Comparison of standardized and nonstandardized nuclear grade of renal cell carcinoma to predict outcome among 2,042 patients

MR Virtual Biopsy of Solid Renal Masses: An Algorithmic Approach

Between 1983 and 2002, the incidence of solid renal tumors increased from 7.1 to 10.8 cases per 100,000. This is in large part due to the increase in the volume of ultrasound and cross-sectional imaging, although a majority of solid renal tumors are still found incidentally. Ultrasound and computed tomography (CT) have been the mainstay of renal mass screening and diagnosis but recent advances in magnetic resonance (MR) technology have made this the optimal choice when diagnosing and staging renal tumors. Our purpose in writing this review is to survey the modern MR imaging approach to benign and malignant solid renal tumors, consolidate the various imaging findings into an easy-to-read reference, and provide an imaging-based, algorithmic approach to renal mass characterization for clinicians. MR is at the forefront of renal mass characterization, surpassing ultrasound and CT in its ability to describe multiple tissue parameters and predict tumor biology. Cutting-edge MR protocols and the integration of diagnostic algorithms can improve patient outcomes, allowing the imager to narrow the differential and better guide oncologic and surgical management.

An Image-Based Identification of Aggressive Breast Cancer Circulating Tumor Cell Subtypes

Using previously established CTC lines from breast cancer patients, we identified different morphometric subgroups of CTCs with one of them having the highest tumorigenic potential in vivo despite the slowest cell proliferation in vitro. This subgroup represents 32% of all cells and contains cells with small cell volume, large nucleus to cell, dense nuclear areas to the nucleus, mitochondria to cell volume ratios and rough texture of cell membrane and termed "Small cell, Large mitochondria, Rough membrane" (SLR). RNA-seq analyses showed that the SLR group is enriched in pathways and cellular processes related to DNA replication, DNA repair and metabolism. SLR upregulated genes are associated with poor survival in patients with ER+ breast cancer based on the KM Plotter database. The high tumorigenic potential, slow proliferation, and enriched DNA replication/repair pathways suggest that the SLR subtype is associated with stemness properties. Our new findings provide a simple image-based identification of CTC subpopulations with elevated aggressiveness, which is expected to provide a more accurate prediction of patient survival and therapy response than total CTC numbers. The detection of morphometric and transcriptomic profiles related to the SLR subgroup of CTCs also opens opportunities for potential targeted cancer treatment.

Local recurrence of renal cell carcinoma after partial nephrectomy: applicability of the apparent diffusion coefficient of MRI as an imaging marker - a multicentre study

Purpose

The goal of the study was an assessment of the diagnostic performance of diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) of magnetic resonance imaging (MRI) in distinguishing local recurrence (LR) of renal cell carcinoma (RCC) from benign conditions after partial nephrectomy.

Material and methods

Thirty-nine patients after partial nephrectomy for solid RCC were enrolled in the study. Patients were followed up using MRI, which included DWI sequence (b = 800 s/mm²). All patients with MRI features of LR were included in the main group (n = 14) and patients without such features – into the group of comparison (n = 25). Apparent diffusion coefficient (ADC) values of suspicious lesions were recorded. In all patients with signs of locally recurrent RCC, surgical treatment was performed followed by pathologic analysis.

Results

The mean ADC values of recurrent RCC demonstrated significantly higher numbers compared to benign fibrous tissues and were 1.64 ± 0.15 × 10^-3 mm²/s vs. 1.02 ± 0.26 × 10^-3 mm²/s (p < 0.001). The mean ADC values of RCCs’ LR and benign post-op changes in renal scar substantially differed from mean ADC values of healthy kidneys’ parenchyma; the latter was 2.58 ± 0.05 × 10^-3 mm²/s (p < 0.001). In ROC analysis, the use of ADC with a threshold value of 1.28 × 10^-3 mm²/s allowed us to differentiate local recurrence of RCC from benign postoperative changes with 100% sensitivity, 80% specificity, and accuracy: AUC = 0.980 (p < 0.001).

Conclusions

The apparent diffusion coefficient of DWI of MRI can be used as a potential imaging marker for the diagnosis of local recurrence of RCC.

Updates in Grading of Renal Cell Carcinomas Beyond Clear Cell Renal Cell Carcinoma and Papillary Renal Cell Carcinoma

The World Health Organization (WHO) recommends grading of clear cell renal cell carcinoma (RCC) and papillary RCC using the WHO/International Society of Urological Pathology (ISUP) grade, which is primarily based on nuclear features. As the spectrum of RCC continues to evolve, with more recently described subtypes in the past decade, literature evidence on grading these subtypes is limited or not available for some tumor types. Herein, we outline a pragmatic approach to the topic of grading RCC, dividing the contemporarily described RCC subtypes into 7 categories based on the potential clinical applicability of grading as a useful prognostic parameter: (1) RCC subtypes that are reasonably validated and recommended for WHO/ISUP grading; (2) RCC subtypes where WHO/ISUP is not applicable; (3) RCC subtypes where WHO/ISUP grading is potentially clinically useful; (4) inherently aggressive RCC subtypes where histologic classification itself confers an aggressive biologic potential; (5) renal epithelial tumors where WHO/ISUP grading provides potentially misleading prognostic implication; (6) renal epithelial neoplasms where low WHO/ISUP grade features are a prerequisite for accurate histologic classification; and (7) renal epithelial neoplasms with no or limited data on grading or incomplete understanding of the biologic potential. Our aim in outlining this approach is 2-fold: (a) identify the gaps in understanding and application of grading in RCC subtypes so that researchers in the field may perform additional studies on the basis of which the important pathologic function of assignment of grade may be recommended to be performed as a meaningful exercise across a wider spectrum of RCC; and (b) to provide guidance in the interim to surgical pathologists in terms of providing clinically useful grading information in RCC based on currently available clinicopathologic information.

Application and comparison of Fuhrman nuclear grading system with the novel tumor grading system for chromophobe renal cell carcinoma and its correlation with disease-specific events

Introduction

The grading system of chromophobe renal cell carcinoma (ChRCC) is not well established. In this study, we aimed to compare the application of Fuhrman nuclear grade (FNG) with the novel chromophobe tumor grade (CTG). We also evaluated the correlation of these two grading systems with the clinical outcome.

Materials and Methods

Consecutive cases of ChRCC diagnosed on nephrectomy during 2005-2014 were identified. The clinical details of the patients were retrieved. Histopathology slides were reviewed and the nuclear grading was assigned using standard FNG and the CTG system. The CTG and FNG gradings were correlated with clinical outcome.

Results

A total of 80 cases were retrieved. Distribution of FNG was as follows: FNG-1, 1 (1.3%); FNG-2, 23 (28.3%); FNG-3, 44 (55.0%); and FNG-4, 12 (15%). CTG distribution was as follows: CTG-1, 48 (60.0%); CTG-2, 20 (25.0%); and CTG-3 12 (15.0%). Follow-up data was available in 46 cases; the median follow-up was 23.9 months (range 1-96.4 months). The median time to recurrence/metastasis was 17.2 months (range 3.2-31.2 months). Mean disease-free survival (DFS) was 68.5 months. Both CTG (P < 0.001) and FNG (P = 0.001) correlated with DFS; however, only CTG retained this significance when only the nonsarcomatous cases were analyzed. On receiver operating characteristics curve analysis, CTG had higher predictive accuracy for DFS for the entire group, while FNG lost the statistical significance when the nonsarcomatous cases were analyzed. CTG (P = 0.001) but not FNG (P = 0.106) correlated with the disease-specific adverse events in non-sarcomatous cases.

Conclusions

It is possible to apply CTG in ChRCC. It is a better predictor of DFS and disease-specific adverse events. CTG is more appropriate and applicable than the FNG in grading ChRCC.

Chromophobe renal cell carcinoma: current and controversial issues

It has been 35 years since Professor Thoenes and his colleagues discovered chromophobe renal cell carcinoma (RCC). Since then, our knowledge about this tumour entity has changed and novel tumour entities have been discovered. The aim of this review is to discuss recent molecular findings and open questions in diagnosing chromophobe-like/oncocytic neoplasms. The broader differential diagnosis of chromophobe-like and oncocytoma-like neoplasms includes SDH-deficient renal cell carcinoma, fumarate hydratase (FH) deficient RCC, epitheloid angiomyolipoma ('oncocytoma like'), MiT family translocation RCC and the emerging entity of eosinophilic solid and cystic renal cell carcinoma. After separation of these tumours from chromophobe RCC, it becomes evident that chromophobe RCC are low malignant tumours with a 5-6% risk of metastasis. Recent next generation sequencing (NGS) and DNA methylation profiling studies have confirmed Thoenes' theory of a distal tubule derived origin of chromophobe RCC and renal oncocytomas. Comprehensive genomic analyses of chromophobe RCC have demonstrated a low somatic mutation rate and identified TP53 and PTEN as the most frequently mutated genes, whereas 'unclassified' RCC with oncocytic or chromophobe-like features can show somatic inactivating mutations of TSC2 or activating mutations of MTOR as the primary molecular alterations. For the future, it would be desirable to create a category of 'oncocytic/chromophobe RCC, NOS' with the potential of further molecular studies for identification of TSC1/2 mutations in these rare tumours.

Noninvasive Fuhrman grading of clear cell renal cell carcinoma using computed tomography radiomic features and machine learning

PURPOSE

To identify optimal classification methods for computed tomography (CT) radiomics-based preoperative prediction of clear cell renal cell carcinoma (ccRCC) grade.

MATERIALS AND METHODS

Seventy-one ccRCC patients (31 low grade and 40 high grade) were included in this study. Tumors were manually segmented on CT images followed by the application of three image preprocessing techniques (Laplacian of Gaussian, wavelet filter, and discretization of the intensity values) on delineated tumor volumes. Overall, 2530 radiomics features (tumor shape and size, intensity statistics, and texture) were extracted from each segmented tumor volume. Univariate analysis was performed to assess the association between each feature and the histological condition. Multivariate analysis involved the use of machine learning (ML) algorithms and the following three feature selection algorithms: the least absolute shrinkage and selection operator, Student's t test, and minimum Redundancy Maximum Relevance. These selected features were then used to construct three classification models (SVM, random forest, and logistic regression) to discriminate high from low-grade ccRCC at nephrectomy. Lastly, multivariate model performance was evaluated on the bootstrapped validation cohort using the area under the receiver operating characteristic curve (AUC) metric.

RESULTS

The univariate analysis demonstrated that among the different image sets, 128 bin-discretized images have statistically significant different texture parameters with a mean AUC of 0.74 ± 3 (q value < 0.05). The three ML-based classifiers showed proficient discrimination between high and low-grade ccRCC. The AUC was 0.78 for logistic regression, 0.62 for random forest, and 0.83 for the SVM model, respectively.

CONCLUSION

CT radiomic features can be considered as a useful and promising noninvasive methodology for preoperative evaluation of ccRCC Fuhrman grades.

Multi-institutional re-evaluation of prognostic factors in chromophobe renal cell carcinoma: proposal of a novel two-tiered grading scheme

A histological grading system of chromophobe renal cell carcinoma (chRCC) is highly desirable to identify approximately 5-10% of tumors at risk for progression. Validation studies failed to demonstrate a correlation between the four-tiered WHO/ISUP grade and outcome. Previous proposals with three-tiered chromophobe grading systems could not be validated. In this study, the presence of sarcomatoid differentiation, necrosis, and mitosis was analyzed in a Swiss cohort (n = 42), an Italian cohort (n = 103), a German cohort (n = 54), a Japanese cohort (n = 119), and The Cancer Genome Atlas cohort (n = 64). All 3 histological parameters were significantly associated with shorter time to tumor progression and overall survival in univariate analysis. Interobserver variability for identification of these parameters was measured by Krippendorff's alpha coefficient and showed high concordance for the identification of sarcomatoid differentiation and tumor necrosis, but only low to medium concordance for the identification of mitosis. Therefore, we tested a two-tiered tumor grading system (low versus high grade) based only on the presence of sarcomatoid differentiation and/or necrosis finding in the combined cohorts (n = 382). pT stage, patient's age (> 65 vs ≤ 65), lymph node and/or distant metastasis, and the two-tiered grading system (low versus high grade) were significantly associated with overall survival and were independent prognostic parameters in multivariate analysis (Cox proportional hazard). This multi-institutional evaluation of prognostic parameters suggests tumor necrosis and sarcomatoid differentiation as reproducible components of a two-tiered chromophobe tumor grading system.

Automated Renal Cancer Grading Using Nuclear Pleomorphic Patterns

PURPOSE

Nuclear pleomorphic patterns are essential for Fuhrman grading of clear cell renal cell carcinoma (ccRCC). Manual observation of renal histopathologic slides may lead to subjective and inconsistent assessment between pathologists. An automated, image-based system that classifies ccRCC slides by quantifying nuclear pleomorphic patterns in an objective and consistent interpretable fashion can aid pathologists in histopathologic assessment.

METHODS

In the current study, histopathologic tissue slides of 59 patients with ccRCC who underwent surgery at Singapore General Hospital were assembled retrospectively. An automated image classification pipeline detects and analyzes prominent nucleoli in ccRCC images to classify them as either low (Fuhrman grade 1 and 2) or high (Fuhrman grade 3 and 4). The pipeline uses machine learning and image pixel intensity-based feature extraction techniques for nuclear analysis. We trained classification systems that concurrently analyze different permutations of multiple prominent nucleoli image patches.

RESULTS

Given the parameters for feature combination and extraction, we present experimental results across various configurations for the classification of a given ccRCC histopathologic image. We also demonstrate that the image score used by the pipeline, termed fraction value, is correlated ( R = 0.59) with an existing multigene assay-based scoring system that has previously been demonstrated to be a strong indicator of prognosis in patients with ccRCC.

CONCLUSION

The current method provides an objective and fully automated way by which to process pathologic slides. The correlation study with a multigene assay-based scoring system also allows us to provide quantitative interpretation for already established nuclear pleomorphic patterns in ccRCC. This method can be extended to other cancers whose corresponding grading systems use nuclear pattern information.

Monosomy of Chromosome 9 Is Associated With Higher Grade, Advanced Stage, and Adverse Outcome in Clear-cell Renal Cell Carcinoma

BACKGROUND

Clear-cell renal cell carcinoma (ccRCC) is one of the most common malignancies in humans and is usually associated with poor outcomes. Cancers are considered to be genetic diseases. Therefore, a better understanding of genetic alterations that are related to disease progression or poor prognosis can help to more precisely identify high-risk patients and treat them more effectively. The aim of this study was to examine the frequency of whole chromosome 9 loss (monosomy of chromosome 9) and its prognostic value in patients with ccRCC.

MATERIALS AND METHODS

Single nucleotide polymorphism-based chromosome microarray (CMA) analysis was performed on 103 resected specimens from patients with ccRCC who had undergone partial or radical nephrectomy between January 2002 and March 2017 at Fox Chase Cancer Center. Monosomy 9 was correlated with clinicopathologic parameters and recurrence-free survival.

RESULTS

Chromosome 9 loss was detected in 31 (30%) of 103 tumors. Tumors with chromosome 9 loss had higher histologic grade (3 and 4; P < .001) and pathologic stage (P < .001). In 59 patients with non-metastatic ccRCC, chromosome 9 loss was also associated with higher recurrence rate and shorter recurrence-free survival (RFS) (12-month RFS, 77.8%; 95% confidence interval, 36.5%-93.9% for chromosome 9 loss vs. 95.7%; 95% confidence interval, 84.0%-98.9% for no loss; P = .002).

CONCLUSIONS

Chromosome 9 loss was found in 30% of patients with ccRCC and correlated with higher grade, advanced stage, and shorter RFS in patients with Stage I to III ccRCC.

Unenhanced CT Texture Analysis of Clear Cell Renal Cell Carcinomas: A Machine Learning-Based Study for Predicting Histopathologic Nuclear Grade

OBJECTIVE. The purpose of this study is to investigate the predictive performance of machine learning (ML)-based unenhanced CT texture analysis in distinguishing low (grades I and II) and high (grades III and IV) nuclear grade clear cell renal cell carcinomas (RCCs). MATERIALS AND METHODS. For this retrospective study, 81 patients with clear cell RCC (56 high and 25 low nuclear grade) were included from a public database. Using 2D manual segmentation, 744 texture features were extracted from unenhanced CT images. Dimension reduction was done in three consecutive steps: reproducibility analysis by two radiologists, collinearity analysis, and feature selection. Models were created using artificial neural network (ANN) and binary logistic regression, with and without synthetic minority oversampling technique (SMOTE), and were validated using 10-fold cross-validation. The reference standard was histopathologic nuclear grade (low vs high). RESULTS. Dimension reduction steps yielded five texture features for the ANN and six for the logistic regression algorithm. None of clinical variables was selected. ANN alone and ANN with SMOTE correctly classified 81.5% and 70.5%, respectively, of clear cell RCCs, with AUC values of 0.714 and 0.702, respectively. The logistic regression algorithm alone and with SMOTE correctly classified 75.3% and 62.5%, respectively, of the tumors, with AUC values of 0.656 and 0.666, respectively. The ANN performed better than the logistic regression (p < 0.05). No statistically significant difference was present between the model performances created with and without SMOTE (p > 0.05). CONCLUSION. ML-based unenhanced CT texture analysis using ANN can be a promising noninvasive method in predicting the nuclear grade of clear cell RCCs.

Grading of renal cell carcinoma

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

Clear Cell Renal Cell Carcinoma: Machine Learning-Based Quantitative Computed Tomography Texture Analysis for Prediction of Fuhrman Nuclear Grade

OBJECTIVE

To evaluate the performance of quantitative computed tomography (CT) texture analysis using different machine learning (ML) classifiers for discriminating low and high nuclear grade clear cell renal cell carcinomas (cc-RCCs).

MATERIALS AND METHODS

This retrospective study included 53 patients with pathologically proven 54 cc-RCCs (31 low-grade [grade 1 or 2]; 23 high-grade [grade 3 or 4]). In one patient, two synchronous cc-RCCs were included in the analysis. Mean age was 57.5 years. Thirty-four (64.1%) patients were male and 19 were female (35.9%). Mean tumour size based on the maximum diameter was 57.4 mm (range, 16-145 mm). Forty patients underwent radical nephrectomy and 13 underwent partial nephrectomy. Following pre-processing steps, two-dimensional CT texture features were extracted using portal-phase contrast-enhanced CT. Reproducibility of texture features was assessed with the intra-class correlation coefficient (ICC). Nested cross-validation with a wrapper-based algorithm was used in feature selection and model optimisation. The ML classifiers were support vector machine (SVM), multilayer perceptron (MLP, a sort of neural network), naïve Bayes, k-nearest neighbours, and random forest. The performance of the classifiers was compared by certain metrics.

RESULTS

Among 279 texture features, 241 features with an ICC equal to or higher than 0.80 (excellent reproducibility) were included in the further feature selection process. The best model was created using SVM. The selected subset of features for SVM included five co-occurrence matrix (ICC range, 0.885-0.998), three run-length matrix (ICC range, 0.889-0.992), one gradient (ICC = 0.998), and four Haar wavelet features (ICC range, 0.941-0.997). The overall accuracy, sensitivity (for detecting high-grade cc-RCCs), specificity (for detecting high-grade cc-RCCs), and overall area under the curve of the best model were 85.1%, 91.3%, 80.6%, and 0.860, respectively.

CONCLUSIONS

The ML-based CT texture analysis can be a useful and promising non-invasive method for prediction of low and high Fuhrman nuclear grade cc-RCCs.

KEY POINTS

• Based on the percutaneous biopsy literature, ML-based CT texture analysis has a comparable predictive performance with percutaneous biopsy. • Highest predictive performance was obtained with use of the SVM. • SVM correctly classified 85.1% of cc-RCCs in terms of nuclear grade, with an AUC of 0.860.

Variation in nuclear size and PD-L2 positivity correlate with aggressive chromophobe renal cell carcinoma

Chromophobe renal cell carcinoma (CRCC) is not amenable to International Society for Urologic Pathology-endorsed nucleolar grading. Novel grading approaches were proposed, but the rarity of adverse pathology hampers their discriminatory value. We investigate simple linear micrometer measurements and a proposed immunostain in CRCCs. 32 patients' CRCCs were studied: 12 adverse cases (stage pT3, recurrence, or metastasis), 15 controls (stage ≤pT2, no recurrence or metastasis after >3 years), and 8 metastases (3 were paired with primary adverse cases). The ratio of greatest dimensions of largest and smallest nuclei, in each of 5 "worst" high-power fields, excluding those with degenerative features, was designated variation in nuclear size (VNS). Percent multinucleate cells (PMC) were also counted. Mouse anti PD-L2 monoclonal antibody immunostaining was performed. Mean VNS measured in adverse primary and control primary tumors were 3.7 ± 0.5 and 2.4 ± 0.4 respectively (P < .001), and 3.4 ± 0.4 for metastases (P < .001). Optimal VNS cut-off was 2.5, with sensitivity and specificity 0.85 and 0.81, respectively. PMCs were 6.0 ± 3.0 for adverse group, 5.7 ± 2.7 for controls, and 4.1 ± 1.6 for metastases (P = NS). PD-L2 could not discriminate adverse versus good primary tumors (χ²1.6, P = .2), but was higher in metastases (χ² 6.9, P < .01), or metastases plus adverse primary tumors (χ² 4.8, P = .03), compared to good-pathology primary tumors. In conclusion, VNS is an easily obtained measurement that can predict adverse behavior of chromophobe RCC, and may impart value for needle biopsy reporting and the choice of active surveillance. PD-L2 was elevated in metastases but was less useful for primary tumors.

Can diffusion-weighted magnetic resonance imaging of clear cell renal carcinoma predict low from high nuclear grade tumors

OBJECTIVE

To assess the diagnostic performance of the apparent diffusion coefficient (ADC) in predicting the Fuhrman nuclear grading of clear cell renal cell carcinomas (ccRCC).

MATERIALS AND METHODS

A total of 129 patients who underwent partial and radical nephrectomies with pathology-proven ccRCC were retrospectively evaluated. Histopathological characteristics and nuclear grades were analyzed. In addition, conventional magnetic resonance imaging (MRI) features were assessed in consensus by two radiologists to discriminate nuclear grading. ADC values were obtained from a region of interest (ROI) measurement in the ADC maps calculated from diffusion-weighted imaging (DWI) using b values of 50, 500, and 800 s/mm². The threshold values for predicting and differentiating low-grade cancers (Fuhrman I-II) from high grade (Fuhrman III-IV) was obtained using binary logistic regression. The ADC cut-off value for differentiating low- and high-grade tumors was determined using classification analysis.

RESULTS

Significant associations (P < 0.001) were found between nuclear grading, conventional MR features, and DWI. Hemorrhage, necrosis, perirenal fat invasion, enhancement homogeneity, and cystic component were identified as independent predictors of tumor grade. High-grade ccRCC had significantly lower mean ADC values compared to low-grade tumors. An ADC cut-off value of 1.6 × 10^-3 mm²/s had an optimal predictive percentage of 65.5% for low-grade tumors above this threshold and 81% for high-grade ccRCC below this threshold. Overall predictive accuracy was 70.5%.

CONCLUSION

The addition of ADC values to a model based on MRI conventional features demonstrates increased sensitivity and high specificity improving the distinguishing accuracy between both high-grade and low-grade ccRCC.

Pathological T3a Upstaging of Clinical T1 Renal Cell Carcinoma: Outcomes According to Surgical Technique and Predictors of Upstaging

Purpose

To evaluate the prognosis of pT3a upstaging from cT1 renal cell carcinoma, and to compare the outcomes of partial or radical nephrectomy in cases of pT3a upstaging.

Materials and Methods

We reviewed the records of patients who underwent partial or radical nephrectomy for cT1 at our center between January 2001 and October 2013. We compared the 2-year recurrence-free survivals for cases with pT1 or pT3a upstaging, and for partial or radical nephrectomy in cases with pT3a upstaging. Clinicopathological parameters were analyzed in univariate and multivariate analyses to evaluate their associations with upstaging.

Results

Among the 1,009 eligible patients, 987 patients were included in the analysis. The mean follow-up was 48.5 ± 27.8 months in whole patients. The 2-year recurrence-free survival was worse in the pT3a upstaging group, compared to the pT1 group (87.3% vs. 98.7%; p < 0.001). Partial nephrectomy and radical nephrectomy had no significant difference in 2-year recurrence-free survivals (91.9% vs. 83.7%; p = 0.251). The multivariate analysis revealed that upstaging was associated with old age, cT1b stage, clinical symptoms, and a high Fuhrman grade.

Conclusions

Pathological T3a upstaging of cT1 renal cell carcinoma was associated with a poorer prognosis, compared to pT1 disease. However, the surgical technique (radical or partial nephrectomy) did not affect the recurrence rate. Therefore, clinicians should select the treatment method based on the clinical stage, and consider the pathological stage during the follow-up.

Pathology, therapy and prognosis of papillary renal carcinoma

Papillary renal cell carcinoma (pRCC) accounts for approximately 10% of renal parenchymal tumors. There are two pRCC subtypes reported in several studies, but at present, there is limited molecular evidence to validate this pRCC subtyping in the daily routine. The utility of subtyping pRCC is based on reports describing that pRCC subtype is an independent predictor of outcome, with type 1 tumors showing significantly better survival than type 2 tumors. In this article, we summarize the relevant knowledge on pRCC regarding tumor features: clinical presentation, histopathology, electron microscopy, immunohistochemistry, cytogenetics, genetic/molecular and prognosis. We present an overview of the currently available pRCC treatment options and some of the new promising agents.

Comparison of utility of tumor size and apparent diffusion coefficient for differentiation of low- and high-grade clear-cell renal cell carcinoma

BACKGROUND

There is a significant correlation between tumor size and tumor grade for clear-cell renal cell carcinoma (RCC) in pathology. Thus, apparent diffusion coefficient (ADC) of clear-cell RCC might be influenced by tumor size.

PURPOSE

To compare the utility of tumor size and ADC for distinguishing low-grade from high-grade clear-cell RCC.

MATERIAL AND METHODS

Forty-nine patients undergoing preoperative magnetic resonance imaging were retrospectively assessed. ADC values were calculated using b-value combinations of 0 and 800 s/mm(2) at 1.5 T. Two radiologists in consensus measured ADC values via small region of interest (ROI) (mean ROI area, 88.8 mm(2); range, 80-108 mm(2)) placement on an area of solid tumor on a single slice. Maximum tumor diameter was measured at the maximum tumor area. A single pathologist reviewed all pathological slides to determine the nuclear grade according to the Fuhrman classification. The utility of ADC, tumor size, and ADC/size ratio for distinguishing low-grade from high-grade tumors was assessed. Receiver-operating characteristic (ROC) analysis and regression analysis of the each index were performed. The correlation between ADC and tumor size was also investigated.

RESULTS

The 49 clear-cell RCC included 34 low-grade and 15 high-grade tumors. The differences of ADC, tumor size, and ADC/size ratio between high-grade and low-grade tumors were statistically significant (P <0.05). The area under the ROC curve of ADC, tumor size, and ADC/size ratio were 0.802, 0.763, and 0.804 respectively. However, using regression analysis, only ADC (P <0.05) was statistically significant index as independent risk factors for high-grade clear-cell RCC. Moreover, weak significant correlation was observed between tumor size and ADC (R(2) = 0.3865, P <0.01).

CONCLUSION

There was a weak significant correlation between tumor size and ADC value of clear-cell RCC. Using ROC and regression analysis, ADC was statistically significant index for distinguishing low-grade from high-grade clear-cell RCC more than tumor size and ADC/size ratio.

AIF downregulation and its interaction with STK3 in renal cell carcinoma

Apoptosis-inducing factor (AIF) plays a crucial role in caspase-independent programmed cell death by triggering chromatin condensation and DNA fragmentation. Therefore, it might be involved in cell homeostasis and tumor development. In this study, we report significant AIF downregulation in the majority of renal cell carcinomas (RCC). In a group of RCC specimens, 84% (43 out of 51) had AIF downregulation by immunohistochemistry stain. Additional 10 kidney tumors, including an oxyphilic adenoma, also had significant AIF downregulation by Northern blot analysis. The mechanisms of the AIF downregulation included both AIF deletion and its promoter methylation. Forced expression of AIF in RCC cell lines induced massive apoptosis. Further analysis revealed that AIF interacted with STK3, a known regulator of apoptosis, and enhanced its phosphorylation at Thr180. These results suggest that AIF downregulation is a common event in kidney tumor development. AIF loss may lead to decreased STK3 activity, defective apoptosis and malignant transformation.

The survival benefit of lymph node dissection at the time of removal of kidney, prostate and urothelial carcinomas: what is the evidence?

INTRODUCTION

Lymph node dissection (LND) has been advocated by oncologic surgeons to completely eradicate cancer. However, evidence for that strategy is solely based on poor quality data. Some randomized studies done outside the field of urology failed to show any benefit to LND. Our objective was to evaluate whether LND at the time of removal of prostate, kidney and urothelial carcinomas results in a survival benefit.

METHODS

For that purpose, we performed a systematic literature review.

RESULTS

For kidney cancer, LND might be able to cure some patients with N+ disease. In N0 patients, although a randomized trial has been completed, the value of LND remains uncertain. LND at the time of radical prostatectomy can be useful in some patients with lymph node invasion. However, studies on the impact of LND in pN0 patients are retrospective and conflictive. Extended LND has been recommended when performing a radical cystectomy based on improved outcomes observed in retrospective studies. However, these studies are limited by selection biases and results of ongoing randomized trials will specify the template and the advantages of LND when removing a bladder cancer. Recent data of large series of radical nephro-ureterectomies for upper tract urothelial carcinomas are conflicting. Some found a benefit of LND in N0 patients while others did not.

CONCLUSION

The studies that support LND at the time of surgery for prostate, kidney and urothelial carcinomas have low level of evidence. This should encourage urologists to design and perform well-designed randomized trials to assess the potential survival impact of a commonly done procedure.

The chromophobe tumor grading system is the preferred grading scheme for chromophobe renal cell carcinoma

PURPOSE

The prognostic usefulness of the Fuhrman nuclear grading system has been questioned for chromophobe renal cell carcinoma due to its frequent nuclear and nucleolar pleomorphism. Chromophobe tumor grade, a novel 3-tier tumor grading system based on geographic nuclear crowding and anaplasia, was recently reported to be superior to the Fuhrman system. We compared the 2 scoring systems in a large sporadic chromophobe renal cell carcinoma cohort to determine which grading scheme provides the most predictive assessment of clinical risk.

MATERIALS AND METHODS

We identified a total of 84 cases of sporadic chromophobe renal cell carcinoma in 82 patients from a total of 2,634 cases (3.2%) spanning 1989 to 2010. A subset of 11 tumors had secondary areas of sarcomatoid transformation. All cases were reviewed for Fuhrman nuclear grade and chromophobe tumor grade according to published parameters by an expert genitourinary pathologist blinded to clinicopathological information.

RESULTS

The distribution of Fuhrman nuclear grades 1 to 4 was 0%, 52.4%, 32.9% and 14.7% of cases, and the distribution of chromophobe tumor grades 1 to 3 was 48.8%, 36.5% and 14.7%, respectively. Metastasis developed in 20 patients (24.4%). Survival analysis revealed statistically significant differences in recurrence-free survival when adjusted for chromophobe tumor grade and Fuhrman nuclear grade. Chromophobe tumor grade showed a slightly higher AUC for recurrence-free survival and overall survival than the Fuhrman nuclear grading system. Neither chromophobe tumor grade nor Fuhrman nuclear grade was retained as an independent predictor of outcome in multivariate modeling when patients with sarcomatoid lesions were excluded.

CONCLUSIONS

Chromophobe tumor grade effectively stratifies patients with chromophobe renal cell carcinoma across all grading levels. Since it does not rely on nuclear features, it avoids the hazard of overestimating the malignant potential of chromophobe renal cell carcinoma. Overall chromophobe tumor grade has higher predictive accuracy than the Fuhrman nuclear grading system.

Dynamic physical properties of dissociated tumor cells revealed by dielectrophoretic field-flow fractionation

Metastatic disease results from the shedding of cancer cells from a solid primary tumor, their transport through the cardiovascular system as circulating tumor cells (CTCs) and their engraftment and growth at distant sites. Little is known about the properties and fate of tumor cells as they leave their growth site and travel as single cells. We applied analytical dielectrophoretic field-flow fractionation (dFFF) to study the membrane capacitance, density and hydrodynamic properties together with the size and morphology of cultured tumor cells after they were harvested and placed into single cell suspensions. After detachment, the tumor cells exhibited biophysical properties that changed with time through a process of cytoplasmic shedding whereby membrane and cytoplasm were lost. This process appeared to be distinct from the cell death mechanisms of apoptosis, anoikis and necrosis and it may explain why multiple phenotypes are seen among CTCs isolated from patients and among the tumor cells obtained from ascitic fluid of patients. The implications of dynamic biophysical properties and cytoplasmic loss for CTC migration into small blood vessels in the circulatory system, survival and gene expression are discussed. Because the total capacitance of tumor cells remained higher than blood cells even after they had shed cytoplasm, dFFF offers a compelling, antibody-independent technology for isolating viable CTCs from blood even when they are no larger than peripheral blood mononuclear cells.

Fine-needle aspiration of renal cell carcinoma: is accurate Fuhrman grading possible on cytologic material?

The Fuhrman grading system of renal cell carcinoma (RCC) consists of four grades based on nuclear size/contour and nucleolar conspicuousness. Fuhrman grading of histpathologic material is an independent prognostic parameter for RCC. Although widely used in surgical pathology, Fuhrman grading is not routinely performed on cytologic material. Thirty-three cases of renal fine needle aspirations (FNAs) with histologically proven RCC were retrieved from the cytopathology archives at Johns Hopkins Hospital. Fuhrman grade was determined independently and blindly by three faculty cytopathologists and compared with the Fuhrman grade of the subsequent surgical pathology specimen. The 33 resection specimens had the following Fuhrman grades: 0/33, grade I; 24/33 (73%), grade II; 9/33 (27%), grade III; and 0/33, grade IV. After Fuhrman grading was applied to the FNA material, diagnostic sensitivity was 83% for grade II versus 44% for grade III. The specificity and accuracy were 50 and 75%, respectively, for grade II versus 100% and 84% for grade III. Diagnostic sensitivity for grade II tumors ranged from 38 to 83%, grade III 44-62%. Diagnostic specificity for grade II tumors ranged from 50 to 78%, grade III 80-100%. Accuracy ranged from 48 to 75% for grade II and 75-87% for grade III. Using a two-tier grading model, accuracy improved to 84.2%. In our experience, Fuhrman grading of FNA specimens yielded variable results. There was only moderate agreement between cytopathologists, with an overall tendency to undergrade the tumor when compared with the resection specimen. Averaging the participants' grading and using a two-tier instead of four-tier system improved overall performance.

Lymph node dissection at the time of radical nephrectomy for high-risk clear cell renal cell carcinoma: indications and recommendations for surgical templates

BACKGROUND

Observational studies suggest a proportion of patients with lymph node metastases will benefit from lymph node dissection (LND) at the time of nephrectomy for clear cell renal cell carcinoma (RCC).

OBJECTIVE

Our aim was to report the performance of five previously identified high-risk pathologic features assessed by intraoperative examination on prediction of lymph node metastases and propose a template for LND based on locations of lymph node involvement.

DESIGN, SETTING, AND PARTICIPANTS

The study included a historical cohort of consecutive patients from a single institution who received LND in conjunction with nephrectomy for high-risk clear cell RCC between 2002 and 2006.

INTERVENTIONS

All patients underwent nephrectomy and LND.

MEASUREMENTS

Patients were considered high risk for nodal metastasis if two or more of the following features were identified during intraoperative pathologic assessment of the primary tumor: nuclear grade 3 or 4, sarcomatoid component, tumor size ≥10 cm, tumor stage pT3 or pT4, or coagulative tumor necrosis. Based on these features, LND was performed at the time of nephrectomy, and the numbers and sites of regional lymph node metastasis were recorded for each patient.

RESULTS AND LIMITATIONS

Of the 169 high-risk patients, 64 (38%) had lymph node metastases. All patients with nodal metastases had nodal involvement within the primary lymphatic sites of each kidney prior to involvement of the nodes overlying the contralateral great vessel. A limitation of the study is the lack of a standardized LND performed throughout the study period.

CONCLUSIONS

Pathologic features of renal tumors are associated with the risk of regional lymph node metastases and lymph node metastases that appear to progress though the primary lymphatic drainage of each kidney. Based on these findings we recommend that when performing LND the lymph nodes from the ipsilateral great vessel and the interaortocaval region be removed from the crus of the diaphragm to the common iliac artery.

A novel tumor grading scheme for chromophobe renal cell carcinoma: prognostic utility and comparison with Fuhrman nuclear grade

Chromophobe renal cell carcinoma (RCC) is a histologic subtype of RCC that portends a favorable prognosis. It is controversial whether the Fuhrman nuclear grade of chromophobe RCC has prognostic utility. Irregular nuclei, prominent nucleoli, and nuclear pleomorphism are inherently present in chromophobe RCC. Hence, the Fuhrman nuclear grade is higher even though the majority of these tumors have a favorable outcome. In this study, the prognostic utility of a novel 3-tiered tumor grading system in which the innate nuclear atypia of chromophobe RCC was discounted, herein referred to as chromophobe tumor grade from a series of 124 chromophobe RCC, was compared with Fuhrman nuclear grade. Chromophobe tumor grade is based on the assessment of geographic nuclear crowding and anaplasia. The Fuhrman nuclear grade distribution between the tumors was grade 1 (1%), grade 2 (19%), grade 3 (74%), and grade 4 (6%), whereas the chromophobe tumor grade distribution was grade 1 (74%), grade 2 (16%), and grade 3 (10%). Neither Fuhrman nuclear grade nor chromophobe tumor grade was significantly associated with patient's age or sex and chromophobe RCC cell types, but both showed a significant association with tumor size. Both Fuhrman nuclear grade and chromophobe tumor grade showed statistically significant positive associations with broad alveolar growth, necrosis, vascular invasion, and with pathologic stage; however, all these associations tended to be dictated by tumors with sarcomatoid change. When tumors with sarcomatoid change were excluded, a strong positive association persisted between chromophobe tumor grade and pathologic stage. In contrast, there was no such association between Fuhrman nuclear grade and stage in nonsarcomatoid chromophobe RCCs. Characterizing aggressive chromophobe RCC with aggressive behavior with the time from surgery to first occurrence of metastasis, local recurrence, or death owing to disease, we found that both Fuhrman nuclear grade and chromophobe tumor grade were highly associated with adverse outcome. However, as with the pathologic stage, only a significant association between chromophobe tumor grade and outcome was retained among nonsarcomatoid chromophobe RCCs. Multivariable Cox regression analysis also tended to support chromophobe tumor grade rather than Fuhrman nuclear grade as an independent predictor of adverse outcome, controlling for other univariably significant risk factors [estimated relative hazard=3.68 (P=0.026) vs. 1.86 (P=0.42)]. In conclusion, the novel chromophobe tumor grading system proposed herewith provides superior prognostic value to that of the Fuhrman nuclear grade in chromophobe RCC and will potentially help stratify patients of chromophobe RCC who are at a greater risk of disease progression.

Mining tissue microarray data to uncover combinations of biomarker expression patterns that improve intermediate staging and grading of clear cell renal cell cancer

PURPOSE

Tumor stage and nuclear grade are the most important prognostic parameters of clear cell renal cell carcinoma (ccRCC). The progression risk of ccRCC remains difficult to predict particularly for tumors with organ-confined stage and intermediate differentiation grade. Elucidating molecular pathways deregulated in ccRCC may point to novel prognostic parameters that facilitate planning of therapeutic approaches.

EXPERIMENTAL DESIGN

Using tissue microarrays, expression patterns of 15 different proteins were evaluated in over 800 ccRCC patients to analyze pathways reported to be physiologically controlled by the tumor suppressors von Hippel-Lindau protein and phosphatase and tensin homologue (PTEN). Tumor staging and grading were improved by performing variable selection using Cox regression and a recursive bootstrap elimination scheme.

RESULTS

Patients with pT2 and pT3 tumors that were p27 and CAIX positive had a better outcome than those with all remaining marker combinations. A prolonged survival among patients with intermediate grade (grade 2) correlated with both nuclear p27 and cytoplasmic PTEN expression, as well as with inactive, nonphosphorylated ribosomal protein S6. By applying graphical log-linear modeling for over 700 ccRCC for which the molecular parameters were available, only a weak conditional dependence existed between the expression of p27, PTEN, CAIX, and p-S6, suggesting that the dysregulation of several independent pathways are crucial for tumor progression.

CONCLUSIONS

The use of recursive bootstrap elimination, as well as graphical log-linear modeling for comprehensive tissue microarray (TMA) data analysis allows the unraveling of complex molecular contexts and may improve predictive evaluations for patients with advanced renal cancer.

Prognostic impact of histological subtype on surgically treated localized renal cell carcinoma

PURPOSE

Despite the clear demonstration that different histological subtypes of renal cell carcinoma show distinct pathogenesis and genetic alterations, the impact of histology on prognosis remains controversial. We evaluated our experience with tumor histology in patients with localized renal cell carcinoma.

MATERIALS AND METHODS

We identified 1,863 patients with localized clear cell, papillary or chromophobe renal cell carcinoma who were treated surgically between 1989 and 2006 at our tertiary care center. Cox proportional hazards regression models were used to evaluate the relationship between tumor histology and outcome, defined as metastasis or death from disease, adjusting for age, sex, operation type, American Society of Anesthesiologists score, TNM stage and tumor size.

RESULTS

Of 1,863 patients 1,333 (72%) had clear cell histology, and 310 (17%) and 220 (12%) had papillary and chromophobe renal cell carcinoma, respectively. Median followup in patients without an event was 3.4 years. On univariate analysis patients with clear cell histology had a worse clinical outcome. Five-year probability of freedom from metastasis or death from disease was 86% (95% CI 84, 88), 95% (95% CI 91, 97) and 92% (95% CI 85, 96) in patients with clear cell, papillary and chromophobe histology, respectively (p <0.001). On multivariate analysis chromophobe (HR 0.40; 95% CI 0.20, 0.80) and papillary (HR 0.62; 95% CI 0.34, 1.14) histology was also significantly associated with better outcome (p = 0.014).

CONCLUSIONS

Clear cell histology seems to be independently associated with worse outcomes in patients who undergo surgery for renal cell carcinoma even after controlling for widely accepted factors influencing prognosis.

Advances and controversies in grading and staging of renal cell carcinoma

Despite the considerable progress made in our understanding of the pathogenesis, genetics, and pathology of renal cell carcinoma (RCC), difficulties remain relating to the prediction of clinical outcome for individual cases. Although there is evidence to show that high-grade tumors have a poorer prognosis when compared to those of low grade, debate remains regarding the predictive value of grading, especially for those tumors classified into the intermediate grades. Numerous composite morphologic and nuclear grading systems have been proposed for RCC and although that of the Fuhrman classification have achieved widespread usage, the validity of the grading criteria of this classification has been questioned. In addition, there are few studies that have attempted to validate the Fuhrman system for RCCs beyond that of the clear cell subtype. Recent studies have indicated that grading of papillary RCC should be based on nucleolar prominence alone and that the components of the Fuhrman grading classification do not provide prognostic information for chromophobe RCC. Independent of tumor grade, the prognostic importance of tumor stage for RCC is well recognized. The Union Internationale Contre le Cancer/American Joint Committee for Cancer Staging and End Results Reporting TNM staging system is now in its sixth edition (2002) and recent refinements have focused on defining size cut points that will identify apparently localized tumors that will develop recurrence and/or metastases despite attempted curative surgery. In parallel with these studies it has been shown that infiltration of the renal sinus is an important prognostic factor, being observed in almost all tumors >7 cm in diameter. Questions remain as to the appropriate stratification of regional extension of RCC, as defined in the T3 tumor-staging category. Recent modifications to this category have been suggested combining the level of infiltration of the venous outflow tract with the presence or absence of infiltration of the adrenal gland and/or perirenal fat. Similarly, the utility of classifying lymph node involvement by tumor is debated, although it is well recognized that lymph node infiltration is associated with a poor prognosis. Although the current TNM classification does provide useful prognostic information it would appear that further modifications are justified to enhance the predictive value of staging for RCC.

Expression of cortactin and survivin in renal cell carcinoma associated with tumor aggressiveness

PURPOSE

We tested the hypothesis that the expression of cortactin and survivin in renal cell carcinomas (RCCs) correlates with more advanced stages of the disease.

METHODS

Immunohistochemical analysis of cortactin and survivin expression (scored on a scale of 0-400) was performed in 124 renal cell carcinomas including clear cell renal cell carcinoma (CRCC), papillary RCC (PRCC), CRCC with sarcomatoid differentiation (SRCC), chromophobe RCC (ChRCC), and CRCC with granular cell differentiation (GRCC).

RESULTS

Higher cortactin scores in CRCC were significantly correlated with higher T (p = 0.021) and N stages (p = 0.036), and nuclear grade (p = 0.012). Higher cortactin immunostaining scores were associated with higher mortality (p = 0.035). In addition, the survivin scores were significantly higher in the more aggressive GRCC and SRCC than in CRCC, suggesting a significant role of survivin expression in transformation of tumor cells to a more malignant phenotype.

CONCLUSIONS

Higher expression of cortactin and survivin significantly correlated with advanced clinicopathological stage. Our findings support the potential targeting of survivin and cortactin for the development of novel therapeutic strategies for renal cell carcinoma.

The diagnostic and prognostic utility of claudin expression in renal cell neoplasms

This study evaluated the expression patterns of claudins 1, 3, 4, 7, and 8 in human renal cell carcinomas and oncocytomas and correlated expression with patient prognosis. Tissue microarrays were created from paraffin-embedded tissue samples from 141 patients with renal cell carcinomas or oncocytoma (90 clear cell, 22 papillary, 17 chromophobe renal cell carcinomas, and 12 oncocytomas). The staining pattern for claudins 3, 4, 7, and 8 was membranous and/or cytoplasmic, whereas claudin 1 was predominantly membranous in both nonneoplastic renal tissue and tumors. Negative to weak claudin 3 staining was predominantly detected in Fuhrman's grade 1 and 2 clear cell renal cell carcinomas (78%; P=0.016), suggesting that upregulation of claudin 3 potentially occurs concomitantly with increasing grade of clear cell renal cell carcinomas. In addition, Kaplan-Meier univariate analysis showed a significant inverse correlation between moderate to strong claudin 3 and 4 expression with overall survival in clear cell renal cell carcinomas (P=0.038 and P=0.031). Moderate to strong claudin 7 expression was significantly more common in chromophobe renal cell carcinomas (94%) than in oncocytomas (55%; P=0.041). Claudin 8 staining was moderate to strong in 92% of oncocytomas, which differentiated them from papillary and clear cell renal cell carcinomas (14 and 12%; both P<0.0001). Only negative to weak claudin 8 staining was detected in all chromophobe renal cell carcinomas, whereas there were no claudin 8 negative oncocytomas and 8% exhibited a weak staining pattern (P<0.0001). Due to their distinctive expression patterns, claudins 7 and 8 can be used as useful immunohistochemical markers for the separation of chromophobe renal cell carcinomas from oncocytomas, whereas claudins 3 and 4 may serve as indicators of prognosis in clear cell renal cell carcinomas.

Percentage of high-grade carcinoma as a prognostic indicator in patients with renal cell carcinoma

BACKGROUND

The prognostic value of Fuhrman nuclear grade for patients with renal cell carcinoma has been well-characterized. However, to the authors' knowledge, the prognostic significance of the amount of high-grade renal cell carcinoma has not been previously analyzed.

METHODS

The authors identified 898 consecutive renal cell carcinoma cases treated with nephrectomy between 1989 and 2003. Histopathologic features that were captured based on re-review of all slides included histologic type, pathologic stage, conventional Fuhrman grade, and percentage of Fuhrman grade 3 and 4 carcinoma, as ascertained by visual inspection of histologic slides. The clinical endpoints were metastasis-free survival, cancer-specific survival, and overall survival.

RESULTS

Kaplan-Meier analysis demonstrated that both conventional Fuhrman grading and the percentage of Fuhrman grade 3 and 4 carcinoma were highly correlated with all 3 measures of patient survival (P < .0001). The creation of 3 categories of the percentage of Fuhrman grade 3 and 4 carcinoma (0%, 1-50%, and 51-100%) generated distinctly separate survival curves. On Cox proportional hazards multivariate analysis, TNM stage, tumor size, and the percentage of Fuhrman grade 3 and 4 carcinoma were all found to be significantly associated with all 3 types of patient survival (all P values <.05).

CONCLUSIONS

The determination of the percentage of renal cell carcinoma that is 0%, 1% to 50%, or 51% to 100% high Fuhrman grade 3 and 4 is a simple and powerful measurement of patient outcome after surgery that provides additional prognostic information beyond stage, tumor size, and conventional Fuhrman grade. This prognostic information could be useful in the stratification of patients into prognostic groups for the development of more individualized follow-upschedules and for enrollment into clinical trials.

Questionable relevance of gamma delta T lymphocytes in renal cell carcinoma

Adoptive gammadelta T cell immunotherapy has moved briskly into clinical trials prompted by several small studies suggesting abundant accumulation of gammadelta T cells within renal cell carcinoma (RCC). In this study, we re-examined levels of gammadelta T cells within RCC tumors and correlated levels of these cells with pathologic features and outcome associated with this form of cancer. Tissues from 248 consecutive clear cell RCC tumors obtained from 2000 to 2003 were stained and quantified for total CD3+ and gammadelta T cells per mm2. Wilcoxon rank sum and Kruskal-Wallis tests were used to evaluate associations between T cell amounts and prognostic factors (age, gender, tumor size, stage, grade, tumor necrosis). Cox models were used to assess associations with RCC-specific death. Median numbers of total CD3+ and gammadelta T cells were 281/mm2 (interquartile range (IQR): 149-536) and 2.6/mm2 (IQR: 1.3-4.6), respectively. The median percentage of CD3+ T cells that were gammadelta T cells was 1.0% (IQR: 0.4-1.9). This low percentage of intratumoral gammadelta T cells was diluted even further with rising CD3+ T cell infiltration. Percentages of gammadelta T cells were not associated with even one single clinicopathologic feature examined. Median follow-up for this study was 3.1 years (48 patients died of RCC) and Cox analysis failed to demonstrate that gammadelta T cells (hazard ratio=1.02, p=0.25) were predictive of RCC-specific death. gammadelta T cells are rare and not recruited nor expanded within RCC tumors. Percentages of gammadelta T cells fail to correlate with any prognostic features of RCC nor specific death. As such, the role of gammadelta T cells in RCC immunobiology remains questionable.

Identification of copy number alterations and its association with pathological features in clear cell and papillary RCC

We report and characterize the copy number alterations (CNAs) in 35 clear cell and 12 papillary renal cell carcinomas (RCC) using Affymetrix 100K SNP arrays. Novel gain and loss regions are identified in both subtypes. In addition, statistically significant CNA are detected and associated with the pathological features: VHL mutation status, tumor grades, and sarcomatoid component in clear cell RCC and in types 1 and 2 of papillary RCC. Florescence in situ hybridization confirmed the copy number gain in the transforming growth factor, beta-induced gene (TGFBI), which is a possible oncogene for clear cell RCC.

Comparison of digital image analysis versus visual assessment to assess survivin expression as an independent predictor of survival for patients with clear cell renal cell carcinoma

We previously used quantitative digital image analysis to report that high immunohistochemical tumor expression levels of survivin independently predict poor outcome among patients with clear cell renal cell carcinoma. However, given the cumbersome and costly nature of digital image analysis, we evaluated simple visual assessment as an alternative to digital image analysis for assessing survivin as a predictor of clear cell renal cell carcinoma patient outcomes. We identified 310 patients treated surgically for unilateral, sporadic, clear cell renal cell carcinoma at our institution between 1990 and 1994. Survivin expression was quantified independently by digital image analysis and visual assessment in paraffin slides using a commercially available antibody. We examined the agreement between the 2 methods using the kappa statistic and then used Cox regression to compare the ability of the 2 methods to predict renal cell carcinoma death. The kappa statistic comparing high survivin expression determined by digital image analysis versus visual assessment was .68, indicating substantial agreement between the 2 methods. Moreover, even after multivariate adjustment, the association of high survivin expression with risk of renal cell carcinoma death was similar for both visual assessment (risk ratio = 2.01; 95% confidence interval, 1.26-3.22) and digital image analysis (risk ratio = 1.75; 95% confidence interval, 1.10-2.80). Finally, among patients with "moderate risk" (Stage, Size, Grade, and Necrosis scores 3-6) and "high risk" (Stage, Size, Grade, and Necrosis scores 7 or greater) clear cell renal cell carcinoma, high survivin expression determined by visual assessment was significantly associated with poorer survival (P = .006 and P = .017, respectively). Herein, we demonstrate substantial agreement between survivin quantification by digital image analysis and visual assessment. We further confirm that high survivin expression assessed by visual assessment remains an independent predictor of aggressive clear cell renal cell carcinoma behavior. Thus, visual assessment represents an economical, widely available, and reliable method to assess survivin as a predictor of clear cell renal cell carcinoma patient outcomes.