Proposal for revision of the TNM classification system for renal cell carcinoma

LINC02532 Contributes to Radiosensitivity in Clear Cell Renal Cell Carcinoma through the miR-654-5p/YY1 Axis

Background: Studies have shown that long non-coding RNAs (lncRNAs) play essential roles in tumor progression and can affect the response to radiotherapy, including in clear cell renal cell carcinoma (ccRCC). LINC02532 has been found to be upregulated in ccRCC. However, not much is known about this lncRNA. Hence, this study aimed to investigate the role of LINC02532 in ccRCC, especially in terms of radioresistance. Methods: Quantitative real-time PCR was used to detect the expression of LINC02532, miR-654-5p, and YY1 in ccRCC cells. Protein levels of YY1, cleaved PARP, and cleaved-Caspase-3 were detected by Western blotting. Cell survival fractions, viability, and apoptosis were determined by clonogenic survival assays, CCK-8 assays, and flow cytometry, respectively. The interplay among LINC02532, miR-654-5p, and YY1 was detected by chromatin immunoprecipitation and dual-luciferase reporter assays. In addition, in vivo xenograft models were established to investigate the effect of LINC02532 on ccRCC radioresistance in 10 nude mice. Results: LINC02532 was highly expressed in ccRCC cells and was upregulated in the cells after irradiation. Moreover, LINC02532 knockdown enhanced cell radiosensitivity both in vitro and in vivo. Furthermore, YY1 activated LINC02532 in ccRCC cells, and LINC02532 acted as a competing endogenous RNA that sponged miR-654-5p to regulate YY1 expression. Rescue experiments indicated that miR-654-5p overexpression or YY1 inhibition recovered ccRCC cell functions that had been previously impaired by LINC02532 overexpression. Conclusions: Our results revealed a positive feedback loop of LINC02532/miR-654-5p/YY1 in regulating the radiosensitivity of ccRCC, suggesting that LINC02532 might be a potential target for ccRCC radiotherapy. This study could serve as a foundation for further research on the role of LINC02532 in ccRCC and other cancers.

Modified cancer TNM classification for localized renal cell carcinoma based on the prognostic analysis of 3748 cases from a single center

The optimal cutoff point for evaluating the prognosis of localized renal cell carcinoma (LRCC) remains unclear. This study aimed to verify the efficacy of tumor diameter in the 2010 American Joint Committee on Cancer (AJCC) TNM staging system and contribute to the modification of TNM staging on the prognosis of this disease. A total of 3748 patients with LRCC were enrolled and grouped according to the 2010 AJCC TNM staging system. COX analysis was used to stratify the prognosis. The optimal cutoff point of the tumor diameter in the T1 and T2 prognosis was explored. There were 3330 (88.9%) patients in stage T1 and 418 (11.1%) in stage T2. The cancer-specific mortality rate was 2.7% (100/3748). The mean follow-up was 49.8 months. A tumor diameter of 7 cm can determine the prognosis of patients at stages T1 and T2; however, 4.5 cm and 11 cm as the cutoff points for T1 and T2 sub-classification of patients with LRCC might show better recognition ability than 4 cm and 10 cm, respectively. The 2010 AJCC TNM stage can predict the prognosis of LRCC in stages T1 and T2. In addition, a tumor diameter of 4.5 cm and 11 cm might be the optimal cutoff points for the sub-classification of stages T1 and T2.

Potential prognostic value of miRNAs as biomarker for progression and recurrence after nephrectomy in renal cell carcinoma: a literature review

OBJECTIVES

We provide a systematic literature review on tissue miRNAs in patients with RCC to evaluate and summarize their usefulness as prognostic markers. We undertook a systematic search for articles in English using the PubMed-Medline database from January 2010 to December 2020. Studies were identified and selected according to the PRISMA criteria and the PICO methodology. The population consisted of RCC patients undergoing nephrectomy and the main outcome of interest was recurrence-free survival (RFS). Only studies providing hazard ratios (HRs) from multivariate or univariate analyzes with corresponding 95% confidence intervals (CI) and/or area under the curve (AUC) were considered.

CONTENT

All nine included studies (1,541 patients) analyzed the relationship between tissue miRNA expression levels (up or downregulated) and RFS. Some of these found that the methylation status of miR-9-1, miR-9-3 and miR-124 was associated with a high risk of relapse. Moreover, miR-200b overexpression was associated with OS. MiR-210 overexpression indicated a shorter OS than those who were miR-210 negative. Finally, patients with high miR-125b expression had shorter CSS than those with low expression; similarly, patients with low miR-126 expression also had shorter CSS time.

SUMMARY AND OUTLOOK

Several studies tested the usefulness of specific miRNAs to predict RCC recurrence. Some of them showed a fair accuracy and strong relationship between specific miRNA over or under-expression and survival outcomes. However, results from these studies are preliminary and miRNAs use in routine clinical practice is still far to come.

Myc-associated zinc-finger protein promotes clear cell renal cell carcinoma progression through transcriptional activation of the MAP2K2-dependent ERK pathway

Background

The dysfunction of myc-related zinc finger protein (MAZ) has been proven to contribute to tumorigenesis and development of multiple cancer types. However, the biological roles and clinical significance of MAZ in clear cell renal carcinoma (ccRCC) remain unclear.

Methods

MAZ expression was examined in ccRCC and normal kidney tissue by quantitative real-time PCR and Western blot. Statistical analysis was used to evaluate the clinical correlation between MAZ expression and clinicopathological characteristics to determine the relationship between MAZ expression and the survival of ccRCC patients. The biological roles of MAZ in cells were investigated in vitro using MTT and colony assays. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to investigate the relationship between MAZ and its potential downstream signaling molecules.

Results

MAZ expression is elevated in ccRCC tissues, and higher levels of MAZ were correlated with poor survival of patients with ccRCC. MAZ upregulation elevates the proliferation ability of ccRCC cells in vitro, whereas silencing MAZ represses this ability. Our results further reveal that MAZ promotes cell growth, which is dependent on ERK signaling. Importantly, we found that MAZ positively regulates MAP2K2 expression in ccRCC cells. Mechanistically, MAZ binds to the MAP2K2 promoter and increases MAP2K2 transcription. Furthermore, MAP2K2 levels were shown to be increased in ccRCC tissues and to be associated with a poor prognosis of ccRCC patients. MAP2K2 upregulation activates the ERK signaling pathway and promotes ccRCC progression.

Conclusion

These results reveal that the MAZ/MAP2K2/ERK signaling axis plays a crucial role in promoting ccRCC progression, which suggests the potential therapeutic utility of MAZ in ccRCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02020-9.

High MCM6 Expression as a Potential Prognostic Marker in Clear-cell Renal Cell Carcinoma

AIM

Minichromosome maintenance (MCM) proteins are involved in initiation of DNA replication and cell-cycle progression. Loss of MCM function results in genomic instability and causes carcinogenesis. Among MCM genes, the role and prognostic value of MCM6 expression in clear-cell renal cell carcinoma (ccRCC) has not been elucidated.

MATERIALS AND METHODS

We assessed the mRNA expression level of MCM6 using the Gene Expression Profiling Interactive Analysis database and investigated MCM6 protein expression by immunohistochemistry in 238 ccRCC cases.

RESULTS

High MCM6 expression was significantly associated with increasing tumor size, pT, stage, tumor necrosis, and metastasis. Furthermore, high MCM6 expression was significantly associated with shorter overall and disease-free survival, and was an independent unfavorable prognostic marker. Regarding patients with metastasis, high MCM6-expressing ccRCC conferred significantly shorter survival than for those with low expression.

CONCLUSION

A high MCM6 expression level may be a promising biomarker to predict tumor progression, metastasis, and survival in patients with ccRCC.

Characteristics and Outcome of Children with Renal Cell Carcinoma: A Narrative Review

Pediatric renal cell carcinoma (RCC) is a rare type of kidney cancer, most commonly occurring in teenagers and young adolescents. Few relatively large series of pediatric RCC have been reported. Knowledge of clinical characteristics, outcome and treatment strategies are often based on the more frequently occurring adult types of RCC. However, published pediatric data suggest that clinical, molecular and histological characteristics of pediatric RCC differ from adult RCC. This paper summarizes reported series consisting of ≥10 RCC pediatric patients in order to create an up-to-date overview of the clinical and histopathological characteristics, treatment and outcome of pediatric RCC patients.

LINC01094 triggers radio-resistance in clear cell renal cell carcinoma via miR-577/CHEK2/FOXM1 axis

Background

Radioresistance is an obstacle to limit efficacy of radiotherapy. Meanwhile, long non-coding RNAs (lncRNAs) have been reported to affect radioresistance. Here, we aimed to investigate lncRNAs involving radioresistance development of clear cell renal cell carcinoma (ccRCC), the most frequent type of renal cell carcinoma (RCC).

Methods

The mRNA and protein expressions of genes were measured via qRT-PCR and western blot. The relationships among genes were verified by RIP and luciferase reporter assay. The radioresistance of ccRCC cells was evaluated through clonogenic survival assay, MTT assay and TUNEL assay.

Results

LINC01094 was over-expressed in ccRCC cell lines. LINC01094 expression was increased along with the radiation exposure time and the final stable level was 8 times of the initial level. Knockdown of LINC01094 resulted in enhanced radiosensitivity of ccRCC cells. Mechanically, LINC01094 was a ceRNA of CHEK2 by sponging miR-577. Also, the enhancement of LINC01094 on ccRCC radioresistance was mediated by CHEK2-stabilized FOXM1 protein.

Conclusion

LINC01094 facilitates ccRCC radioresistance by targeting miR-577/CHEK2/FOXM1 axis, blazing a new trail for overcoming radioresistance in ccRCC.

miR-429-CRKL axis regulates clear cell renal cell carcinoma malignant progression through SOS1/MEK/ERK/MMP2/MMP9 pathway

The pathogenesis and tumorigenesis of clear cell renal cell carcinoma (ccRCC) remain unclear. The deregulations of miR-429, a member of miR-200 family, and v-crk sarcoma virus CT10 oncogene homologue (avian)-like (CRKL), an adaptor protein of CRK family, are involved in the development, metastasis and prognosis of various cancers. Current study aimed to demonstrate the differential expressions of miR-429 and CRKL with their correlationship and molecular regulation mechanism in ccRCC malignancy. miR-429 and CRKL separately showed suppressing and promoting effects in ccRCC. Lower miR-429 expression and higher CRKL expression were negatively correlated in surgical cancerous tissues by promoting the advance of ccRCC. By binding to the 3'-UTR of CRKL, miR-429 reversely regulated CRKL for its functionalities in ccRCC cells. CRKL knockdown and overexpression separately decreased and increased the in vitro migration and invasion of 786-O cells, which were consistent with the influences of miR-429 overexpression and knockdown on 786-O through respectively downregulating and upregulating CRKL via SOS1/MEK/ERK/MMP2/MMP9 pathway. The enhancements of CRKL expression, migration and invasion abilities and SOS1/MEK/ ERK/MMP2/MMP9 activation induced by TGF-β stimulation in 786-O cells could be antagonized by miR-429 overexpression. Exogenous re-expression of CRKL abrogated miR-429 suppression on the migration and invasion of 786-O cells. Collectively, miR-429 deficiency negatively correlated with CRKL overexpression promoted the aggressiveness of cancer cells and advanced the clinical progression of ccRCC patients. miR-429-CRKL axial regulation provides new clues to the fundamental research, diagnosis and treatment of ccRCC.

GRIM-19 deficiency promotes clear cell renal cell carcinoma progression and is associated with high TNM stage and Fuhrman grade

Clear cell renal cell carcinoma (ccRCC) exhibits the highest mortality among all urological malignancies. The investigation of the potential disease progression markers can improve ccRCC diagnosis and treatment. Gene associated with retinoid-interferon-induced mortality-19 (GRIM-19) is involved in carcinogenesis and cancer progression in a variety of cancer types including RCC. While, its role in ccRCC remains unclear, this cancer type is considered the most aggressive RCC subtype. In the present study, RT-qPCR, western blotting and immunohistochemical (IHC) assays demonstrated that GRIM-19 protein and mRNA levels were downregulated in ccRCC tumor tissues compared with the corresponding levels noted in paracancerous non-tumor tissues. The deficiency of this protein contributed in relaxed and/or collapsed structures of the kidney tubules and collecting duct noted in tumor tissues. Moreover, the reduction in GRIM-19 expression was associated with high tumor, lymph nodes and metastasis (TNM) stage and Fuhrman grade of ccRCC tumors. The data suggested that GRIM-19 acted as a tumor suppressor and that its deficiency promoted ccRCC development and progression. GRIM-19 can be considered a potential tumor marker for ccRCC.

Upregulation of ERp57 promotes clear cell renal cell carcinoma progression by initiating a STAT3/ILF3 feedback loop

Background

ERp57 dysfunction has been shown to contribute to tumorigenesis in multiple malignances. However, the role of ERp57 in clear cell renal carcinoma (ccRCC) remains unclear.

Methods

Cell proliferation ability was measured by MTT and colony forming assays. Western blotting and quantitative real-time PCR (qRT-PCR) were performed to measure protein and mRNA expression. Co-immunoprecipitation (CoIP) and proximity ligation assay (PLA) were performed to detect protein-protein interaction. Chromatin immunoprecipitation (ChIP), ribonucleoprotein immunoprecipitation (RIP), and oligo pull-down were used to confirm DNA–protein and RNA–protein interactions. Promoter luciferase analysis was used to detect transcription factor activity.

Results

Here we found ERp57 was overexpressed in ccRCC tissues, and the higher levels of ERp57 were correlated with poor survival in patients with ccRCC. In vivo and in vitro experiments showed that ccRCC cell proliferation was enhanced by ERp57 overexpression and inhibited by ERp57 deletion. Importantly, we found ERp57 positively regulated ILF3 expression in ccRCC cells. Mechanically, ERp57 was shown to bind to STAT3 protein and enhance the STAT3-mediated transcriptional activity of ILF3. Furthermore, ILF3 levels were increased in ccRCC tissues and associated with poor prognosis. Interestingly, we revealed that ILF3 could bind to ERp57 and positively regulate its expression by enhancing its mRNA stability. Furthermore, ccRCC cell proliferation was moderated via the ERp57/STAT3/ILF3 feedback loop.

Conclusions

In summary, our results indicate that the ERp57/STAT3/ILF3 feedback loop plays a key role in the oncogenesis of ccRCC and provides a potential therapeutic target for ccRCC treatment.

miR-4521-FAM129A axial regulation on ccRCC progression through TIMP-1/MMP2/MMP9 and MDM2/p53/Bcl2/Bax pathways

Clear cell renal cell carcinoma (ccRCC) is the most aggressive RCC subtype with high metastasis, chemotherapy and radiotherapy resistance, and poor prognosis. This study attempted to establish the deregulations of miR-4521 and FAM129A together with their correlation to and mechanism of regulation of ccRCC development and progression. FAM129A acted as tumor promotor and miR-4521 acted as a suppressor in ccRCC. As measured in surgical tumorous tissues from ccRCC patients, FAM129A overexpression and miR-4521 deficiency together contributed to ccRCC progression by promoting advances in patients' TNM stage and Fuhrman grade. Both the FAM129A knockdown and miR-4521 overexpression could reduce the in vitro migration and invasion abilities of renal cancer cells 786-O and ACHN, through the TIMP-1/MMP2/MMP9 pathway and could decrease their proliferation by promoting their apoptosis through the MDM2/p53/Bcl2/Bax pathway. By directly targeting the 3'-UTR domain of FAM129A, miR-4521 was negatively correlated with FAM129A/FAM129A levels in ccRCC progression and renal cancer cell malignancies. This work establishes the miR-4521-FAM129A axial regulation mechanism in ccRCC. Micro-4521 deficiency leads to FAM129A/FAM129A upregulation, which synergistically enhances the migration and invasion of renal cancer cells due to the induced decrease of TIMP-1 and increases of MMP2 and MMP9, and increases their growth through escaping apoptosis by suppressing p53 by way of upregulation of induced MDM2. The current work provides new clues to assist fundamental research into the diagnosis and treatment of ccRCC.

[Sporadic kidney cancer of young subjects: Study of the clinical and pathological features of a bicentric cohort]

INTRODUCTION

The epidemiology of kidney cancer is evolving with a net increase in the incidence of renal tumors, globally, and in young people in particular.

OBJECTIVE

To evaluate the incidence and clinical and pathological characteristics of sporadic renal tumors in young subjects and their risk factors.

MATERIAL AND METHODS

A retrospective study aimed at collecting clinical, epidemiological and anatomopathological information from the 118 patients aged 18 to 40 treated for a sporadic kidney tumor in two Parisian university hospital centers between 2003 and 2013.

RESULTS

Our study showed a very significant increase in the incidence of renal tumors in our 11 years of decline (P=6.10^-15). The mode of discovery also seems to have evolved with a majority of tumors (67 %), due to the considerable growth of imaging in recent decades. We also showed a different pathological distribution compared to the literature with a significant increase in the number of papillary tumors (16.9 %) and chromophobes (15.2 %), in addition to a decrease in the number of carcinomas (43.2 %) as well as the appearance of a new pathological entity of particular clinical severity: renal carcinoma related to translocation Xp11.2 (15.3 %) (P<10^-5). Among the risk factors, hypertension seems to be a definite risk factor while tobacco and obesity do not have a significant influence.

CONCLUSION

Our study showed a marked increase in the incidence of renal tumors with specific clinical and epidemiological features in a population of young subjects. The role and importance of oncogenetic management as well as the study of environmental factors could lead to the identification of new risk factors and corollary to their prevention.

LEVEL OF EVIDENCE

4.

Combination of mTOR and MAPK Inhibitors-A Potential Way to Treat Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by a unique biology, with a long history of poor response to conventional cancer treatments. In the past few years, there have been significant advancements to understand the biology of RCC. This has led to the introduction of novel targeted therapies in the management of patients with metastatic disease. Patients treated with targeted therapies for RCC had shown positive impact on overall survival, however, no cure is possible and patients need to undergo treatment for long periods of time, which raises challenges to manage the associated adverse events. Moreover, many patients may not respond to it and even response may not last long enough in the responders. Many inhibitors of the Mammalian target of Rapamycin (mTOR) signaling pathway are currently being used in treatment of advanced RCC. Studies showed that inhibitions of mTOR pathways induce Mitogen-Activated Protein Kinase (MAPK) escape cell death and cells become resistant to mTOR inhibitors. Because of this, there is a need to inhibit both pathways with their inhibitors comparatively for a better outcome and treatment of patients with RCC.

Introduction to small renal tumours and prognostic indicators

Over the past years, the widespread use of radiological imaging for evaluating abdominal symptoms unrelated to kidney cancer has been linked to a significant increase in the percentage of renal tumours incidentally detected at an asymptomatic stage. The definition of 'small' renal tumours has changed over the years. Presently, according to dimensional criteria, surgical indications and prognostic impact, small renal tumours are defined as masses ≤4 cm in size. Classical preoperative variables that influence the decision-making process in the management of T1a renal tumours can be classified as patient-related and tumour-related factors. Age is an independent predictor of cancer-specific survival (CSS), with older patients exhibiting significantly worse survival. An accurate classification of the anatomical and topographical characteristics of small renal masses based on available nephrometry systems is necessary for standard preoperative evaluation of patients eligible for partial nephrectomy (PN). Renal tumour biopsies (RTBs) can be indicated in patients eligible for active surveillance or ablative treatments, those with other primary tumours, those with prior renal lesions and/or those with multiple synchronous tumours, showing a median diagnostic rate of 92%. Small renal tumours typically have a good prognosis. Patient age, mode of presentation, nuclear grading, coagulative necrosis and histologic subtype can influence the prognosis of this subgroup of RCC.

Collecting system invasion and Fuhrman grade but not tumor size facilitate prognostic stratification of patients with pT2 renal cell carcinoma

PURPOSE

The 7th edition of TNM for renal cell carcinoma introduced a subdivision of pT2 tumors at a 10 cm cutoff. In the present multicenter study the influence of tumor size as well as further clinical and histopathological parameters on cancer specific survival in patients with pT2 tumors was evaluated.

MATERIALS AND METHODS

A total of 670 consecutive patients with pT2 tumors (10.4%) of 6,442 surgically treated patients with all tumor stages were pooled (mean followup 71.4 months). Tumors were reclassified according to the current TNM classification, and subdivided in stages pT2a and pT2b. Cancer specific survival was analyzed using the Kaplan-Meier method, and univariable and multivariable analyses were used to assess the influence of several parameters on survival.

RESULTS

Tumor size continuously applied and subdivided at 10 cm or alternative cutoffs did not significantly influence cancer specific survival. In addition to N/M stage, Fuhrman grade and collecting system invasion also had an independent influence on survival. Integration of a dichotomous variable subsuming Fuhrman grade and collecting system invasion (grade 3/4 and/or collecting system invasion present vs grade 1/2 and collecting system invasion absent) into multivariate models including established prognostic parameters resulted in improvement of predictive abilities by 11% (HR 2.3, p <0.001) for all pT2 cases and 151% (HR 3.1, p <0.001) for stage pT2N0M0 cases.

CONCLUSIONS

Tumor size did not have a significant influence on cancer specific survival in pT2 tumors, neither continuously applied nor based on various cutoff values. To enhance prognostic discrimination, multifactorial staging systems including pathological features should be implemented. The prognostic relevance of the variable subsuming Fuhrman grade and collecting system invasion should be considered for future evaluation.

Staging of renal cell carcinoma: Current concepts

The most important and widely utilized system for providing prognostic information following surgical management for renal cell carcinoma (RCC) is currently the tumor, nodes, and metastasis (TNM) staging system. An accurate and clinically useful staging system is an essential tool used to provide patients with counseling regarding prognosis, select treatment modalities, and determining eligibility for clinical trials. Data published over the last few years has led to significant controversies as to whether further revisions are needed and whether improvements can be made with the introduction of new, more accurate predictive prognostic factors. Staging systems have also evolved with an increase in the understanding of RCC tumor biology. Molecular tumor biomarkers are expected to revolutionize the staging of RCC by providing more effective prognostic ability over traditional clinical variables alone. This review will examine the components of the TNM staging system, current staging modalities including comprehensive integrated staging systems, and predictive nomograms, and introduce the concept of molecular staging for RCC.

Linkage of microRNA and proteome-based profiling data sets: a perspective for the priorization of candidate biomarkers in renal cell carcinoma?

Despite recent advances in the understanding of the biology of renal cell carcinoma (RCC) and the implementation of novel targeted therapies, the overall 5 years' survival rate for RCC patients remains disappointing. Late presentation, tumor heterogeneity and in particular the lack of molecular biomarkers for early detection and classification represent major obstacles. Global, untargeted comparative analysis of RCC vs tumor adjacent renal epithelium (NN) samples by high throughput analyses both at the transcriptome and proteome level have identified signatures, which might further clarify the molecular differences of RCC subtypes and might allow the identification of suitable therapeutic targets and diagnostic/prognostic biomarkers, but none thereof has yet been implemented in routine clinical use. The increasing knowledge regarding the functional role of noncoding microRNA (miR) in physiological, developmental, and pathophysiological processes by shaping the protein expression profile might provide an important link to improve the definition of disease-relevant regulatory networks. Taking into account that miR profiling of RCC and NN provides robust signatures discriminating between malignant and normal tissues, the concept of evaluating and scoring miR/protein pairs might represent a strategy for the selection and prioritization of potential biomarkers and their translation into practical use.

Prognostic variables and nomograms for renal cell carcinoma

The term renal cell carcinoma (RCC) is used to describe a heterogeneous group of tumors that vary histologically, genetically and molecularly. Extensive research has been conducted to identify characteristics that predict outcomes among patients with RCC. In addition to histological subtype these include tumor size, patient age, mode of presentation and various hematological indices, among others. Several groups have incorporated these clinical and pathological features into nomograms which help the clinician better define individual patient prognosis and direct the optimum therapeutic approach. In the present article we review these prognostic variables and nomograms for RCC.

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

BACKGROUND

A new edition of the TNM was recently released that includes modifications for the staging system of kidney cancers. Specifically, T2 cancers were subclassified into T2a and T2b (< or =10 cm vs >10 cm), tumors with renal vein involvement or perinephric fat involvement were classified as T3a cancers, and those with adrenal involvement were classified as T4 cancers.

OBJECTIVE

Our aim was to validate the recently released edition of the TNM staging system for primary tumor classification in kidney cancer.

DESIGN, SETTING, AND PARTICIPANTS

Our multicenter retrospective study consisted of 5339 patients treated in 16 academic Italian centers.

INTERVENTION

Patients underwent either radical or partial nephrectomy.

MEASUREMENTS

Univariable and multivariable Cox regression models addressed cancer-specific survival (CSS) after surgery.

RESULTS AND LIMITATIONS

In the study, 1897 patients (35.5%) were classified as pT1a, 1453 (27%) as pT1b, 437 (8%) as pT2a, 153 (3%) as pT2b, 1059 (20%) as pT3a, 117 (2%) as pT3b, 26 (0.5%) as pT3c, and 197 (4%) as pT4. At a median follow-up of 42 mo, 786 (15%) had died of disease. In univariable analysis, patients with pT2b and pT3a tumors had similar CSS, as did patients with pT3c and pT4 tumors. Moreover, both pT3a and pT3b stages included patients with heterogeneous outcomes. In multivariable analysis, the novel classification of the primary tumor was a powerful independent predictor of CSS (p for trend <0.0001). However, the substratification of pT1 tumors did not retain an independent predictive role. The major limitations of the study are retrospective design, lack of central pathologic review, and the small number of patients included in some substages.

CONCLUSIONS

The recently released seventh edition of the primary tumor staging system for kidney tumors is a powerful predictor of CSS. However, some of the substages identified by the classification have overlapping prognoses, and other substages include patients with heterogeneous outcomes. The few modifications included in this edition may have not resolved the most critical issues in the previous version.

Urinary collecting system invasion is an independent prognostic factor of organ confined renal cell carcinoma

PURPOSE

We evaluated urinary collecting system invasion as a prognostic parameter of renal cell carcinoma.

MATERIALS AND METHODS

A total of 1,124 patients who underwent nephrectomy for a renal tumor at 5 European centers were included in this retrospective study. Several variables were analyzed including urinary collecting system invasion, age, sex, TNM stage, Fuhrman grade, histological subtype, Eastern Cooperative Oncology Group performance status and cancer specific survival.

RESULTS

There were 771 males (68.6%) and 353 females (31.4%) in this study, and median age was 61 years (range 14 to 88). Median tumor size was 6 cm (range 1 to 24). Tumors were organ confined and Fuhrman grade was recorded as 1 or 2 in 67.1% and 62.3% of cases, respectively. Symptoms were present at diagnosis, and Eastern Cooperative Oncology Group performance status was 1 or more in 50.3% and 16.1% of the cases, respectively. Median followup was 43 months (range 1 to 299). At the end of followup 246 patients (21.9%) died of cancer. In 132 cases (11.7%) urinary collecting system invasion was noted. Urinary collecting system invasion was associated with symptoms, TNM stage, Fuhrman grade, tumor size (p <0.001) and Eastern Cooperative Oncology Group performance status (p = 0.003), but not with histological subtype (p = 0.7). On univariate analysis TNM stage, Fuhrman grade, symptoms, Eastern Cooperative Oncology Group performance status, tumor size and urinary collecting system invasion (p = 0.0001) were significant predictors of cancer specific survival. Urinary collecting system invasion was an independent prognostic parameter only in the setting of pT1-T2 tumors. When the urinary collecting system was invaded the 5 and 10-year probabilities of survival were 43% and 41%, respectively.

CONCLUSIONS

Urinary collecting system invasion appears to be an independent prognostic parameter of organ confined renal cell carcinoma. Our data support the need to integrate this parameter in further TNM revisions.

Renal cell carcinoma: A clinicopathological follow-up study after radical nephrectomy

OBJECTIVE

To examine the prognostic significance of performance status, tumour stage, histological subtype, nuclear grade and histological tumour necrosis (HTN) in a population of consecutive patients subjected to radical nephrectomy for renal cell carcinoma (RCC).

MATERIAL AND METHODS

The cohort consisted of 110 males and 86 females with a mean age of 66 years (range 39-88 years). The Eastern Cooperative Oncology Group performance status (ECOG PS) was determined in all cases. The tumours were staged according to the 2002 TNM classification of the American Joint Committee on Cancer. Histological subtype was diagnosed using the Heidelberg classification. Nuclear grading was performed by means of Fuhrman's method. The median follow-up period was 65 months (mean 83 months; range 1-232 months).

RESULTS

Median overall survival (OS) was 65 months and median cancer-specific survival (CSS) was 171 months. CSS was correlated with TNM classification, with the longest survival occurring for stage I and II tumours, shorter survival for stage III tumours and shortest survival for stage IV tumours (p<0.001). A significant difference in CSS was found between T1N0M0 and T2N0M0 tumours (p<0.01). A 15-year CSS of 100% was revealed in patients with tumours </=4 cm in size. There was a significant difference in CSS between low nuclear grade (NG; 1+2) and high NG (3+4) tumours (p<0.001). HTN and ECOG PS were found to be independent prognostic factors (p<0.01).

CONCLUSION

ECOG PS, TNM stage, nuclear grade and tumour necrosis were found to be independent prognostic factors for survival.

Reassessing the current UICC/AJCC TNM staging for renal cell carcinoma

CONTEXT

The outcome prediction for renal cell cancer (RCC) remains controversial, and although many parameters have been tested for prognostic significance, only a few have achieved widespread acceptance in clinical practice. The TNM staging system defines local extension of the primary tumour (T), involvement of regional lymph nodes (N), and presence of distant metastases (M).

OBJECTIVE

This review focuses on reassessing the current TNM staging system for RCC.

EVIDENCE ACQUISITION

A literature search in English was performed using the National Library of Medicine database and the following keywords: renal cell cancer, kidney neoplasm, and staging. We scrutinized 1952 references, and 62 were selected for review based on their pertinence, study size, and overall contribution to the field.

EVIDENCE SYNTHESIS

The prognostic significance of tumour size for localized RCC has been investigated in a large number of studies. As a consequence, many modifications of the TNM staging system were primarily made to the size cut points between stage I and II tumours. The latest three revisions of the TNM system are systematically reviewed. For the heterogeneous group of locally advanced RCCs, involving different anatomic structures surrounding the kidney, the situation is still the subject of controversial scientific dispute. In detail, perirenal fat invasion, direct infiltration of the ipsilateral adrenal gland, invasion of the urinary collecting system, infiltration of renal sinus fat, and vena cava and renal vein thrombosis are disputed. Finally, staging of lymph node metastases and distant metastatic disease is discussed.

CONCLUSIONS

Special emphasis should be put on renal sinus invasion for stage evaluation. Retrospective studies relying on material collected at a time when no emphasis was placed on adequate sampling of the renal sinus should be treated with caution. In view of new treatment opportunities, the current TNM staging system of RCC and any other staging system must be dynamic.

Radiologic evaluation of small renal masses (I): pretreatment management

When characterizing a small renal mass (SRM), the main question to be answered is whether the mass represents a surgical or nonsurgical lesion or, in some cases, if followup studies are a reasonable option. Is this a task for a urologist or a radiologist? It is obvious that in the increasing clinical scenario where this decision has to be made, both specialists ought to work together. This paper will focus on the principles, indications, and limitations of ultrasound, CT, and MRI to characterize an SRM in 2008 with a detailed review of relevant literature. Special emphasis has been placed on aspects regarding the bidirectional information between radiologists and urologists needed to achieve the best radiological approach to an SRM.

Epidemiology, clinical staging, and presentation of renal cell carcinoma

The increasing incidence of renal cell carcinoma over the past 2 decades can be partly explained by the expanding use of abdominal imaging. As a result, the most incident renal cancers today are small, localized, and asymptomatic. However, the well-documented rise in all stages of RCC calls into question the nature of these asymptomatic lesions. The expected "screening effect" of detecting RCC when it is small and localized, with subsequent decreases in disease-specific mortality, has not been observed. Disease-specific mortality is actually rising, especially in African American patients. Effective interventions aimed at reducing obesity, hypertension, and smoking may help in reducing the incidence of RCC in the future.

Age, tumor size and relative survival of patients with localized renal cell carcinoma: a surveillance, epidemiology and end results analysis

PURPOSE

Recent data demonstrate that age may be a significant independent prognostic variable following treatment for renal cell carcinoma. We analyzed data from the SEER (Surveillance, Epidemiology and End Results) database to evaluate the relative survival of patients treated surgically for localized renal cell carcinoma as related to tumor size and patient age.

MATERIALS AND METHODS

Patients in the SEER database with localized renal cell carcinoma were stratified into cohorts by age and tumor size. Three and 5-year relative survival, the ratio of observed survival in the cancer population to the expected survival of an age, sex and race matched cancer-free population, was calculated with SEER-Stat. Brown's method was used for hypothesis testing.

RESULTS

A total of 8,578 patients with surgically treated, localized renal cell carcinoma were identified. While 3 and 5-year survival for patients with small (less than 4 cm) renal cell carcinoma was no different from that of matched cancer-free controls, patients treated for large (greater than 7 cm) localized renal cell carcinoma experienced decreased 5-year relative survival across all age groups. Therefore, age was not a significant predictor of relative survival for patients with small (less than 4 cm) or large (greater than 7 cm) tumors. However, a statistically significant trend toward lower relative survival with increasing age was demonstrated in patients with medium size tumors (4 to 7 cm). Hypothesis testing confirmed these findings.

CONCLUSIONS

These data suggest that relative survival is high in patients with tumors less than 4 cm and lower in patients with tumors larger than 7 cm regardless of age. However, increasing age may be related to worse outcomes in patients with tumors 4 to 7 cm. The cause of this observation warrants further investigation.

Perinephric and renal sinus fat infiltration in pT3a renal cell carcinoma: possible prognostic differences

OBJECTIVE

To evaluate the influence of perinephric (PN) and renal sinus (RS) fat infiltration on cancer-specific survival beyond other prognostic factors, as the Tumour-Node-Metastasis (TNM) classification system defines stage T3a renal cell carcinoma (RCC) as infiltration of perirenal fat and/or direct infiltration of the adrenal gland. Perirenal fat invasion is differentiated into RS and PN fat infiltration, but not further classified for the prognosis.

PATIENTS AND METHODS

From 1990 to October 2007 106 patients with advanced RCC (T3a) were followed prospectively at one academic centre; all had a radical nephrectomy. To identify prognostic effects of PN, RS or RS + PN fat infiltration, univariable and multivariable Cox proportional hazard regression models were applied, including lymph node status, metastases, presence of sarcomatoid features and tumour necrosis, Fuhrman's grade, Karnofsky performance status, and tumour size.

RESULTS

PN fat invasion alone was present in 58, RS in 21, and PN + RS in 27 patients. The median follow-up was 2.9 years; 49 patients died from RCC. In univariable and multivariable analyses RS fat infiltration was an unfavourable prognostic factor (adjusted hazard ratio, HR, 2.24, P = 0.019). Univariable analysis of RS + PN fat infiltration showed the worst prognostic effect (HR 3.25, P < 0.001). In multivariable analysis this combination was an independent prognostic factor (HR 2.75, P = 0.007), as was the presence of metastasis (HR 5.64, P < 0.001). In this group of RS + PN fat infiltration the 5-year cancer-specific survival was 31%.

CONCLUSION

Univariable and multivariable analyses showed that the combination of RS and PN fat infiltration is an independent unfavourable prognostic marker. We recommend that perirenal fat infiltration should be further differentiated into RS fat or PN infiltration in the TNM classification. This will better stratify patient prognosis and might allow those in need of adjuvant therapy to be identified.

Watchful waiting for small renal masses

Small renal masses (SRMs; < 4 cm in diameter) account for most renal tumors treated today. Incidental early detection of SRMs by abdominal imaging results in favorable grade and stage migration to renal cell carcinoma, and also increases detection of benign renal tumors. As a result, most SRMs manifest indolent biological behavior with excellent prognosis. Despite the increased use of minimally invasive laparoscopic surgery, nephron-sparing techniques, and percutaneous ablation therapy, selected patients are managed by initial active surveillance, reserving therapy for progression. Older patients and those with competing risks due to medical comorbidities are excellent candidates for active surveillance; their risk of early progression due to growth or metastases appears to be low. Active surveillance should not be recommended for younger, healthier patients until prognostic factors are better defined. Needle core use for improved histopathologic characterization of SRMs should be considered before recommending treatment.

Risk stratification and prognostication of renal cell carcinoma

OBJECTIVES

To review the most recent data on prognostic factors and describe the characteristics and prognostic accuracy of the most important prognostic systems available to predict the risk of recurrence, progression, and mortality in patients with renal cell carcinoma (RCC).

METHODS

The study was based on a non-systematic review of literature.

RESULTS

Clinical (performance status, and mode of presentation), anatomical (size and extension of the primary tumor, lymph node involvement, and distant metastasis), and histological factors (histological subtypes, nuclear grade, and tumor necrosis) are the most largely evaluated prognostic factors in RCC. Valuable prognostic accuracy has been shown for several laboratory parameters (erythrocyte sedimentation rate, platelet count, serum calcium, hemoglobin, and lactate dehydrogenase levels) and a few genetical and molecular markers (CAIX, B7-H1, and B7-H4). A few integrating systems have been proposed and validated, integrating both clinical and pathological (UCLA Integrating Staging Systems, Kattan nomogram, and Sorbellini nomogram) or only pathological variables (SSIGN score).

CONCLUSIONS

Several large and methodologically consistent studies have been published. The chance to integrate the data derived from each prognostic factor into prognostic algorithms and scores has allowed improving significantly the stratification of the prognosis of patients with RCC. The currently available prognostic systems can be further improved through the inclusion of molecular and genetic variables. Integrating prognostic systems should be used to design randomized controlled trials (RCTs), which will evaluate the efficacy of the new-targeted therapies in either neoadjuvant, adjuvant, or salvage treatments of patients with RCC.

Mathematical models for prognostic prediction in patients with renal cell carcinoma

OBJECTIVES

The objectives of this study are to catalogue all models developed to predict survival of RCC patients and to identify the ones to be used in different situations.

METHODS

A systematic review was performed searching with a free text and MeSH strategy 3 electronic databases. For each model, the following parameters were identified: number, features of the patients; evaluation endpoints; clinical and/or pathological variables included; concordance indexes (cI).

RESULTS

The research retrieved 156 records. Eleven articles proposed new models, 5 articles external validations. We retrieved 2 mathematical models including clinical variables only (Yaycioglu, cI 0.651; Cindolo, cI 0.672); 2 algorithms including also pathological variables (SSIGN, cI 0.819; UISS, cI 0.79-0.84), 5 nomograms (Kattan, cI 0.76-0.86; Sorbellini, cI 0.82; Kim 2004, cI 0.79, Kim 2005, cI 0.68; Karakiewicz, cI 0.86); 2 algorithms for patients with metastatic disease (Motzer, Leibovich).

CONCLUSIONS

The SSIGN was the most accurate algorithm for conventional RCC, while the UISS allowed the evaluation of patients regardless of tumor histotype. The Sorbellini nomogram is applicable only for patients with conventional RCC, while the Kattan and Karakiewicz nomograms also provide information for other histotypes. Metastatic patients can be evaluated with Leibovich and Motzer algorithms. Two models combine molecular markers and clinical features (Kim 2004-2005).

Nephron-sparing surgery and percutaneous biopsies in renal-cell carcinoma: a global impression among endourologists

BACKGROUND AND PURPOSE

On the one hand, nephron-sparing surgery (NSS) in small renal tumors is a safe and effective alternative to radical nephrectomy. On the other hand, the role of preoperative percutaneous needle biopsies (PNB) remains controversial. The purpose of this study was to evaluate the global current use of NSS in the treatment of renal-cell carcinoma (RCC) and the use of PNB among endourologists.

MATERIALS AND METHODS

One thousand questionnaires were distributed during the 23rd World Congress of Endourology and SWL. Six questions regarding NSS and two questions regarding PNB were presented. Two hundred twenty-two questionnaires were returned.

RESULTS

Of the respondents, 86.6% perform NSS for small renal tumors, whereas 13.4% perform only radical nephrectomies; 7.5% will consider NSS only in patients with a solitary kidney, and 0.5% will never consider NSS. The techniques for NSS, in descending order of preference, are partial nephrectomy, enucleation, cryoablation, radiofrequency ablation, and high-intensity focused ultrasound. The mean and maximum diameter of the tumor in patients with a normal contralateral kidney for which the urologists perform NSS is 4.0 cm. For a centrally located tumor, NSS is an option for 27.2% of the respondents. Regarding PNB in patients with suspicion of RCC, 55.9% of respondents never obtain renal biopsies in the preoperative assessment and 41.8% obtain them only in rare cases. The majority (90%) prefer histologic over cytologic biopsies.

CONCLUSIONS

Nephron-sparing surgery is evolving to a global worldwide standard treatment for small renal tumors. Percutaneous needle biopsy remains a highly debated procedure.

Efficacy and Safety of TachoSil ® as Haemostatic Treatment versus Standard Suturing in Kidney Tumour Resection: A Randomised Prospective Study

OBJECTIVE

Elective nephron-sparing surgery (NSS) for renal cell carcinoma (RCC) has gained general acceptance as an alternative to radical nephrectomy. To achieve haemostasis without risk of local ischaemia and necrosis of kidney parenchyma after standard haemostatic suturing, we investigated TachoSil's efficacy and safety as atraumatic haemostatic treatment after kidney tumour resection.

METHODS

A total of 185 patients scheduled for NSS for small, superficial kidney tumours were included in an open, randomised, prospective, multicentre, parallel-group trial. Primary objectives were to test haemostatic efficacy and safety of TachoSil versus standard suturing. Efficacy was tested by comparing intraoperative time to haemostasis (primary end point). Secondary objectives included proportion of subjects with haemostasis after 10 min of trial treatment, occurrence of haematoma on day 2 after surgery, volume and haemoglobin concentration of postoperative drainage fluid, and surgeon's rating of usefulness of trial treatments. Safety was evaluated by occurrence of adverse events.

RESULTS

In the intent-to-treat population, time to haemostasis was significantly shorter with TachoSil versus standard suturing (mean: 5.3 vs. 9.5 min [p<0.0001]). Haemostasis was obtained within 10 min in 92% of patients in the TachoSil group and in 67% in the standard treatment group (p<0.0001). Differences in other secondary end points were not statistically significant. Both treatments were well tolerated. Surgeons rated TachoSil higher in terms of convenience to prepare and apply, and impression of efficacy.

CONCLUSION

TachoSil was superior to standard suturing in obtaining intraoperative control of haemorrhage and was as well tolerated as standard haemostatic treatment during NSS.

TNM staging system for renal-cell carcinoma: current status and future perspectives

The Tumour, Nodes, and Metastasis (TNM) staging system is a method of stratifying patients with cancer and is based on data obtained from large multicentre studies that involved large numbers of patients, and have a good level of evidence. However, despite continual revisions to the methodology to incorporate evidence from new clinical studies, the optimum stratification of patients with renal-cell carcinoma (RCC) using the TNM staging system remains controversial and further revisions, in our opinion, are needed. Revision of the TNM staging system for renal-cell cancer could also result in the simultaneous update of the integrated prognostic systems that are currently used along side this traditional method of staging. These integrated systems could become key instruments for guiding patient counselling, for appropriate follow up strategies, for patient selection for clinical trials, and for appropriate assessment of results if the perception that they are complex is overcome. This perception is driven by the presence of more than one system, the heterogeneity of clinical and pathological variables included in the methodology, and the need for robust comparative studies between the various systems. Therefore, in everyday clinical practice, the TNM system is regarded as a more reliable method of staging. In this Essay, we aim to highlight the problems associated with the current version of the TNM staging system and highlight areas in which this grading instrument can be improved in future to become a more refined and standardised method of communication between all clinicians involved in clinical management of RCC.

Does Stage T3a Renal Cell Carcinoma Embrace a Homogeneous Group of Patients?

PURPOSE

Renal cell carcinoma invading the perinephric fat is classified as a stage T3a tumor in the 2002 TNM version. Based on long-term followup we examined the prognostic significance of this definition.

MATERIALS AND METHODS

We evaluated the outcome in 237 consecutive patients with localized renal cell carcinoma operated on between January 1985 and December 1997. Median followup was 8 years. Disease-free survival was analyzed using univariate and multivariate analyses. Based on this we proposed and tested a new TNM system against the 2002 TNM version.

RESULTS

Tumor recurrence was diagnosed in 48 patients (20.2%) at a median of 21.5 months. Diameter based analysis of stage T3a revealed that this was an inhomogeneous group that included patients with small tumors and an excellent prognosis along with patients with large tumors and a poor prognosis. Based on this information we initiated a modified TNM staging system that ignores perinephric fat invasion. In the proposed staging system stage T1a includes tumors 4 cm or less and stage T1b includes tumors more than 4 but 7 cm or less. Stage T2 is divided into T2a-tumors greater than 7 but 10 cm or less and T2b-tumors greater than 10 cm. Stage T3a is reserved for renal vein tumor invasion. The proposed TNM performed better than the 2002 version using the Nagelkerke R(2) test (0.439 vs 0.359), and the Hosmer and Lemeshow test (0.335 vs 0.191).

CONCLUSIONS

The current definition of stage T3a renal cell carcinoma embraces an inhomogeneous group of patients with marked differences in prognosis. We believe that tumor invasion into the perinephric fat does not necessarily predict aggressive biological behavior.

Update on the epidemiology and biology of renal cortical neoplasms

A new era is developing in the understanding of the diagnosis, classification, and management of renal-cell carcinoma (RCC). Historically, RCC has been divided into subtypes on the basis of the histopathologic findings alone. Now, genetic alterations, nuclear characteristics, and clinical criteria are routinely incorporated into the classification. The greater use of axial imaging that began in the 1980s dramatically increased the incidence of RCC, but there has not been a decrease in the percentage of cases that are metastatic. Nevertheless, many incidental lesions prove to be benign, so there is renewed enthusiasm for biopsy before treatment is selected. Genetic conditions associated with RCC, such as Von Hippel Lindau and Birt-Hogg-Dube syndromes, along with genetic analyses of tumors, have provided considerable insight into the pathogenesis of these lesions. Renal-cell carcinoma is resistant to chemotherapy, and high-dose interleukin-2 is the only regimen currently approved by the Food and Drug Administration for the treatment of advanced RCC. Stem cell transplantation is an evolving therapy. The vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and transforming growth factor-alpha pathways are promising targets for medical therapy of RCC. Bevacizumab, a monoclonal antibody that acts as a competitive blocker of the VEGF receptor; sorafenib, an oral well-tolerated tyrosine kinase inhibitor that blocks the intracellular second-messenger system associated with the VEGF receptor; sunitinib, a multitarget inhibitor of kinases associated with the VEGF and PDGF receptors; temsirolimus (CCI-779), a kinase blocker that inhibits the mammalian target of rapamycin pathway; and erlotinib, an inhibitor of the tyrosine kinases associated with the EGF receptor, have shown promise. Combinations of the above therapies and cytokines also are being investigated, as there may be synergistic effects.

Imaging of kidney cancer

Advances in molecular genetics have expanded the understanding of renal cell tumors. Now it is understood that renal cortical tumors are a family of neoplasms with distinct cytogenetics and molecular defects, unique histopathologic features, and different malignant potentials. Imaging contributes to clinical management of patients with renal tumors in providing diagnostic information for tumor detection, characterization, staging, treatment planning, and follow-up.