A critical analysis of the actual role of minimally invasive surgery and active surveillance for kidney cancer. Eur Urol. 2010;57:223-232. [PMID: 19853989 DOI: 10.1016/j.eururo.2009.10.023]

Renal anatomical classification systems cannot predict the occurrence of vascular complications after partial nephrectomy

OBJECTIVES

To determine the relationship between renal tumor complexity and vascular complications after partial nephrectomy using PADUA, RENAL, and ZS scores.

METHODS

Between January 2007 and December 2018, a total of 1917 patients with available cross-sectional imaging were enrolled in the study. Logistic regressions were used to identify independent predictors of vascular complications.

RESULTS

Of 1917 patients, 31 (1.6%) developed vascular complications, including 10 females and 21 males. The high-complexity category was significantly associated with a decreased risk of vascular complication in PADUA (OR = 0.256; 95%CI = 0.086-0.762; P = 0.014) and ZS score (OR = 0.279; 95%CI = 0.083-0.946; P = 0.040). Laparoscopic partial nephrectomy and robot-assisted laparoscopic partial nephrectomy were independent risk factors for vascular complications. Meanwhile, the incidence was significantly reduced in the recent 4 years in the high score tumor group alone in PADUA (0.2% [1/474] vs. 2.2% [3/139], P = 0.038) and ZS score (0.2% [1/469] vs. 2.7% [3/112], P = 0.024). In the first 8 years, laparoscopic partial nephrectomy and robot-assisted laparoscopic partial nephrectomy were the only two independent risk factors for vascular complications. In the recent 4 years, only the high-complexity category was significantly associated with a decreased risk of vascular complication in the PADUA score (OR = 0.110; 95%CI = 0.013-0.938; P = 0.044).

CONCLUSION

The renal anatomic classification system cannot predict the occurrence of vascular complications after partial nephrectomy.

Role of AI and Radiomic Markers in Early Diagnosis of Renal Cancer and Clinical Outcome Prediction: A Brief Review

Globally, renal cancer (RC) is the 10th most common cancer among men and women. The new era of artificial intelligence (AI) and radiomics have allowed the development of AI-based computer-aided diagnostic/prediction (AI-based CAD/CAP) systems, which have shown promise for the diagnosis of RC (i.e., subtyping, grading, and staging) and prediction of clinical outcomes at an early stage. This will absolutely help reduce diagnosis time, enhance diagnostic abilities, reduce invasiveness, and provide guidance for appropriate management procedures to avoid the burden of unresponsive treatment plans. This survey mainly has three primary aims. The first aim is to highlight the most recent technical diagnostic studies developed in the last decade, with their findings and limitations, that have taken the advantages of AI and radiomic markers derived from either computed tomography (CT) or magnetic resonance (MR) images to develop AI-based CAD systems for accurate diagnosis of renal tumors at an early stage. The second aim is to highlight the few studies that have utilized AI and radiomic markers, with their findings and limitations, to predict patients' clinical outcome/treatment response, including possible recurrence after treatment, overall survival, and progression-free survival in patients with renal tumors. The promising findings of the aforementioned studies motivated us to highlight the optimal AI-based radiomic makers that are correlated with the diagnosis of renal tumors and prediction/assessment of patients' clinical outcomes. Finally, we conclude with a discussion and possible future avenues for improving diagnostic and treatment prediction performance.

Anatomical variability of kidney arterial vasculature based on zonal and segmental topography

Introduction

To date, there is no unified approach to the lobar, zonal, and segmental structure of the kidney vasculature. There is no recognizable approach to define basic characteristics in regard to the lobes and segments identifying of the kidney. The branching of the renal artery has often been the subject of scientific research. This study aimed to analyze the arterial anatomy on the basis of zonal and segmental topography.

Materials and methods

This study is a prospective cadaver study on autopsy material using corrosion casting and CT imaging techniques. The arterial vasculature was visualized using corrosive casting. In this study, 116 vascular casts were included. We identified the number of arteries in the kidney hilum, their topography, branching variations of the renal artery, and local blood supply zones of renal masses considering second- and third-order renal artery branches. We used a micro-CT BRUKER SkyScan 1178, digital camera, Mimics-8.1, and R.

Results

This study has shown that RA divides into two or three zonal arteries, forming a two- or three-zonal vascular supply system. In the case of the two-zonal system, 54.3% of cases accounted for RA branching into ventral and dorsal arteries, whereas 15.5% of cases referred to superior polar and inferior polar zonal arteries. The three-zonal system implies 4 types of RA branching: 1) superior polar, ventral, and dorsal zonal branches (12.9%); 2) ventral, dorsal, and inferior polar zonal branches (9.5%); 3) two ventral and one dorsal zonal branches (5.2%), and 4) superior polar, central, and inferior polar zonal branches (2.5%).

Conclusions

The results of this research make us reconsider Grave's classification theory.

Predictive Value of CT-Based Radiomics in Distinguishing Renal Angiomyolipomas with Minimal Fat from Other Renal Tumors

Objectives

This study is aimed at determining whether CT-based radiomics models can help differentiate renal angiomyolipomas with minimal fat (AMLmf) from other solid renal tumors.

Methods

This retrospective study included 58 patients with a postoperative pathologically confirmed AMLmf (observation group) and 140 patients with other common renal tumors (control group). Non-contrast-enhanced CT and contrast-enhanced CT data were evaluated. Radiomics features were extracted from manually delineated volume of interest (VOIs). The least absolute shrinkage and selection operator (LASSO) regression was used for feature screening. Five classifiers, including logistic regression, multilayer perceptron (MLP), support vector machine (SVM), k-nearest neighbor (KNN), and logistic regression (LR), were used, with leave-out validation (128 training, 60 testing). The diagnostic performance of the classifier was evaluated and compared by receiver operating characteristic curve (ROC) analysis.

Results

Among the 1029 extracted features, prediction models of AMLmf were composed, by 2, 10, 4, and 9 selected features for precontrast phase (PCP), corticomedullary phase (CMP), nephrographic phase (NP), and excretory phase (EP), respectively. Models of CMP and NP achieved adequate performance after using MLP classifier, with prediction accuracy of 0.767 (AUC 0.85, sensitivity 0.76, and specificity 0.78) and 0.783 (AUC 0.83, sensitivity 0.79, and specificity 0.78), respectively. MLP model of features selected from the combination of the all features had the best diagnostic performance (accuracy 0.8500, sensitivity 0.8095, specificity 0.9444, and AUC 0.9193).

Conclusions

Radiomics features may help to distinguish benign AMLmf from common malignant kidney masses, which may contribute to the selection of interventions for renal tumors.

A Comprehensive Computer-Assisted Diagnosis System for Early Assessment of Renal Cancer Tumors

Renal cell carcinoma (RCC) is the most common and a highly aggressive type of malignant renal tumor. In this manuscript, we aim to identify and integrate the optimal discriminating morphological, textural, and functional features that best describe the malignancy status of a given renal tumor. The integrated discriminating features may lead to the development of a novel comprehensive renal cancer computer-assisted diagnosis (RC-CAD) system with the ability to discriminate between benign and malignant renal tumors and specify the malignancy subtypes for optimal medical management. Informed consent was obtained from a total of 140 biopsy-proven patients to participate in the study (male = 72 and female = 68, age range = 15 to 87 years). There were 70 patients who had RCC (40 clear cell RCC (ccRCC), 30 nonclear cell RCC (nccRCC)), while the other 70 had benign angiomyolipoma tumors. Contrast-enhanced computed tomography (CE-CT) images were acquired, and renal tumors were segmented for all patients to allow the extraction of discriminating imaging features. The RC-CAD system incorporates the following major steps: (i) applying a new parametric spherical harmonic technique to estimate the morphological features, (ii) modeling a novel angular invariant gray-level co-occurrence matrix to estimate the textural features, and (iii) constructing wash-in/wash-out slopes to estimate the functional features by quantifying enhancement variations across different CE-CT phases. These features were subsequently combined and processed using a two-stage multilayer perceptron artificial neural network (MLP-ANN) classifier to classify the renal tumor as benign or malignant and identify the malignancy subtype as well. Using the combined features and a leave-one-subject-out cross-validation approach, the developed RC-CAD system achieved a sensitivity of 95.3%±2.0%, a specificity of 99.9%±0.4%, and Dice similarity coefficient of 0.98±0.01 in differentiating malignant from benign tumors, as well as an overall accuracy of 89.6%±5.0% in discriminating ccRCC from nccRCC. The diagnostic abilities of the developed RC-CAD system were further validated using a randomly stratified 10-fold cross-validation approach. The obtained results using the proposed MLP-ANN classification model outperformed other machine learning classifiers (e.g., support vector machine, random forests, relational functional gradient boosting, etc.). Hence, integrating morphological, textural, and functional features enhances the diagnostic performance, making the proposal a reliable noninvasive diagnostic tool for renal tumors.

Natural history and growth kinetics of clear cell renal cell carcinoma in sporadic and von Hippel-Lindau disease

Background

To evaluate and compare the natural history and growth kinetics of sporadic clear cell renal cell carcinoma (ccRCC) with those of ccRCC in von Hippel-Lindau disease (VHL).

Methods

Sixty patients in the sporadic group with 61 tumors and 15 patients in the VHL group with 30 tumors whom all underwent delayed surgery after at least 12 months of active surveillance (AS) were enrolled to conduct a retrospective cohort study. The growth rate was calculated, and the growth kinetics between the sporadic and VHL groups were compared. The patient and tumor characteristics were reviewed, and their correlation with growth rate was analyzed.

Results

The mean growth rate of sporadic ccRCC was 0.91 cm/year (ranging from 0–4.74 cm/year) and that of VHL ccRCC was 0.47 cm/year (ranging from 0.04–1.89 cm/year). The growth rate of sporadic ccRCC showed a tendency of being faster than that of VHL ccRCC but did not reach statistical significance (P=0.07). The factors affecting the growth rate were different between the two groups. For VHL ccRCC, the only factor that correlated with growth rate was initial tumor diameter (P<0.001), but for sporadic ccRCC, the only factor was pathological nuclear grade (P<0.001).

Conclusions

The growth rate of VHL-associated ccRCC might be slower than that of sporadic ccRCC. Furthermore, we identified a disparity in growth kinetics between sporadic and VHL-associated ccRCC.

Impact of postoperative acute kidney injury on predicting the upstaging of chronic kidney disease after robot-assisted partial nephrectomy

INTRODUCTION

The aim of our study was to assess the impact of acute kidney injury (AKI) on postoperative upstaging of chronic kidney disease (CKD) after robot-assisted partial nephrectomy (RAPN).

METHODS

This study consisted of 110 patients who had undergone RAPN and were followed up for at least 6 months after surgery. Patients were classified as AKI or non-AKI based on their serum creatinine level and estimated glomerular filtration rate within 7 days after surgery. Patient characteristics, outcome of RAPN and estimated glomerular filtration rate, and CKD upstage 6 months after surgery were compared between the AKI and non-AKI groups.

RESULTS

A total of 26 patients (23.6%) experienced AKI after surgery. RENAL (radius, exophytic/endophitic properties, nearness of the tumor to the collecting system or sinus, anterior/posterior, location relative to the polar lines) nephrometry scores were ≥7 for 22 (84.6%) in the AKI group and 39 (46.4%) in the non-AKI group (P = .0006). A significantly smaller proportion of patients in the AKI group than in the non-AKI group recovered 90% of baseline function (38.5% vs 81.0%, P < .0001). CKD upstaging occurred in a total of 27 patients 24.5%) and in a significantly larger proportion of patients in the AKI group than in the non-AKI group (42.3% vs 19.0%, P = .0160). There was no significant difference in characteristics and perioperative outcomes between the patients with and without CKD, except for in those experiencing AKI.

CONCLUSION

After RAPN, AKI can be associated with CKD upstaging.

Deep Learning Based on MRI for Differentiation of Low- and High-Grade in Low-Stage Renal Cell Carcinoma

Pretreatment determination of renal cell carcinoma aggressiveness may help to guide clinical decision-making.

PURPOSE

To evaluate the efficacy of residual convolutional neural network using routine MRI in differentiating low-grade (grade I-II) from high-grade (grade III-IV) in stage I and II renal cell carcinoma.

STUDY TYPE

Retrospective.

POPULATION

In all, 376 patients with 430 renal cell carcinoma lesions from 2008-2019 in a multicenter cohort were acquired. The 353 Fuhrman-graded renal cell carcinomas were divided into a training, validation, and test set with a 7:2:1 split. The 77 WHO/ISUP graded renal cell carcinomas were used as a separate WHO/ISUP test set.

FIELD STRENGTH/SEQUENCE

1.5T and 3.0T/T₂ -weighted and T₁ contrast-enhanced sequences.

ASSESSMENT

The accuracy, sensitivity, and specificity of the final model were assessed. The receiver operating characteristic (ROC) curve and precision-recall curve were plotted to measure the performance of the binary classifier. A confusion matrix was drawn to show the true positive, true negative, false positive, and false negative of the model.

STATISTICAL TESTS

Mann-Whitney U-test for continuous data and the chi-square test or Fisher's exact test for categorical data were used to compare the difference of clinicopathologic characteristics between the low- and high-grade groups. The adjusted Wald method was used to calculate the 95% confidence interval (CI) of accuracy, sensitivity, and specificity.

RESULTS

The final deep-learning model achieved a test accuracy of 0.88 (95% CI: 0.73-0.96), sensitivity of 0.89 (95% CI: 0.74-0.96), and specificity of 0.88 (95% CI: 0.73-0.96) in the Fuhrman test set and a test accuracy of 0.83 (95% CI: 0.73-0.90), sensitivity of 0.92 (95% CI: 0.84-0.97), and specificity of 0.78 (95% CI: 0.68-0.86) in the WHO/ISUP test set.

DATA CONCLUSION

Deep learning can noninvasively predict the histological grade of stage I and II renal cell carcinoma using conventional MRI in a multiinstitutional dataset with high accuracy.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

NSD2 Promotes Renal Cancer Progression Through Stimulating Akt/Erk Signaling

Background

Nuclear receptor suppressor of variegation, enhancer of zeste, and trithorax (SET) domain-containing 2 (NSD2), is a well-known histone lysine methyltransferase (HMTase). The aim of this study was to investigate the biological role of NSD2 in clear cell renal cell carcinoma (ccRCC).

Methods

GEO and OncoLnc databases were used to identify NSD2 expression and estimate its clinical value in ccRCC. Immunohistochemistry (IHC) was applied to further evaluate NSD2 protein level in ccRCC tissues. The expression of NSD2 in different cell lines and the transfection efficiency were determined by quantitative real-time PCR and Western blot analysis. The effect of NSD2 and the underlying mechanism in ccRCC progression were investigated via MTT, flow cytometry, Western blotting and xenograft tumor assays.

Results

NSD2 was over-expressed in both ccRCC tissues and cell lines. NSD2 expression could discriminate ccRCC samples from normal samples, and moreover, high NSD2 expression was characterized with a short overall survival (OS) time. Additionally, knockdown of NSD2 suppressed proliferation and induced apoptosis of cancer cells by inhibiting Akt/Erk signaling and regulating Bcl-2 and Bax expression. Meanwhile, up-regulation of NSD2 contributed to the opposite effects. Silencing of NSD2 reduced xenograft tumor growth in vivo.

Conclusion

NSD2 serves as an oncogenic factor in the progression of ccRCC via activation of Akt/Erk signaling.

Knockdown of NSD2 Suppresses Renal Cell Carcinoma Metastasis by Inhibiting Epithelial-Mesenchymal Transition

Background: Renal cell carcinoma (RCC) accounts for around 85% of all primary kidney neoplasms, which is one of top 10 common cancers worldwide. Nuclear receptor suppressor of variegation, enhancer of zeste, and trithorax (SET) domain-containing 2 (NSD2), belonging to NSD protein family, functions as an oncogene in the pathogenesis of multiple cancers. Methods: GEO database was used to analyze the expression of NSD2 mRNA in renal cancer. Furthermore, NSD2 protein level in clear cell RCC (ccRCC) tissues was detected by immunohistochemistry (IHC). Knockdown efficiency of different siRNAs was evaluated by quantitative real-time PCR (qRT-PCR) and western blot analysis. The biological role and molecular mechanism of NSD2 in RCC metastasis were investigated via a series of functional experiments. Results: NSD2 mRNA was massively amplified in several types of renal cancer, especially in metastatic ccRCC. The expression level of NSD2 protein was elevated in ccRCC tissues, but not correlated with pathological grading. The migratory and invasive properties were significantly repressed in NSD2-silenced RCC cells, concurrent with an increase of E-cadherin expression and a decrease of N-cadherin and Vimentin expression. Conclusion: Down-regulation of NSD2 could potently suppress cell migration and invasion through inhibiting epithelial-mesenchymal transition (EMT), indicating that NSD2 may be a potential therapeutic target for metastatic RCC.

A Decision-Support Tool for Renal Mass Classification

We investigate the viability of statistical relational machine learning algorithms for the task of identifying malignancy of renal masses using radiomics-based imaging features. Features characterizing the texture, signal intensity, and other relevant metrics of the renal mass were extracted from multiphase contrast-enhanced computed tomography images. The recently developed formalism of relational functional gradient boosting (RFGB) was used to learn human-interpretable models for classification. Experimental results demonstrate that RFGB outperforms many standard machine learning approaches as well as the current diagnostic gold standard of visual qualification by radiologists.

Focal therapy versus robot-assisted partial nephrectomy in the management of clinical T1 renal masses: A systematic review and meta-analysis

BACKGROUND

Robot-assisted partial nephrectomy (RPN) and focal therapy (FT) have both been successfully employed in the management of small renal masses. However, despite this being the era of minimally invasive surgery, few comparative studies exist on RPN and FT. The aim of our study is to review perioperative, renal functional and oncologic outcomes of FT and RPN in cT1 renal masses.

METHODS

Literature published in Medline, EMBASE, and Cochrane Library databases up to April 22, 2018, was systematically searched. We included literature comparing outcomes of FT (radiofrequency ablation, cryoablation, microwave ablation, and irreversible electroporation) and RPN. Studies that reported only on laparoscopic partial nephrectomy or open partial nephrectomy, and review articles, editorials, letters, or cost analyses were excluded. In total, data from 1166 patients were included.

RESULTS

From 858 total articles, 7 nonrandomized, observational studies were included. Compared with RPN, FT was associated with a significantly lower decrease of estimated glomerular filtration rate (weighted mean difference [WMD] -8.06 mL/min/1.73 m; confidence interval [CI] -15.85 to -0.26; P = .04), and lower estimated blood loss (WMD -49.61 mL; CI -60.78 to -38.45; P < .001). However, patients who underwent FT had a significantly increased risk of local recurrence (risk ratio [RR] 9.89; CI 4.24-23.04; P < .001) and distant metastasis (RR 6.42; CI 1.70-24.33; P = .006). However, operative times, lengths of stay, and complication rates were revealed to be similar between FT and RPN.

CONCLUSION

RPN has a substantial advantage in preventing cancer recurrence. However, in the era of minimally invasive surgery, FT has advantages in renal function preservation and less bleeding. Long-term follow-up for survival rates and comparative analysis of microwave ablation and irreversible electroporation are needed to extend FT for patients with significant morbidities and for those who need sufficient renal function preservation with minimal bleeding.

Differentiation of Predominantly Solid Enhancing Lipid-Poor Renal Cell Masses by Use of Contrast-Enhanced CT: Evaluating the Role of Texture in Tumor Subtyping

OBJECTIVE

The purpose of this study was to assess the accuracy of a panel of texture features extracted from clinical CT in differentiating benign from malignant solid enhancing lipid-poor renal masses.

MATERIALS AND METHODS

In a retrospective case-control study of 174 patients with predominantly solid nonmacroscopic fat-containing enhancing renal masses, 129 cases of malignant renal cell carcinoma were found, including clear cell, papillary, and chromophobe subtypes. Benign renal masses-oncocytoma and lipid-poor angiomyolipoma-were found in 45 patients. Whole-lesion ROIs were manually segmented and coregistered from the standard-of-care multiphase contrast-enhanced CT (CECT) scans of these patients. Pathologic diagnosis of all tumors was obtained after surgical resection. CECT images of the renal masses were used as inputs to a CECT texture analysis panel comprising 31 texture metrics derived with six texture methods. Stepwise logistic regression analysis was used to select the best predictor among all candidate predictors from each of the texture methods, and their performance was quantified by AUC.

RESULTS

Among the texture predictors aiding renal mass subtyping were entropy, entropy of fast-Fourier transform magnitude, mean, uniformity, information measure of correlation 2, and sum of averages. These metrics had AUC values ranging from good (0.80) to excellent (0.98) across the various subtype comparisons. The overall CECT-based tumor texture model had an AUC of 0.87 (p < 0.05) for differentiating benign from malignant renal masses.

CONCLUSION

The CT texture statistical model studied was accurate for differentiating benign from malignant solid enhancing lipid-poor renal masses.

Development and validation of a training and assessment tool for laparoscopic radical nephrectomy

INTRODUCTION

Laparoscopic radical nephrectomy(LRN) is a cornerstone in managing renal cancer and small renal masses. Twenty-first century surgical training faces challenges, thus must be efficient and safe so surgeons attain relevant skills, protecting patients and operative outcomes. This study aimed to systematically develop a tool for training and assessment in LRN and validate the developed tool for use by trainee urologists.

METHODS

This prospective, longitudinal, multi-institutional study was undertaken from September 2014 - June 2015. Healthcare Failure Mode and Effect Analysis was utilised for development and followed by validation where the assessment tool was distributed to five specialists to increase content validity. Four experts were observed as a multi-institutional approach. Hand-assisted, transperitoneal and retroperitoneal approaches were considered.

RESULTS

The LRN Assessment Tool comprised four phases, 17 processes, 41 sub-processes. Four surgeons and operating teams were observed across four hospitals for 19.5hours (5.75h hand-assisted, 8.75h trans-peritoneal, 5h retro-peritoneal). After hazard analysis, three checklists were constructed. Those for hand-assisted LRN and transperitoneal LRN contained four phases, 20 processes, 33 sub-processes and that for retroperitoneal LRN contained four phases, 20 processes, 30 sub-processes. These were merged to form one assessment tool. The final result was a four phase LRN Assessment Tool with 17 processes, 41 sub-processes. All participants agreed the final LRN Assessment Tool included pertinent steps.

CONCLUSIONS

The LRN Assessment Tool was developed using Healthcare Failure Mode and Effect Analysis risk analysis to ensure hazardous procedural sub-steps were included. Validation ascertained important processes were not overlooked. Full application through a pilot study must be undertaken.

The C.L.A.M.P. Nephrometry score: A system for preoperative assessment of laparoscopic partial nephrectomy with Segmental Renal Artery Clamping

Laparoscopic partial nephrectomy with segmental renal artery clamping is associated with a less warm ischemic injury and better postoperative affected renal function compared with main renal artery clamping. However, its indication remains unclear. We established a standardized nephrometry scoring system (The C.L.A.M.P. Nephrometry Score) to evaluate its flexibility in preoperative assessment. This scoring system based on 5 components. The ranking (C)oefficient of each score and the (L)ocation of the clamping position of the target artery and areas of the target artery entering the renal sinus: (A)nterior boundary, (M)ulti-boundary and (P)osterior boundary. We applied this system to analyze data from 106 consecutive patients who underwent SRAC during LPN and divided these patients into 3 groups based on their C.L.A.M.P. scores. The rate of conversion to main renal artery clamping and clamping success rate and the affected side GFR reduction showed significant differences among the groups (P < 0.001). However, parameters such as blood loss, Warm ischemia time and postoperative hospitalization were not significantly different. The C.L.A.M.P. nephrometry score shows strong ability in distinguishing different complexities of artery characteristics and plays a promising role in identifying patients who are suitable for the SRAC technique.

Expression of CK19, CD105 and CD146 are associated with early metastasis in patients with renal cell carcinoma

The present study was designed in order to explore the association between the early metastasis of renal cell carcinoma (RCC) and biological markers of tumor cells. A total of 200 patients with RCC, who received a nephrectomy between January 2015 and October 2015, were enrolled in the present study, while 100 healthy patients served as controls. The expression of cytokeratin 19 (CK19), endoglin (CD105) and cluster of differentiation 146 (CD146) were detected using immunohistochemical staining and western blotting. All three markers were highly expressed in tumor tissues compared with adjacent normal tissues. Subsequently, an enzyme-linked immunosorbent assay was used to detect the differential expression of CK19, CD105 and CD146. The results revealed that there was a statistically significant difference in the expression of CK19 and CD105 between the two groups (P<0.05), whereas CD146 did not exhibit a statistically significant difference. The results of further experiments revealed no significant difference between four time points (Q1, 1 day pre-operation; Q2, 1 day post-operation; Q3, 1 week post-operation; and Q4, 1 month post-operation). Then, subgroup analysis was performed based on whether patients were circulating tumor cell (CTC)-positive or not, and the difference between the Q1 time point and other three time points (Q2-4). The results revealed no difference between the CTC-positive and -negative groups, and no difference between the time points Q1 and Q2. However, the expression of CK19 and CD105 exhibited a significant difference between CTC-positive and CTC-negative groups according to the difference between the time points Q1 and Q3. Furthermore, on the basis of the difference between Q1 and Q4, the expression of CK19, CD105 and CD146 were significantly different (P<0.05). Taken together, the results suggested that CK19, CD105 and CD146 markers of peripheral blood may be considered to be effective tools to evaluate the early metastasis in a CTC-positive condition. CK19, CD105 and CD146 may be useful for CTC in evaluating the prognosis of patients with RCC, although a larger sample size is necessary for further investigation.

EZH2 enhances the invasive capability of renal cell carcinoma cells via activation of STAT3

The enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) gene has been recognized to be a proto-oncogene and to be linked to human malignancies. However, the additional functions of EZH2 in renal cell carcinoma (RCC) are not completely understood. In the present study, a possible role of EZH2 in RCC was identified. EZH2 was demonstrated to promote the cell proliferation and invasion potential of 769-P cells, and inhibition of EZH2 was demonstrated to prevent these two processes in 786-O cells. Mechanically, EZH2 was demonstrated to increase the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and upregulate 72 kDa type IV collagenase (MMP-2) expression. When cells were treated with small interfering RNA targeting STAT3 or Stattic, a specific inhibitor of STAT3, the invasive ability of the cells was decreased and downregulation of MMP-2 was observed. Based on these results, in the present study it was hypothesized that EZH2 may serve a critical role in the progression of RCC. Its ability to facilitate invasion makes EZH2 a promising target for the management of advanced RCC.

Growth kinetics of small renal mass: Initial analysis of active surveillance registry

Purpose

To evaluate the clinical safety and natural history of active surveillance (AS) for incidentally diagnosed small renal mass (SRM).

Materials and Methods

We analyzed prospective data for patients who underwent AS for SRM. From 2010 to 2016, 37 SRMs of less than 3 cm were registered. Computed tomography (CT) and magnetic resonance imaging were used for initial diagnosis and CT, ultrasonography, and chest CT were performed at 6-month intervals. If there was no change in size during 2 years, follow-ups were performed annually. If the growth rate was more than 0.5 cm/y, if the diameter was more than 4 cm, or if clinical progression was observed, we regarded it as progression of SRM and recommended active treatment. We compared the growth rate and clinical course of SRM between patients who remained on surveillance and those who had progressed disease.

Results

The mean age was 63 years (range, 30–86 years) and the mean diameter was 1.8 cm (range, 0.6–2.8 cm) at diagnosis. The mean follow-up period was 27.3 months (range, 6–80 months) and the average growth rate was 0.2 cm/y (range, 0–1.9 cm/y). Six patients (16.2%) showed progression of SRM. Three patients wanted continuous observation, and partial nephrectomy was performed on 3 other patients. None of the patients had clinical progression, including metastasis.

Conclusions

We could delay active treatment for patients with an SRM with scheduled surveillance if the SRM grew relatively slowly. If more long-term AS results are documented for more patients, AS could be an alternative treatment modality for SRM.

Comparison of the Clinical Efficacy of Retroperitoneal Laparoscopic Partial Nephrectomy and Radical Nephrectomy for Treating Small Renal Cell Carcinoma: Case Report and Literature Review

Background

Renal cell carcinoma (RCC) is a common malignancy of the urinary system with high rates of morbidity and mortality.

Objectives

This study aimed to investigate and analyze the clinical efficacy of retroperitoneal laparoscopic partial nephrectomy and laparoscopic radical nephrectomy for the treatment of small RCC.

Methods

In this retrospective study of 45 patients with small RCC, the patients were divided into two treatment groups: Group A (retroperitoneal laparoscopic partial nephrectomy, 25 cases) and Group B (retroperitoneal laparoscopic radical nephrectomy, 20 cases).

Results

There were no statistically significant differences in the operative time, amount of intraoperative blood loss, length of hospital stay, preoperative creatinine level, postoperative creatinine level after 24 hours, and survival rate after 1, 2, and 3 years between the two groups (P > 0.05).

Conclusions

There were no significant differences in the survival rates and short-term postoperative complications between the laparoscopic partial nephrectomy group and the laparoscopic radical nephrectomy group for small RCC, but the former was slightly more effective.

Renal artery pseudoaneurysm after robotic-assisted partial nephrectomy: case report

Renal artery pseudoaneurysm is an uncommonly recognized complication following partial nephrectomy. It is more common with trauma and percutaneous renal intervention. Furthermore, it is rarely reported with minimally invasive laparoscopic partial nephrectomy. Herein, we report the first case to our knowledge of renal artery pseudoaneurysm following a robotic-assisted partial nephrectomy.

Ultrasound-guided radiofrequency ablation for cT1a renal masses in poor surgical candidates: mid-term, single-center outcomes

OBJECTIVES

Surgical management of small renal masses can be challenging in frail patients and thus modalities such as radiofrequency ablation (RFA) have emerged as valid alternative options. The aim of the current study was to present mid-term oncological and functional results on a series of patients with cT1a renal cell carcinomas (RCCs) who were unfit for surgery and underwent RFA using ultrasound guidance under local anesthesia.

METHODS

Data from patients fulfilling the study selection criteria were retrospectively collected. RENAL nephrometry score was used for tumor description. Parametric tests were used for data analysis and survival curves were estimated using the Kaplan-Meier method.

RESULTS

Overall, 32 patients (mean±standard deviation age, 72.4 ± 7.6 years) with biopsy-proven RCCs (tumor size, 23.75 ± 10.44 mm and RENAL score, 5.28 ± 1.33) underwent 32 RFA sessions. Twenty-seven patients (84.4%) had low complexity masses and five patients had masses of intermediate complexity (15.6%) according to RENAL score categorization. Over a follow-up period of 22.1 ± 13.7 months, one case of primary treatment failure was recognized (primary technical success 97.0%), and overall, three patients were diagnosed with residual disease (primary technique effectiveness 90.6%). No major complications occurred during the postprocedure 90-day follow up, while no difference was found in serum creatinine and estimated glomerular filtration rate pre and post procedure. Patients with intermediate-complexity renal lesions had shorter time to recurrence in comparison to low-complexity masses (p = 0.002). All patients were alive at the time of study data analysis without diagnosed metastases.

CONCLUSIONS

Percutaneous RFA of small RCCs using ultrasound-based guidance under local anesthesia can be an effective alternative method for managing patients who are unfit for surgery.

Thermal ablative therapies for treatment of localised renal cell carcinoma: a systematic review of the literature

BACKGROUND AND AIMS

Small renal masses are commonly diagnosed incidentally. The majority are malignant and require intervention. The gold standard treatment is partial nephrectomy unless the patient has significant co-morbidities when surveillance or ablative therapies are utilised. The latter are relatively novel and their long-term efficacy and safety remain generally poorly understood. We performed a literature review to establish the current evidence on the oncological outcome of thermal ablative techniques in small renal masses treatment.

METHODS AND RESULTS

A systematic literature search was performed using PubMed, supplemented with additional references. Articles were reviewed for data on indications, tumour characteristics, ablative techniques, oncological outcome, impact on renal function and complications. The vast majority of articles identified were observational studies. There has not been any direct comparison against partial nephrectomy. Radiofrequency ablation and cryoablation are the techniques that are more commonly used. They have favourable oncological results on intermediate follow-up and indications that successful outcome is sustained long term. The morbidity and impact on renal function appear to be minimal.

CONCLUSION

Thermal ablative therapies are valid alternatives to partial nephrectomy for the treatment of small renal masses in patients unfit for surgery. Prospective long-term data will be needed before the indications for their use expand further.

A model for assuring clamping success during laparoscopic partial nephrectomy with segmental renal artery clamping

OBJECTIVES

A model for assuring clamping success was established for laparoscopic partial nephrectomy (LPN) with segmental renal artery clamping (SRAC).

MATERIALS AND METHODS

Patients (n = 107; December 2009-September 2011) who underwent LPN with SRAC dependent on the experience of the surgeon and CTA were retrospectively reviewed to determine the optimal characteristics of target arteries. After multiple logistic regression analysis, variables used to build a nomogram were selected using a backward elimination scheme. A model for a clamping program customized to the patient was designed. The surgical outcomes of patients (n = 141; October 2011-June 2014) who subsequently underwent LPN-SRAC with the applied model were compared with those of the first group of patients.

RESULTS

Five potential predictors were initially assessed: segmental renal artery angle, target artery diameter, and distance (d) to the abdominal aorta, renal hilum (d RH), and kidney midline (d KML). The regression equation was set up as: [Formula: see text]Comparing the patient groups, those for whom the new SRAC model was applied had a significantly better success rate of clamping (P < 0.001), less total operative time (P < 0.001), and less operative blood loss (P = 0.042). No obvious differences were observed in time of warm ischemia, postoperative hospitalization, RENAL nephrometry score, or number of final clamped branches.

CONCLUSIONS

The model for assuring clamping success was helpful in designing an SRAC program and thus benefiting the LPN procedure.

Clinical Application of High-intensity Focused Ultrasound in Cancer Therapy

The treatment of cancer is an important issue in both developing and developed countries. Clinical use of ultrasound in cancer is not only for the diagnosis but also for the treatment. Focused ultrasound surgery (FUS) is a noninvasive technique. By using the combination of high-intensity focused ultrasound (HIFU) and imaging method, FUS has the potential to ablate tumor lesions precisely. The main mechanisms of HIFU ablation involve mechanical and thermal effects. Recent advances in HIFU have increased its popularity. Some promising results were achieved in managing various malignancies, including pancreas, prostate, liver, kidney, breast and bone. Other applications include brain tumor ablation and disruption of the blood-brain barrier. We aim at briefly outlining the clinical utility of FUS as a noninvasive technique for a variety of types of cancer treatment.

Utilization and perioperative complications of laparoscopic cryoablation vs. robotic partial nephrectomy for localized renal tumors

Objective:

To compare the utilization, perioperative complications and predictors of LCA versus RPN in the treatment of localized renal tumors.

Methods:

From the Nationwide Inpatient Sample we identified patients undergoing RPN or LCA for the treatment of localized renal tumors from October 2008 through 2010. Patient and hospital-specific factors which predict postoperative complications and use of LCA were investigated.

Results:

14,275 patients with localized renal tumors were identified: 70.3% had RPN and 29.7% had LCA. LCA was more common in older patient and at hospitals without robotic consoles. No difference was identified in perioperative complications (0.2% vs. 0.2%), transfusion (5.1% vs. 6.2%), length of stay (2.9 vs. 3.0 days) or median cost ($41,753 vs. $44,618) between the groups, LCA vs. RPN. On multivariate analysis sicker patients were more likely to have LCA (OR 1.34, p=0.048) and sicker patients had greater postoperative complications (OR 3.30, p<0.001); LCA did not predict more complications (OR 1.63, p=0.138) and LCA was performed at hospitals without RCs (OR 0.02, p<0.001). Limitations include observational study design, inability to assess disease severity, operative time, or body mass index, which may affect patient selection and outcomes.

Conclusions:

More patients had RPN vs. LCA; surgical technique was not predictive of postoperative complications. As technology develops to treat localized renal tumors, it will be important to continue to track outcomes and costs for procedures including RPN and LCA.

Trends in the Use of Nephron-Sparing Surgery over 7 Years: An Analysis Using the R.E.N.A.L. Nephrometry Scoring System

OBJECTIVE

To analyze trends in the use of partial nephrectomy, we evaluated which individual factors of renal nephrometry score (RNS) influenced the operative approach bi-annually from 2008 to 2014.

MATERIALS AND METHODS

We performed a retrospective review of renal cell carcinoma treated by surgery in 2008, 2010, 2012, and 2014. The complexity of renal masses was measured using the R.E.N.A.L. nephrometry scoring system with CT or MRI. Group comparison in terms of operation year and surgical type (partial nephrectomy versus radical nephrectomy) was performed. We developed a nomogram to quantitate the likelihood of selecting partial nephrectomy over radical nephrectomy.

RESULTS

A total of 1106 cases (237 in 2008, 225 in 2010, 292 in 2012, and 352 in 2014) were available for the study. Over the study period, the proportion of partial nephrectomies performed increased steadily from 21.5% in 2008 to 66.5% in 2014 (p < 0.05). Furthermore, use of partial nephrectomy increased steadily in all RNS complexity groups (low, moderate, and high) (p < 0.05). In the analysis of individual components of RNS, values of the R and N components increased statistically by year in the partial nephrectomy group (p < 0.05). Average AUC was 0.920.

CONCLUSIONS

The proportion of partial nephrectomies performed sharply increased over the study period. Additionally, over the study period, more partial nephrectomies were performed for renal masses of larger size and closer to the collecting system and main renal vessels. A nomogram developed based on this recent data set provides significant predictive value for surgical decision making.

Accuracy of preoperative CT T staging of renal cell carcinoma: which features predict advanced stage?

AIMS

To characterise CT findings in renal cell carcinoma (RCC), and establish which features are associated with higher clinical T stage disease, and to evaluate patterns of discrepancy between radiological and pathological staging of RCC.

MATERIALS AND METHODS

Preoperative CT studies of 92 patients with 94 pathologically proven RCCs were retrospectively reviewed. CT stage was compared with pathological stage using the American Joint Committee on Cancer (AJCC), 7(th) edition (2010). The presence or absence of tumour necrosis, perinephric fat standing, thickening of Gerota's fascia, collateral vessels were noted, and correlated with pT stage. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) for predicting pT stage ≥pT3a were derived separately for different predictors using cross-tabulations.

RESULTS

Twenty-four lesions were pathological stage T1a, 21 were T1b, seven were T2a, 25 were T3a, 11 were T3b, four were T3c, and two were T4. There were no stage T2b. Sixty-three (67%) patients had necrosis, 27 (29%) thickening of Gerota's fascia (1 T1a), 25 had collateral vessels (0 T1a), 28 (30%) had fat stranding of <2 mm, 20 (21%) of 2-5mm and one (1%) of >5 mm. For pT stage ≥pT3a, the presence of perinephric fat stranding had a sensitivity, specificity, PPV and NPV of 74%, 65%, 63%, and 76%, respectively. Presence of tumour necrosis had a sensitivity, specificity, PPV, and NPV of 81%, 44%, 54%, and 72%, respectively. Thickening of Gerota's fascia had a sensitivity, specificity, PPV, and NPV of 52%, 90%, 81% and 70%, respectively; and enlarged collateral vessels had a sensitivity, specificity, PPV, and NPV value of 52%, 94%, 88%, and 71% respectively.

CONCLUSION

The presence of perinephric stranding and tumour necrosis were not reliable signs for pT stage >T3a. Thickening of Gerota's fascia and the presence of collateral vessels in the peri- or paranephric fat had 90% and 94% specificity, with 82% and 88% PPV, respectively, for the presence of tumour stage for pT stage >T3a. These are considered reliable signs of locally advanced renal cancer.

Enhancer of zeste homolog 2 (EZH2) promotes tumour cell migration and invasion via epigenetic repression of E-cadherin in renal cell carcinoma

OBJECTIVE

To investigate the molecular mechanism and clinical significance for an oncogenic role of enhancer of zeste homolog 2 (EZH2) in renal cell carcinoma (RCC).

MATERIALS AND METHODS

Immunohistochemistry analyses of EZH2, histone H3 trimethyl Lys27 (H3K27me3) and E-cadherin were performed in tumour tissue samples from 257 patients with RCC. Regulatory effects of EZH2 on E-cadherin expression were examined by quantitative real-time polymerase chain reaction, Western blot, chromatin immunoprecipitation assay and immunohistochemical staining. Migration and invasion assays were performed in RCC cell lines. Tumour xenograft experiments with RCC cells were carried out in nude mice.

RESULTS

EZH2 promoted migration and invasion in RCC cell lines. Silencing EZH2 with short-hairpin EZH2 (shEZH2) or 3-deazaneplanocin A (DZNep) inhibited migration and invasion (P < 0.001), up-regulated the expression of E-cadherin in vitro, inhibited tumour growth, and prolonged survival in vivo (P = 0.022). EZH2 expression accompanied with E-cadherin repression was associated with advanced disease stage (P = 0.004) and poor overall (P < 0.001) and disease-free survival (P < 0.001).

CONCLUSION

EZH2 may contribute to RCC progression and is a potential therapeutic target for advanced RCC.

Tumor Enucleation for Renal Cell Carcinoma

The increased number of small renal masses (SRMs) detected annually has led to a rise in the use of nephron-sparing surgery (NSS). These techniques aim to preserve the largest amount of healthy renal tissue possible while maintaining the same oncologic outcomes as radical nephrectomy (RN). Additionally, partial nephrectomy (PN) has been linked to a lower risk of chronic kidney disease, cardiovascular morbidity, and mortality when compared to RN. There has been continual progress toward resecting less renal parenchyma. While the predominant surgical method of performing NSS is through traditional PN, simple enucleation (SE) of the tumor has increased in popularity over recent years. SE is a technique that aims to preserve the maximal amount of renal parenchyma possible by utilizing the renal tumor pseudocapsule to bluntly separate the lesion from its underlying parenchyma, offering the smallest possible margin of excised healthy renal tissue. Several studies have demonstrated the oncological safety of SE compared with PN in the treatment of SRMs, with lower overall incidence of positive surgical margins. Additionally, SE has been shown to have similar 5- and 10-year progression-free and cancer-specific survival as PN. We present a review of the literature and an argument for SE to be a routine consideration in the treatment of all renal tumors amenable to NSS.

Textural differences in apparent diffusion coefficient between low- and high-stage clear cell renal cell carcinoma

OBJECTIVE

The purpose of this article is to evaluate differences in texture measures on apparent diffusion coefficient (ADC) maps between low- and high-stage clear cell renal cell carcinomas (RCCs).

MATERIALS AND METHODS

In this retrospective study, 61 patients with clear cell RCC at pathologic examination and who underwent preoperative MRI with diffusion-weighted imaging were included. Clear cell RCCs were clinically staged on review of preoperative MRI by a board-certified radiologist blinded to the pathologic findings. Whole lesions were segmented on ADC maps by two readers independently, from which first-order texture features (i.e., mean and skewness) and second-order texture features (i.e., cooccurrence matrix measures) were calculated. Texture metrics were compared between low- and high-stage clear cell RCC.

RESULTS

In 61 patients, there were 62 clear cell RCCs (33 low stage [stages I and II] and 29 high stage [stages III and IV]) at pathologic examination. Staging accuracy of qualitative interpretation was 100% for low-stage lesions and 37.9% (11/29) for high-stage lesions. There was no statistically significant difference in mean ADC between high- and low-stage clear cell RCCs (1.77×10(-3) vs 1.80×10(-3) mm2/s; p=0.7). However, high-stage clear cell RCCs were larger (6.96±2.93 vs 3.49±1.57 cm; p<0.0001) and had statistically significantly (p≤0.0001) higher ADC skewness (0.02±0.33 vs -0.52±0.65) and cooccurrence matrix correlation (0.64±0.11 vs 0.49±0.13). Multivariate logistic regression identified size, skewness, and cooccurrence matrix correlation as significant independent predictors of high stage (AUC=0.92). Interreader correlation in texture metrics ranged from 0.82 to 0.89.

CONCLUSION

First- and second-order ADC texture metrics differ between low- and high-stage clear cell RCCs. A model that includes size and ADC texture measures may help to stage clear cell RCCs noninvasively.

Safety and Postoperative Outcomes of Regional versus Global Ischemia for Partial Nephrectomy: A Systematic Review and Meta-Analysis

OBJECTIVE

To analyze current evidence comparing the safety and outcomes of regional and global ischemia for partial nephrectomy (PN).

MATERIALS AND METHODS

A systematic search of the PubMed and Web of Science databases was conducted in May 2014 to identify studies comparing the safety and outcomes of regional and global ischemia for PN. A systematic review and meta-analysis was also performed.

RESULTS

Six retrospective observational studies were selected for the analysis, including 363 patients who underwent PN (162 regional ischemia and 201 global ischemia cases). Operation times were not statistically different [weighted mean difference (WMD) = 20.35 min, 95% CI: -0.28-40.97, p = 0.05], but estimated blood loss was significantly higher in the regional ischemia group (WMD = 52.04 ml, 95% CI: 14.30-89.78, p = 0.007) than in the global ischemia group. Complication rates [odds ratio (OR) = 1.16; 95% CI: 0.63-2.15, p = 0.63] and blood transfusion rates (OR = 1.85; 95% CI: 0.86-4.01, p = 0.12) of the two groups were not significantly different. The regional ischemia group showed better postoperative renal function (WMD = 4.23 ml/min, 95% CI: 2.61-5.85, p < 0.00001) than the global ischemia group, and all cases in the regional ischemia group showed negative margins.

CONCLUSIONS

Regional ischemia is as safe to perform as global ischemia, and the former leads to better postoperative renal functions than the latter. These findings support the application of regional ischemia for PN.

Emerging HIFU applications in cancer therapy

High intensity focused ultrasound (HIFU), is a promising, non-invasive modality for treatment of tumours in conjunction with magnetic resonance imaging or diagnostic ultrasound guidance. HIFU is being used increasingly for treatment of prostate cancer and uterine fibroids. Over the last 10 years a growing number of clinical trials have examined HIFU treatment of both benign and malignant tumours of the liver, breast, pancreas, bone, connective tissue, thyroid, parathyroid, kidney and brain. For some of these emerging indications, HIFU is poised to become a serious alternative or adjunct to current standard treatments--including surgery, radiation, gene therapy, immunotherapy, and chemotherapy. Current commercially available HIFU devices are marketed for their thermal ablation applications. In the future, lower energy treatments may play a significant role in mediating targeted drug and gene delivery for cancer treatment. In this article we introduce currently available HIFU systems, provide an overview of clinical trials in emerging oncological targets, and briefly discuss selected pre-clinical research that is relevant to future oncological HIFU applications.

Laparoscopic resection of pancreatic adenocarcinoma: Dream or reality?

Laparoscopic pancreatic surgery is in its infancy despite initial procedures reported two decades ago. Both laparoscopic distal pancreatectomy (LDP) and laparoscopic pancreaticoduodenectomy (LPD) can be performed competently; however when minimally invasive surgical (MIS) approaches are implemented the indication is often benign or low-grade malignant pathologies. Nonetheless, LDP and LPD afford improved perioperative outcomes, similar to those observed when MIS is utilized for other purposes. This includes decreased blood loss, shorter length of hospital stay, reduced post-operative pain, and expedited time to functional recovery. What then is its role for resection of pancreatic adenocarcinoma? The biology of this aggressive cancer and the inherent challenge of pancreatic surgery have slowed MIS progress in this field. In general, the overall quality of evidence is low with a lack of randomized control trials, a preponderance of uncontrolled series, short follow-up intervals, and small sample sizes in the studies available. Available evidence compiles heterogeneous pathologic diagnoses and is limited by case-by-case follow-up, which makes extrapolation of results difficult. Nonetheless, short-term surrogate markers of oncologic success, such as margin status and lymph node harvest, are comparable to open procedures. Unfortunately disease recurrence and long-term survival data are lacking. In this review we explore the evidence available regarding laparoscopic resection of pancreatic adenocarcinoma, a promising approach for future widespread application.

A synchronous hepatocellular carcinoma and renal cell carcinoma treated with radio-frequency ablation

Radio-frequency ablation (RFA) is a curative treatment for hepatocellular carcinoma (HCC). Percutaneous RFA has been shown to be beneficial for patients with small renal cell carcinoma (RCC) lacking indications for resection. We experienced the case of a 53-year-old male who had conditions that suggested HCC, RCC, and alcoholic liver cirrhosis. Abdominal contrast-enhanced computed tomography (CT) and magnetic resonance image showed liver cirrhosis with 2.8 cm ill-defined mass in segment 2 of the liver and 1.9 cm hypervascular mass in the left kidney. These findings were compatible with the double primary cancers of HCC and RCC. Transarterial chemoembolization (TACE) was performed to treat the HCC. After the TACE, a focal lipiodol uptake defect was noticed on a follow up CT images and loco-regional treatment was recommended. Therefore, we performed RFAs to treat HCC and RCC. There was no evidence of recurrence in the follow up image after 1 month.

Landmarks in the diagnosis and treatment of renal cell carcinoma

The most common renal cancer is renal cell carcinoma (RCC), which arises from the renal parenchyma. The global incidence of RCC has increased over the past two decades by 2% per year. RCC is the most lethal of the common urological cancers: despite diagnostic advances, 20-30% of patients present with metastatic disease. A clearer understanding of the genetic basis of RCC has led to immune-based and targeted treatments for this chemoresistant cancer. Despite promising results in advanced disease, overall response rates and durable complete responses are rare. Surgery remains the main treatment modality, especially for organ-confined disease, with a selective role in advanced and metastatic disease. Smaller tumours are increasingly managed with biopsy, minimally invasive interventions and surveillance. The future promises multimodal, integrated and personalized care, with further understanding of the disease leading to new treatment options.

Comparison between laparoscopic and open radical nephrectomy for the treatment of primary renal tumors in children: single-center experience over a 5-year period

OBJECTIVES

To compare the outcomes of laparoscopic nephrectomy (LN) with open radical nephrectomy (ORN) in the management of consecutive pediatric neoplasms.

PATIENTS AND METHODS

Retrospective cohort study of consecutive children treated for primary renal tumors between 2006 and 2011, segregated based on surgical modality (LN/ORN). Pre-, intra- and postoperative data and outcomes were collected.

RESULTS

Demographics from the 45 patients (13 LN, 32 ORN) were similar, and tumors in the LN group were smaller [6.59 ± 1.8 cm vs. 10.99 ± 2.99 cm ORN (p < 0.05)]. Six patients had preoperative chemotherapy (two LN, four ORN). No tumor ruptures occurred with either technique. Wilms tumor (seven LN, 24 ORN) was the most common diagnosis, followed by renal cell carcinoma (four LN, four ORN). Procedure length was similar between groups (282 ± 79 LN, 263 ± 81 min ORN). Mean length of stay was significantly shorter for LN (2.9 vs. 5.9 days; p = 0.002). Postoperative narcotic requirements and use of nasogastric tube were higher in the ORN group. After a median follow-up of 18 (LN) and 33 months (ORN), 1 and 4 recurrences occurred, respectively.

CONCLUSIONS

LN is an attractive alternative to open surgery in carefully selected cases of pediatric renal tumors. Procedure length and incidence of intra-operative rupture were not increased, while post-operative recovery and hospital stay were shorter for LN. Longer follow-up is mandatory to confirm comparable oncological outcomes to ORN.