Sarcomatoid renal carcinoma: the final common dedifferentiation pathway of renal epithelial malignancies

Renal Cell Carcinoma of Variant Histology: New Biologic Understanding Leads to Therapeutic Advances

Renal cell carcinoma (RCC) is one of the 10 most commonly diagnosed solid tumors. Most RCCs are histologically defined as clear cell, comprising approximately 75% of diagnoses. However, the remaining RCC cases are composed of a heterogeneous combination of diverse histopathologic subtypes, each with unique pathogeneses and clinical features. Although the therapeutic approach to both localized and metastatic RCCs has dramatically changed, first with the advent of antiangiogenic targeted therapies and more recently with the approval of immune checkpoint inhibitor (ICI)-based combinations, these advances have primarily benefited the clear cell RCC patient population. As such, there remains critical gaps in the optimization of treatment regimens for patients with non-clear cell, or variant, RCC histologies. Herein, we detail recent advances in understanding the biology of RCC with variant histology and how such findings have guided novel clinical studies investigating precision oncology approaches for these rare subtypes. Among the most common variant histology RCCs are papillary RCC, comprising approximately 15%-20% of all diagnoses. Although a histopathologically diverse subset of tumors, papillary RCC is canonically associated with amplification of the MET protooncogene; recently completed and ongoing trials have investigated MET-directed therapies for this patient population. Finally, we discuss the unique biology of RCC with sarcomatoid dedifferentiation and the recent clinical findings detailing its paradoxical sensitivity to ICIs.

Sarcomatoid and Rhabdoid Renal Cell Carcinoma: Clinical, Pathologic, and Molecular Genetic Features

Renal cell carcinoma (RCC) with sarcomatoid and rhabdoid morphologies has an aggressive biological behavior and a typically poor prognosis. The current 2022 WHO classification of renal tumors does not include them as distinct histologic entities but rather as transformational changes that may arise in a background of various distinct histologic types of RCC. The sarcomatoid component shows malignant spindle cells that may grow as intersecting fascicles, which is reminiscent of pleomorphic undifferentiated sarcoma. The rhabdoid cells are epithelioid cells with eccentrically located vesicular nuclei with prominent nucleoli and large intracytoplasmic eosinophilic inclusions. Studies have shown that RCCs with sarcomatoid and rhabdoid differentiation have distinctive molecular features. Sarcomatoid RCC harbors shared genomic alterations in carcinomatous and rhabdoid components, but also enrichment of specific genomic alterations in the sarcomatoid element, suggesting molecular pathways for development of sarcomatoid growth from a common clonal ancestor. Rhabdoid differentiation also arises through clonal evolution although less is known of specific genomic alterations in rhabdoid cells. Historically, treatment has lacked efficacy, although recently immunotherapy with PD-1/PD-L1/CTLA-4 inhibitors has produced significant clinical responses. Reporting of sarcomatoid and rhabdoid features in renal cell carcinoma is required by the College of American Pathologists and the International Collaboration on Cancer Reporting. This manuscript reviews the clinical, pathologic, and molecular features of sarcomatoid RCC and rhabdoid RCC with emphasis on the morphologic features of these tumors, significance of diagnostic recognition, the molecular mechanisms of tumorigenesis and differentiation along sarcomatoid and rhabdoid lines, and advances in treatment, particularly immunotherapy.

Molecular underpinnings of dedifferentiation and aggressiveness in chromophobe renal cell carcinoma

Sarcomatoid dedifferentiation is common to multiple renal cell carcinoma (RCC) subtypes, including chromophobe RCC (ChRCC), and is associated with increased aggressiveness, resistance to targeted therapies, and heightened sensitivity to immunotherapy. To study ChRCC dedifferentiation, we performed multiregion integrated paired pathological and genomic analyses. Interestingly, ChRCC dedifferentiates not only into sarcomatoid but also into anaplastic and glandular subtypes, which are similarly associated with increased aggressiveness and metastases. Dedifferentiated ChRCC shows loss of epithelial markers, convergent gene expression, and whole genome duplication from a hypodiploid state characteristic of classic ChRCC. We identified an intermediate state with atypia and increased mitosis but preserved epithelial markers. Our data suggest that dedifferentiation is initiated by hemizygous mutation of TP53, which can be observed in differentiated areas, as well as mutation of PTEN. Notably, these mutations become homozygous with duplication of preexisting monosomes (i.e., chromosomes 17 and 10), which characterizes the transition to dedifferentiated ChRCC. Serving as potential biomarkers, dedifferentiated areas become accentuated by mTORC1 activation (phospho-S6) and p53 stabilization. Notably, dedifferentiated ChRCC share gene enrichment and pathway activation features with other sarcomatoid RCC, suggesting convergent evolutionary trajectories. This study expands our understanding of aggressive ChRCC, provides insight into molecular mechanisms of tumor progression, and informs pathologic classification and diagnostics.

The Natural History of Renal-Cell Carcinoma with Sarcomatoid Differentiation, a Stage-by-Stage Analysis

BACKGROUND

Sarcomatoid differentiation in patients diagnosed with renal cell carcinoma (sRCC) imply aggressive behavior and often metastatic disease at the time of diagnosis. We aim to examine the overall survival (OS) in patients with sRCC using the National Cancer Database (NCDB).

MATERIALS AND METHODS

We identified patients diagnosed with sRCC between 2010-2015. We employed Kaplan-Meier curves and multivariable Cox proportional hazards regression models to examine the impact of several potential risk factors on OS in patients diagnosed with sRCC.

RESULTS

In total, 8582 patients with renal cancer were found to have sarcomatoid differentiation, with 4105 patients (47.8%) being diagnosed with AJCC stage IV disease. The median OS was 17.2 months (IQR 5.4, 68.7 months). Compared to patients who did not undergo surgery, OS was significantly longer in patients undergoing partial or total nephrectomy across all stages. This result remained consistent on multivariable Cox proportional hazards regression adjusting for patient and tumor characteristics (Surgery: Hazard ratio 0.54, 95%Confidence interval 0.43 - 0.68, P < .001).

CONCLUSION

In our cohort sRCC was found to have an unfavorable median OS, which was mainly caused by the high number of cases diagnosed with late-stage disease. Additionally, surgery was associated with favorable OS across all stages. This study supports the notion that surgical therapy, even in the setting of cytoreductive surgery, provides a survival benefit in patients with sRCC.

The significance of sarcomatoid and rhabdoid dedifferentiation in renal cell carcinoma

Dedifferentiation in renal cell carcinoma (RCC), either sarcomatoid or rhabdoid, is an infrequent event that may occur heterogeneously in the setting of any RCC histology and is associated with poor outcomes. Sarcomatoid dedifferentiation is associated with inferior survival with angiogenesis targeted therapy and infrequent responses to cytotoxic chemotherapy. However, immune checkpoint therapy has significantly improved outcomes for patients with sarcomatoid dedifferentiation. Biologically, sarcomatoid dedifferentiation has increased programmed death-ligand 1 (PD-L1) expression and an inflamed tumor microenvironment, in addition to other distinct molecular alterations. Less is known about rhabdoid dedifferentiation from either a clinical, biological, or therapeutic perspective. In this focused review, we will discuss the prognostic implications, outcomes with systemic therapy, and underlying biology in RCC with either sarcomatoid or rhabdoid dedifferentiation present.

Sarcomatoid-associated gene risk index for clear cell renal cell carcinoma

Sarcomatoid renal cell carcinoma is a de-differentiated form of kidney cancer with an extremely poor prognosis. Genes associated with sarcomatoid differentiation may be closely related to the prognosis of renal cell carcinoma. The prognosis of renal cell carcinoma itself is extremely variable, and a new prognostic model is needed to stratify patients and guide treatment. Data on clear cell renal cell carcinoma with or without sarcomatoid differentiation were obtained from TCGA database, and a sarcomatoid-associated gene risk index (SAGRI) and column line graphs were constructed using sarcomatoid-associated genes. The predictive power of the SAGRI and column line graphs was validated using an internal validation set and an independent validation set (E-MTAB-1980). The SAGRI was constructed using four sarcoma-like differentiation-related genes, COL7A1, LCTL, NPR3, ZFHX4, and had a 1-year AUC value of 0.725 in the training set, 0.712 in the internal validation set, and 0.770 in the independent validation set for TCGA training cohort, with high model reliability. The molecular characteristics among the SAGRI subgroups were analyzed by multiple methods, and results suggested that the SAGRI-HIGH subgroup may benefit more from immunotherapy to improve prognosis. SAGRI satisfactorily predicted the prognosis of patients with clear cell renal cell carcinoma with or without sarcomatoid differentiation.

The Role of Cytoreductive Nephrectomy and Targeted Therapy on Outcomes of Patients With Metastatic Sarcomatoid Renal Cell Carcinoma: A Population-Based Analysis

Sarcomatoid renal cell carcinoma (sRCC) is a rare but aggressive form of kidney cancer with a poor prognosis. Despite recent advances in therapies for kidney cancers, an effective management strategy for sRCC is uncertain. We evaluated the impact of targeted therapy and cytoreductive nephrectomy (CN) on survival outcomes of patients with metastatic sRCC. We identified patients diagnosed with sRCC between January 1, 1973, and December 31, 2014, within the Surveillance, Epidemiology and End Results (SEER) database. Patients with metastatic sRCC were stratified based on the era of diagnosis (before or after the introduction of targeted systemic therapy in 2006) and the status of CN. Cancer-specific survival (CSS) and overall survival (OS) were analyzed. Data of 993 patients with metastatic sRCC were available for analysis. The median age was 62 years. Most patients were male (69%), Caucasian (71%), and were diagnosed in the targeted therapy era (83%); 53% of patients underwent CN. CSS and OS of the whole cohort were 5.0 months and 4.0 months, respectively. While the introduction of targeted therapy did not improve outcomes, CN improved CSS and OS in both pre-targeted therapy and targeted therapy era. On multivariable analysis, CN was a predictor of an improved CSS (hazard ratio [HR] 0.54, p < 0.0001) and OS (HR 0.51, p < 0.0001). Among other factors, older age at diagnosis, higher T stages, and node positivity were associated with worse outcomes. Our results showed that the introduction of targeted therapy did not improve outcomes in patients with metastatic sRCC. CN improved survival in both pre-targeted and targeted therapy eras.

Immunotherapy-based combinations in the first-line treatment of metastatic renal cell carcinoma with sarcomatoid features: a systematic review and network meta-analysis

PURPOSE OF REVIEW

To perform indirect comparisons of efficacy and safety of first-line immune checkpoint inhibitor (ICI)-based combination therapies for renal cell carcinoma with sarcomatoid features (sRCC).

RECENT FINDINGS

Five trials were included in our network meta-analyses comprising 568 patients. The combinations nivolumab plus ipilimumab and nivolumab plus cabozantinib achieved significant improvement of progression-free survival (PFS), overall survival (OS), and objective response rates (ORR). Nivolumab plus ipilimumab was associated with the highest likelihood of achieving a complete response. All the included combinations significantly improved PFS and ORR. The combinations of pembrolizumab plus axitinib did not show a statistically significant association with OS. Nivolumab plus cabozantinib had the highest likelihood of improving PFS and OS.

SUMMARY

Our network meta-analysis demonstrates that sRCC are responsive to immune-based combinations. The dual ICI with nivolumab plus ipilimumab improved all efficacy outcomes and achieved the highest complete response rates (CRR). Although the association of nivolumab plus cabozantinib with CRR was not statistically significant, this combination demonstrated the highest likelihood of PFS and OS improvements.

Sarcomatoid Renal Cell Carcinoma: The Present and Future of Treatment Paradigms

Sarcomatoid renal cell carcinoma (sRCC) is an aggressive form of kidney cancer that is associated with poor prognosis. It can arise from any histologic type of renal cell carcinoma. The majority of cases will present with advanced or metastatic disease requiring systemic therapy. Nephrectomy is the treatment of choice in locally resectable disease. The therapeutic options for sRCC have evolved in the past decade. Cytotoxic chemotherapy and monotherapy with targeted therapy (VEGF and mTOR) have historically shown poor response rates and survival in the treatment of metastatic sRCC. The use of checkpoint inhibitors and their combination with targeted therapy against VEGF has changed the landscape and outcomes for renal cell carcinoma. Given the rarity of sRCC most of the data on treatment is from small cohorts or extrapolation from larger clinical trials. The benefit from the combination of checkpoint inhibitors and targeted therapy to VEGF has shown promise in the sRCC population in post hoc analysis of large clinical trials. Future research focusing on further characterizing the unique biologic and clinical features of sRCC is critical in advancing the knowledge and developing effective therapy to improve clinical outcomes and survival.

Feline sarcomatoid renal cell carcinoma with peritoneal carcinomatosis and effusion

A 9-y-old, castrated male, domestic medium-hair cat diagnosed previously with chronic kidney disease developed anorexia and vomiting. Ultrasonography revealed abdominal effusion and a left renal perihilar mass. Cytologic evaluation of the peritoneal fluid and mass identified atypical epithelioid cells suspected to be of renal epithelial or possible mesothelial origin. Immunohistochemical (IHC) evaluation of a formalin-fixed, paraffin-embedded peritoneal fluid cell block indicated both pancytokeratin and vimentin expression in the atypical epithelioid cell population. With scanning electron microscopic evaluation, similar epithelioid cells lacked the cell-surface microvilli expected of mesothelium, supporting an antemortem diagnosis of probable carcinoma. On postmortem examination, the left kidney was effaced by an infiltrative neoplasm with myriad similar nodules throughout the peritoneum. The neoplasm was composed primarily of polygonal-to-spindle-shaped cells with strong vimentin and weak pancytokeratin cytoplasmic immunolabeling. Further IHC characterization with PAX8, CK18, KIT, napsin A, SMA, desmin, CD18, and claudin 5 was performed. Histologic and IHC findings supported a diagnosis of sarcomatoid renal cell carcinoma with peritoneal carcinomatosis. An in vitro cell culture line of neoplastic cells harvested from the primary tumor was successfully established for future research endeavors.

Undifferentiated and dedifferentiated urological carcinomas: lessons learned from the recent developments

Loss of the morphological and immunophenotypic characteristics of a neoplasm is a well-known phenomenon in surgical pathology and occurs across different tumor types in almost all organs. This process may be either partial, characterized by transition from well differentiated to undifferentiated tumor component (=dedifferentiated carcinomas) or complete (=undifferentiated carcinomas). Diagnosis of undifferentiated carcinoma is significantly influenced by the extent of sampling. Although the concept of undifferentiated and dedifferentiated carcinoma has been well established for other organs (e.g. endometrium), it still has not been fully defined for urological carcinomas. Accordingly, undifferentiated/ dedifferentiated genitourinary carcinomas are typically lumped into the spectrum of poorly differentiated, sarcomatoid, or unclassified (NOS) carcinomas. In the kidney, dedifferentiation occurs across all subtypes of renal cell carcinoma (RCC), but certain genetically defined RCC types (SDH-, FH- and PBRM1- deficient RCC) seem to have inherent tendency to dedifferentiate. Histologically, the undifferentiated component displays variable combination of four patterns: spindle cells, pleomorphic giant cells, rhabdoid cells, and undifferentiated monomorphic cells with/without prominent osteoclastic giant cells. Any of these may occasionally be associated with heterologous mesenchymal component/s. Their immunophenotype is often simple with expression of vimentin and variably pankeratin or EMA. Precise subtyping of undifferentiated (urothelial versus RCC and the exact underlying RCC subtype) is best done by thorough sampling supplemented as necessary by immunohistochemistry (e.g. FH, SDHB, ALK) and/ or molecular studies. This review discusses the morphological and molecular genetic spectrum and the recent develoments on the topic of dedifferentiated and undifferentiated genitourinary carcinomas.

Pathological eradication of recurrent metastatic renal cell carcinoma with sarcomatoid component by nivolumab plus ipilimumab combination therapy

Although immuno-oncology combination therapy with nivolumab plus ipilimumab has recently shown a notable antitumor effect for first-line metastatic renal cell carcinoma, the eradication of the disease is extremely rare. Moreover, conventional treatments for renal cell carcinoma show little efficacy in the case of a poor prognostic pathological feature of sarcomatoid dedifferentiation. We report a case of pathological eradication of recurrent metastatic renal cell carcinoma with sarcomatoid component after laparoscopic radical nephrectomy by nivolumab plus ipilimumab combination therapy. A 57-year-old male patient received four cycles of nivolumab plus ipilimumab and thirty cycles of nivolumab for local recurrence and liver metastasis after laparoscopic radical nephrectomy for T3a renal cell carcinoma with sarcomatoid component. He underwent partial hepatectomy for the remaining small hepatic lesion after immuno-oncology therapy. Pathology of the surgical specimen showed no viable cancer cells. The patient was alive with no evidence of disease a year after partial hepatectomy. Our case encourages clinicians to achieve a second cure for patients with recurrent metastatic renal cell carcinoma after radical nephrectomy even though the resected kidney pathology showed sarcomatoid component.

Sarcomatoid renal cell carcinoma: biology, natural history and management

Sarcomatoid dedifferentiation is an uncommon feature that can occur in most histological subtypes of renal cell carcinomas (RCCs) and carries a decidedly poor prognosis. Historically, conventional treatments for sarcomatoid RCCs (sRCCs) have shown little efficacy, and median survival is commonly 6–13 months. Despite being first described in 1968, the mechanisms driving sarcomatoid dedifferentiation remain poorly understood, and information and treatment options available to physicians and patients are limited. When diagnosed at an early stage, surgical intervention remains the treatment of choice. However, preoperative identification through routine imaging or biopsy is unreliable and most patients present with advanced disease and systemic symptoms. For these patients, the role of cytoreductive nephrectomy is disputed. The expansion of immunotherapies approved for RCCs has generated a search for biomarkers that might be indicative of treatment response in sRCCs, although a proven effective systemic agent remains elusive. PDL1 expression is increased in sarcomatoid dedifferentiated renal tumours, which suggests that patients with sRCCs could benefit from PD1 and/or PDL1 immune checkpoint blockade therapy. Treatment outcomes for sarcomatoid tumours have remained relatively consistent compared with other RCCs, but further investigation of the tumour–immune cell microenvironment might yield insights into further therapeutic possibilities.

In this Review, Blum et al. summarize the current knowledge on sarcomatoid renal cell carcinoma, a diagnosis characterized by the presence of sarcomatoid dedifferentiation and a poor prognosis. They discuss the origin, presentation, molecular biology and treatment of this disease.

Sarcomatoid dedifferentiation is not considered to be a unique histological subtype of renal cell carcinomas (RCCs); rather, it can be present within any subtype of RCCs.

Sarcomatoid dedifferentiation appears in ~4% of all RCCs, but is present in ~20% of all metastatic RCCs. According to WHO guidelines, any RCC with sarcomatoid dedifferentiation is a WHO–International Society of Urological Pathology grade 4 lesion.

Sarcomatoid dedifferentiation is often heterogeneously present within RCCs, making routine imaging and biopsy unreliable for preoperative detection. Surgical resection for localized disease is the standard of care, with subsequent close monitoring of patients following surgery.

In patients with metastatic disease, conventional therapies such as surgery and systemic agents have been ineffective and overall 5-year survival remains at 23.5–33%.

Previous genomic analyses have failed to identify definitive mutational drivers of disease. However, sarcomatoid RCCs (sRCCs) have been shown to have higher PD1 and PDL1 expression than other subtypes of RCCs. Newer combinations of immune checkpoint inhibitor immunotherapies could yield improved responses and outcomes.

Studies investigating sRCCs are limited by patient numbers owing to the low incidence of sRCCs and their advanced stage at presentation. Multi-institutional efforts to establish a consensus on treatment recommendations based on highly powered data are essential.

Updates in Histologic Grading of Urologic Neoplasms

CONTEXT.—

Tumor histology offers a composite view of the genetic, epigenetic, proteomic, and microenvironmental determinants of tumor biology. As a marker of tumor histology, histologic grading has persisted as a highly relevant factor in risk stratification and management of urologic neoplasms (ie, renal cell carcinoma, prostatic adenocarcinoma, and urothelial carcinoma). Ongoing research and consensus meetings have attempted to improve the accuracy, consistency, and biologic relevance of histologic grading, as well as provide guidance for many challenging scenarios.

OBJECTIVE.—

To review the most recent updates to the grading system of urologic neoplasms, including those in the 2016 4th edition of the World Health Organization (WHO) Bluebook, with emphasis on issues encountered in routine practice.

DATA SOURCES.—

Peer-reviewed publications and the 4th edition of the WHO Bluebook on the pathology and genetics of the urinary system and male genital organs.

CONCLUSIONS.—

This article summarizes the recently updated grading schemes for renal cell carcinoma, prostate adenocarcinomas, and bladder neoplasms of the genitourinary tract.

Atezolizumab plus Bevacizumab Versus Sunitinib for Patients with Untreated Metastatic Renal Cell Carcinoma and Sarcomatoid Features: A Prespecified Subgroup Analysis of the IMmotion151 Clinical Trial

Patients with metastatic renal cell carcinoma with sarcomatoid features (sRCC) have a poor prognosis and have shown limited responsiveness to inhibition of the VEGF pathway. We conducted a prespecified analysis of the randomised, phase 3 IMmotion151 trial in previously untreated patients with advanced or metastatic RCC to assess the effectiveness of atezolizumab + bevacizumab versus sunitinib in a subgroup of patients with sarcomatoid features. Patients whose tumour had any component of sarcomatoid features were included and received atezolizumab + bevacizumab (n = 68) or sunitinib (n = 74). Baseline characteristics were similar between the groups. Median progression-free survival was significantly longer in the group receiving atezolizumab + bevacizumab overall (8.3 vs 5.3 mo; hazard ratio [HR] 0.52 95% confidence interval [CI] 0.34-0.79) and in the subset of patients with PD-L1-positive tumours (8.6 vs 5.6 mo; HR 0.45, 95% CI 0.26-0.77). More patients receiving atezolizumab + bevacizumab achieved an objective response (49% vs 14%), including complete responses (10% vs 3%), and reported greater symptom improvements versus sunitinib. Safety was consistent with the known profiles of each drug and with that reported in the overall safety-evaluable population of IMmotion151. This analysis supports enhanced activity of atezolizumab + bevacizumab in patients with sRCC. PATIENT SUMMARY: In this report, we looked at patients with a specific type of kidney cancer (tumours with sarcomatoid features) that has been hard to treat. A treatment with two drugs (atezolizumab and bevacizumab) appeared to help patients live longer without the disease getting worse than another drug (sunitinib) that is often used. Patients who took the two drugs also said they were better able to carry out their everyday activities than patients who took sunitinib. The combination of these two drugs may work better in patients with this type of advanced kidney cancer.

Recurrent metastatic clear cell renal carcinoma with sarcomatoid dedifferentiation treated with surgery and Cabozantinib

Renal cell carcinoma with sarcomatoid dedifferentiation is an entity of RCC that has undergone an anaplastic transformation with both a carcinomatous and a sarcomatous component. The standard treatment in metastatic patients is immunotherapy.

The aim of this article is to describe our case of metastatic recurrent RCC with sarcomatoid dedifferentiation in a 59 year old male patient treated with nephrectomy and multiple metastasectomies followed by Cabozantinib.

Consecutive PET-CT scans showed no evidence of recurrence, three years after the last metastasectomy, and the patient is having currently a normal life.

Sarcomatoid dedifferentiation remains a poor prognosis factor in RCC. Surgery for metastases followed by Cabozantinib may be a therapeutic option in metastatic young patients. However, a prospective randomized trial would be the best option to validate this approach.

Construction and validation of a novel prognostic nomogram for patients with sarcomatoid renal cell carcinoma: a SEER-based study

OBJECTIVE

The only one established prognostic nomogram for patients with sarcomatoid renal cell carcinoma (sRCC) was based on a small sample-sized study without external validation, and a nomogram can be applied to western sRCC patients has not yet been developed. Therefore, our study aimed to construct and validate an effective nomogram to predict overall survival (OS) for these patients.

METHODS

The independent predictors for OS were identified and the nomogram was constructed on the basis of a retrospective study of a training cohort consisted of 428 non-Hispanic white sRCC patients registered in the Surveillance, Epidemiology and End Results (SEER) database from January 2010 to December 2015. Then, the discriminative performance of the nomogram was assessed by the concordance index (C-index). OS calibrations of the nomogram were also performed by comparing the nomogram-predicted probability to the observed survival rate. Furthermore, our nomogram was externally validated using two independent cohorts consisted of 71 non-Hispanic black patients and 82 Hispanic patients, respectively.

RESULTS

Age at diagnosis, T stage, N stage, bone metastases, liver metastases, lung metastases and nephrectomy were identified as independent predictors for OS. In the training cohort and two validation cohorts, the C-indexes of the nomogram were 0.737, 0.801 and 0.764, respectively. Besides, excellent agreements between the nomogram prediction and the actual observation were achieved in all cohorts.

CONCLUSIONS

The current study constructed and validated an effective prognostic nomogram for patients with sRCC, which can be used to perform accurate predictions of the 0.5-, 1-, and 2-year possibilities of OS.

Impact of sarcomatoid differentiation and rhabdoid differentiation on prognosis for renal cell carcinoma with vena caval tumour thrombus treated surgically

Background

Sarcomatoid differentiation in renal cell carcinoma (RCC) with vena caval tumour thrombus has been shown to be associated with aggressive behaviours and poor prognosis; however, evidence of the impact of rhabdoid differentiation on prognosis is lacking. This study evaluated the impact of sarcomatoid differentiation and rhabdoid differentiation on oncological outcomes for RCC with vena caval tumour thrombus treated surgically.

Methods

We retrospectively analysed patients treated surgically for RCC with vena caval tumour thrombus at our institute from Jan 2015 to Nov 2018. Prognostic variables were evaluated for associations with progression-free survival (PFS) and cancer-specific survival (CSS) by Kaplan–Meier survival analysis and log-rank test. Univariate and multivariate analyses were performed to determine independent prognostic variables.

Results

We identified 125 patients with RCC and vena caval tumour thrombus, including 17 (13.6%) with sarcomatoid differentiation alone, 8 (6.4%) with rhabdoid differentiation alone and 3 (2.4%) with both sarcomatoid and rhabdoid differentiation. Compared to pure RCC, patients with sarcomatoid differentiation but not rhabdoid differentiation have worse PFS (p = 0.018 and p = 0.095, respectively). The univariate and multivariate analyses both showed sarcomatoid differentiation as a significant predictor of PFS. Compared to pure RCC, patients with sarcomatoid differentiation (p = 0.002) and rhabdoid differentiation (p = 0.001) both had significantly worse CSS. The univariate analysis showed sarcomatoid differentiation, rhabdoid differentiation, metastasis and blood transfusion as significant predictors of CSS (All, p < 0.05). In the multivariate analysis, sarcomatoid differentiation (HR 3.90, p = 0.008), rhabdoid differentiation (HR 3.01, p = 0.042), metastasis (HR 3.87, p = 0.004) and blood transfusion (HR 1.34, p = 0.041) all remained independent predictors of CSS.

Conclusions

Sarcomatoid differentiation and rhabdoid differentiation are both independent predictors of poor prognosis in RCC with vena caval tumour thrombus treated surgically.

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

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

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Percentage grade 4 tumour predicts outcome for clear cell renal cell carcinoma

Heterogeneity of tumour grading is common in clear cell renal cell carcinoma (ccRCC). WHO/ISUP grading specifies that RCC should be graded based on the highest grade present in at least one high power field. This does not take into account the proportion of high grade tumour present in a cancer, which may itself influence outcome. Cases of ccRCC accessioned by Aquesta Uropathology, Brisbane, Australia, between 2008 and 2015, were reviewed and grading assigned according to WHO/ISUP criteria. For tumours classified as grade 3 (G3) and 4 (G4), the percentage of tumour showing G3 and G4 morphology was assessed for each case. Survival analysis, with time to the development of metastases as the clinical outcome, was performed for six grading subclasses (G3 <10%, G3 10-50%, G3 >50%, G4 <10%, G4 10-50%, G4 >50%). Of the 681 cases of ccRCC in the series, there were 153 cases classified as G3 (91 cases) and G4 (62 cases) for which follow-up was available. During the follow-up period of <1-89 months, 19 (20.9%) patients with G3 and 30 (48.3%) patients with G4 cancers developed metastatic disease. The three subgroups of <10%, 10-50% and >50% G3 tumour were not significant in predicting outcome (p=0.47). Separating G3 into two groups of ≤50% vs >50% was also not significantly associated with outcome (p=0.22). For the three subgroups of G4 ccRCC (<10%, 10-50% and >50% G4) a higher percentage of G4 correlated with time to the development of metastases (p=0.01). Even though G4 tumours as a whole had a significantly worse outcome than G3 tumours (p=0.0004), the difference between G4 <10% and G3 tumours was not significant (p=0.27). On multivariate analysis, that included pT staging category and tumour size, there was a significant difference in survival between G4<10% and G4>50% tumours (p=0.018). The results of the study suggest that for ccRCC, WHO/ISUP G4 category should incorporate the percentage of G4 tumour present.

Emerging entities of renal cell neoplasia

The current classification of renal cell carcinoma (RCC) was formulated at the meeting of the World Health Organization Renal Tumor Panel in 2015, with the results published in the fourth edition of the World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs Bluebook in 2016. At that meeting a number of tumor types were designated as emerging or provisional entities as it was felt that they were insufficiently characterized to merit inclusion as a recognized type of RCC. One tumor type included in this designation was thyroid-like follicular RCC. Since the publication of the 2016 classification this tumor type has been further characterized and in addition to this, detailed studies on three other types of RCC (multifocal oncocytoma-like tumors associated with oncocytosis, eosinophilic solid and cystic RCC and biphasic squamoid alveolar RCC) have been published. It is now apparent that these four tumors are unique morphotypes and genotypes of RCC, and are likely to be included in the next edition of the World Health Organization classification of renal tumors. Multifocal oncocytoma-like tumors associated with oncocytosis is a benign process characterized by the presence of hundreds to thousands of oncocytic tumors in a single kidney. These tumors occur sporadically and are unrelated to the tumors of Birt-Hogg-Dubé syndrome. Eosinophilic solid and cystic RCC is characterized by a solid and cystic architecture with tumor cells consisting of bulky eosinophilic and granular cytoplasm with intracytoplasmic vacuolation. Thyroid-like follicular RCC occurs in younger patients with a female predominance. The tumor bears a striking resemblance to follicular carcinoma of the thyroid with follicles containing intraluminal proteineacous material resembling thyroglobulin. Immunostains for thyroid markers are negative. Finally, biphasic squamoid alveolar RCC consists of aggregates of large cells with pale eosinophilic cytoplasm usually arranged in a glomeruloid/alveolar pattern and surrounded by a border of basophilic cells with scanty cytoplasm. The genotype of the tumor, as well its recorded association with typical papillary RCC, has led to the suggestion that it is related to type 1 papillary RCC.

Retrospective review of experience with sarcomatoid renal cell carcinoma: Multimodality treatment remains an unmet goal

Background:

Sarcomatoid change in Renal cell carcinoma(RCC) is associated with adverse outcomes with median survival of 6 months.

Settings and Design:

This is a retrospective study of patients diagnosed of sarcomatoid RCC(sRCC) between 2007 and 2013 which were followed up till 2017.

Methods and Material:

Patients (n=22) were grouped based on whether they received additional chemotherapy following nephrectomy. Two groups were followed up until 2017 and overall survival was record. Overall survival curves were estimated by Kaplan-Meier method and compared using Log Rank (Mantel-Cox) test between two groups.

Statistical analysis used:

Kaplan-Meier method and Log Rank (Mantel-Cox) test.

Results:

The patients who had chemotherapy had 13.4 cm of mean tumour size with a mean survival of 20.4 ± 8.3 months. The patients who did not undergo chemotherapy had mean tumour size of 11.7 cm with a mean survival of 21 ± 5.9 months. There was no much statistical difference between the two groups in OS with P value = 0.99.

Conclusion:

The current adjuvant chemotherapy used in sRCC patients who develop metastasis gives no survival advantage.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Genomic classifications of renal cell carcinoma: a critical step towards the future application of personalized kidney cancer care with pan-omics precision

Over the past 20 years, classifications of kidney cancer have undergone major revisions based on morphological refinements and molecular characterizations. The 2016 WHO classification of renal tumors recognizes more than ten different renal cell carcinoma (RCC) subtypes. Furthermore, the marked inter- and intra-tumor heterogeneity of RCC is now well appreciated. Nevertheless, contemporary multi-omics studies of RCC, encompassing genomics, transcriptomics, proteomics, and metabolomics, not only highlight apparent diversity but also showcase and underline commonality. Here, we wish to provide an integrated perspective concerning the future 'functional' classification of renal cancer by bridging gaps among morphology, biology, multi-omics, and therapeutics. This review focuses on recent progress and elaborates the potential value of contemporary pan-omics approaches with a special emphasis on cancer genomics unveiled through next-generation sequencing technology, and how an integrated multi-omics approach might impact precision-based personalized kidney cancer care in the near future. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Sarcomatoid renal cell carcinoma: Biology and treatment advances

Sarcomatoid transformation in renal cell carcinoma, so called sacromatoid RCC (sRCC), is associated with an aggressive behavior and a poor prognosis. Current therapeutic approaches are largely ineffective. Recent studies looking into the genomic and molecular characterization of sRCCs have provided insights into the biology and pathogenesis of this entity. These advances in molecular signatures may help development of effective treatment strategies. We herein present a review of recent developments in the pathology, biology, and treatment modalities in sRCC.

Phase 2 Trial of Capecitabine, Gemcitabine, and Bevacizumab in Sarcomatoid Renal-Cell Carcinoma

BACKGROUND

Patients with sarcomatoid renal-cell carcinomas (sRCC) have poor outcomes and limited treatment options. Preclinical and clinical data suggest susceptibility to cytotoxic agents and vascular endothelial growth factor-targeted therapies. We designed a phase 2 trial to evaluate the efficacy and safety of capecitabine, gemcitabine, and bevacizumab in sRCC.

PATIENTS AND METHODS

Patients with metastatic or unresectable sRCC were eligible for inclusion. Patients received oral capecitabine 800 mg/m2 twice daily on days 1 to 21 of a 28-day cycle, intravenous gemcitabine 900 mg/m2 on days 1 and 15, and intravenous bevacizumab 10 mg/kg on days 1 and 15. Primary end points were progression-free survival and time to treatment failure (TTF). Secondary end points were safety, objective response rate, and overall survival.

RESULTS

Thirty-four patients were enrolled onto the trial. One patient was excluded from survival analysis and 4 from response analysis as a result of missing data. Median progression-free survival was 5.5 months (95% confidence interval [CI], 3.4-7.7), median TTF was 4.2 months (95% CI, 2.4-6.0), and median overall survival was 12 months (95% CI, 10.6-13.4). Objective response rate was 20% (5 partial responses, 1 complete response), and disease control rate was 73%. Thirty-one (91%) of the 34 patients discontinued treatment. The most common reason for treatment discontinuation was progressive disease, which occurred in 24 patients (71%). The most common grade 3 toxicity was rash (including hand-foot syndrome) in 24% patients.

CONCLUSION

The combination of capecitabine, gemcitabine, and bevacizumab is an option for patients with sRCC; however, response rates are low. Novel therapies are needed to improve outcomes in patients with sRCC.

Prognostic implications of sarcomatoid and rhabdoid differentiation in patients with grade 4 renal cell carcinoma

OBJECTIVE

Sarcomatoid and rhabdoid differentiation are associated with poor outcomes in renal cell carcinoma (RCC). We examined the impact of differentiation on cancer-specific survival (CSS) in surgically treated patients with grade 4 RCC.

MATERIALS AND METHODS

Using our institutional database of 1176 nephrectomies from 2005 to 2013, we identified patients with grade 4 RCC or any grade and the presence of sarcomatoid or rhabdoid differentiation. We divided the cohort based on differentiation: no differentiation, rhabdoid only, sarcomatoid only, and sarcomatoid and rhabdoid. CSS was analyzed using the Kaplan-Meier method and Cox proportional hazards modeling.

RESULTS

Of 264 patients with grade 4 RCC, 159 (60.2 %) exhibited differentiation, including 45 (28.3 %) with rhabdoid only, 87 (54.7 %) with sarcomatoid only, and 27 (16.9 %) with rhabdoid and sarcomatoid. Sarcomatoid differentiation, either alone or with rhabdoid differentiation, was associated with worse median CSS than no differentiation (1.1 vs. 3.3 years, p < 0.01, and 0.9 vs. 3.3 years, p < 0.01, respectively). In patients with non-metastatic (HR 1.95, 95 % CI 1.19-3.19, p = 0.008) and metastatic (HR 2.22, 95 % CI 1.45-3.41, p < 0.001) RCC, sarcomatoid differentiation was associated with an increased risk of cancer-specific death. On multivariable analysis, sarcomatoid differentiation was an independent predictor of RCC death in patients with non-metastatic (HR 1.72, 95 % CI 1.04-2.84, p = 0.03) and metastatic (HR 1.74, 95 % CI 1.05-2.90, p = 0.03) disease. Rhabdoid differentiation alone was not associated with worse CSS (p = 0.55).

CONCLUSIONS

In grade 4 RCC, sarcomatoid differentiation is associated with increased mortality risk across all stages of disease. Rhabdoid differentiation is not associated with additional mortality risk.

Prognostic value of preoperative inflammatory response biomarkers in patients with sarcomatoid renal cell carcinoma and the establishment of a nomogram

To examine the prognostic role of inflammatory response biomarkers in sarcomatoid renal cell carcinoma (sRCC). From January 2004 to May 2015, 103 patients with sRCC were enrolled in this study. Preoperative neutrophil to lymphocyte ratio (NLR), derived neutrophil to lymphocyte ratio (dNLR), platelet to lymphocyte ratio (PLR) and lymphocyte to monocyte ratio (LMR) were analyzed. Besides well-established clinicopathological prognostic factors, we evaluated the prognostic value of this four markers using Kaplan-Meier method and Cox regression models. Additionally, a nomogram was established to predict the prognosis of sRCC patients. Elevated NLR, dNLR and PLR were significantly associated with worse overall survival (OS), nevertheless, elevated LMR showed an adverse effect on reduced OS. Multivariate analysis revealed that NLR (HR = 4.07, 95% CI = 1.50–11.00, P = 0.006) retained as independent factor. Incorporation of the NLR into a prognostic model including T stage, M stage, tumor necrosis and percentage of sarcomatoid generated a nomogram, which accurately predicted OS for sRCC patients. Preoperative NLR may serve as a potential prognostic biomarker in patients with sRCC and may help with clinical decisions about treatment intervention in clinical practice. The proposed nomogram can be used for the prediction of OS in patients with sRCC.

Genomic characterization of sarcomatoid transformation in clear cell renal cell carcinoma

The presence of sarcomatoid features in clear cell renal cell carcinoma (ccRCC) confers a poor prognosis and is of unknown pathogenesis. We performed exome sequencing of matched normal-carcinomatous-sarcomatoid specimens from 21 subjects. Two tumors had hypermutation consistent with mismatch repair deficiency. In the remainder, sarcomatoid and carcinomatous elements shared 42% of somatic single-nucleotide variants (SSNVs). Sarcomatoid elements had a higher overall SSNV burden (mean 90 vs. 63 SSNVs, P = 4.0 × 10(-4)), increased frequency of nonsynonymous SSNVs in Pan-Cancer genes (mean 1.4 vs. 0.26, P = 0.002), and increased frequency of loss of heterozygosity (LOH) across the genome (median 913 vs. 460 Mb in LOH, P < 0.05), with significant recurrent LOH on chromosomes 1p, 9, 10, 14, 17p, 18, and 22. The most frequent SSNVs shared by carcinomatous and sarcomatoid elements were in known ccRCC genes including von Hippel-Lindau tumor suppressor (VHL), polybromo 1 (PBRM1), SET domain containing 2 (SETD2), phosphatase and tensin homolog (PTEN). Most interestingly, sarcomatoid elements acquired biallelic tumor protein p53 (TP53) mutations in 32% of tumors (P = 5.47 × 10(-17)); TP53 mutations were absent in carcinomatous elements in nonhypermutated tumors and rare in previously studied ccRCCs. Mutations in known cancer drivers AT-rich interaction domain 1A (ARID1A) and BRCA1 associated protein 1 (BAP1) were significantly mutated in sarcomatoid elements and were mutually exclusive with TP53 and each other. These findings provide evidence that sarcomatoid elements arise from dedifferentiation of carcinomatous ccRCCs and implicate specific genes in this process. These findings have implications for the treatment of patients with these poor-prognosis cancers.

The establishment of KORCC (KOrean Renal Cell Carcinoma) database

PURPOSE

The purpose of this article is to report establishment of the 1st Web-based database (DB) system to collect renal cell carcinoma (RCC) data in Korea.

MATERIALS AND METHODS

The new Web-based DB system was established to collect basic demographic and clinicopahtological characteristics of a large cohort of patients with RCC in Korea. Data from a total of 6,849 patients were collected from 8 tertiary care hospitals that agreed to participate in organizing the Korean Renal Cell Carcinoma (KORCC) study group as of 1 July 2015. Basic demographic and clinicopathological characteristics were collected. The data of patients who underwent surgical treatments were analyzed to characterize Korean RCC.

RESULTS

We established the 1st Web-based DB of Korean RCC, a database comprising renal mass management cases from multiple centers in Korea. The data of 5,281 patients who underwent surgical management (mean follow-up, 32 months) were analyzed. The most common symptom was incidentally detected renal mass (76.9%). Clinical T1a was the most common (54.3%) stage and mean tumor size was 4.8±4.2 cm. Radical nephrectomy accounted for 62.7% of cases and an open approach was used in 50.7% and 52.2% of radical and partial nephrectomies, respectively. The 5-year overall, cancer-specific and recurrence-free survival rates were 88.1%, 92.2%, and 88.0%, respectively.

CONCLUSIONS

We report the 1st establishment of a Web-based DB system to collect RCC data in Korea. This DB system will provide a solid basis for the characterization of Korean RCC.

Does postoperative radiation therapy impact survival in non-metastatic sarcomatoid renal cell carcinoma? A SEER-based study

INTRODUCTION

The effect of adjuvant radiation therapy on survival in sarcomatoid renal cell carcinoma (sRCC) with no evidence of distant metastasis remains unclear.

METHODS

Subjects diagnosed with non-metastatic sRCC were identified using the Surveillance Epidemiology and End Results (SEER) (2004-2012) database and divided into groups based on their surgical treatment (ST): no surgery or radiation therapy (NSR); partial nephrectomy (PNE); radical nephrectomy with ureterectomy and bladder cuff resection (RNE + UE + BLAD); and radical nephrectomy (RNE). Certain radical nephrectomy cases also received adjuvant external-beam radiation therapy (RNE + RAD). The Kaplan-Meier method was used to estimate overall survival (OS). A multivariable competing risks regression analysis was used to calculate disease-specific survival (DSS) probability and to determine factors associated with cause-specific mortality (CSM).

RESULTS

A total of 408 patients were included in this study. The 5-year OS and predicted DSS were significantly higher in the patients who underwent STs (i.e., PNE, RNE + UE + BLAD, RNE, and RNE + RAD) (20.1-54.0 and 20.1-59.9 %, respectively) than in the NSR group (9.0 and 11.6 %, respectively) (P < 0.001). ST was independently associated with a decreased CSM (P < 0.0001). No significant differences in OS or the 1-, 3-, or 5-year DSS probabilities between the RNE and RNE + RAD groups were observed. RNE + RAD was not significantly associated with a decrease in 1-year CSM [subhazard ratio (SHR) 0.95; 95 % CI 0.23-3.96; P = 0.947].

CONCLUSIONS

Adjuvant external-beam radiation therapy did not increase OS in non-metastatic sRCC patients.

Histologic subtype impacts cancer-specific survival in patients with sarcomatoid-variant renal cell carcinoma treated surgically

PURPOSE

To report survival outcomes of patients treated surgically for sarcomatoid-variant renal cell carcinomas (sRCC) and to assess whether the underlying histologic subtype is an independent predictor of outcome.

METHODS

One hundred and fifty-one patients underwent surgery at a referral center between 1991 and 2014 and had sRCC in final pathology. Kaplan-Meier curves for metastasis-free survival and cancer-specific survival (CSS) were calculated, and the log-rank test assessed differences between clear cell sRCC and nonclear cell sRCC. Cox regression models were generated to test the prognostic value of histologic subtype.

RESULTS

Of 151 patients, 120 (79 %) had clear cell sRCC and 31 (21 %) had nonclear cell sRCC. Ninety-eight (65 %) patients had M0/Mx disease at presentation. Among those M0/Mx patients, metastasis-free survival probabilities were 49 % at 2 years [95 % confidence interval (CI) 38-60] and 39 % at 5 years (95 % CI 28-50), while CSS probabilities were 50 % at 2 years (95 % CI 41-58) and 32 % at 5 years (95 % CI 24-41). There was no significant difference in metastasis-free survival between clear cell and nonclear cell sRCC (p = 0.8). However, patients with nonclear cell sRCC had significantly lower CSS than patients with clear cell sRCC (p = 0.035). In multivariable analyses, nonclear cell sRCC conferred a higher risk of cancer-specific death compared with clear cell sRCC (HR 2.30, 95 % CI 1.38-3.82, p = 0.001).

CONCLUSIONS

In a cohort of patients treated surgically, the underlying histologic subtype of sRCC had an impact on CSS. These results present valuable information for individual counseling and patient selection in clinical trials.

Percentage of sarcomatoid component as a prognostic indicator for survival in renal cell carcinoma with sarcomatoid dedifferentiation

OBJECTIVE

Renal cell carcinoma with sarcomatoid dedifferentiation (sRCC) is associated with higher stage of presentation and worse survival. The objective of this study was to examine the clinicopathologic characteristics associated with overall survival (OS), specifically examining the percentage of sarcomatoid component (PSC).

METHODS

We reviewed clinicopathologic data for all nephrectomized patients with confirmed sRCC. Histologic slides were rereviewed by dedicated genitourinary pathologists to ascertain PSC. Patient characteristics were tabulated overall and by disease stage. Cutpoints in the PSC providing a meaningful difference in OS were identified by recursive partitioning analysis (RPA). Factors selected included age group, gender, race, clinical stage, tumor histology, presurgical systemic therapy, lymphovascular invasion, and tumor size. The Kaplan-Meier method and log-rank test were used to assess differences in OS.

RESULTS

Among 186 patients with sRCC, 64 (34%) had localized, and 122 (66%) had metastatic disease at presentation. Patients had primarily clear cell histology (73%). Median follow-up was 12.1 months (range: 0.1-242.2mo). Median OS was 12.6 months (95% CI: 10.7-14.9mo). Univariate RPA identified a PSC cutpoint of 10% as prognostically significant. Patients with PSC>10% were at higher risk of death when compared with patients with PSC≤10% (45% vs. 61% 1-y OS; P = 0.04). Multivariate RPA revealed that tumor size, presence of metastatic disease, and PSC were significantly associated with OS. Among 4 identified groups, patients with localized disease and tumor size≤10cm were most likely to be alive at 1 year (89%), and patients with metastatic disease and PSC>40% were least likely to be alive at 1 year (28%; P<0.001).

CONCLUSION

PSC appears to be a prognostic factor in patients with sRCC, with larger percentage of involvement portending a worse survival, especially in patients with metastatic disease.

Clinicopathologic characteristics and prognostic factors of sarcomatoid renal cell carcinoma

OBJECTIVES

We seek to summarize the clinicopathologic characteristics and prognostic factors of sarcomatoid renal cell carcinoma (SRCC), an uncommon type of renal cell carcinoma.

METHODS AND MATERIALS

Between 2004 and 2012, 23 patients with SRCC were treated at a large urology center in south central China. We collect patient's clinicopathologic features from medical records to assess diagnosis, prognostic factors and efficacy of systemic therapy. Clinical data were absent in 3 cases, and 20 patients were enrolled in the final study.

RESULTS

Immunohistochemically, almost all SRCC expressed cytokeratin (91%), epithelial membrane antigen (87%) and vimentin (100%). Sarcomatoid differentiation occurs in various kinds of subtypes of RCC with almost the same probability. The median tumor size was 10.5 cm. The CT findings of these tumors revealed low-density (n = 5; 25%) or mixed (n = 15; 75%) masses with necrotic areas and often showed an infiltrative morphology (n = 15; 75%). All 20 cases demonstrated heterogeneous enhancement, and eleven (55%) cases demonstrated >50% necrosis. Six cases complicated with calculus and hydronephrosis. Sixteen (80%) patients demonstrated invasions of tissues localized in Gerota's fascia, and 8 (40%) tumors invaded beyond Gerota's fascia. Fifteen (75%) patients demonstrated lymph node metastasis, and sixteen (80%) patients had distant metastasis. Five patients received systemic therapy, and one patient given high-dose interferon-α had a completely response, and one patient received chemotherapy based on gemcitabine had partial response. The median overall survival of all patients was 5.8 months. Patients without distant metastasis had a median overall survival of 35 months compared with 3 months of those with distant metastasis (P < 0.002). The percentage of the sarcomatoid components did not have an obvious influence to the prognosis (P = 0.197).

CONCLUSIONS

Heterogeneity, hugeness, infiltration and necrosis are typical image features of SRCC. The prognosis of SRCC is poor and clinic stage especially the existence of distant disease is the important factor influencing prognosis.

The ISUP system of staging, grading and classification of renal cell neoplasia

There have been significant changes in the staging, classification and grading of renal cell neoplasia in recent times. Major changes have occurred in our understanding of extra-renal extension by renal cell cancer and how gross specimens must be handled to optimally display extra-renal spread. Since the 1981 World Health Organization (WHO) classification of renal tumors, in which only a handful of different entities were reported, many new morphological types have been described in the literature, resulting in 50 different entities reported in the 2004 WHO classification. Since 2004, further new entities have been recognized and reported necessitating an update of the renal tumor classification. There have also been numerous grading systems for renal cell carcinoma with Fuhrman grading, the most widely used system. In recent times, the prognostic value and the applicability of the Fuhrman grading system in practice has been shown to be, at best, suboptimal. To address these issues and to recommend reporting guidelines, the International Society of Urological Pathology (ISUP) undertook a review of adult renal neoplasia through an international consensus conference in Vancouver in 2012. The conduct of the conference was based upon evidence from the literature and the current practice amongst recognized experts in the field. Working groups selected to deal with key topics evaluated current data and identified points of controversy. A pre-meeting survey of the ISUP membership was followed by the consensus conference at which a formal ballot was taken on each key issue. A 65% majority vote was taken as consensus. This review summarizes the outcome and recommendations of this conference with regards to staging, classification and grading of renal cell neoplasia.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC): a rapid autopsy report of metastatic renal cell carcinoma

Rapid ("warm") autopsies of patients with advanced metastatic cancer provide invaluable insight into the natural history, pathobiology, and morphology of advanced and treatment-resistant tumors. Here, we report a rapid autopsy case of a hereditary leiomyomatosis and renal cell carcinoma (HLRCC) patient with advanced metastatic renal cell carcinoma (RCC)-the first such case described for either a primary renal tumor or HLRCC-related cancer. Mutations in the fumarate hydratase (FH) gene underlie HLRCC, a rare syndrome involving cutaneous and uterine leiomyomata and aggressive kidney tumors. Loss of heterozygosity at the wild-type FH gene locus results in profound cellular metabolic derangement, "pseudohypoxic" upregulation of hypoxia-inducible factor 1α (HIF-1α)-dependent transcription, and aberrant protein succination; these molecular changes drive oncogenesis of kidney tumors in HLRCC patients. The current index patient had a high-grade RCC with classic morphologic features of HLRCC, including large nuclei with prominent eosinophilic nucleoli and perinucleolar clearing. In addition, this patient's RCC demonstrated extensive sarcomatoid and rhabdoid features-morphologies not previously well described in HLRCC-associated kidney tumors. Here, we report the extent of metastatic dissemination and supplement this unique tumor morphology with mitochondrial enzyme histochemistry and extended immunohistochemical analysis. Tumor cells strongly expressed PAX8, vimentin, CD10, and the HIF target GLUT1 and showed increased nuclear p53 accumulation; the expression of other RCC markers was negative. We also detail microscopic tubular epithelial changes in the grossly uninvolved ipsilateral renal parenchyma and demonstrate sporadic, aberrant upregulation of the HIF targets GLUT1 and CAIX in dysplastic peritumoral tubules.

Epithelial-to-mesenchymal transition in renal neoplasms

Epithelial-to-mesenchymal transition (EMT) describes a phenotypical change induced in epithelial cells that lose their cell-cell basement membrane contacts and their structural polarity to become spindle-shaped and morphologically similar to mesenchymal/myofibroblast cell. The abnormal induction of EMT has been demonstrated to contribute to cancer dissemination and progression. Renal cell carcinoma (RCC) with sarcomatoid differentiation (sarcomatoid RCC) represents a good example of EMT both morphologically and immunohistochemically. Early spindle cell changes can at times be identified in RCC and likely represent an early step toward EMT. Herein, we present a review of the current understanding of EMT in renal neoplasms including some known signaling regulation, the association of sarcomatoid differentiation in RCC with aggressive behavior and dismal prognosis, and EMT-related tumor biology in sarcomatoid RCC. A better perception of the EMT may contribute toward an improved understanding of the development of sarcomatoid RCC. In addition, a distinct signature for sarcomatoid RCC may have utility in the differential diagnosis for prognostic stratification as well as in identifying novel genes and pathway targets for therapeutic intervention.