Classification of renal cell carcinoma: Workgroup No. 1. Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC)

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.

Predictive genomic biomarkers of therapeutic effects in renal cell carcinoma

BACKGROUND

In recent years, there have been great improvements in the therapy of renal cell carcinoma. Nevertheless, the therapeutic effect varies significantly from person to person. To discern the effective treatment for different populations, predictive molecular biomarkers in response to target, immunological, and combined therapies are widely studied.

CONCLUSION

This review summarized those studies from three perspectives (SNPs, mutation, and expression level) and listed the relationship between biomarkers and therapeutic effect, highlighting the great potential of predictive molecular biomarkers in metastatic RCC therapy. However, due to a series of reasons, most of these findings require further validation.

Evolution in the Pathologic Classification of Renal Neoplasia

The pathologic classification of renal tumors is a dynamic and complex process, which has evolved to a "histomolecular" driven system. Despite advances in molecular characterization, most renal tumors can be diagnosed by morphology with or without using a limited set of immunohistochemical stains. If access to molecular resources and specific immunohistochemical markers is limited, pathologists may face difficulties in following an optimal algorithm to classify renal tumors. In this article, we detail the historical evolution of renal tumor classification, including a synopsis of major changes introduced by the current fifth edition World Health Organization 2022 classification of renal epithelial tumors.

Late recurrence of chromophobe renal cell carcinoma to unusual sites after 12 years of radical nephrectomy and radiotherapy: a rare case report from Syria

In 2020, renal cell carcinoma (RCC) had an incidence of 73 750 new cases. This cancer is well known for its ability to give early and late metastases to some usual and unusual sites. The term 'late recurrence' is widely used to indicate a period exceeding 10 years from curative nephrectomy. This not-understood behaviour is almost specific to RCC, and it happens in a range between 4.3 and 11% of cases of RCC.

Case Presentation

We report a case of a 67-year-old nonalcoholic smoker Syrian male presented with a 2-month painful mass located at the left upper posterolateral abdominal wall's region. He has had a history of left chromophobe cell RCC treated with radical nephrectomy with adjuvant radiotherapy for 12 years. In light of computed tomography's findings, a surgical biopsy was performed, and a pathological and immunohistochemical examination confirmed the diagnosis of chromophobe RCC.

Clinical Discussion

Malignant cells seeding the surgical cut path and staying dormant for 12 years is the best theory of many to explain our case.

Conclusion

We reported evidence for the potential of a relatively indolent histologic type of RCC (i.e. chromophobe cell carcinoma) to cause late recurrence after 12 years to a very rare site (i.e. abdominal wall's superficial muscles). Research should focus on addressing late recurrence to determine the best surveillance protocols; investigating malignant cells seeding during surgery to improve surgical oncology's outcomes; and studying late recurrence's genetics to boost our targeted therapy options.

Low grade oncocytic tumors of the kidney: a clinically relevant approach for the workup and accurate diagnosis

Renal oncocytoma and chromophobe renal cell carcinoma were accepted as unique renal tumors in the late 1990s. Since their formal description, criteria for diagnosis have evolved and additional distinct tumor subtypes originally considered as one these two entities are now recognized. The last two decades have witnessed unprecedented interest in the spectrum of low grade oncocytic renal neoplasms in three specific areas: (1) histologic characterization of tumors with overlapping morphologic features between oncocytoma and chromophobe renal cell carcinoma; (2) description of potentially unique entities within this spectrum, such as eosinophilic vacuolated tumor and low-grade oncocytic tumor; and (3) better appreciation of the association between a subset of low grade oncocytic tumors and hereditary renal neoplasia. While this important work has been academically rewarding, the proposal of several histologic entities with overlapping morphologic and immunophenotypic features (which may require esoteric adjunctive immunohistochemical and/or molecular techniques for confirmation) has created frustration in the diagnostic pathology and urology community as information evolves regarding classification within this spectrum of renal neoplasia. Pathologists, including genitourinary subspecialists, are often uncertain as to the "best practice" diagnostic approach to such tumors. In this review, we present a practical clinically relevant algorithmic approach to classifying tumors within the low grade oncocytic family of renal neoplasia, including a proposal for compressing terminology for evolving categories where appropriate without sacrificing prognostic relevance.

Papillary renal cell carcinoma: a single institutional study of 199 cases addressing classification, clinicopathologic and molecular features, and treatment outcome

The morphologic spectrum of type 1 papillary renal cell carcinoma (PRCC) is not well-defined, since a significant proportion of cases have mixed type 1 and 2 histology. We analyzed 199 cases of PRCC with any (even if focal) type 1 features, with a median follow-up of 12 years, to identify clinicopathological features associated with outcome. Ninety-five tumors (48%) of the cohort contained some type 2 component (median amount: 25%; IQR: 10%, 70%). As a group they showed high rates of progression-free (PFS) and cancer-specific survival (CSS). Tumor size, mitotic rate, lymphovascular invasion, sarcomatoid differentiation, sheet-like architecture, and lack of tumor circumscription were significantly associated with CSS (p ≤ 0.015) on univariate analysis. While predominant WHO/ISUP nucleolar grade was associated with PFS (p = 0.013) and CSS (p = 0.030), the presence of non-predominant (<50%) nucleolar grade did not show association with outcome (p = 0.7). PFS and CSS showed no significant association with the presence or the amount of type 2 morphology. We compared the molecular alterations in paired type 1 and type 2 areas in a subset of 22 cases with mixed type 1 and 2 features and identified 12 recurrently mutated genes including TERT, ARID1A, KDM6A, KMT2D, NFE2L2, MET, APC, and TP53. Among 78 detected somatic mutations, 61 (78%) were shared between the paired type 1 and type 2 areas. Copy number alterations, including chromosome 7 and 17 gains, were similar between type 1 and 2 areas. These findings support that type 2 features in a PRCC with mixed histology represent either morphologic variance or clonal evolution. Our study underscores the notion that PRCC with any classic type 1 regions is best considered as type 1 PRCC and assigned the appropriate WHO/ISUP nucleolar grade. It provides additional evidence that type 2 PRCC as a separate category should be re-assessed and likely needs to be abandoned.

Papillary Renal Cell Carcinoma With Microcystic Architecture Is Strongly Associated With Extrarenal Invasion and Metastatic Disease

Papillary renal cell carcinoma (PRCC) is well-recognized as a morphologically and molecularly heterogenous group of kidney tumors with variable clinical behavior. Our goal was to analyze a unique histologic pattern of PRCC we have observed in routine practice to evaluate for potential clinical significance or distinct molecular signature. We identified 42 cases of PRCC showing a morphologically distinct architecture characterized by numerous epithelial-lined cysts containing the papillary tumor (herein called "microcysts"), which are typically separated by fibrous stroma. Of the initial 42 case test set with microcystic features, 23 (55%) were stage pT3a or higher. Most tumors had strong and diffuse cytoplasmic immunoreactivity for CK7 (93%, 37/40) and AMACR (100%, 40/40). Fumarate hydratase staining was retained in all cases tested (39/39). We performed next-generation sequencing on 15 of these cases with available tissue and identified chromosomal alterations commonly reported in historically "type 1" PRCC, notably multiple chromosomal gains, particularly of chromosomes 7 and 17, and MET alterations. However, alterations in pathways associated with more aggressive behavior (including SETD2, CDKN2A, and members of the NRF pathway) were also identified in 6 of 15 cases tested (40%). Given this molecular and immunophenotypic data, we subsequently reviewed an additional group of 60 consecutive pT2b-pT3 PRCCs to allow for comparisons between cases with and without microcysts, to assess for potential associations with other recently described histologic patterns (ie, "unfavorable architecture": micropapillary, solid, and hobnail), and to assess interobserver reproducibility for diagnosing architectural patterns and grade. Of the total combined 102 PRCCs, 67 (66%) had microcystic architecture within the intrarenal component but were commonly admixed with other patterns (39% had micropapillary, 31% solid, and 31% hobnail). Twenty-seven cases (26%) had metastatic disease, and 24 of these 27 (89%) had microcystic architecture in the intrarenal tumor. Within the pT3 subset, 21 of 22 cases with metastases (95%) had extrarenal invasion as either individual microcysts in renal sinus fat or aggregates of microcysts bulging beyond the confines of the capsule. Backward elimination and stepwise regression methods to detect features significantly associated with adverse outcome identified solid architecture (hazard ratio [HR]: 6.3; confidence interval [CI]: 2.1-18.8; P=0.001), hobnail architecture (HR: 5.3; CI: 1.7-16.7; P=0.004), and microcystic architecture at the tumor-stromal interface (HR: 4.2; CI: 1.1-16.7; P=0.036) as strongest. Of architectural patterns and grade, the microcystic pattern had a substantial interobserver agreement (κ score=0.795) that was highest among the 6 observers. In summary, PRCCs with microcystic architecture represents a subset of historically "type 1" PRCC with a predilection for morphologically distinctive extrarenal involvement and metastatic disease. Microcysts co-vary with other "unfavorable" architectural patterns also associated with higher risk for aggressive disease (ie, micropapillary, hobnail, and solid), but microcysts were more common and have superior interobserver reproducibility. These findings suggest that microcystic PRCC should be recognized as a potentially aggressive histologic pattern of growth in PRCC.

A Mitochondrial Dysfunction and Oxidative Stress Pathway-Based Prognostic Signature for Clear Cell Renal Cell Carcinoma

Mitochondria not only are the main source of ATP synthesis but also regulate cellular redox balance and calcium homeostasis. Its dysfunction can lead to a variety of diseases and promote cancer and metastasis. In this study, we aimed to explore the molecular characteristics and prognostic significance of mitochondrial genes (MTGs) related to oxidative stress in clear cell renal cell carcinoma (ccRCC). A total of 75 differentially expressed MTGs were analyzed from The Cancer Genome Atlas (TCGA) database, including 46 upregulated and 29 downregulated MTGs. Further analysis screened 6 prognostic-related MTGs (ACAD11, ACADSB, BID, PYCR1, SLC25A27, and STAR) and was used to develop a signature. Kaplan-Meier survival and receiver operating characteristic (ROC) curve analyses showed that the signature could accurately distinguish patients with poor prognosis and had good individual risk stratification and prognostic potential. Stratified analysis based on different clinical variables indicated that the signature could be used to evaluate tumor progression in ccRCC. Moreover, we found that there were significant differences in immune cell infiltration between the low- and high-risk groups based on the signature and that ccRCC patients in the low-risk group responded better to immunotherapy than those in the high-risk group (46.59% vs 35.34%, P = 0.008). We also found that the expression levels of these prognostic MTGs were significantly associated with drug sensitivity in multiple ccRCC cell lines. Our study for the first time elucidates the biological function and prognostic significance of mitochondrial molecules associated with oxidative stress and provides a new protocol for evaluating treatment strategies targeting mitochondria in ccRCC patients.

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.

[Oncocytic tumours of the kidney-new differential diagnoses]

BACKGROUND

Recent developments in differential diagnosis have led to new knowledge about oncocytic renal neoplasms.

OBJECTIVES

Overview of differential diagnosis of oncocytic tumours.

MATERIALS AND METHODS

We performed a literature search on oncocytic renal tumours and mapped known tumour types. Possible differential diagnoses are discussed.

RESULTS

Besides the tumour types already acknowledged by the 2016 WHO classification, there is new evidence regarding the group of hard-to-classify oncocytic neoplasms. Findings point to immunohistochemical and molecular characteristics that may lead to the establishment of new entities in the future. In addition, important differential diagnosis can now be identified, facilitating specific therapies for oncocytic renal tumours.

CONCLUSION

A correct diagnosis of oncocytic renal tumours not only improves prognostic assessment (and, if necessary, specific therapies) but is also clinically relevant regarding a possible association with hereditary tumour syndromes.

An Effective Hypoxia-Related Long Non-Coding RNAs Assessment Model for Prognosis of Clear Cell Renal Carcinoma

Hypoxia is a significant clinical feature and regulates various tumor processes in clear cell renal carcinoma (ccRCC). Increasing evidence has demonstrated that long non-coding RNAs (lncRNAs) are closely associated with the survival outcomes of ccRCC patients and regulates hypoxia-induced tumor processes. Thus, this study aimed to develop a hypoxia-related lncRNA (HRL) prognostic model for predicting the survival outcomes in ccRCC. LncRNAs in ccRCC samples were extracted from The Cancer Genome Atlas database. Hypoxia-related genes were downloaded from the Molecular Signatures Database. A co-expression analysis between differentially expressed lncRNAs and hypoxia-related genes in ccRCC samples was performed to identify HRLs. Univariate and multivariate Cox regression analyses were performed to select nine optimal lncRNAs for developing the HRL model. The prognostic model showed good performance in predicting prognosis among patients with ccRCC, and the validation sets reached consistent results. The model was also found to be related to the clinicopathologic parameters of tumor grade and tumor stage and to tumor immune infiltration. In conclusion, our findings indicate that the hypoxia-lncRNA assessment model may be useful for prognostication in ccRCC cases. Furthermore, the nine HRLs included in the model might be useful targets for investigating the tumorigenesis of ccRCC and designing individualized treatment strategies.

Chromophobe renal cell carcinoma: current and controversial issues

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

A network meta-analysis of efficacy and safety of first-line and second-line therapies for the management of metastatic renal cell carcinoma

WHAT IS KNOWN AND OBJECTIVE

Metastatic renal cell carcinoma (mRCC) is the most common type of kidney cancers. Disease-specific survival for mRCC has been significantly improved with the introduction of new targeted agents since 2005. However, there is a lack of head-to-head clinical trials comparing the efficacy between therapies. This study compared indirectly progression-free survival (PFS) and overall survival (OS) among first-line and second-line therapies in patients with mRCC using network meta-analysis (NMA).

METHODS

The PubMed, MEDLINE, Cochrane Library and Web of Science were searched to identify phase II or phase III randomized controlled trials (RCTs) of targeted and biological therapies in patients with mRCC published between January 2000 and June 2020. The Bayesian fixed-effect NMA was performed to evaluate relative PFS and OS of first-line and second-line therapies of axitinib, bevacizumab, cabozantinib, everolimus, lenvatinib, nivolumab, ipilimumab, pazopanib, sorafenib, sunitinib, temsirolimus, tivozanib, avelumab and pembrolizumab, which were approved by the Food and Drug Administration or European Medicines Agency. End points were compared using hazard ratio (HR) and 95% credible interval (CrI). The surface under the cumulative ranking curve (SUCRA) was estimated to assess the probability of being the best treatment.

RESULTS AND DISCUSSION

A total of 26 RCTs (first line: 19, second line: 9) with 13 893 patients were included in the NMA. For the first-line therapy, cabozantinib was associated with the highest improved PFS (HR = 0.26, 95% CrI = 0.14-0.44) followed by avelumab + axitinib and pembrolizumab + axitinib (HR = 0.27, SUCRA = 90%). Pembrolizumab + axitinib had a high likelihood of being the preferred treatment when using OS as the outcome measure (HR = 0.41, 95% CrI = 0.16-0.85). Avelumab + axitinib had the lowest HR compared with placebo + interferon on discontinuations due to AE (HR = 1.04, 95% CrI = 0.54-1.86). For second-line therapy, cabozantinib was identified as the most effective treatment option when assessing PFS (HR = 0.17, 95% CrI = 0.12-0.24). Axitinib had the lowest HR of OS and discontinuation due to AE (HR = 0.54, 95% CrI = 0.40-0.71; HR = 0.98, 95% CrI = 0.42-1.97, respectively). Pazopanib was the second choice in terms of OS (HR = 0.56, 95% CrI = 0.28-1.00; SUCRA = 76%) compared with placebo.

WHAT IS NEW AND CONCLUSION

With respect to PFS and OS improvement, cabozantinib, avelumab + axitinib and pembrolizumab + axitinib are likely to be the preferred options for the first-line therapy and cabozantinib and axitinib for the second-line therapy in the management of mRCC. Regarding safety, avelumab + axitinib and temsirolimus were considered preferred treatment options in first-line and second-line therapies. More future research is needed to establish subgroup analyses, allowing evaluation of the impact of some of the differences in patient characteristics, including treatment effect modifiers.

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.

Scale-Up Evaluation of a Composite Tumor Marker Assay for the Early Detection of Renal Cell Carcinoma

The early detection of renal cell carcinoma (RCC) using tumor markers remains an attractive prospect for the potential to downstage the disease. To validate the scale-up clinical performance of potential tumor markers for RCC (as a single marker and as a composite tumor marker composed of nicotinamide N-methyltransferase (NNMT), L-Plastin (LCP1), and non-metastatic cells 1 protein (NM23A)), the scale-up assay was performed. Patients with RCC from multiple domestic institutes were included in the clinical evaluation for reassessment and improvement of the established triple markers of our product. For the diagnostic performance of the composite markers, the best-split cutoff points of each marker (147 pg/mL for NNMT, 1780 pg/mL for LCP1, and 520 pg/mL for NM23A) were installed. Serum levels of NNMT, LCP1, and NM23A were greatly increased in subjects with RCC (p < 0.0001). In 1042 blind sample tests with control individuals (n = 500) and patients with RCC (n = 542), the diagnostic sensitivity and specificity of the composite three-marker assay were 0.871 and 0.894, respectively, and the resulting AUC (Area under Curve) of ROC (Receiver Operating Characteristic) was 0.917. As a single marker, the diagnostic accuracies of NNMT, LCP1, and NM23A, as estimated by ROC, were 0.833, 0.844, and 0.601, respectively. The composite three-marker assay with NNMT, LCP1, and NM23A is a more improved novel serum marker assay for the early detection of RCC in cases of renal mass or unknown condition. The NNMT, LCP1, and NM23A triple marker assay could be a powerful diagnostic tumor marker assay to screen the early stage of RCC.

HNF-1β as an immunohistochemical marker for distinguishing chromophobe renal cell carcinoma and hybrid oncocytic tumors from renal oncocytoma

The histologic features of renal oncocytoma (RO) are similar to those for the more aggressive chromophobe renal cell carcinoma (ChRCC). To assess immunohistochemical markers of the two, the sensitivity and specificity of cytokeratin 7 (CK7) and C-kit, as well as hepatocyte nuclear factor-1β (HNF-1β), were analyzed. Typical cases of ChRCC and RO at Severance Hospital between July 2014 and July 2018 were selected retrospectively. Among 44 cases, 17 were unanimously compatible with ChRCC, 16 were RO, and 11 cases were indeterminate. Samples from all selected cases were used for immunostaining with antibodies against CK7, C-kit, HNF-1β, and CD10. Immunostaining demonstrated complete loss of HNF-1β expression in 11 out of 17 (64.7%) ChRCC cases and a partial, but significant loss in > 50% of tumor cells in the remaining 6 cases (35.3%). In contrast, HNF-1β expression was preserved in tumor cells of RO cases. Fourteen of 17 ChRCC cases (82.4%) were diffusely positive for CK7, whereas cases of RO were focal positive or negative. C-kit staining did not show a significant difference between ChRCC and RO. Two of five ChRCC cases showing diffuse immunoreactivity for CD10 had poor prognoses of local invasion, distant metastasis, or death. Loss of HNF-1β expression is a useful marker with which to diagnose ChRCC, especially in cases with confusing histologic findings or equivocal CK7 staining. Additionally, CD10 staining in high-grade ChRCC aids in diagnosis and prediction of the clinical prognosis.

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.

Delayed Recurrence of Chromophobe Renal Cell Carcinoma Presenting as Metastatic Duodenal Ulcer

Renal cancers are one of the common causes of cancer-related morbidity and mortality worldwide. Most primary cases are localized at presentation and are treated with partial or radical nephrectomy with curative intent. However, renal cell carcinoma (RCC) is known for its potential recurrence, sometimes several years after initial management. Many of these recurrent cases commonly metastasize to the liver, kidney, or bone and herald a poor prognosis. We present a case study of nonclear cell RCC, which recurred 33 years after nephrectomy and masqueraded as a duodenal ulcer -- an extremely rare site for metastasis. This is unique as it describes a presentation only sparingly documented in the medical literature and highlights a more extended period of recurrence than currently reported. Moreover, our patient’s tumor was chromophobe cell variety, a rare sub-type of nonclear cell RCC, which to our knowledge has never been known to cause duodenal metastasis. Studies have implicated a prognostic role of lymph node involvement at the time of initial diagnosis to predict future recurrence. This case is a drop in the mighty ocean to prompt further investigation on the utility of life-long surveillance protocols and further research evaluating the role of lymph node dissection in preventing such recurrences and high mortality. 

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.

Knockdown of PLOD3 suppresses the malignant progression of renal cell carcinoma via reducing TWIST1 expression

Procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD3), also known as lysyl hydroxylase 3 (LH3) has been demonstrated to be overexpressed in several kinds of cancers and facilitate cell migration. Currently, we aimed to reveal the role of PLOD3 in renal cell carcinoma (RCC) progression, and explore whether TWIST1 (Twist family bHLH transcription factor 1) is involved in this process. Fifty-eight paired RCC tissues and normal tissues were collected and subjected to qPCR and immunohistochemistry (IHC) technology to detect the expression levels of PLOD3. The clinical value of PLOD3 in predicting RCC progression was then explored. Cell-Counting Kit-8 (CCK-8), wound healing, transwell chambers and tumor-bearing experiments were applied to monitor cell proliferation, migration, invasion and tumorigenesis. Protein levels were determined by using western blotting technology to assess cell apoptosis and epithelial to mesenchymal transition (EMT). PLOD3 expression was enhanced in RCC tissues and cells, which predicted higher T (tumor), N (lymph node) and M (metastasis) stages, histological grade and TNM (tumor, lymph node, metastasis) stage. PLOD3 downregulation in RCC A498 cells obviously inhibited cell proliferation, migration, invasion, EMT and tumorigenesis and increased cell apoptosis. PLOD3 overexpression led to opposite results in RCC A704 cells. PLOD3 downregulation reduced the expression levels of TWIST1, β-catenin and p-AKT. In addition, TWIST1 overexpression rescued the repressions of cell proliferation, migration, invasion, EMT and the activation of β-catenin and AKT signaling in addition to apoptosis promotion induced by PLOD3 downregulation. Collectively, this study illustrated that PLOD3 knockdown suppressed RCC malignance via inhibiting TWIST1-mediated activation of β-catenin and AKT signaling.

Development and External Validation of Radiomics Approach for Nuclear Grading in Clear Cell Renal Cell Carcinoma

BACKGROUND AND PURPOSE

Nuclear grades of clear cell renal cell carcinoma (ccRCC) are usually confirmed by invasive methods. Radiomics is a quantitative tool that uses non-invasive medical imaging for tumor diagnosis and prognosis. In this study, a radiomics approach was proposed to analyze the association between preoperative computed tomography (CT) images and nuclear grades of ccRCC.

METHODS

Our dataset included 320 ccRCC patients from two centers and was divided into a training set (n = 124), an internal test set (n = 123), and an external test set (n = 73). A radiomic feature set was extracted from unenhanced, corticomedullary phase, and nephrographic phase CT images. The maximizing independent classification information criteria function and recursive feature elimination with cross-validation were used to select effective features. Random forests were used to build a final model for predicting nuclear grades, and area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of radiomic features and models.

RESULTS

The radiomic features from the three CT phases could effectively distinguished the four nuclear grades. A combined model, merging radiomic features and clinical characteristics, obtained good predictive performances in the internal test set (AUC 0.77, 0.75, 0.79, and 0.85 for the four grades, respectively), and performance was further confirmed in the external test set, with AUCs of 0.75, 0.68, and 0.73 (no fourth-level data).

CONCLUSION

The combination of CT radiomic features and clinical characteristics could discriminate the nuclear grades in ccRCC, which may help in assisting treatment decision making.

Clinicopathologic features and prognostic factors in patients with renal cell carcinoma with sarcomatoid differentiation

Renal cell carcinoma with sarcomatoid differentiation (RCCs) is rare, accounting for 1-8% of all RCC histological subtypes. In this study, we examined 139 patients with RCCs and aimed to explore their clinicopathologic features and prognostic factors. From January 2007 to January 2019, patients who were pathologically diagnosed with RCCs were included in this retrospective study. Data on clinicopathologic features and overall survival were collected. The expression of CK, vimentin, CK7, and CD10 in the sarcomatoid regions of RCCs was detected. The Kaplan-Meier curves and log-rank tests were used to describe the effect of clinicopathologic characteristics on overall survival. A Cox regression model was used to evaluate risk factors for prognosis. A total of 139 patients with RCCs were identified. The median age at diagnosis was 60 years. The median survival time of all patients was 39 months. The three- and five-year survival rates were 50.2% and 44.0%, respectively. A high pathologic T stage (pT3 and pT4), microvascular invasion, and lymph node metastasis were significant predictors of prognosis. Pathologic T4 stage and lymph node metastasis were independent prognostic factors for overall survival in patients with RCCs. Furthermore, the expression of CD10 was a prognostic factor for overall survival. In this study, a relatively large cohort of patients with RCCs was analyzed. We summarized the clinicopathologic features of RCCs and explored the risk factors for prognosis. Our findings may provide valuable prediction for clinical strategy.

Comparison of survival outcomes in patients with metastatic papillary vs. clear-cell renal cell carcinoma: a propensity-score analysis

BACKGROUND

To compare survival outcomes of metastatic patients harbouring either papillary (pRCC) or clear-cell (ccRCC) renal cell carcinoma in overall population and according to treatment modality.

METHODS

Within the Surveillance, Epidemiology and End Results database (2006-2015), we identified 6800 patients (585 papillary and 6215 clear-cell) with metastatic RCC. Propensity-score (PS) matching, Kaplan-Meier plots and multivariable Cox-regression models (CRMs) were used.

RESULTS

Overall, 585 (8.6%) patients harboured pRCC. Rates of nodal metastases were higher in patients with pRCC (49.7 vs. 23.3%; p < 0.001). Median overall survival (OS) was 13 vs. 18 months for pRCC vs. ccRCC patients. After multivariable adjustments, no difference in OS was recorded. Furthermore, after propensity-score matching, virtually the same results were recorded. Median OS of pRCC vs. ccRCC was 8 vs. 4 months for no treatment (NT), 11 vs. 12 months for targeted therapy alone (TT), 17 vs. 35 months for cytoreductive nephrectomy alone (CN) and 18 vs. 25 months for combination of CN with TT.

CONCLUSIONS

Metastatic pRCC patients exhibit poor survival, regardless of treatment received. Moreover, pRCC patients are more likely to present nodal metastases, compared to ccRCC patients, as demonstrated by twofold higher rates of lymph node invasion at diagnosis. These observations indicate that papillary variant represents more prognostically unfavorable tumor histology, in the context of metastatic RCC.

Papillary Renal Neoplasm With Reverse Polarity: A Morphologic, Immunohistochemical, and Molecular Study

We evaluated the clinicopathologic and chromosomal characteristics of a distinct subset of papillary renal tumors and compared them to a control series of papillary renal cell carcinoma types 1 and 2. Of the 18 patients, 9 were women and 9 were men, ranging in age from 46 to 80 years (mean, 64 y; median, 66 y). The tumors ranged in diameter from 0.6 to 3 cm (mean, 1.63 cm; median, 1.4 cm). Fourteen tumors were WHO/ISUP grade 2 and 4 were grade 1. All were stage category pT1. The tumors had branching papillae with thin fibrovascular cores, covered by cuboidal to columnar cells with granular eosinophilic cytoplasm, smooth luminal borders, and mostly regular and apically located nuclei with occasional nuclear clearing and inconspicuous nucleoli. Tubule formation and clear cytoplasmic vacuoles were observed in 5 and 9 tumors, respectively. Ten tumors had pseudocapsules. Psammoma bodies, necrosis, mitotic figures and intracellular hemosiderin are absent from all tumors. In contrast, papillary renal cell carcinoma type 1 consisted of delicate papillae covered by a single layer of cells with scanty pale cytoplasm with nuclei generally located in a single layer on the basement membrane of the papillary cores, while type 2 tumors had broad papillae covered by pseudostratified cells with eosinophilic cytoplasm and more randomly located nuclei. Both had occasional psammoma bodies, foamy macrophages and intracellular hemosiderin. Immunohistochemically, all were positive for pancytokeratin AE1/AE3, epithelial membrane antigen, MUC1, CD10, GATA3, and L1CAM. Cytokeratin 7 was positive in 16 tumors (1 had <5% positivity). CD117 and vimentin were always negative. α-methylacyl-CoA-racemase (AMACR/p504s) showed variable staining (range, 10% to 80%) in 5 tumors. However, all tumors in the control group were negative for GATA3 and positive for AMACR/p504s and vimentin immunostains. Fluorescence in situ hybridization analysis of the study group demonstrated chromosome 7 trisomy in 5 tumors (33%), trisomy 17 in 5 tumors (33%), and trisomy 7 and 17 in 3 tumors (20%). Chromosome Y deletion was found in 1 of 7 male patients and chromosome 3p was present in all tumors. No tumor recurrence or metastasis occurred. In summary, we propose the term papillary renal neoplasm with reverse polarity for this entity.

Spindle cell renal cell carcinoma diagnosed after sunitinib treatment for chromophobe renal cell carcinoma

INTRODUCTION

Chromophobe renal cell carcinoma presents in early pathological stages with a lower risk of metastasis. However, aggressive features and metastasis can occur. A rare case of rapidly progressive disease with histological changes is presented.

CASE PRESENTATION

A 56-year-old woman had a right renal tumor with multiple lymph node metastases, and the pathological diagnosis of the biopsy specimens from the primary tumor was chromophobe renal cell carcinoma. After sunitinib treatment, the metastatic lymph node had decreased in size and the numbers of circulating tumor cells were decreased, consequently, cytoreductive nephrectomy was performed. However, rapid progression of lymph node metastases was observed. Histopathological examination showed that the renal tumor was diagnosed as spindle cell renal carcinoma.

CONCLUSION

It appears that the primary tumor underwent epithelial-mesenchymal transition; further tissue specimen collection and analysis might be needed.

Correlating Transcriptional Networks to Papillary Renal Cell Carcinoma Survival: A Large-Scale Coexpression Analysis and Clinical Validation

We aimed to investigate the potential mechanisms of progression and identify novel prognosis-related biomarkers for papillary renal cell carcinoma (PRCC) patients. The related data were derived from The Cancer Genome Atlas (TCGA) and then analyzed by weighted gene coexpression network analysis (WGCNA). The correlation between each module and the clinical traits were analyzed by Pearson's correlation analysis. Pathway analysis was conducted to reveal potential mechanisms. Hub genes within each module were screened by intramodule analysis, and visualized by Cytoscape software. Furthermore, important hub genes were validated in an external dataset and clinical samples. A total of 5,839 differentially expressed genes were identified. By using WGCNA, we identified 21 coregulatory gene clusters based on 289 PRCC samples. We found many modules were significantly associated with clinicopathological characteristics. The gray, pink, light yellow, and salmon modules served as prognosis indicators for PRCC patients. Pathway enrichment analyses found that the hub genes were significantly enriched in the cancer-related pathways. With the external Gene Expression Omnibus (GEO) validation dataset, we found that PCDH12, GPR4, and KIF18A in the pink and yellow modules were continually associated with the survival status of PRCC, and their expressions were positively correlated with pathological grade. Notably, we randomly chose PCDH12 for validation, and the results suggested that the PRCC patients with higher pathological grades (II + III) mostly had higher PCDH12 protein expression levels compared with those patients in grade I. These validated hub genes play critical roles in the prognosis prediction of PRCC and serve as potential biomarkers for future personalized treatment.

Molecular Genetics of Renal Cell Tumors: A Practical Diagnostic Approach

Renal epithelial cell tumors are composed of a heterogeneous group of tumors with variable morphologic, immunohistochemical, and molecular features. A "histo-molecular" approach is now an integral part of defining renal tumors, aiming to be clinically and therapeutically pertinent. Most renal epithelial tumors including the new and emerging entities have distinct molecular and genetic features which can be detected using various methods. Most renal epithelial tumors can be diagnosed easily based on pure histologic findings with or without immunohistochemical examination. Furthermore, molecular-genetic testing can be utilized to assist in arriving at an accurate diagnosis. In this review, we presented the most current knowledge concerning molecular-genetic aspects of renal epithelial neoplasms, which potentially can be used in daily diagnostic practice.

Prognostic analysis of postoperative clinically nonmetastatic renal cell carcinoma

Objectives

To investigate the survival characteristics of postoperative nonmetastatic renal cell carcinoma (RCC) patients, and the predictive value of a prognostic model.

Materials and Methods

We retrospectively evaluated data from 1202 postoperative nonmetastatic RCC patients who were treated between 1999 and 2012 at West China Hospital, Sichuan University (Chengdu, China). In addition, we also evaluated data relating to 53 205 cases acquired from the Surveillance, Epidemiology, and End Results (SEER) program. Survival analysis was performed on the cases, and subgroups, using the Kaplan‐Meier and Cox regression methods. The concordance index of the Stage Size Grade Necrosis (SSIGN), Leibovich, and the UCLA integrated staging system, scores was determined to evaluate the accuracy of these outcome prediction models.

Results

The 5‐year overall survival rate for RCC cases in West China Hospital was 87.6%; this was higher than that observed for SEER cases. Survival analysis identified several factors that exerted significant influence over prognosis, including the time of surgery, Eastern Cooperative Oncology Group performance status, tumor stage, size, nuclear differentiation, pathological subtypes, along with necrotic and sarcomatoid differentiation. Moreover tumor stage, size, and nuclear grade were all identified as independent predictors for both our cases and those from the SEER program. Patient groups with advanced RCC, and poorly differentiated RCC subgroups, were both determined to have a poor prognosis. The SSIGN model yielded the best predictive value as a prognostic model, followed by the Leibovich, and UCLA integrated staging system; this was the case for our patients, and for sub‐groups with a poor prognosis.

Conclusion

The prognosis of RCC was mostly influenced by tumor stage, size, and nuclear differentiation. SSIGN may represent the most suitable prognostic model for the Chinese population.

[Renal cell carcinoma diagnosis and prognosis within the context of the WHO classification 2016]

BACKGROUND

Histological classification of renal cell carcinoma (RCC) has become more and more important for clinical management, but relatively few is known regarding the swiftness with which the 2016 World Health Organization (WHO) classification of RCC was adopted in the daily routine diagnostics.

AIM

To retrospectively review the histological diagnosis of RCC within the context of 2016 WHO classification followed by survival analysis.

MATERIAL AND METHODS

Retrospective register based analysis of RCC diagnosis between 1998 and 2017 and survival analysis.

RESULTS

1440 RCC cases were registered between 1998 and 1917. According to 2016 WHO classification, 77.7% clear cell RCC and 22.3% non-clear cell RCC were diagnosed. A total of 37 rare subtypes were recorded, among those 1% MiT family translocation RCC, 0.35% acquired cystic disease-associated RCC, 0.35% multilocular cystic renal neoplasm of low malignant potential, 0.35% collecting duct carcinoma, 0.3% mucinous tubular and spindle cell carcinoma, 0.1% clear cell papillary RCC and 0.1% RCC with (angio)leiomyomatous stroma. Cox regression analysis showed significant different overall survival and progression-free survival between the histological subtypes.

DISCUSSION

The complexity of the 2016 WHO classification of RCC put high demands on histopathological diagnostics. At University Medicine Center Rostock morphological distinct RCC entities have been mostly diagnosed by conventional means via hematoxillin and eosin stained slides, but beyond immunohistochemistry additionally molecular techniques were established. The histologic subtyping of RCC according to 2016 WHO classification has prognostic significance and might have predictive significance for unique therapeutic approaches.

The Association Between hMLH1 and hMSH2 Polymorphisms and Renal Tumors in Northeastern China

Aim: Although hMLH1 and hMSH2 are closely associated with the development and drug resistance of multiple types of tumors, their role in renal tumors remains unclear. This study was designed to examine the relationship between renal tumor development and polymorphisms in the hMLH1 and hMSH2 genes. Methods: The study included 180 patients with renal tumors that were confirmed by pathological examination and 199 healthy controls. The clinical and pathological stages of the tumor samples were determined, and DNA was extracted from the peripheral blood of the subjects. Polymorphisms in the hMLH1 and hMSH2 loci were identified using the 1000 genomes database and the multiplex ligase detection method. Correlation analyses was performed using single nucleotide polymorphism tests. Results: 88.9% (160/180) of the tumor specimens were identified as clear cell renal cell carcinoma (CCRC) and 89.4% (161/180) were stage I carcinomas. Three hMLH1 and nine hMSH2 polymorphic sites were identified, and the frequency of the AA genotype of the hMSH2 rs2303424 variant was found to be significantly higher in the renal tumor group (odds ratio [OR] = 1.37, 95% confidence interval [CI]: 1.02-1.86) in the additive model (p = 0.029), the recessive model (p = 0.005), and codominant model (p = 0.02). Multiple testing corrections were performed and the differences between the clear cell carcinoma and control samples remained significant. Compared with the controls, the distribution of the GG genotype of the hMSH2 rs11886591 locus was significantly higher in the clear cell carcinoma group (OR = 0.80, 95% CI: 0.59-1.10, p = 0.04) after multiple testing corrections in the dominant model. Conclusion: The AA genotype at the rs2303424 locus and GG genotype at rs11886591 locus of the DNA repair gene hMSH2 were closely associated with the development of renal tumors. Further studies are needed on larger cohorts to confirm this correlation.

Vimentin Overexpressions Induced by Cell Hypoxia Promote Vasculogenic Mimicry by Renal Cell Carcinoma Cells

Vasculogenic mimicry (VM), the novel approach for tumor cells to obtain blood supply, was reported to be involved in antiangiogenic resistance and poor prognosis in renal cell carcinoma (RCC). However, the molecular mechanisms underlying VM formed by RCC cells are still not clearly depicted. In the present study, we found that OS-RC-2 acquired the VM forming ability accompanied with the increased expressions of Vimentin and AXL and decreased expression of E-Cadherin by CoCl₂ treatment. Downregulation of Vimentin by siRNA severely impaired the capability of OS-RC-2 and 786-O to form VM structures induced by cell hypoxia in vitro. Moreover, knockdown of Vimentin inhibited cell migration and invasion, which could be prompted by hypoxia induction in RCC cells. In our clear cell RCC tissues, we found that VM was positively correlated with Vimentin overexpression and both predicted poor prognosis. In conclusion, Vimentin plays an important role in hypoxia induced VM formation of RCC cells and targeted Vimentin might be beneficial for RCC therapy.

Comparative study of renal cell carcinoma in patients less than 40 years of age and older age patients: A retrospective single-center study

BACKGROUND

Renal cell carcinoma (RCC) is typically found in the older age group between 50 and 70 years of age. However, diagnosis of renal cancer is increasing more rapidly in patients less than 40 years if age compared to older age patients.

AIMS AND OBJECTIVES

To compare the clinicopathological spectrum and survival in patients with RCC in relation to age in a tertiary care hospital in eastern India.

STUDY DESIGN

Retrospective cohort study.

MATERIALS AND METHODS

Patients operated between February 2008 and January 2017 for renal masses having clinical and radiological suspicion and histopathologically proven RCC were analyzed from hospital records. Clinicopathological data and survival study were compared between patients less than 40 years of age and older age patients. STATISTICAL ANALYSIS USED: Statistical and survival analysis was done using Statistical Package for the Social Sciences 20.

RESULTS

Among 198 patients, 36 (18.2%) patients less than 40 years were diagnosed with RCC and 162 in older patients. In these 36 younger patients, 17 (47.2%) were male and 19 (52.7%) were female. A total of 63.8% in younger age group and 69.1% of older patients were diagnosed with stage 1 and 2 RCC; comparing younger to older patients, younger patients had high number of papillary carcinoma (22.2% vs. 11.7%, P = 0.096). Younger patients have shown marginally better 5-year overall survival and disease-free survival (P > 0.05).

CONCLUSION

Our study concludes that younger age patients were more affected by RCC specially papillary RCC, when compared to western population. In addition females had more incidence of RCC. Prognosis was similar in both groups.

Tumor Enucleation vs. Partial Nephrectomy for T1 Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Purpose: Tumor enucleation (TE) and partial nephrectomy (PN) have both become main treatment strategies for T1 renal cell carcinoma (RCC), despite the discrepancy between their safety margin. We performed a meta-analysis on all the relevant trials in order to compare the clinical efficacy and safety of TE with those of PN for RCC treatment. Methods: In this meta-analysis, randomized controlled trials or retrospective studies were included if they compared TE and PN therapy in patients with localized renal cancer. The main outcomes extracted were perioperative data and post-operative outcomes. Subgroups for analyses were undertaken according to tumor size and duration of follow up. Data were pooled using the generic variance method with a fixed or random effects model and expressed as mean differences or odds ratios with 95% CI. Results: A total of 13 studies containing 1,792 patients undergoing TE and 3,068 undergoing PN were identified. Our study showed that the patients received TE had significantly shorter operative time (MD = -28.46, 95% CI = -42.09, -14.83, P < 0.0001), less hospital day (MD = -0.68, 95% CI = -1.04, -0.31, P = 0.0003), less estimate blood loss (MD = -59.90, 95% CI = -93.23, -26.58, P = 0.0004) and smaller change in estimated glomerular filtration rate (fixed effect: MD = 4.66, 95% CI = 1.67, 7.66, P = 0.002), fewer complications (fixed effect: OR = 0.65, 95% CI = 0.50, 0.85, P = 0.001) compared with those received PN. However, there were no significant differences in terms of warm ischemic time, positive margin rates, recurrence rates and survival rates between the two groups. All the subgroup analyses presented consistent results with the overall analyses. Conclusions: Our findings suggested that TE is not only less-traumatizing and beneficial for recovery, but also better for renal function protection. Moreover, it did not show the evidence of an increase relapse rate or mortality rate when compared with PN.

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.

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.

The history of urologic pathology: an overview

This article begins with the testis and a legendary figure, Sir Astley Cooper, who wrote an early text on the organ. The early 20th century saw the first major development, the description of the seminoma by the French investigator Maurice Chevassu, but the pace of knowledge did not accelerate until after World War II with a major article from the Armed Forces Institute of Pathology (AFIP) by Nathan B. Friedman and Robert A. Moore, soon followed by the first series testis fascicle by Frank J. Dixon and Moore. Other noteworthy contributions were made by two masters of gonadal pathology, Gunnar Teilum and Robert E. Scully. In the 1970s, Niels E. Skakkebaek played a seminal role in elaborating in-situ neoplasia of the testis. The school of British testicular tumour authored, in the mid-1970s, under the editorship of Roger C. B. Pugh, one of the best texts on testicular pathology. Advances in more recent years have been largely spearheaded by Thomas M. Ulbright of the Indiana University School of Medicine. Observations on the prostate gland date back to Andreas Vesalius and William Cheselden, the latter appearing to have introduced the word for the gland. Note is made of contributions on the anatomy and histology of the gland by Oswald Lowsley, L. M. Franks, and John McNeal. Diagnosing carcinoma of the prostate was brought into the modern age in a landmark 1953 article by Robert S. Totten et al. In the 1960s, Donald F. Gleason introduced a grading system that is now in use worldwide. The topic of premalignant lesions has been well established only for approximately three decades, based initially on the work of Dr McNeal and David G. Bostwick. One of the first to write a book on the bladder was the remarkable British surgeon-pathologist Sir Henry Thompson. Workers at the AFIP, including Colonel James E. Ash and Fatallah K. Mostofi, wrote many outstanding articles on bladder pathology. The roles of other institutions, such as Johns Hopkins University, the Mayo Clinic, and St Peter's Hospital Institute of Urology, London, and those who worked there are noted. Knowledge of the pathology of the urachus dates largely back to the remarkable book on the topic in 1916 by the Hopkins investigator Thomas S. Cullen. Information on renal tumours dates largely to the work of Paul Grawitz, but awareness of the many variants of renal cell carcinoma in general was slow to evolve, and has only accelerated in recent years. The AFIP group of Dr Mostofi, ably assisted by Colonel Charles J. Davis and Isabell A. Sesterhenn, has contributed to knowledge of renal neoplasia with articles of note on oncocytoma, metanephric adenoma, and medullary carcinoma. In the mid-1980s, the German workers Wolfgang Thoenes and Stephan Störkel recognised the distinctive tumour known as chromophobe renal cell carcinoma. Work on renal tumours in the young owes much to J. Bruce Beckwith. The observational talents of numerous investigators have, in just over a century, advanced our knowledge of diseases of the urinary tract and testis remarkably.

Patterns of Relapse and Implications for Post-Nephrectomy Surveillance in Patients with High Risk Nonclear Cell Renal Cell Carcinoma: Subgroup Analysis of the Phase 3 ECOG-ACRIN E2805 Trial

PURPOSE

The natural history of nonclear cell renal cell carcinoma following surgery with curative intent remains poorly defined with postoperative surveillance informed by guidelines largely intended for clear cell renal cell carcinoma. We evaluated relapse patterns and potential implications for post-nephrectomy surveillance in patients with nonclear cell renal cell carcinoma enrolled in the E2805 trial, the largest randomized trial of adjuvant antiangiogenic therapy of high risk renal cell carcinoma.

MATERIALS AND METHODS

We retrospectively analyzed the records of patients with completely resected nonclear cell renal cell carcinoma. Participants received up to 54 weeks of postoperative therapy with sunitinib, sorafenib or placebo and underwent surveillance imaging at standardized intervals for 10 years. For recurrence rates by site the cumulative incidence was estimated, accounting for competing risks. The adequacy of strict adherence to post-nephrectomy surveillance guidelines was evaluated.

RESULTS

A total of 403 patients with nonclear cell renal cell carcinoma were enrolled in the study. During a median followup of 6.2 years 36% of nonclear cell renal cell carcinomas recurred. Five-year recurrence rates were comparable for nonclear and clear cell renal cell carcinoma in the 1,541 patients, including 34.6% (95% CI 29.8-39.4) and 39.5% (95% CI 36.9-42.1), respectively. However, patients with nonclear cell renal cell carcinoma were significantly more likely to have abdominal sites of relapse (5-year recurrence rate 26.4% vs 18.2%, p = 0.0008) and significantly less likely to experience relapse in the chest (5-year recurrence rate 13.7% vs 20.9%, p = 0.0005). Current surveillance guidelines would potentially capture approximately 90% of relapses at any site.

CONCLUSIONS

Nonclear cell renal cell carcinoma may show a distinct pattern of relapse compared to clear cell renal cell carcinoma. Our findings emphasize the importance of cross-sectional, long-term imaging in patients with high risk, resected, nonclear cell renal cell carcinoma.

Transglutaminase 2: The Maestro of the Oncogenic Mediators in Renal Cell Carcinoma

Transglutaminase 2 (TG2) is a multifunctional crosslinking enzyme that displays transamidation, protein disulfide isomerase, protein kinase, as well as GTPase and ATPase activities. TG2 can also act as an adhesion molecule involved in the syndecan and integrin receptor signaling. In recent years, TG2 was implicated in cancer progression, survival, invasion, migration, and stemness of many cancer types, including renal cell carcinoma (RCC). Von Hippel-Lindau mutations leading to the subsequent activation of Hypoxia Inducible Factor (HIF)-1-mediated signaling pathways, survival signaling via the PI3K/Akt pathway resulting in Epithelial Mesenchymal Transition (EMT) metastasis and angiogenesis are the main factors in RCC progression. A number of studies have shown that TG2 was important in HIF-1- and PI3K-mediated signaling, VHL and p53 stabilization, glycolytic metabolism and migratory phenotype in RCC. This review focuses on the role of TG2 in the regulation of molecular pathways nurturing not only the development and propagation of RCC, but also drug-resistance and metastatic potential.

Unclassified renal cell carcinoma: diagnostic difficulties and treatment modalities

Over the past few decades, the classification system of renal cell carcinoma (RCC) variants has witnessed tremendous and ongoing refinement driven by genomic profiling and morphological correlation that have provided valuable insights into tumor biology and characterization of this heterogeneous subset of tumors. The importance of accurate classification cannot be understated given the downstream impact on treatment decisions, risk stratification, and need for genetic testing. While the morphologic heterogeneity across these tumors is increasingly being recognized, all non-clear-cell RCCs are commonly categorized under one therapeutic category with management strategies that largely derive from clear-cell RCCs. As research in metastatic RCC progresses, there is a growing focus on rare subtypes and unclassified tumors, which is rapidly changing the treatment paradigm for non-clear-cell RCC. This review focuses on the histomorphologic diagnostic challenges of unclassified RCCs discussing the utility of contemporary diagnostic tools. It further discusses the current state of knowledge and guidelines for management of this class of tumors.

Ki-67 index and percentage of sarcomatoid differentiation were two independent prognostic predictors in sarcomatoid renal cell carcinoma

Purpose

To identify whether and which of pathological features of sarcomatoid differentiation (SD) in renal cell carcinoma (RCC) can be used as independent predictors associated with overall survival (OS).

Materials and methods

After institutional review board approval, patients with a diagnosis of sarcomatoid RCC (sRCC), spindled RCC, or RCC with the presence of spindle cells between 2003 and 2017 were further selected and re-examined. The primary pathological features including histological subtypes, tumor necrosis, Ki-67 index of SD, and the percent of SD (%SD) were included into analysis. Histological subtypes were categorized into clear-cell RCC and nonclear-cell RCC. Ki-67 index of SD was confirmed by immunohistochemical staining. %SD was estimated through reviewing all of the tumor sections microscopically and then giving an approximate %SD within the entire tumor. The clinical relevant prognostic predictor's association with OS was analyzed within Cox proportional hazards regression models. Survival curves were generated using the Kaplan-Meier method, and OS differences were compared using the log-rank test.

Results

A total of 2,089 consecutive patients of RCC were referred to our department, of whom 62 (3.0%) patients were identified with histological element of SD after re-examining the available slides of suspicious cases. Finally, 53 patients were included into survival analysis after excluding 9 patients without adequate information. Thirty-eight (71.7%) patients died at last follow-up. The median OS for all patients was 11.0 months from the date of surgery. In patients with clinical distant metastasis (cM₁), the median OS was only 3 compared with 21 months for patients with no clinical distant metastasis (cM₀). Tumor stage, status of clinical distant metastasis, Ki-67 index, and %SD were independent predictors of multivariate analysis in overall 53 patients. However, in the cohort of cM₀ patients, we found that only %SD and Ki-67 index were two independent predictors of OS in multivariate analysis.

Conclusion

Patients with sRCC are associated with very poor prognosis. Ki-67 index of SD and %SD were identified as the two most important independent predictors particularly for nonmetastatic patients. The limitations of our study were also observed, and further studies are needed.

Long Non-Coding RNA DUXAP8 Enhances Renal Cell Carcinoma Progression via Downregulating miR-126

Background

Renal cell carcinoma (RCC) is one of the common malignant tumors in the urinary system, which endangers human health for a long time. The past decade, the molecular biology of renal cell carcinoma has made considerable progress, so that we have a more profound understanding of renal cell carcinoma. Molecular biological mechanism of renal cell carcinoma remains to be explored. Evidence indicates that long non-coding RNAs (lncRNAs) may be important players in human cancer progression, including RCC. In this study, we found that a newly discovered pseudogene-derived lncRNA named DUXAP8, a 2107-bp RNA, was remarkably upregulated in RCC.

Material/Methods

Expression of lncRNA DUXAP8 was determined by a qRT-PCR assay in RCC tissues. The proliferation and invasion of RCC cell were measured by a cell proliferation assay and a Transwell invasion assay. Expression of miR-126 was detected by real-time PCR. Interactions between lncRNA DUXAP8 and miR-126 were measured by a luciferase reporter assay and an RNA-pull down assay. In vivo experiments were used to detect tumor formation.

Results

Together, our study not only identifies lncRNA DUXAP8 as a negative regulator of renal cancer with potential clinical value, but also reveals a regulatory mechanism by long non-coding RNAs to control tumor development.

Conclusions

Results from this study provide evidence that lncRNA DUXAP8 enhances renal cell carcinoma progression via downregulating of miR-126, which offers a new approach for the treatment of RCC.

Nomograms for predicting long-term overall survival and disease-specific survival of patients with clear cell renal cell carcinoma

Objectives

The aim of this study was to establish comprehensive and practical nomograms, based on significant clinicopathological parameters, for predicting the overall survival (OS) and the disease-specific survival (DSS) of patients with clear cell renal cell carcinoma (ccRCC).

Patients and methods

The data of 35,151 ccRCC patients, diagnosed between 2004 and 2014, were obtained from the database of the Surveillance, Epidemiology, and End Results (SEER) program. The Kaplan–Meier method and Cox proportional hazards regression model were used to evaluate the prognostic effects of multiple clinicopathological variables on survival. Based on Cox models, a nomogram was constructed to predict the probabilities of OS and DSS for an individual patient. The predictive performance of nomograms was evaluated using the concordance index (C-index) and calibration curves.

Results

According to univariate and multivariate analyses, age at diagnosis, sex, race, marital status, surgical approach, tumor node metastasis (TNM) stage, and Fuhrman grade significantly correlated with the survival outcomes. These characteristics were used to establish nomograms. The nomograms showed good accuracy in predicting 3-, 5-, and 10-year OS and DSS, with a C-index of 0.79 (95% CI, 0.79–0.80) for OS and 0.87 (95% CI, 0.86–0.88) for DSS. All calibration curves revealed excellent consistency between predicted and actual survival.

Conclusion

Nomograms were developed to predict death from ccRCC treated with nephrectomy. These new prognostic tools could aid in improving the predictive accuracy of survival outcomes, thus leading to reasonable individualized treatment.

Incidence of bone metastasis and factors contributing to its development and prognosis in newly diagnosed renal cell carcinoma: a population-based study

Purpose

The purpose of this study was to assess the incidence of and the risk factors and prognostic factors for bone metastasis (BM) in initial metastatic renal cell carcinoma (RCC) based on a large population analysis.

Patients and methods

Data were obtained for a total of 45,824 RCC patients recorded in the database of the Surveillance, Epidemiology, and End Results program of the National Cancer Institute between 2010 and 2014. Multivariate logistic and Cox regression analyses were used to identify the risk factors and prognostic factors associated with BM in RCC patients. Kaplan-Meier analysis was used to estimate the overall survival of RCC patients, and the difference between the survival curves was tested by log-rank tests.

Results

A total of 1,509 (3.29%) patients were diagnosed with bone metastases at initial diagnosis. Male gender, higher T stage, lymph node involvement, poor tumor grade, presence of lung, liver, and brain metastases, and the collecting duct type of RCC were positively associated with BM occurrence. The median survival time for RCC patients with bone metastases was 12.0 (95% confidence interval [CI]: 10.69-13.31) months, and the survival time for those with collecting duct, clear-cell, papillary, and chromophobe subtypes of RCC were 3 (95% CI: 0.23-5.77), 13 (95% CI: 11.60-14.40), 8 (95% CI: 5.09-10.91), and 11 (95% CI: 5.02-16.98) months; these differences were significantly different (P<0.01). Older age, higher T stage, lymph node involvement, poor tumor grade, the presence of lung, liver, and brain metastases, collecting duct RCC, and the absence of surgical treatments were the factors associated with worse prognoses.

Conclusion

BM was highly prevalent and significantly decreased the survival rate of RCC patients. A number of factors associated with the development and prognosis of BM were identified, and these insights provide preventive guidelines for screening and treatment of BM in RCC patients.

Thyroid and renal tumors in patients treated with long-term lithium: case series from a lithium clinic, review of the literature and international pharmacovigilance reports

BACKGROUND

Cancer had never been considered as a relevant problem in patients treated with lithium until 2015, when a document published by the European Medicine Agency concluded that long-term use of lithium might induce renal tumors. A few months later, we observed the case of a woman treated with lithium for 18 years who was diagnosed with both thyroid and renal tumors.

METHODS

This study aimed to investigate the correlation between lithium treatment and thyroid or renal tumors. We analyzed clinical records in our lithium clinic database, causes of death of patients who had been visited at least once at the lithium clinic, reports of lithium adverse reactions in the European and WHO pharmacovigilance databases, and published cases of thyroid and renal tumors in long-term lithium-treated patients.

RESULTS

Of the 1871 lithium patients who had been visited at least once between 1980 and 2013, eight had been diagnosed with thyroid papillary carcinoma and two with clear-cell renal-cell carcinoma. No cases of thyroid cancer and only one case of renal tumor were the cause of death according to the 375 available death certificates. VigiAccess database contained a total of 29 and 14 cases of renal and thyroid tumors, respectively. EudraVigilance database contained 21 cases of renal and 8 of thyroid neoplasms. Literature search yielded 6 published cases of thyroid papillary carcinoma and 25 cases of various renal tumors. However, two population-based studies did not find any increased risks of cancer in patients exposed to lithium, whereas two nationwide studies did not find any excess of renal tumors.

CONCLUSION

So far it has not been possible epidemiologically to confirm an increased risk of thyroid or renal cancers associated with lithium. Such a conclusion is supported by the findings of low rates and mortalities of thyroid or renal cancers from the present lithium clinic data.

A family case with germline TSC1 and mtDNA mutations developing bilateral eosinophilic chromophobe renal cell carcinomas without other typical phenotype of tuberous sclerosis

AIM

We examined the genetic alterations in a mother and son with multiple eosinophilic chromophobe renal cell carcinomas (chRCCs) showing no other features.

METHODS

Germline DNA and bilateral renal cell carcinoma DNA were genetically analysed by whole-exome sequencing. Candidate gene alterations in the first patient's germline were investigated in her child's germline and the chRCCs.

RESULTS

We detected several germline gene alterations in the mother. Among the identified alterations, TSC1 and mitochondrial DNA mutations were also confirmed in her son. Regarding somatic alterations in bilateral chRCCs, no common candidate gene alteration was found.

CONCLUSION

To the best of our knowledge, this is the first report of whole-exome sequencing revealing bilateral eosinophilic chRCCs associated with tuberous sclerosis complex in a family case without classical phenotype. These results suggest that germline TSC1 and mitochondrial DNA gene mutations may be involved in the development of chRCCs in some cases.