Validation of the 2009 TNM version in a large multi-institutional cohort of patients treated for renal cell carcinoma: are further improvements needed?

Predicting Recurrence After Radical Surgery for High-Risk Renal Cell Carcinoma: Development and Internal Validation of the "TOWARDS" Score

BACKGROUND

Considering the reported greater benefits of immunotherapy and its unignorable adverse events in adjuvant therapy for high-risk renal cell carcinoma (hrRCC), accurate prediction may optimize drug use.

METHODS

The primary objective of this study was to generate a score-based prognostic model of recurrence-free survival in hrRCC. The study retrospectively evaluated 456 patients at two institutions who underwent radical surgery for nonmetastatic pT3-4 and/or N1-2 or pT2 and G4 disease. Clinical variables deemed universally available were selected through backward stepwise analysis and fitted by a multivariable Cox proportional hazards regression model. A point-based score was derived from regression coefficients. Discrimination, calibration, and decision curve analyses were conducted to evaluate predictive performance. Internal validation with bootstrapping was performed to correct for optimism.

RESULTS

The mean follow-up period was 55.3 months, and the median follow-up period was 28.0 months. During the follow-up period, the recurrence rate was 48.2% (n = 220) during a median of 75.7 months. Stepwise variable selection retained age, Eastern Cooperative Oncology Group (ECOG) performance status, presence or absence of symptoms, size of the primary tumor, pathologic T stage, pathologic N stage, tumor grade, and histology. Subsequently, the TOWARDS score (range 0-53) was developed from these variables. Internal validation showed an optimism-corrected C-index of 0.723 and a calibration slope of 0.834. The decision curve analysis showed the superiority of this score over the University of California, Los Angeles (UCLA) Integrated Staging System and GRade, Age, Nodes, and Tumor score.

CONCLUSIONS

The authors' novel TOWARDS scoring model had good accuracy for predicting disease recurrence in patients with hrRCC, and the clinical practicability was superior to that of the existing models.

Prognostic significance of pT3a staging subclassifications in renal cell carcinoma: Not all pT3a are equal

OBJECTIVE

To examine the prognostic significance of perinephric fat, renal sinus fat, and renal vein invasion in patients with pT3a renal cell carcinoma (RCC) by histologic type.

METHODS

A population-based retrospective cohort study of patients with pT3aN0M0 RCC was performed using Surveillance, Epidemiology, and End Results (SEER) data for the years 2010 through 2019. Cox proportional hazards models were used to examine the relationship between pT3a subclassification groups and cancer-specific survival (CSS) by histological subtype (clear cell, papillary, chromophobe, and other).

RESULTS

The cohort consisted of 10,170 patients with pT3a RCC, including 8,446 (83.0%) with clear cell RCC and 1,724 (17.0%) with nonclear cell RCC (nccRCC). Median follow up was 36 months. Differences in CSS by pT3a subclassification groups were observed in all histological subtypes but were most pronounced in nccRCC, specifically papillary RCC. Compared to perinephric fat (PF) invasion only, renal vein (RV) invasion (HR = 4.9, 95%CI: 2.5-9.3, P < 0.01), renal sinus fat invasion (HR = 3.0, 95%CI: 1.4-6.2), RV and PF invasion (HR = 7.5, 95%CI: 3.5-16.0), and combination of all three characteristics (HR = 4.4, 95%CI: 1.2-15.5) were associated with worse CSS in patients with papillary RCC.

CONCLUSION

We examined the prognostic role of pT3a staging subclassifications in RCC by histologic subtype and observed survival differences, particularly in papillary RCC. Our findings highlight the need to refine pT3a staging criteria to help guide individualized, multimodal treatment strategies for locally advanced RCC.

TGMIL: A hybrid multi-instance learning model based on the Transformer and the Graph Attention Network for whole-slide images classification of renal cell carcinoma

BACKGROUND AND OBJECTIVES

The pathological diagnosis of renal cell carcinoma is crucial for treatment. Currently, the multi-instance learning method is commonly used for whole-slide image classification of renal cell carcinoma, which is mainly based on the assumption of independent identical distribution. But this is inconsistent with the need to consider the correlation between different instances in the diagnosis process. Furthermore, the problem of high resource consumption of pathology images is still urgent to be solved. Therefore, we propose a new multi-instance learning method to solve this problem.

METHODS

In this study, we proposed a hybrid multi-instance learning model based on the Transformer and the Graph Attention Network, called TGMIL, to achieve whole-slide image of renal cell carcinoma classification without pixel-level annotation or region of interest extraction. Our approach is divided into three steps. First, we designed a feature pyramid with the multiple low magnifications of whole-slide image named MMFP. It makes the model incorporates richer information, and reduces memory consumption as well as training time compared to the highest magnification. Second, TGMIL amalgamates the Transformer and the Graph Attention's capabilities, adeptly addressing the loss of instance contextual and spatial. Within the Graph Attention network stream, an easy and efficient approach employing max pooling and mean pooling yields the graph adjacency matrix, devoid of extra memory consumption. Finally, the outputs of two streams of TGMIL are aggregated to achieve the classification of renal cell carcinoma.

RESULTS

On the TCGA-RCC validation set, a public dataset for renal cell carcinoma, the area under a receiver operating characteristic (ROC) curve (AUC) and accuracy of TGMIL were 0.98±0.0015,0.9191±0.0062, respectively. It showcased remarkable proficiency on the private validation set of renal cell carcinoma pathology images, attaining AUC of 0.9386±0.0162 and ACC of 0.9197±0.0124. Furthermore, on the public breast cancer whole-slide image test dataset, CAMELYON 16, our model showed good classification performance with an accuracy of 0.8792.

CONCLUSIONS

TGMIL models the diagnostic process of pathologists and shows good classification performance on multiple datasets. Concurrently, the MMFP module efficiently diminishes resource requirements, offering a novel angle for exploring computational pathology images.

Purely Off-Clamp Laparoscopic Partial Nephrectomy Stands the Test of Time: 15 Years Functional and Oncologic Outcomes from a Single Center Experience

BACKGROUND

Nephron-sparing surgery represents the gold standard treatment for organ-confined renal tumors. We present 15-years of outcomes after off-clamp laparoscopic partial nephrectomy (ocLPN).

METHODS

a retrospective analysis was performed on patients who underwent ocLPN between May 2001 and December 2005. Baseline demographic, clinical, pathologic, surgical, functional and survival data were collected. The Kaplan-Meier method evaluated group-specific oncologic outcomes at 5, 10 and 15 years and the log rank test assessed differences between groups. The same analysis investigated the probabilities of developing a significant renal function impairment (sRFI) and achieving ROMeS. Cox analyses identified predictors of this latter tricomposite outcome.

RESULTS

We included 63 patients whose median tumor size was 3 cm (IQR:2-4). At 15 years, the chances of developing local recurrence, metachronous renal cancers or distant metastases were 2 ± 2%, 23 ± 6% and 17 ± 5%, respectively. Consequently, disease-free, cancer-specific and overall-survival probabilities were 68 ± 6%, 90 ± 4% and 72 ± 6%. MCRSS and UCISS well predicted oncologic outcomes. Overall, nine (14%) patients experienced an sRFI and 33 (52%) achieved ROMeS. Age (HR: 1.046; p = 0.033) and malignant histology (low-risk cancers HR: 3.233, p = 0.048) (intermediate/high risk cancers HR: 5.721, p = 0.023) were independent predictors of ROMeS non-achievement.

CONCLUSIONS

At 15 years from ocLPN, most of patients will experience both excellent functional and oncologic outcomes.

Comparison of Long-term Outcomes for Young and Healthy Patients with cT1a and cT3a Renal Cell Carcinoma Treated with Partial Nephrectomy

Partial nephrectomy (PN) is recommended for renal cell carcinoma (RCC) of <4 cm. We hypothesized that there is no difference in all-cause mortality (ACM) between cT1a, cT1b, and cT3a <4 cm RCC following PN. The National Cancer Database was interrogated to identify patients aged <60 yr with a Charlson comorbidity index ≤1 diagnosed between 2004 and 2017. Cox proportional-hazard models stratified for cT stage were used to predict 10-yr ACM. A total of 30 195 patients (25 121 cT1a, 4884 cT1b, and 190 cT3a <4 cm) who underwent PN with median follow-up of 64.36 mo (interquartile range 42.91-93.77) were included. Cox analysis revealed no significant difference in 10-yr ACM between cT1a and cT3a <4 cm (hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.58-1.90; p = 0.88). However, the cT1b group had higher ACM (HR 1.31, 95% CI 1.15-1.48; p < 0.01). The positive surgical margin (PSM) rate was higher for cT3a <4 cm than for cT1a tumors (14.2% vs 6.3%; p < 0.01). However, there was no difference in 10-yr ACM rate between cT1a and cT3a <4 cm (10.9% vs 9.7%; p = 0.42). Our results suggest that PN is an option for cT3a RCC <4 cm, particularly in cases in which maximum nephron preservation is essential, such as patients with chronic kidney disease or a solitary kidney, although a higher PSM risk should be appreciated. PATIENT SUMMARY: We found that partial removal of the kidney for localized advanced kidney cancer is safe. The rate of surgical margins positive for the presence of tumor is higher in localized advanced kidney cancer than for less advanced cancers, but there was no difference in 10-year predicted mortality.

On-Clamp vs. Off-Clamp Robot-Assisted Partial Nephrectomy for cT2 Renal Tumors: Retrospective Propensity-Score-Matched Multicenter Outcome Analysis

We compared perioperative outcomes after on-clamp versus off-clamp robot-assisted partial nephrectomy (RAPN) for >7 cm renal masses. A multicenter dataset was queried for patients who had undergone RAPN for a cT2cN0cM0 kidney tumor from July 2007 to February 2022. The Trifecta achievement (negative surgical margins, no severe complications, and ≤ 30% postoperative estimated glomerular filtration rate (eGFR) reduction) was considered a surrogate of surgical quality. Overall, 316 cases were included in the analysis, and 58% achieved the Trifecta. A propensity-score-matched analysis generated two cohorts of 89 patients homogeneous for age, ASA score, preoperative eGFR, and RENAL score (all p > 0.21). Compared to the on-clamp approach, OT was significantly shorter in the off-clamp group (80 vs. 190 min; p < 0.001), the incidence of sRFD was lower (22% vs. 40%; p = 0.01), and the Trifecta rate higher (66% vs. 46%; p = 0.01). In a crude analysis, >20 min of hilar clamping was associated with a significantly higher risk of sRFD (OR: 2.30; 95%CI: 1.13−4.64; p = 0.02) and with reduced probabilities of achieving the Trifecta (OR: 0.46; 95%CI: 0.27−0.79; p = 0.004). Purely off-clamp RAPN seems to be a safe and viable option to treat cT2 renal masses and may outperform the on-clamp approach regarding perioperative surgical outcomes.

Predictive features of pre-operative computed tomography and magnetic resonance imaging for advanced disease in renal cell carcinoma

OBJECTIVE

We evaluated predictive features of pre-operative computed tomography and magnetic resonance imaging for advanced disease in renal cell carcinoma.

MATERIALS AND METHODS

92 patients with pathologically confirmed diagnosis of renal cell carcinoma were included in our study. Patients were divided into two groups according to preoperative imaging as computed tomography (CT) (55 patients) and magnetic resonance imaging (MRI) (37 patients). Within the imaging groups, the patients were divided into two groups according to pathological tumor stage: 1-2 (pT1-2) versus ≥ pT3a. It was evaluated whether there was a difference between the two groups in terms of the presence of pre-operative imaging (CT and MRI) features. Predictive value of these features for ≥ pT3a disease was evaluated both for CT and MRI.

RESULTS

The cut-off value for the Gerota's fascia thickness in predicting ≥ pT3a disease was calculated as 0.205 cm. Positive predictive value (PPV) for Gerota's fascia thickness was 52.4% (31.0-73.7) and 66.7% (40.0-93.3) for CT and MRI respectively. The PPV value for renal capsule invasion was 75.0% (53.8-96.2) and 90.0% (71.4-108.6) for CT and MRI respectively. PPV of perirenal fat invasion for CT and MRI was 69.2% (44.1-94.3) and 81.8% (59.0-104.6) respectively.

CONCLUSION

Renal capsular invasion and perirenal fat invasion are reliable signs for locally advanced (≥ pT3a) renal cell carcinoma both in CT and MRI. Gerota's fascia thickness has relatively low PPV value for prediction of locally advanced disease. Presence of enlarged collateral vessels, tumor necrosis, perinephric stranding are not reliable signs. For all predictors MRI seems more reliable than CT.

The changing trends of image-guided biopsy of small renal masses before intervention-an analysis of European multinational prospective EuRECA registry

Objectives

To evaluate the use of pre-cryoablation biopsy for small renal masses (SRMs) and the effects of increasing uptake on histological results of treated SRMs.

Methods

From 2015 to 2019, patients with sporadic T1N0M0 SRMs undergoing percutaneous, laparoscopic, or open cryoablation from 14 European institutions within the European Registry for Renal Cryoablation (EuRECA) were included for the retrospective analysis. Univariate and multivariate logistic models were used to evaluate the trends, histological results, and the factors influencing use of pre-cryoablation biopsy.

Results

In total, 871 patients (median (IQR) age, 69 (14), 298 women) undergoing cryoablation were evaluated. The use of pre-cryoablation biopsy has significantly increased from 42% (65/156) in 2015 to 72% (88/122) in 2019 (p < 0.001). Patients treated for a benign histology are significantly more likely to have presented later in the trend, where pre-cryoablation biopsy is more prevalent (OR: 0.64, 95% CI 0.51–0.81, p < 0.001). Patients treated for undiagnosed histology are also significantly less likely to have presented in 2018 compared to 2016 (OR 0.31, 95% CI 0.10–0.97, p = 0.044). Patients aged 70+ are less likely to be biopsies pre-cryoablation (p < 0.05). R.E.N.A.L. nephrometry score of 10+ and a Charlson Comorbidity Index > 1 are factors associated with lower likelihood to not have received a pre-cryoablation biopsy (p < 0.05).

Conclusion

An increased use of pre-cryoablation biopsy was observed and cryoablation patients treated with a benign histology are more likely to have presented in periods where pre-cryoablation biopsy is not as prevalent. Comparative studies are needed to draw definitive conclusions on the effect of pre-cryoablation biopsy on SRM treatments.

Key Points

• The use of biopsy pre-ablation session has increased significantly from 42% of all patients in 2015 to 74% in 2019.

• Patients are less likely to be treated for a benign tumour if they presented later in the trend, where pre-cryoablation biopsy is more prevalent, compared to later in the trend (OR 0.64, 95% CI 0.51–0.81, p < 0.001).

• Patients with comorbidities or a complex tumour (R.E.N.A.L. nephrometry score > 10) are less likely to not undergo biopsy as a separate session to cryoablation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-022-08556-2.

piRNAs and PIWI Proteins as Diagnostic and Prognostic Markers of Genitourinary Cancers

piRNAs (PIWI-interacting RNAs) are small non-coding RNAs capable of regulation of transposon and gene expression. piRNAs utilise multiple mechanisms to affect gene expression, which makes them potentially more powerful regulators than microRNAs. The mechanisms by which piRNAs regulate transposon and gene expression include DNA methylation, histone modifications, and mRNA degradation. Genitourinary cancers (GC) are a large group of neoplasms that differ by their incidence, clinical course, biology, and prognosis for patients. Regardless of the GC type, metastatic disease remains a key therapeutic challenge, largely affecting patients’ survival rates. Recent studies indicate that piRNAs could serve as potentially useful biomarkers allowing for early cancer detection and therapeutic interventions at the stage of non-advanced tumour, improving patient’s outcomes. Furthermore, studies in prostate cancer show that piRNAs contribute to cancer progression by affecting key oncogenic pathways such as PI3K/AKT. Here, we discuss recent findings on biogenesis, mechanisms of action and the role of piRNAs and the associated PIWI proteins in GC. We also present tools that may be useful for studies on the functioning of piRNAs in cancers.

Association of Extrarenal Invasion Patterns and Tumor Size with the Differences in Survival Outcomes of T3a Renal Cell Carcinoma: A Proposal Modified T3a Stage System is Needed

Objective

T3a renal cell carcinoma (RCC) did not consider tumor size and different extrarenal invasion patterns in the current TNM staging system. Here, we want to investigate the association of survival outcomes with different extrarenal invasion patterns and tumor size of T3a RCC.

Methods

We identified T3a RCC patients from the Surveillance, Epidemiology, and End Results database in 2004–2015. The extrarenal invasion patterns included renal vein invasion, renal sinus/peri-sinus fat invasion, or perinephric fat invasion. Cox proportional hazards models and Fine and Gray models were used to estimate overall survival (OS) and cancer-specific survival (CSS), and the hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. C-index is used to evaluate the predictive ability of the model. Restricted cubic splines were used to estimate the HRs of tumor size on the risk of OS and CSS.

Results

In total, 4834 T3a RCC patients were included in the analysis. Of them, 1403 (29%) present isolated extrarenal invasion pattern, while 1403 (71%) were any combined invasion pattern, which was associated with a higher risk of lymph-node/distant metastasis and a worse OS and CSS compared with isolated extrarenal invasion pattern, but a comparable CSS and OS were observed between each isolated invasion pattern. In restricted cubic splines, a non-linear shape was observed for the association between the tumor size and OS and CSS, compared with the smallest tumor size group (≤4cm), the adjusted HR of the largest tumor size group (≥10cm) was 1.59 for all-cause mortality, and 2.27 for tumor-specific mortality, respectively. However, in a cohort of T3a RCC with a combined invasion pattern, tumor size is not an independent risk factor for prognosis. Finally, the model added two covariates of tumor size and invasion patterns that could improve the predictive ability of OS and CSS for T3a patients (c-index: +1.2%, +1.3%, respectively).

Conclusion

Tumor size and extrarenal invasion type are valid parameters of the OS and CSS for T3a RCC patients and need to be considered for the next generation of the T-stage system.

U-Net Modelling-Based Imaging MAP Score for Tl Stage Nephrectomy: An Exploratory Study

We evaluate the stability of the clinical application of the MAP scoring system based on anatomical features of renal tumour images, explore the relevance of this scoring system to the choice of surgical procedure for patients with limited renal tumours, and investigate the effectiveness of automated segmentation and reconstruction 3D models of renal tumour images based on U-net for interpretative cognitive navigation during laparoscopy Tl stage radical renal tumour cancer surgery. A total of 5 000 kidney tumour images containing manual annotations were applied to the training set, and a stable and efficient full CNN algorithm model oriented to clinical needs was constructed to regionalism and multistructure and to finely automate segmentation of kidney tumour images, output modelling information in STL format, and apply a tablet computer to intraoperatively display the Tl stage kidney tumour model for cognitive navigation. Based on a training sample of MR images from 201 patients with stage Tl renal tumour cancer, an adaptation of the classical U-net allows individual segmentation of important structures such as renal tumours and 3D visualisation to visualise the structural relationships and the extent of tumour invasion at key surgical sites. The preoperative CT and clinical data of 225 patients with limited renal tumours treated surgically at our hospital from August 2011 to August 2012 were retrospectively analysed by three imaging physicians using the MAP scoring system for the total score and the variables R (maximum diameter), E (exogenous/endogenous), N (distance from the renal sinus), A (ventral/dorsal), L (relationship along the longitudinal axis of the kidney), and h (whether in contact with the renal hilum). The score for each variable (contact with the renal hilum) was statistically compared with each other for the three observers. Patients were divided into three groups according to the total score-low, medium, and high-and according to the surgical procedure-radical and partial resection. The correlation between the total score and the score of each variable and the choice of surgical procedure was analysed. The agreement rate of the total score and the score of each variable for all three observers was over 90% (P ≤ 0.001). The map scoring system based on the anatomical features of renal tumour imaging was well stabilized, and the scores were significantly correlated with the surgical approach.

Kidney tumor diffusion-weighted magnetic resonance imaging derived ADC histogram parameters combined with patient characteristics and tumor volume to discriminate oncocytoma from renal cell carcinoma

PURPOSE

To assess the ability to discriminate oncocytoma from RCC based on a model using whole tumor ADC histogram parameters with additional use of tumor volume and patient characteristics.

METHOD

In this prospective study, 39 patients (mean age 65 years, range 28-79; 9/39 (23%) female) with 39 renal tumors (32/39 (82%) RCC and 7/39 (18%) oncocytoma) underwent multiparametric MRI between November 2014 and June 2018. Two regions of interest (ROIs) were drawn to cover both the entire tumor volume and a part of healthy renal cortex. ROI ADC maps were calculated using a mono-exponential model and ADC histogram distribution parameters were calculated. A logistic regression model was created using ADC histogram parameters, radiographic and patient characteristics that were significantly different between oncocytoma and RCC. A ROC curve of the model was constructed and the AUC, sensitivity and specificity were calculated. Furthermore, differences in intra-patient ADC histogram parameters between renal tumor and healthy cortex were calculated. A separate ROC curve was constructed to differentiate oncocytoma from RCC using statistically significant intra-patient parameter differences.

RESULTS

ADC standard deviation (p = 0.008), entropy (p = 0.010), tumor volume (p = 0.012), and patient sex (p = 0.018) were significantly different between RCC and oncocytoma. The regression model of these parameters combined had an ROC-AUC of 0.91 with a sensitivity of 86% and specificity of 84%. Intra-patient difference in ADC 25th percentile (p < 0.01) and entropy (p = 0.030) combined had a ROC-AUC of 0.86 with a sensitivity and specificity of 86%, and 81%, respectively.

CONCLUSION

A model combining ADC standard deviation and entropy with tumor volume and patient sex has the highest diagnostic value for discrimination of oncocytoma. Although less accurate, intra-patient difference in ADC 25th percentile and entropy between renal tumor and healthy cortex can also be used. Although the results of this preliminary study do not yet justify clinical use of the model, it does stimulate further research using whole tumor ADC histogram parameters.

How accurate is radiological imaging for perirenal fat and renal vein invasion in renal cell carcinoma?

OBJECTIVE

To evaluate the accuracy of radiological staging, especially renal venous and perirenal fat invasion, in renal cell carcinoma (RCC).

MATERIAL AND METHODS

Data of 4823 renal tumour patients from Renal Tumor Database of Association of Uro-oncology in Turkey were evaluated. Of 4823 patients, 3309 RCC patients had complete radiological, and histopathological data were included to this study. The Pearson chi-squared test (χ² ) was used to compare radiological and histopathological stages.

RESULTS

The mean (SD) age of 3309 patients was 58 (12.3). Preoperative radiological imaging was performed using computed tomography (CT) (n = 2510, 75.8%) or magnetic resonance imaging (MRI) (n = 799, 24.2%). There was a substantial concordance between radiological and pathological staging (к = 0.52, P < .001). Sensitivities of radiological staging in stages I, II, III and IV were 90.7%, 67.3%, 27.7% and 64.2%, respectively. The sensitivity in stage III was lower than the other stages. Subanalysis of stage IIIa cases revealed that, for perirenal fat invasion and renal vein invasion, sensitivity values were 15.4% and 11.3%, respectively.

CONCLUSIONS

There was a substantial concordance between radiological (CT and/or MRI) and pathological T staging in RCC. However, this is not true for T3 cases. Sensitivity of preoperative radiological imaging in patients with pT3a tumours is insufficient and lower than the other stages. Consequently, preoperative imaging in patients with T3 RCC has to be improved, in order to better inform the patients regarding prognosis of their disease.

Epigenetic Biomarkers of Renal Cell Carcinoma for Liquid Biopsy Tests

Renal cell carcinomas (RCC) account for 2–3% of the global cancer burden and are characterized by the highest mortality rate among all genitourinary cancers. However, excluding conventional imagining approaches, there are no reliable diagnostic and prognostic tools available for clinical use at present. Liquid biopsies, such as urine, serum, and plasma, contain a significant amount of tumor-derived nucleic acids, which may serve as non-invasive biomarkers that are particularly useful for early cancer detection, follow-up, and personalization of treatment. Changes in epigenetic phenomena, such as DNA methylation level, expression of microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), are observed early during cancer development and are easily detectable in biofluids when morphological changes are still undetermined by conventional diagnostic tools. Here, we reviewed recent advances made in the development of liquid biopsy-derived DNA methylation-, miRNAs- and lncRNAs-based biomarkers for RCC, with an emphasis on the performance characteristics. In the last two decades, a mass of circulating epigenetic biomarkers of RCC were suggested, however, most of the studies done thus far analyzed biomarkers selected from the literature, used relatively miniature, local, and heterogeneous cohorts, and suffered from a lack of sufficient validations. In summary, for improved translation into the clinical setting, there is considerable demand for the validation of the existing pool of RCC biomarkers and the discovery of novel ones with better performance and clinical utility.

Prognostic Evaluation of the Site of Invasion in Pathological Stage T3a Renal Cell Carcinoma

BACKGROUND/AIM

To investigate the prognostic values of fat invasion (FI) and renal vein invasion (RVI) in pT3a renal cell carcinoma (RCC), as single factors or concomitant presence.

PATIENTS AND METHODS

We retrospectively reviewed the data of 173 patients who underwent radical or partial nephrectomy for RCC in our Institution.

RESULTS

At a median follow-up time of 48 months, patients with RVI showed significantly increased risk of disease recurrence and worse cancer-specific survival (CSS) when compared to those with FI (p=0.007, p=0.022, respectively). Having combined RVI and FI did not show inferior prognosis compared to those with RVI only. In multivariable analysis, RVI was an independent factor for disease recurrence (HR=2.06, 95% CI=1.10-3.87, p=0.024) and CSS (HR=2.46, 95% CI=1.01-6.0, p=0.048).

CONCLUSION

For patients with T3a renal tumors, RVI was associated with inferior prognosis compared to those with FI.

A three-feature prediction model for metastasis-free survival after surgery of localized clear cell renal cell carcinoma

After surgery of localized renal cell carcinoma, over 20% of the patients will develop distant metastases. Our aim was to develop an easy-to-use prognostic model for predicting metastasis-free survival after radical or partial nephrectomy of localized clear cell RCC. Model training was performed on 196 patients. Right-censored metastasis-free survival was analysed using LASSO-regularized Cox regression, which identified three key prediction features. The model was validated in an external cohort of 714 patients. 55 (28%) and 134 (19%) patients developed distant metastases during the median postoperative follow-up of 6.3 years (interquartile range 3.4-8.6) and 5.4 years (4.0-7.6) in the training and validation cohort, respectively. Patients were stratified into clinically meaningful risk categories using only three features: tumor size, tumor grade and microvascular invasion, and a representative nomogram and a visual prediction surface were constructed using these features in Cox proportional hazards model. Concordance indices in the training and validation cohorts were 0.755 ± 0.029 and 0.836 ± 0.015 for our novel model, which were comparable to the C-indices of the original Leibovich prediction model (0.734 ± 0.035 and 0.848 ± 0.017, respectively). Thus, the presented model retains high accuracy while requiring only three features that are routinely collected and widely available.

Tumor Stage and Substage Predict Cancer-specific Mortality After Nephrectomy for Nonmetastatic Renal Cancer: Histological Subtype-specific Validation

BACKGROUND

For patients with nonmetastatic renal cell carcinoma (nmRCC) treated with nephrectomy, prediction of cancer-specific mortality (CSM) by T stage and substage has not been validated for the separate histological subtypes.

OBJECTIVE

To investigate the ability of pathological T stage and substage to predict CSM for patients with clear-cell, papillary, or chromophobe nmRCC treated with nephrectomy.

DESIGN, SETTING, AND PARTICIPANTS

Using the SEER database for 2004-2016, we identified 87 149 patients with T1-4 N0/X M0 nmRCC treated with nephrectomy for the clear-cell (65 715; 75.4%), papillary (14 587; 16.7%), or chromophobe (6847; 7.9%) histological subtype.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier plots and Cox regression models were used to estimate CSM.

RESULTS AND LIMITATIONS

For all three histological subtypes, patients with T1a-T3a disease exhibited more favorable CSM than patients with T3b-T4 RCC. For clear-cell RCC, there were clinically meaningful and statistically significant differences for virtually all intergroup comparisons among T1a-T3a stages. For papillary T1a-T3a RCC, clinically meaningful differences disappeared, although the statistical significance remained. For chromophobe T1a-T3a RCC, no clinically meaningful or statistically significant differences were observed. For all three histological subtypes, patients with T3b-T4 RCC exhibited virtually uniformly unfavorable CSM, with no clinically meaningful intergroup CSM differences.

CONCLUSION

The use of T stage and substage for stratification of patients with nmRCC treated with nephrectomy revealed differences in CSM among T1a-T3a cases, but not T3b-T4. The magnitude of the CSM difference was greatest for clear-cell, intermediate for papillary, and marginal for chromophobe RCC.

PATIENT SUMMARY

For patients with kidney cancer, the stage of their disease assessed after surgery on the affected kidney can predict how likely they are to die from their cancer. This prediction varies for different subtypes of kidney cancer.

Computed tomography features predicting aggressiveness of malignant parenchymal renal tumors suitable for partial nephrectomy

The aim of this study was to identify and standardize computed tomography (CT) features having a potential role in predicting aggressiveness of malignant parenchymal renal tumors suitable for partial nephrectomy (PN). We performed a non-systematic review of the recent literature to evaluate the potential impact of CT variables proposed by the Society of Abdominal Radiology Disease-Focused Panel on Renal Cell Carcinoma in predicting aggressiveness of newly diagnosed malignant parenchymal renal tumors. The analyzed variables were clinical tumor size, tumor growth rate, enhancement characteristics, amount of cystic component, polar and capsular location, tumor margins and distance between tumor and renal sinus. Unfavorable behavior was defined as: 1) renal cell carcinoma (RCC) with stage ≥pT3; 2) nuclear grade 3 or 4; 3) presence of sarcomatoid de-differentiation; or 4) non-clear cell subtypes with unfavorable prognosis (type 2 papillary RCC, collecting duct or renal medullary carcinoma, unclassified RCC). Beyond clinical tumor size, tumor growth rate, enhancement characteristics, amount of cystic component, tumor margins and distance between tumor and renal sinus are highly relevant features predicting an unfavorable behavior. Moreover, several studies supported the role of necrosis as preoperative predictor of tumor aggressiveness. Peritumoral and intratumoral vasculature as well as capsule status are emerging variables that need to be further evaluated. Tumor size, enhancement characteristics, tumor margins and distance to the renal sinus are highly relevant CT features predicting biological aggressiveness of malignant parenchymal renal tumors. Combination of these parameters might be useful to generate tools to predict the unfavorable behavior of renal tumors suitable for PN.

Using texture analysis as a predictive factor of subtype, grade and stage of renal cell carcinoma

OBJECTIVE

The aim of this study was to evaluate the correlation between the tissue texture analysis and the histological subtypes, grade and stage of the disease in patients with renal cell carcinoma (RCC).

MATERIALS AND METHODS

Seventy-seven patients who underwent computed tomography due to renal mass and diagnosed with RCC as a result of pathological examination were retrospectively analyzed. In these analyses, the demographic characteristics, pathological and radiological findings of the patients were evaluated. The masses were introduced to the Radiomics extension of the software and the first- and second-order texture analysis parameters were obtained. The correlation of these parameters with histological subtype, Fuhrman grade and TNM stage was investigated.

RESULTS

In the comparison of the Radiomics values by stages, "minimum", "Long Run Low Gray-level Emphasis" values were higher in the stage 1-2 group, while "Energy", "Total energy", "Range", "Joint Average", "Sum Average", "Gray-Level Non-Uniformity", "Short-Run High Gray-level Emphasis ", "Run Length Non-Uniformity "and "High Gray-Level Run Emphasis "values were higher in the stage 3-4 group. Of these parameters, only "Gray-Level Non-Uniformity" and "Run Length Non-Uniformity'' values were significantly lower in tumors with low Fuhrman grade (1-2) and low TNM stage (1-2). There was no statistically significant correlation between the parameters found to be significant in histological subtype differentiation and Fuhrman grade and TNM stage.

CONCLUSION

This study demonstrates that "Gray-Level Non-Uniformity" and "Run Length Non-Uniformity "parameters in the texture analysis method can be used to evaluate the prognosis in patients with RCC.

Staging of renal cell carcinoma: current progress and potential advances

Formal staging classifications for renal cell carcinoma (RCC) were first proposed in 1978 and were incorporated into the Tumour, Nodes, Metastases (TNM) system initially published by the Union Internationale Contre le Cancer (UICC) in 1978. There has been a gradual evolution of grading criteria through six separate editions of the UICC TNM Classification, with the latest edition being published in 2016. Somewhat surprisingly there were no changes to the T category criteria from the 2009 to the 2016 editions of the classification, although an erratum has subsequently been published that incorporated the minor changes included in the eighth edition of the TNM Classification published by the American Joint Committee on Cancer. Localised tumours are staged according to the size of the primary tumour, with the TNM classification recognising that these tumours may exceed 10 cm in diameter. This is unfortunate as there is good evidence to demonstrate that, for clear cell RCC, virtually all tumours >7 cm in diameter and a substantial proportion of tumours <7 cm in diameter, show extra-renal spread. Infiltration of tumour beyond the renal capsule into the peri-renal fat is also categorised as T3a, however the clinical importance of this remains unclear. The classification of microvascular invasion within the renal sinus requires clarification, as does the prognostic significance of tumour in small vessels within the kidney.

Comparison of T2N0M0 and T3aN0M0 in Predicting the Prognosis of Patients With Renal Cell Carcinoma

Background: To investigate the prognostic role of tumor size in patients with pathological T2N0M0 and T3aN0M0 renal cell carcinoma (RCC) treated by radical surgery. Methods: A total of 3,662 cases were retrospectively analyzed from the Surveillance, Epidemiology and End Results (SEER) from 2010 to 2012. Overall survival (OS) and cancer-specific survival (CSS) data were obtained. The log-rank test was used to compare survival distributions and Cox proportional hazards model was used for univariate and multivariate analyses, respectively. Results: In the low-risk T3aN0M0 (perinephric fatty infiltration or sinus fatty infiltration only) group, patients with tumor size ≤ 7 cm were associated with a better OS (P = 0.009) and CSS (P < 0.001) than those with tumor size >7 cm. However, there was no difference in OS (P = 0.129) and CSS (P = 0.539) between T2bN0M0 patients and low-risk T3aN0M0 patients with tumor size ≤ 7 cm. A new T classification grouping patients with both T2bN0M0 and T3aN0M0 with tumor diameter ≤ 7 cm into the same staging category (pT2aN0M0, pT2bN0M0+low-risk pT3aN0M0 [tumor diameter ≤ 7cm], low-risk pT3aN0M0 [tumor diameter >7 cm], high-risk pT3aN0M0) was proposed and it was found as an independent predictive variable for OS and CSS. Conclusions: Findings from the present study suggest that the reclassification of pT2N0M0 and pT3aN0M0 RCC can lead to better prediction of OS and CSS.

A Plea for Surgery in Pancreatic Metastases from Renal Cell Carcinoma: Indications and Outcome from a Multicenter Surgical Experience

BACKGROUND

Pancreatic metastases from renal-cell carcinoma (RCC-PMs) are rare. Surgery may play a role in improving overall (OS) and disease-free survival (DFS).

METHODS

Clinical-pathological features, surgery and follow-up data of patients with RCC-PMs operated on in three pancreatic surgical centers (2000-2019) were retrospectively evaluated.

RESULTS

Thirty-nine patients (21 male/18 female, averaging 65 years) were enrolled. RCC-PMs were metachronous in 36 patients (mean 94 months, up to 24 years after nephrectomy), multiple in 21 patients, and with a median size of 2.5 (range, 0.7-7.5) cm. All the patients underwent pancreatic surgery (33 standard resections, 6 limited resections). Fifteen patients had post-operative complications (morbidity 38.5%). The median DFS was 63 months, and 19 out of 36 patients showed a disease recurrence. The median OS was 134 months, and 13 out of 36 patients were alive with no evidence of disease. At univariate analysis, lymph node positivity (HR 5.1, 95% CI 1.5-18), multi-visceral resection (HR 3.4, 95% CI 1.1-10) and synchronous RCC-PMs (HR 13, 95% CI 3-55) were significantly associated with a short OS.

CONCLUSION

Surgery may allow a DFS up to 17 years in more than one third of patients, even after limited resections. Splenectomy and lymph node dissection are not mandatory.

Identification of CPT1A as a Prognostic Biomarker and Potential Therapeutic Target for Kidney Renal Clear Cell Carcinoma and Establishment of a Risk Signature of CPT1A-Related Genes

This study is aimed at investigating the expression, clinical significance, and biological role of CPT1A in kidney renal clear cell carcinoma (KIRC). We used the TCGA database and clinical pathology of tissue specimens to study the expression of CPT1A in KIRC. The expression of CPT1A in the kidney cancer tissue was significantly lower than that in the normal tissue. Survival curves demonstrated that the expression was correlated with prognosis in patients. We used the plasmid transfection method to explore the biological role of CPT1A in renal cancer cells and performed CCK-8, wound healing, and Transwell invasion experiments. The results demonstrated that CPT1A can inhibit the proliferation, migration, and invasion of renal cancer cells. Subsequently, we employed a bioinformatics analysis to further elucidate the role of CPT1A. The PPI network diagram was plotted, along with the coexpression diagram, between CPT1A and ten associated genes. The heat map was plotted, and the hazard ratio analysis of these eleven genes in KIRC was performed. Furthermore, the CPT1A, LPL, CPT2, and EHHADH genes were used to establish a reliable prognostic risk signature in KIRC. GSEA analysis demonstrated that CPT1A modulates tumor development via a variety of biological pathways in KIRC. We believe that CPT1A most likely suppresses tumor progression by employing tumor "slimming" in KIRC. Collectively, the results indicate the potential of CPT1A as a novel prognostic indicator and potential therapeutic target in KIRC.

SOX6 represses tumor growth of clear cell renal cell carcinoma by HMG domain-dependent regulation of Wnt/β-catenin signaling

Sex-determining region Y box (SOXs) are expressed in various cells and control cell fate and differentiation in a multitude of physiologic processes. SOX6, a main representative of SOXs, is involved in the regulation of carcinogenesis in various human malignancies. However, the role of SOX6 in clear cell renal cell carcinoma (ccRCC) remains unclear. In this study, SOX6 expression in ccRCC and its clinical significance were investigated. In vitro and in vivo assays were used to explore the tumor-related function and the underlying molecular mechanism of SOX6 in ccRCC. We confirmed that SOX6 was frequently downregulated in ccRCC tissues and cell lines. Besides, downregulation of SOX6 was significantly associated with larger tumor sizes, advanced tumor stage, higher Fuhrman grades, and its expression could act as an independent prognostic factor for ccRCC (hazards ratio = 0.590, P = .026). Gain/loss-of-function experiments demonstrated that SOX6 could remarkably inhibit tumor cell growth and foci formation in vitro and xenograft tumorigenesis in vivo, respectively. Mechanistically, SOX6 could influence cell cycle by regulating the G1/the S phase transition and had an inhibitory effect on Wnt/β-catenin signaling as well as its target genes, c-Myc and cyclin D1. Interesting, the tumor-suppressive function of SOX6 was proved to be dependent on its specific high-mobility-group (HMG) domain. In general, our findings indicated that SOX6 was a novel tumor suppressor and prognostic biomarker in ccRCC. SOX6 could inhibit tumor growth by negatively regulating the Wnt/β-catenin signaling pathway in an HMG domain-dependent manner in ccRCC, which might provide a novel therapeutic approach for ccRCC.

Comprehensive long-term assessment of outcomes following robot-assisted partial nephrectomy for renal cell carcinoma: the ROMe's achievement and its predicting nomogram

BACKGROUND

We proposed a new tool (named ROMe's) to summarize long-term outcomes after partial nephrectomy (PN), identified its predictors and generated a predicting nomogram.

METHODS

A retrospective analysis of a multicenter dataset of patients with non-metastatic pT1-3a renal cell carcinoma was performed. Baseline demographic, clinical, pathologic and perioperative data were collected. ROMe's was defined as the concomitant lack of cancer-recurrences, death and newly onset Chronic Kidney Disease (CKD), at long term follow-up. Kaplan-Meier method investigated the predictive role of Trifecta on ROMe's achievement. Univariable and multivariable Cox regression analyses identified its predictors. A nomogram was generated and its accuracy was quantified using concordance index (CI). A calibration plot was obtained with 200 bootstraps resampling to explore nomogram performance at 5 years and decision curve analyses (DCA) assessed the net benefit of the model at 12, 36 and 60 months.

RESULTS

We included 927 patients. The rates of ROMe's were 82%, 72% and 56% at 1, 3 and 5 years follow-up. At Kaplan-Meier analysis, patients who achieved Trifecta displayed a significantly higher probability of ROMe's (log rank P<0.001). Young age (OR=0.982; P=0.001), low RENAL score (OR=0.86; P=0.037), high preoperative filtration rate (OR=1.02; P<0.001) and Trifecta achievement (OR=2.03; P=0.015), were independent predictors of ROMe's. The nomogram showed a CI of 0.76 at 60 months. The 5-years calibration plot confirmed a good discrimination accuracy (0.74); on DCA, the net benefit of using the model was evident for probabilities >30%.

CONCLUSIONS

We conceived a triad to summarize the main long-term oncologic and functional outcomes after PN and generated a predicting nomogram.

Extracellular vesicle isolation from human renal cancer tissue

Renal cell carcinoma is a lethal disease that is often discovered incidentally. New non-invasive biomarkers are needed to aid diagnosis and treatment. Extracellular vesicles (EVs), membranous vesicles secreted by all cells, are a promising potential source for cancer biomarkers, but new methods are required that are both sensitive and specific for cancer identification. We have developed an EV isolation protocol optimized for kidney tumor and normal kidney tissue that yields a high vesicle concentration, confirmed by nanoparticle tracking analysis (NanoSight) and by nanoscale flow cytometry (NanoFCM). Using Western blot, we confirmed presence of EV markers CD81, CD63, flotillin-1, and absence of cellular debris, calnexin. Transmission electron microscopy images demonstrate intact membranous EVs. This new method improves existing protocols with additional steps to reduce contaminants in the EV product. Characterization of our isolation product confirms successful isolation of EVs with minimal contamination. The particle yields of our protocol are consistent and high as assessed by both standard and novel methods. This optimized protocol will contribute to biomarker discovery and biological studies of EVs in renal cancer.

Calcitriol inhibits migration and invasion of renal cell carcinoma cells by suppressing Smad2/3-, STAT3- and β-catenin-mediated epithelial-mesenchymal transition

Low vitamin D status is associated with progression in patients with renal cell carcinoma (RCC). The present study found that vimentin, a mesenchymal marker, was accordingly upregulated, and E-cadherin, an epithelial marker, was downregulated in RCC patients with low vitamin D status. Thus, we investigated the effects of calcitriol or vitamin D3, an active form of vitamin D, on epithelial-mesenchymal transition (EMT) in RCC cells. RCC cells were treated by two models. In model 1, three RCC cell lines, ACHN, 786-O and CAKI-2, were incubated with either LPS (2.0 μg/mL) or transforming growth factor (TGF)-β1 (10 ng/mL) in the presence or absence of calcitriol (200 nmol/L). In model 2, two RCC cell lines, ACHN and CAKI-2, were incubated with calcitriol (200 nmol/L) only. Calcitriol inhibited migration and invasion not only in TGF-β1-stimulated but also in TGF-β1-unstimulated RCC cells. Moreover, calcitriol suppressed E-cadherin downregulation and vimentin upregulation not only in TGF-β1-stimulated but also in TGF-β1-unstimulated ACHN and CAKI-2 cells. Calcitriol attenuated LPS-induced upregulation of MMP-2, MMP-7, MMP-9, MMP-26 and urokinase-type plasminogen activator (u-PA) in ACHN cells. In addition, calcitriol blocked TGF-β1-induced nuclear translocation of ZEB1, Snail and Twist1 in ACHN and CAKI-2 cells. Mechanistically, calcitriol suppressed EMT through different signaling pathways: (i) calcitriol suppressed Smad2/3 phosphorylation by reinforcing physical interaction between vitamin D receptor (VDR) and Smad3 in TGF-β1-stimulated RCC cells; (ii) calcitriol inhibited signal transducer and activator of transcription (STAT)3 activation in LPS-stimulated RCC cells; (iii) calcitriol inhibited β-catenin/TCF-4 activation by promoting integration of VDR with β-catenin in TGF-β1-unstimulated RCC cells. Taken together, calcitriol inhibits migration and invasion of RCC cells partially by suppressing Smad2/3-, STAT3- and β-catenin-mediated EMT.

Cell Adhesion-Related Molecules Play a Key Role in Renal Cancer Progression by Multinetwork Analysis

Renal cell carcinoma (RCC) is one of the most common malignancies in the urinary system. The study aimed to identify genetic characteristics and reveal the underlying mechanisms in RCC. GSE53757, GSE46699, and TCGA KIRC database (n = 897) were analyzed to screen differentially expressed genes (DEGs) in RCC. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, followed by the analysis of the protein-protein interaction (PPI) network of the DEGs by Cytoscape software. In all, 834 DEGs were identified in RCC, including 416 upregulated genes and 418 downregulated genes. The top 10 hub genes, VEGFA, EGFR, EGF, CD44, CD86, FN1, ITGAM, ITGB2, TLR2, and PTPRC, were identified from the PPI network according to the core degree. The following subnetwork revealed that these significant modules were enriched in positive regulation of response to external stimulus, regulation of leukocyte-mediated immunity, and regulation of exocytosis. The expressions of these hub genes were also validated using qRT-PCR and IHC in Changzheng RCC database (n = 160). We especially found that half of the top ten hub genes were cell adhesion-related molecules, which were associated with RCC progression and poor prognosis. In conclusion, these hub genes, particularly cell adhesion-related molecules, could be used as prognostic biomarkers and potential therapeutic targets for RCC.

Surgical quality, cancer control and functional preservation: introducing a novel trifecta for robot-assisted partial nephrectomy

BACKGROUND

In order to improve standard reporting of outcomes after partial nephrectomy, different "trifecta" systems have been conceived. The subjective assessment of the included parameters and the unreliability for off-clamp procedures limited their reproducibility; their role in predicting functional and oncologic outcomes has never been assessed. We propose a new trifecta, based on standardized parameters, that summarizes PN outcomes regardless the clamping technique used and predicts main clinical outcomes.

METHODS

A retrospective analysis of a multicenter, multi-national dataset of patients with non-metastatic cT1-2 renal masses undergoing Robot-assisted partial nephrectomy was performed. Baseline demographic, clinical, pathologic and perioperative data were collected. Trifecta was defined as the coexistence of negative margins, no Clavien-Dindo ≥3 complications and ≤30% postoperative estimated glomerular filtration rate reduction. Univariable and multivariable regression analyses identified predictors of trifecta achievement. Kaplan-Meier method assessed differences in oncological outcomes between patients achieving trifecta or not. Univariable and multivariable Cox regression analysis identified predictors of newly onset chronic kidney disease stage ≥IIIa, recurrence-free and overall survival.

RESULTS

Overall, 1492 patients achieved trifecta. This cohort displayed significantly lower incidence of newly onset IIIa-V chronic kidney disease stages (all P<0.001), higher recurrence-free (P=0.009) and overall (P=0.014) survival probabilities. Patients achieving trifecta had a 65% reduced risk of developing newly onset stage IIIb-V Chronic Kidney Disease and a 55% reduced risk of overall mortality. Heterogeneity of surgical technique is a limitation.

CONCLUSIONS

This novel reproducible trifecta is based on standardized parameters and is an independent predictor of severe chronic kidney disease development and mortality.

Evaluation of individual and cumulative sites of extrarenal tumor invasion in pT3a clear cell renal cell carcinoma

INTRODUCTION

The Tumor-Node-Metastasis classification of renal cell carcinoma (RCC) for pT3a tumors includes sinus fat invasion (SFI), perinephric fat invasion (PFI), renal vein invasion (RVI), and/or pelvicaliceal system invasion (PSI). The purpose of this study was to determine the association between these patterns of invasion (assessed individually and cumulatively) with the development of metastases and cancer-specific mortality (CSM).

MATERIALS AND METHODS

We identified 160 patients who underwent radical nephrectomy for pT3a clear cell RCC between 2011 and 2017. The association between individual patterns of invasion and metastases and cancer-specific survival were evaluated with multivariate logistic regression. Cox Hazard proportion ratios and Kaplan-Meier survival curves were generated for patterns of invasion (assessed individually and cumulatively).

RESULTS

The number of individual invasive patterns was as follows: 97/160 (61%) presented with RVI, 91/160 with SFI (57%), 62/160 with PFI (39%), and 24/160 (15%) with PSI. At multivariate analysis, both PFI and RVI were associated with metastases (P < 0.001 and 0.028, respectively). PFI (hazard ratio [HR] 4.12, 95% confidence interval [CI] 2.14-7.92; P < 0.001), RVI (HR 2.44, 95% CI 1.18-5.01; P = 0.015), SFI (HR 2.13, 95% CI 1.05-4.34; P = 0.036) had higher CSM, while PSI (HR 1.43, 95% CI 0.65-3.16; p = 0.38) did not show increased CSM. Furthermore, cumulative analysis showed that multiple invasive patterns resulted in worse CSM (p < 0.001).

CONCLUSIONS

In our study, PFI was associated with the most aggressive behavior while PSI was the most indolent. Furthermore, the presence of more than one pattern of invasion was associated with worse CSM. These results indicate that reporting of the individual location and cumulative amount of pT3a patterns of invasion in clear cell RCC is clinically relevant.

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.

Extracellular vesicles in urologic malignancies-Implementations for future cancer care

Extracellular vesicles (EVs), a heterogeneous group of vesicles differing in size and shape, cargo content and function, are membrane-bound and nano-sized vesicles that could be released by nearly all variations of cells. EVs have gained considerable attention in the past decades for their functions in modulating intercellular signalling and roles as potential pools for the novel diagnostic and prognostic biomarkers, as well as therapeutic targets in several cancers including urological neoplasms. In general, human and animal cells both can release distinct types of EVs, including exosomes, microvesicles, oncosomes and large oncosomes, and apoptotic bodies, while the content of EVs can be divided into proteins, lipids and nucleic acids. However, the lack of standard methods for isolation and detection platforms rein the widespread usage in clinical applications warranted furthermore investigations in the development of reliable, specific and sensitive isolation techniques. Whether and how the EVs work has become pertinent issues. With the aid of high-throughput proteomics or genomics methods, a fully understanding of contents contained in EVs from urogenital tumours, beyond all doubt, will improve our ability to identify the complex genomic alterations in the process of cancer and, in turn, contribute to detect potential therapeutic target and then provide personalization strategy for patient.

RAC2 acts as a prognostic biomarker and promotes the progression of clear cell renal cell carcinoma

As one of the most commonly reported malignancies of the urinary system, clear cell renal cell carcinoma (ccRCC) is an advanced metastatic tumor with high mortality rates. The Rac family small GTPase 2 (RAC2) is a member of the Rho GTPases. Although Rho GTPases play an important role in numerous different types of tumor, whether they have functions in ccRCC remains uncertain. The present study utilized bioinformatics analyses in order to compare the expression levels of RAC2 in ccRCC tumors vs. adjacent tissues, and assessed the association between RAC2 expression and clinicopathological parameters. Furthermore, reverse transcription‑quantitative PCR, western blotting and immunohistochemistry assays were performed to validate RAC2 expression levels in human ccRCC tissues and cell lines. Functional experiments were also conducted in order to identify the roles of RAC2 in vitro. The results revealed that RAC2 was upregulated in ccRCC tissues and cell lines. In addition, elevated expression levels of RAC2 were significantly associated with a poor overall survival (P=0.0061), higher Tumor‑Node‑Metastasis stage and worse G grade. Receiver operating characteristic analysis indicated that high expression levels of RAC2 could be a diagnostic index for ccRCC (area under the curve, 0.9095; P<0.0001). Furthermore, knockdown of RAC2 in vitro attenuated the proliferation, migration and invasion of renal carcinoma cells. In conclusion, the results of the present study demonstrated that RAC2 may act as a promising prognostic and diagnostic biomarker of ccRCC, and could be considered as a potential therapeutic target for treating ccRCC.

miR-142-3p as a novel biomarker for predicting poor prognosis in renal cell carcinoma patients after surgery

BACKGROUND

miR-142-3p has proved to be involved in tumorigenesis and the development of renal cell carcinoma. The present study aimed to explore the prognostic value of miR-142-3p.

METHODS

Total RNA was extracted from renal cell carcinoma specimens and the expression level of miR-142-3p was measured. Pearson Chi-square test, Kaplan-Meier analysis, as well as univariate and multivariate regression analysis were performed to determine the correlation between miR-142-3p and the prognosis of renal cell carcinoma patients. Receiver operating characteristic curves were constructed to evaluate the predictive efficiency of miR-142-3p for the prognosis of renal cell carcinoma patients. Data from The Cancer Genome Atlas (TCGA) were utilized to validate our findings.

RESULTS

Our results demonstrated that upregulation of miR-142-3p was correlated with shorter overall survival (P=0.002) and was, in the meantime, an independent prognostic factor for renal cell carcinoma patients (P=0.002). The receiver operating characteristic curve combining miR-142-3p expression with tumor stage showed an area under the curve of 0.633 (95% confidence interval 0.563, 0.702). The result of TCGA data was consistent with our findings.

CONCLUSIONS

Our results suggest miR-142-3p expression is correlated with poor prognosis of renal cell carcinoma patients and may serve as a prognostic biomarker in the future.

LINC00997, a novel long noncoding RNA, contributes to metastasis via regulation of S100A11 in kidney renal clear cell carcinoma

Long noncoding RNAs (lncRNAs) play an essential role in cancer development. However, the contribution of the lncRNA LINC00997 to kidney renal clear cell carcinoma (KIRC) has not been thoroughly elucidated to date. In this study, we examined the expression and biological effect of LINC00997 in KIRC development. We also investigated the potential mechanism underlying the observed effects. We found that LINC00997 is highly expressed in multiple carcinomas, being highest in stage IV KIRC in our RNA-Seq datasets. In addition, our data demonstrated that in KIRC patients, higher levels of LINC00997 are correlated with lower overall survival (OS) and disease-free survival (DFS) rates. In 18 cases of KIRC, we found that LINC00997 expression was greater in cancer tissues and metastases than in normal tissues. These results revealed that S100A11 is positively associated with LINC00997 in KIRC, which is positively correlated with metastasis-associated molecules VIM, MMP2 and MMP7. Our in vitro wound healing assay and Transwell tests demonstrated that interfering with either LINC00997 or S100A11 expression reduced migration of 786-O cells by inhibiting VIM, MMP2 and MMP7 expression. Importantly, we verified LINC00997 and STAT3 binding by RIP and determined that both LINC00997 and STAT3 bind to the S100A11 promoter, as shown by dual-luciferase reporter gene assay. In addition, inhibiting LINC00997 or STAT3 expression attenuated S100A11 levels. Consequently, the LINC00997-STAT3-S100A11 axis may promote the development of KIRC, and LINC00997 may represent a potential prognostic biomarker and therapeutic target for KIRC patients.

[Epidemiology and diagnostic assessment of small renal masses]

BACKGROUND

The incidence of small renal masses has been rising over the last few decades. At the same time, mortality of renal cell carcinoma (RCC) is decreasing. These trends can be explained by the availability of improved therapeutic measures and the good prognosis of small renal masses (SRM) turning out to be histopathologically benign or of low malignancy in many cases.

OBJECTIVES

The aim of this article is to present epidemiology and diagnostic assessment of SRM.

MATERIALS AND METHODS

Statistics, basic research, guidelines.

RESULTS

The incidence of SRM is rising due to the widespread use of imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and contrast-enhanced ultrasound (CEUS). Sensitivity is excellent for CEUS and for CECT in the characterization of SRM, while good specificity values can be reached by MRI. For characterization of complex cystic renal masses, CEUS has good diagnostic accuracy.

CONCLUSIONS

Due to improved diagnostic possibilities, SRMs can be diagnosed in early asymptomatic stages. As SRM have a good prognosis and often are of low malignancy therapy, options should be carefully considered; especially in older patients, active surveillance should considered.

Causes of Death and Conditional Survival of Renal Cell Carcinoma

Background: As conditional survival could provide more relevant prognostic information at each follow-up time, the present study aimed to assess conditional overall survival (COS) based on two cohorts and assess the risks of death due to renal cell carcinoma (RCC) vs. other causes. Methods: The Fudan University Shanghai Cancer Center (FUSCC) and Surveillance, Epidemiology, and End Results (SEER) database were used as the source of data for our analysis. COS and cancer-specific survival were evaluated using the Kaplan-Meier method. Results: A total of 90,927 patients (SEER cohort = 88,807, FUSCC cohort = 2,120) were enrolled. Our results suggest that hazards of other causes-related death were always higher than that of cancer-specific death in low-risk RCC patients, but lower in metastatic RCC patients. It exceeded that of cancer-specific death by 8 years in high-risk RCC patients. Only in metastatic RCC patients, the COS improved markedly with survivorship increasing. After surviving 1, 2, 3, 4, and 5 years, the 5 years COS increased by +10, +18, +23, +29, and 35% (the observed 5 years OS: 12%), respectively. Conclusions: COS can better help patients with metastatic RCC rather than other RCC patients. Additionally, COS brings optimism for metastatic RCC patients with expected poorer prognosis psychologically.

Influence of venous tumour extension on local and remote recurrence of stage pT3a pN0 cM0 kidney tumours

INTRODUCTION AND OBJECTIVE

One of the inherent features of kidney tumours is the capacity to spread inside the venous system as tumour thrombi. The aim of this study was to assess in patients with stage pT3apN0cM0 kidney cancer whether venous tumour involvement influenced tumour recurrence.

MATERIALS AND METHODS

A retrospective analysis of patients with stage pT3apN0cM0 kidney cancer treated with radical nephrectomy between 1990-2015. Univariate and multivariate Cox regression analysis to identify predictive variables and independent predictive variables relating to recurrence.

RESULTS

The results of 153 patients were studied. The median follow-up was 82 (IQR 36-117) months. Recurrence-free survival at 5 years was 58.9% with a median of 97 (95% CI 49.9-144.1) months. Seventy-seven (50.3%) patients recurred. Seventy cases 70 (90.9%) had distant metastases, 17 (14.2%) of these patients had local recurrence in the bed of nephrectomy. Tumour necrosis (p=.0001), and microvascular invasion (p=.001) were identified as independent predictors of tumour recurrence in the multivariable analysis.

CONCLUSIONS

In our series, after multivariable analysis, venous tumour extension was not related to recurrence. Tumour necrosis and microvascular infiltration did behave as independent predictive factors of tumour recurrence.

The prognostic value of the site of invasion in T3aN0M0 clear cell renal cell carcinoma

BACKGROUND

The 7th Tumor-Node-Metastasis system for clear cell renal cell carcinoma (ccRCC) classified renal sinus fat invasion (SFI), perirenal fat invasion (PFI), or renal vein invasion (RVI) as stage pT3a. However, their close interactions and prognostic value of them remain controversial. The goal of this study is to further analyze their prognostic values for patients with T3aN0M0 ccRCC.

METHODS

The data of 1,869 pT3aN0M0 ccRCC patients receiving the radical nephrectomy surgery were collected from the National Cancer Institute Surveillance, Epidemiology, and End Results database of United states from 2010 to 2014. These Patients were grouped as SFI, PFI, SFI + RVI, SFI + PFI, PFI + RVI, and SFI + PFI + RVI according to their corresponding manifestations. Cancer-specific survival (CSS) was determined using the Kaplan-Meier method. Univariate and Multivariate cox proportional-hazards regression methods were used to evaluate the impacts of clinical pathologic parameters on CSS.

RESULTS

Patients with SFI or PFI alone had the similar CSS (P = 0.286) and patients with SFI + PFI + RVI had the worst outcomes. Moreover, significantly more patients with SFI + PFI + RVI had tumor diameter ≥7cm than patients with PFI + RVI, SFI + PFI (68.80% vs. 65.32%, 58.77%, and 55.04%, P = 0.026), respectively. Multivariable analysis showed that RVI + PFI (P = 0.013) and PFI + SFI + RVI (P = 0.011) were the independent factors of CSS.

CONCLUSIONS

The results suggest that invasion location can help distinguish patients with T3aN0M0 ccRCC with increased risk of cancer-related mortality.

Current Landscape and the Potential Role of Hypoxia-Inducible Factors and Selenium in Clear Cell Renal Cell Carcinoma Treatment

In the last two decades, the discovery of various pathways involved in renal cell carcinoma (RCC) has led to the development of biologically-driven targeted therapies. Hypoxia-inducible factors (HIFs), angiogenic growth factors, von Hippel–Lindau (VHL) gene mutations, and oncogenic microRNAs (miRNAs) play essential roles in the pathogenesis and drug resistance of clear cell renal cell carcinoma. These insights have led to the development of vascular endothelial growth factor (VEGF) inhibitors, Mechanistic target of rapamycin (mTOR) inhibitors, and immunotherapeutic agents, which have significantly improved the outcomes of patients with advanced RCC. HIF inhibitors will be a valuable asset in the growing therapeutic armamentarium of RCC. Various histone deacetylase (HDAC) inhibitors, selenium, and agents like PT2385 and PT2977 are being explored in various clinical trials as potential HIF inhibitors, to ameliorate the outcomes of RCC patients. In this article, we will review the current treatment options and highlight the potential role of selenium in the modulation of drug resistance biomarkers expressed in clear cell RCC (ccRCC) tumors.

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.