulators in the pathogenesis and development of various cancers. LncRNA PVT1 is reported to function as an oncogene in some tumors. However, the role of PVT1 in RCC remains unknown.

Purpose

To explore the potential effects of lncPVT1 on the development of renal cell carcinoma.

Methods

The expression of PVT1 in renal cancer cell lines and tissues was measured by qRT-PCR. The endogenous PVT1 was silenced by RNAi. Cell viabilities were measured by the MTT assay. The migration and invasion of cells were investigated by the transwell assay. The apoptosis of cells was measured by the Nucleosome ELISA and caspase-3 activity assays. The levels of proteins were measured by the western blot.

Results

We found that PVT1 was upregulated in RCC tissues compared with the adjacent normal tissues. PVT1 expression was closely correlated with TNM stage, Fuhrman grade, lymph node metastasis and tumor size. Kaplan–Meier analysis revealed that high expression of PVT1 was significantly associated with poor overall survival. In accordance, overexpression of PVT1 was observed in RCC cells comto HK-2 cell. Silencing of PVT1 significantly repressed cell viability, induced apoptosis and inhibited cell migration and invasion in vitro. Furthermore, bioinformatic analysis and luciferase reporter assay confirmed that miR-16-5p was a target of PVT1. Silencing of miR-16-5p mostly reversed the regulatory effects on RCC cells induced by downregulation of PVT1.

Conclusion

In summary, our study indicates that targeting PVT1 might represent a rational therapeutic strategy for RCC.

Grading of renal cell carcinoma

Grading of renal cell carcinoma (RCC) has been recognised as a prognostic factor for almost 100 years. Numerous grading systems have been proposed, initially focusing upon a constellation of cytological features and more recently on nuclear morphology. It has been recommended that grading of RCC should be based upon nucleolar prominence/eosinophilia for grades 1-3, while grade 4 requires nuclear anaplasia (including tumour giant cells, sarcomatoid differentiation and/or rhabdoid morphology). The grading system was adopted formally by the International Society of Urological Pathology (ISUP) and subsequently by the World Health Organisation (WHO), being designated the WHO/ISUP grading classification in the fourth edition of the WHO classification tumours of the urinary system and male genital organs (2016). This grading system has been validated for both clear cell and papillary RCC. Validation studies for chromophobe RCC failed to demonstrate a correlation between grade and outcome for both the superseded Fuhrman grading system and the WHO/ISUP grading classification, and it has been recommended that these tumours not be graded. The WHO/ISUP system has been incorporated into the structured reports of the International Cancer Collaboration on Cancer Reporting for both clear cell and papillary RCC. It is also noted that other types of RCC may be graded, but it must be emphasised in the report that this is for descriptive and diagnostic purposes, and not outcome prediction. More recent studies have shown the incorporation of the presence of tumour necrosis into RCC grading to improve outcome prediction, and this has been validated in several studies.

Metastatic Chromophobe Renal Cell Carcinoma: Presence or Absence of Sarcomatoid Differentiation Determines Clinical Course and Treatment Outcomes

BACKGROUND

Sarcomatoid features (SF) in renal cell carcinoma (RCC) denote poor prognosis. Data for metastatic chromophobe RCC (ChRCC) with SF are limited. We studied clinical outcomes and genomic features in this setting.

PATIENTS AND METHODS

We performed a retrospective review of newly diagnosed metastatic ChRCC patients; end points included overall survival (OS), time to treatment failure (TTF), and time to metastatic recurrence (TTR) after nephrectomy for localized disease. A subset of patients underwent next-generation sequencing (NGS). Outcomes were compared using nonparametric tests.

RESULTS

One hundred nine patients with metastatic ChRCC were identified including 29 with SF. Median TTR after nephrectomy was shorter for patients with versus without SF (2.7 months [95% confidence interval (CI), 0.7-6.9] versus 48.8 months [95% CI, 30.8-80.7], log rank P < .001). Median TTF during first-line therapy was shorter for patients with versus without SF (1.8 months [95% CI, 0.9-2.7] vs. 8.0 months [95% CI, 5.1-13.0]; log rank P < .001). No responses were observed in 6 patients treated with nivolumab including 4 with SF. Median OS was inferior for patients with versus without SF (38 months vs.7.5 months; hazard ratio, 4.7 [95% CI, 2.7-8.2]; P < .001). NGS, performed in 22 patients, showed that 64% and 45% harbored tumor protein P53 and phosphatase and tensin homolog alterations, respectively. Microsatellite instability high status was identified in 3 patients.

CONCLUSION

Metastatic ChRCC patients with SF had worse outcomes compared with those without SF. Median TTR < 3 months for this subgroup supports close surveillance after nephrectomy for localized tumors. Lack of benefit with various systemic regimens warrants studying underlying biology and investigating novel agents.

Personalized Treatment for Small Renal Tumors: Decision Analysis of Competing Causes of Mortality

Purpose To compare the effectiveness of personalized treatment for small (≤4 cm) renal tumors versus routine partial nephrectomy (PN), accounting for various competing causes of mortality. Materials and Methods A state-transition microsimulation model was constructed to compare life expectancy of management strategies for small renal tumors by using 1 000 000 simulations in the following ways: routine PN or personalized treatment involving percutaneous ablation for risk factors for worsening chronic kidney disease (CKD), and otherwise PN; biopsy, with triage of renal cell carcinoma (RCC) to PN or ablation depending on risk factors for worsening CKD; active surveillance for growth; and active surveillance when MRI findings are indicative of papillary RCC. Transition probabilities were incorporated from the literature. Effects of parameter variability were assessed in sensitivity analysis. Results In patients of all ages with normal renal function, routine PN yielded the longest life expectancy (eg, 0.67 years in 65-year-old men with nephrometry score [NS] of 4). Otherwise, personalized strategies extended life expectancy versus routine PN: in CKD stages 2 or 3a, moderate or high NS, and no comorbidities, MRI guidance for active surveillance extended life expectancy (eg, 2.60 years for MRI vs PN in CKD 3a, NS 10); and with Charlson comorbidity index of 1 or more, biopsy or active surveillance for growth extended life expectancy (eg, 2.70 years for surveillance for growth in CKD 3a, NS 10). CKD 3b was most effectively managed by using MRI to help predict papillary RCC for surveillance. Conclusion For patients with chronic kidney disease and small renal tumors, personalized treatment selection likely extends life expectancy. © RSNA, 2019 Online supplemental material is available for this article.

VNN3 is a potential novel biomarker for predicting prognosis in clear cell renal cell carcinoma

Although pathological observations provide approximate prognoses, it is difficult to achieve prognosis in patients with existing prognostic factors. Therefore, it is very important to find appropriate biomarkers to achieve accurate cancer prognosis. Renal cell carcinoma (RCC) has several subtypes, the discrimination of which is crucial for proper treatment. Here, we present a novel biomarker, VNN3, which is used to prognose clear cell renal cell carcinoma (ccRCC), the most common and aggressive subtype of kidney cancer. Patient information analyzed in our study was extracted from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) cohorts. VNN3 expression was considerably higher in stages III and IV than in stages I and II. Moreover, Kaplan–Meier curves associated high VNN3 expression with poor prognoses (TCGA, p < .0001; ICGC, p = .00076), confirming that ccRCC prognosis can be predicted via VNN3 expression patterns. Consistent with all patient results, the prognosis of patients with higher VNN3 expression was worse in both low stage (I and II) and high stage (III and IV) (TCGA, p < 0.0001 in stage I and II; ICGC, p = 0.028 in stage I and II; TCGA, p = 0.005 in stage III and IV). Area under the curve and receiver operating characteristic curves supported our results that highlighted VNN3 expression as a suitable ccRCC biomarker. Multivariate analysis also verified the prognostic performance of VNN3 expression (TCGA, p < .001; ICGC, p = .017). Altogether, we suggest that VNN3 is applicable as a new biomarker to establish prognosis in patients with ccRCC.

Dual-Inhibition of mTOR and Bcl-2 Enhances the Anti-tumor Effect of Everolimus against Renal Cell Carcinoma In Vitro and In Vivo

Renal cell carcinoma (RCC) is the predominant type of kidney cancer. Mammalian target of rapamycin (mTOR) inhibitor everolimus is currently used as a second-line therapy for sorafenib or sunitinib-refractory metastatic RCC patients. The clinical limitation confronted during everolimus therapy is the onset of drug resistance that decreases the efficacy of the drug. Elevated level of anti-apoptotic Bcl-2 protein is proposed to be an emerging feedback loop for the acquired drug-resistance in various cancer types. In this study, the Bcl-2 inhibitor ABT-737 was used in combination with everolimus to enhance its anti-tumor effectiveness in everolimus-resistant RCC cell lines. Everolimus and ABT-737 combination synergistically led to a decrease in the proliferation of primary site A-498 and metastatic site Caki-1 RCC cell lines, which was accompanied by a reduction in protein levels of cell cycle and mTOR pathway proteins. In both RCC cell lines, everolimus-ABT-737 combination not only induced apoptosis, caspase and PARP-1 cleavage but also a decrease in Bcl-2 protein levels in parallel with a concomitant increase in Bim and Noxa levels. In order to confirm our in vitro findings, we have generated everolimus-resistant RenCa cell line (RenCa^res) to establish a RCC mouse xenograft model. Animals co-treated with everolimus and ABT-737 exhibited a complete suppression of tumor growth without any notable toxicity. This study thus proposes the everolimus-ABT-737 combination as a novel therapeutic strategy for the treatment of RCC to overcome the current clinical problem of everolimus resistance.

FABP5 regulates the proliferation of clear cell renal cell carcinoma cells via the PI3K/AKT signaling pathway

Clear cell renal cell carcinoma (ccRCC) has been associated with one of the highest mortality rates among all cancers. Fatty acid binding proteins (FABPs) are 14‑15 kDa proteins that are highly abundant in the cytosol of most tissues. FABP5, a member of the FABP family, has been observed to promote tumor cell growth in numerous cancer types. In order to investigate the function of FABP5 in ccRCC cells in the present study, RNA sequencing data from The Cancer Genome Atlas were analyzed to determine the expression levels of FABP5 in ccRCC patient samples. Survival and Cox regression analyses were performed to measure the association between FABP5 expression and clinicopathological features of patients with ccRCC. Subsequent in vitro experiments downregulated or overexpressed FABP5 in Caki‑1 and 786O ccRCC cells using lentiviral vectors to evaluate cell proliferation ability, and a xenograft transplantation model was established to examine the effect of FABP5 on tumorigenesis in vivo. The results demonstrated that FABP5 expression was significantly upregulated in samples from patients with ccRCC when compared with normal tissue samples. High FABP5 expression was also significantly correlated with tumor and metastasis classifications and predicted poor survival in patients with ccRCC. In ccRCC cells, silencing of FABP5 significantly inhibited cell proliferation, while overexpression of FABP5 promoted cell proliferation when compared to the respective controls. In addition, treatment with the phosphatidylinositol‑4,5‑bisphosphate 3‑kinase (PI3K)/AKT inhibitor, LY294002, attenuated the pro‑proliferative effects of exogenous FABP5 expression in Caki‑1 and 786O cells. This indicated that the PI3K/AKT signaling pathway may be partially involved in the FABP5‑mediated increase in ccRCC cell proliferation. Furthermore, FABP5 was observed to regulate tumor growth in nude mice in vivo. In conclusion, the results of the present study suggest that FABP5 may exert a pro‑proliferative role in ccRCC and may be associated with malignant progression and tumorigenesis.

Clinical Features, Survival and Prognostic Factors of Glycogen-Rich Clear Cell Carcinoma (GRCC) of the Breast in the U.S. Population

The World Health Organization (WHO) defines glycogen-rich clear cell carcinoma (GRCC) of the breast as a carcinoma with glycogen accumulation in more than 90% of its tumor cells. Due to the rarity of this disease, its reported survival and clinical associations have been inconsistent due to reliance on case reports and limited case series. As a result, the prognostic implication of this cancer subtype remains unclear. Using the U.S. Surveillance, Epidemiology, and End Results (SEER) program database, we compared the incidence, demographics and prognostic factors of 155 cases of GRCC of the breast to 1,251,584 cases of other (non-GRCC) breast carcinomas. We demonstrate that GRCC is more likely to be identified as high grade, advanced stage, and more likely to have triple negative receptor status. GRCC cases display a poorer prognosis than non-GRCC carcinomas of the breast irrespective of age, AJCC staging, tumor grade, joint hormone receptor/human epidermal growth factor receptor 2 (HER2) status, and treatment. Similar to non-GRCC carcinomas, older age and higher American Joint Committee on Cancer (AJCC)/TNM staging were associated with poorer prognosis for GRCC, while treatment with surgery and radiation were associated with improved survival. Radiation, specifically in the setting of breast-conserving surgery, further improved survival compared to surgery alone. Our study highlights the poorer prognosis associated with glycogen accumulation in breast cancers and hence stresses the importance of identifying this more aggressive tumor type.

Key miRNAs and target genes played roles in the development of clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (CCRCC) is the most aggressive form of renal cell carcinoma (RCC).

OBJECTIVE

This study was aimed to identify the differentially expressed miRNAs and target genes in CCRCC.

METHODS

The miRNA and mRNA next-generation sequencing data were downloaded from The Cancer Genome Atlas (TCGA) dataset. Differential expression analysis was performed, followed by correlation analysis of miRNA-mRNA. Functional enrichment and survival analysis was also performed.

RESULTS

Seven hundred and eighty-seven patients with CCRCC from TCGA data portal were included in this study. A total of 52 differentially expressed miRNAs were identified in CCRCC. Then 2361 differentially expressed genes (DEGs) were identified. Prediction analysis and correlation analysis revealed that 89 miRNA-mRNA pairs were not only predicted by algorithms but also had a significant inverse relationship. Several differentially expressed miRNAs such as hsa-mir-501 and their target genes including AK1, SLC25A15 and PCDHGC3 had a significant prognostic value for CCRCC patients.

CONCLUSIONS

Alterations of differentially expressed miRNAs and target genes may be involved in the development of CCRCC and can be considered as the prognostic markers for CCRCC.

Evaluation of microvascular invasion as a prognostic factor in the progression of non-metastatic renal cancer

Introduction

The aim of this study was to describe the prognostic impact of microvascular invasion (MVI) in patients with non-metastatic renal cell cancer.

Material and methods

We carried out a retrospective, descriptive and analytical study of patients with non-metastatic renal cell carcinoma who had undergone a radical or partial nephrectomy. Patients were divided according to the presence of MVI. In each group, clinical and pathological characteristics were evaluated. Metastasis-free and cancer-specific survival was evaluated by the Kaplan Meier method. The multivariate analysis was performed with Cox proportional method in order to predict risk factors of metastasis and cancer-specific mortality.

Results

A total of 221 patients with a median of 40-month long follow-up were evaluated. Patients with MVI+ were 40 (18%) while those with MVI – were 181 (82%). In the univariate analysis, the presence of MVI had a strong correlation with symptomatic tumors (OR 3.56; p 0.0003), tumor size (OR 12.08; p <0.0001), nuclear grade (OR 6.99; p <0.0001), pathological stage (OR 35.8; p <0.0001), distance metastasis (OR 4.16; p 0.0001), and death by cancer (OR 4.7; p 0.0004). However, in the multivariate analysis it is not presented as an independent predictor of metastasis (HR 0.45; p 0.11) or cancer-specific mortality (HR 0.93; p 0.91).

Conclusions

In our series, MVI is associated with unfavorable tumors characteristics. In spite of this, it does not seem to be an independent predictor for metastasis and death by non-metastatic renal cancer.

Histopathological Prognostic Factors in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (CCRCC) are the most frequent type of renal cell carcinoma. Fuhrman grade and tumor stage are prognostic factors with great importance in survival rate. This study was performed on 75 cases of CCRCC diagnosed by the Anatomical Pathology Laboratory of the County Clinical Emergency Hospital of Craiova between 2014 and 2017. The biological material was represented by pieces of nephrectomy. The cases were analyzed on two criteria: epidemiology (age, sex) and histopathology (Fuhrman grade, tumor stage, architectural pattern, sarcomatoid transformation, and necrosis). Statistical analysis was done using Chi Square tests in IBM SPSS software. Average diagnosis age of CCRCC was 58.8±10.2 years, predominantly in male patients (66.7%). Tumor sizes were between 2 and 14cm, with an average of 6.7±2.9cm. Most cases were determined to be tumor stage III (60%) and Fuhrman grade 2 (56%), followed, in order of frequency, by tumor stages I and II (28% and 10.7%) and Fuhrman grades 3 and 1 (21.3% and 20%). High Fuhrman grade CCRCC were significantly associated with advanced tumor stage (p<0.05, χ² test). Most cases presented a mixed pattern, significantly associated with advanced tumor stages (p<0.05, χ² test). Even though the presence of sarcomatoid transformation was more frequent in advanced tumor stages, it wasn’t significantly linked to them (p<0.05, χ² test). Conclusions: Analyzed histopathological parameters are useful for determining CCRCC aggressiveness. CCRCC in advanced tumor stages is associated with high Fuhrman grade and mixed architectural pattern.

Dissecting LncRNA Roles in Renal Cell Carcinoma Metastasis and Characterizing Genomic Heterogeneity by Single-Cell RNA-seq

Long noncoding RNAs (lncRNA) have recently emerged as important regulators in cancer cell proliferation and metastasis. However, the role of lncRNAs in metastatic clear cell renal cell carcinoma (ccRCC) remains unclear. Here, single-cell RNA sequencing data were analyzed from primary renal cell carcinoma and paired metastatic renal cell carcinoma specimens, and characterized the expression profiles of over 10,000 genes, including 1,874 lncRNAs. Further analysis revealed that lncRNAs exhibit cancer type- and tissue-specific expression across ccRCC cells. Interestingly, a number of lncRNAs (n = 173) associated with ccRCC metastasis, termed ccRCC metastasis-associated lncRNAs (CMAL). Moreover, functional analysis based on a CMAL-PCG coexpression network revealed that CMALs contribute to cell adhesion, immune response, and cell proliferation. In combination with survival analysis, 12 CMALs were identified that participate in TNF and hypoxia-inducible factor 1 signaling to promote ccRCC metastasis. Further investigation on intratumoral heterogeneity showed that some CMALs are selectively expressed in different subpopulations. IMPLICATIONS: To explore ccRCC metastasis, the current study performed a global dissection of lncRNAs and a complex genomic analysis of ccRCC tumor heterogeneity. The data shed light on the discovery of potential lncRNA biomarkers and lncRNA therapeutic targets.

WHO/ISUP classification, grading and pathological staging of renal cell carcinoma: standards and controversies

PURPOSE

Pathological parameters assessed on biopsies and resection specimens have a pivotal role in the diagnosis, prognosis and management of patients with renal cell carcinoma (RCC).

METHODS

A non-systematic literature search was performed, updated to January 2018, to identify key standards and controversies in the pathological classification, grading and staging of RCC.

RESULTS

Although most RCCs exhibit characteristic morphology that enables easy categorisation, RCCs show considerable morphological heterogeneity and it is not uncommon for there to be difficulty in assigning a tumour type, especially with rarer tumour subtypes. The differentiation between benign and malignant oncocytic tumours remains a particular challenge. The development of additional immunohistochemical and molecular tests is needed to facilitate tumour typing, because of the prognostic and therapeutic implications, and to enable more reliable identification of poorly differentiated metastatic tumours as being of renal origin. Any new tests need to be applicable to small biopsy samples, to overcome the heterogeneity of renal tumours. There is also a need to facilitate identification of tumour types that have genetic implications, to allow referral and management at specialist centres. Digital pathology has a potential role in such referral practice.

CONCLUSION

Much has been done to standardise pathological assessment of renal cell carcinomas in recent years, but there still remain areas of difficulty in classification and grading of these heterogeneous tumours.

Clear cell renal cell carcinoma: identifying PTEN expression on multiphasic MDCT

PURPOSE

To investigate whether multiphasic MDCT enhancement profiles can help to identify PTEN expression in clear cell renal cell carcinomas (ccRCCs). Lack of PTEN expression is associated with worsened overall survival, a more advanced Fuhrman grade, and a greater likelihood of lymph mode metastasis.

METHODS

With IRB approval for this retrospective study, we derived a cohort of 103 histologically proven ccRCCs with preoperative 4-phase renal mass MDCT from 2001-2013. Following manual segmentation, a computer-assisted detection algorithm selected a 0.5-cm-diameter region of maximal attenuation within each lesion in each phase; a 0.5-cm-diameter region of interest was manually placed on uninvolved renal cortex in each phase. The relative attenuation of each lesion was calculated as [(Maximal lesion attenuation - cortex attenuation)/cortex attenuation] × 100. Absolute and relative attenuation in each phase were compared using t tests. The performance of multiphasic enhancement in identifying PTEN expression was assessed with logistic regression analysis.

RESULTS

PTEN-positive and PTEN-negative ccRCCs both exhibited peak enhancement in the corticomedullary phase. Relative corticomedullary phase attenuation was significantly greater for PTEN-negative ccRCCs in comparison to PTEN-positive ccRCCs (33.7 vs. 9.5, p = 0.03). After controlling for lesion stage and size, relative corticomedullary phase attenuation had an accuracy of 84% (86/103), specificity of 100% (84/84), sensitivity of 11% (2/19), positive predictive value of 100% (2/2), and negative predictive value of 83% (84/101) in identifying PTEN expression.

CONCLUSION

Relative corticomedullary phase attenuation may help to identify PTEN expression in ccRCCs, if validated prospectively.

Update on the biology and management of renal cell carcinoma

Renal cell cancer (RCC) (epithelial carcinoma of the kidney) represents 2%-4% of newly diagnosed adult tumors. Over the past 2 decades, RCC has been better characterized clinically and molecularly. It is a heterogeneous disease, with multiple subtypes, each with characteristic histology, genetics, molecular profiles, and biologic behavior. Tremendous heterogeneity has been identified with many distinct subtypes characterized. There are clinical questions to be addressed at every stage of this disease, and new targets being identified for therapeutic development. The unique characteristics of the clinical presentations of RCC have led to both questions and opportunities for improvement in management. Advances in targeted drug development and understanding of immunologic control of RCC are leading to a number of new clinical trials and regimens for advanced disease, with the goal of achieving long-term disease-free survival, as has been achieved in a proportion of such patients historically. RCC management is a promising area of ongoing clinical investigation.

MicroRNA‑663 inhibits the proliferation and invasion of clear cell renal cell carcinoma cells by directly targeting PAK4

Accumulating evidence has demonstrated that microRNAs (miRNAs) are key gene regulators and are abnormally expressed in clear cell renal cell carcinoma (ccRCC). The dysregulation of miRNAs has been implicated in the initiation and progression of ccRCC. Therefore, identification of ccRCC‑associated miRNAs may facilitate the determination of promising therapeutic targets for anti‑cancer treatment. In the present study, miRNA‑663 (miR‑663) expression was downregulated in ccRCC tissues and cell lines. Functional experiments suggested that restoration of miR‑663 expression inhibited the proliferation and invasion of ccRCC cells. In addition, p21 activated kinase 4 (PAK4) was validated as a direct target of miR‑663 in ccRCC cells. PAK4 was upregulated in ccRCC tissues, and the expression level of PAK4 was inversely correlated with the miR‑663 expression level. PAK4 restoration partially attenuated the suppressive roles of miR‑663 overexpression on the proliferation and invasion of ccRCC cells. The present results provide novel insight into the mechanism underlying the occurrence and development of ccRCC, suggesting that the miR‑663/PAK4 axis may be a novel therapeutic target for treatment of patients with ccRCC.

Altmetric Versus Bibliometric Perspective Regarding Publication Impact and Force

BACKGROUND

Bibliometric and Altmetric analyses highlight key publications, which have been considered to be the most influential in their field. The hypothesis was that highly cited articles would correlate positively with levels of evidence and Altmetric scores (AS) and rank.

METHODS

Surgery as a search term was entered into Thomson Reuter's Web of Science database to identify all English-language full articles. The 100 most cited articles were analysed by topic, journal, author, year, institution, and AS.

RESULTS

By bibliometric criteria, eligible articles numbered 286,122 and the median (range) citation number was 574 (446-5746). The most cited article (Dindo et al.) classified surgical complications by severity score (5746 citations). Annals of Surgery published most articles and received most citations (26,457). The country and year with most publications were the USA (n = 50) and 1999 (n = 11). By Altmetric criteria, the article with the highest AS was by Bigelow et al. (AS = 53, hypothermia's role in cardiac surgery); Annals of Surgery published most articles, and the country and year with most publications were USA (n = 4) and 2007 (n = 3). Level-1-evidence articles numbered 13, but no correlation was found between evidence level and citation number (SCC 0.094, p = 0.352) or AS (SCC = 0.149, p = 0.244). Median AS was 0 (0-53), and in articles published after the year 2000, AS was associated with citation number (r = 0.461, p = 0.001) and citation rate index (r = 0.455, p = 0.002). AS was not associated with journal impact factor (r = 0.160, p = 0.118).

CONCLUSION

Bibliometric and Altmetric analyses provide important but different perspectives regarding article impact, which are unrelated to evidence level.

Assessment of tumour-associated necrosis provides prognostic information additional to World Health Organization/International Society of Urological Pathology grading for clear cell renal cell carcinoma

AIMS

The aims of this study were to evaluate the impact of tumour-associated necrosis (TAN) on metastasis-free survival for clear cell renal cell carcinoma (RCC), and to determine whether TAN provides survival information additional to World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading.

METHODS AND RESULTS

The study consisted of 376 cases of clear cell RCC treated by nephrectomy, for which follow-up was available. WHO/ISUP grade was assigned, and sections were assessed for the presence of TAN. American Joint Committee on Cancer (AJCC) pT staging category and tumour size were also recorded. The development of metastatic disease was taken as the clinical endpoint, and survival analyses, utilising univariate and multivariate models, were performed. WHO/ISUP grades were: grade 1, 35 cases (9.3%); grade 2, 188 cases (50.0%); grade 3, 91 cases (24.2%); and grade 4, 62 cases (16.5%). Staging categories were pT1-pT2 [234 tumours (62.2%)] and pT3-pT4 [139 tumours (37.0%)]. TAN was seen in 128 cases (34.0%). Neither TAN nor metastases were seen in grade 1 tumours. Among grade 2-4 tumours, those with TAN had a significantly worse prognosis than those without TAN (P = 0.017, P = 0.04, and P = 0.006, respectively). Multivariate analysis (WHO/ISUP grade, pT staging category, and TAN) showed all three variables to be independently associated with outcome (P = 0.009, P = 0.005, and P = 0.001, respectively). For all tumour grades and pT staging categories, it was found that the presence of TAN was associated with a 2.91-fold greater risk of metastatic disease.

CONCLUSION

Tumour-associated necrosis is an important prognostic factor for clear cell RCC, independently of WHO/ISUP grade. This supports the suggestion that TAN could be incorporated into tumour grading criteria.

Kidney transplantation in patients with previous renal cancer: a critical appraisal of current evidence and guidelines

Due to the increasing occurrence of renal cell carcinoma (RCC) in the general population and the high prevalence of chronic kidney disease among cancer patients, many people with a previous RCC may eventually require renal replacement therapy including kidney transplantation. They should accordingly be evaluated to assess their life expectancy and the risk that the chronic immunosuppressive therapy needed after grafting might impair their long-term outcome. Current guidelines on listing patients for renal transplantation suggest that no delay is required for subjects with small or incidentally discovered RCC, while the recommendations for patients who have been treated for a symptomatic RCC or for those with large or invasive tumours are conflicting. The controversial results reported by even recent studies focusing on the cancer risk in kidney graft recipients with a prior history of malignancy do not help to clarify the doubts arising in everyday clinical practice. Several tools, including integrated scoring systems, are currently available to assess the prognosis of patients with a previous RCC and, although they have not been validated in subjects receiving long-term immunosuppressive drugs, they can be used to identify patients suitable to be listed for grafting. Among these, the Leibovich score is currently the most widely used as it has proved simple and reliable enough and helps categorize renal transplant candidates. According to this system, subjects with a score from 0 to 2 are at low risk and may be listed without delay, while those with a score of 6 or higher should be excluded from grafting. In addition, other factors have an established positive prognostic value, including chromophobe or clear cell papillary tumour, or G1 grade cancer; on the contrary, medullary or Bellini's duct carcinoma or those with sarcomatoid dedifferentiation at histological examination should be excluded. All other patients would be better submitted to careful individual evaluation by an Oncologist before being listed for renal transplantation, pending studies specifically focusing on cancer risk evaluation in people already treated for malignancy receiving long-term immunosuppressive therapy.

Association of the Gross Appearance of Intratumoral Vascularity at MDCT With the Carbonic Anhydrase IX Score in Clear Cell Renal Cell Carcinoma

OBJECTIVE

The purpose of this study was to determine whether qualitative MDCT features are associated with the carbonic anhydrase IX (CAIX) score of clear cell renal cell carcinoma (RCC). The CAIX score has been previously found to have prognostic significance for disease-free survival, overall survival, and lymph node involvement.

MATERIALS AND METHODS

A cohort of 105 histologically proven clear cell RCCs in patients who underwent preoperative four-phase renal mass MDCT was derived from 2001 to 2013. Two genitourinary radiologists evaluated each lesion for the gross appearance of intratumoral vascularity, calcification, enhancement pattern, necrosis, margin, collecting system invasion, and renal vein invasion. Immunohistochemical analysis was used to determine the CAIX score (defined as the positive staining percentage multiplied by the staining intensity). Logistic and linear regression analyses were performed.

RESULTS

In a linear regression model controlled for lesion size and stage, the gross appearance of intratumoral vascularity had a significant positive association with CAIX score (β = 38.33, p = 0.010). In a logistic regression model controlled for lesion size and stage, the gross appearance of intratumoral vascularity had an odds ratio of 2.85 (p = 0.019) in differentiating clear cell RCCs with a CAIX score of 200-300 from clear cell RCCs with a CAIX score of 0-199.

CONCLUSION

In clear cell RCCs, the gross appearance of intratumoral vascularity at MDCT was significantly associated with CAIX score, a prognostically significant molecular marker. Current assessment of CAIX score requires pathologic tissue sampling and immunohistochemical analysis. A noninvasive imaging biomarker that may help predict CAIX score may be of great clinical value.

Pathologically examining a minimum of three lymph nodes could better determine node negativity in patients with non-metastatic chromophobe renal cell carcinoma

Objective

To evaluate the prognostic value of lymph node (LN) involvement for patients with chromophobe renal cell carcinoma (chRCC) and ascertain the minimum number of LNs that need to be pathologically examined to reliably diagnose a patient with node negative chRCC.

Methods

From 2004 to 2014, non-metastatic chRCC patients receiving radical nephrectomy together with lymphadenectomy were identified from the Surveillance, Epidemiology and End Results (SEER) database. The primary outcome was overall survival (OS).

Results

Two hundred and forty-six patients received lymph node dissection during the surgery. Of the patients, 24 (10%) had pathologically confirmed positive LN. Multivariate Cox regression model showed that positive LN was an independent unfavorable predictor for OS (HR = 2.83, 95%CI = 1.14-6.98, P = 0.024). More importantly, LN(-) patients with at least three LNs dissected had significantly better OS compared with when 1-2 LNs were examined (P = 0.048). Multivariate analysis confirmed that in LN(-) patients, the examination of three or more LNs could independently predict better OS compared with patients with only 1-2 LNs dissected (HR≥3LNs = 0.362, 95% CI = 0.135-0.972, P = 0.044). Additionally, the likelihood of finding at least one positive LN was significantly higher on dissection of ≥3 LNs compared with examination of 1-2 LNs (15% vs 5%, P = 0.018). Decision curve analysis found a better clinical validity of the '3 LNs examined'-based classification compared with the traditional LN(-)/LN(+) classification.

Conclusion

The proportion of positive LNs in chRCC was far from neglectable and LN metastasis could independently predict unfavorable OS. We recommended a minimum of three LNs should be pathologically examined in order to reliably determine node negative.