Adult Renal Cell Carcinoma: A Review of Established Entities from Morphology to Molecular Genetics

Multiphase comparative study for WHO/ISUP nuclear grading diagnostic model based on enhanced CT images of clear cell renal cell carcinoma

To compare and analyze the diagnostic value of different enhancement stages in distinguishing low and high nuclear grade clear cell renal cell carcinoma (ccRCC) based on enhanced computed tomography (CT) images by building machine learning classifiers. A total of 51 patients (Dateset1, including 41 low-grade and 10 high-grade) and 27 patients (Independent Dateset2, including 16 low-grade and 11 high-grade) with pathologically proven ccRCC were enrolled in this retrospective study. Radiomic features were extracted from the corticomedullary phase (CMP), nephrographic phase (NP), and excretory phase (EP) CT images, and selected using the recursive feature elimination cross-validation (RFECV) algorithm, the group differences were assessed using T-test and Mann-Whitney U test for continuous variables. The support vector machine (SVM), random forest (RF), XGBoost (XGB), VGG11, ResNet18, and GoogLeNet classifiers are established to distinguish low-grade and high-grade ccRCC. The classifiers based on CT images of NP (Dateset1, RF: AUC = 0.82 ± 0.05, ResNet18: AUC = 0.81 ± 0.02; Dateset2, XGB: AUC = 0.95 ± 0.02, ResNet18: AUC = 0.87 ± 0.07) obtained the best performance and robustness in distinguishing low-grade and high-grade ccRCC, while the EP-based classifier performance in poorer results. The CT images of enhanced phase NP had the best performance in diagnosing low and high nuclear grade ccRCC. Firstorder_Kurtosis and firstorder_90Percentile feature play a vital role in the classification task.

Radiogenomics and Texture Analysis to Detect von Hippel-Lindau (VHL) Mutation in Clear Cell Renal Cell Carcinoma

Radiogenomics, a burgeoning field in biomedical research, explores the correlation between imaging features and genomic data, aiming to link macroscopic manifestations with molecular characteristics. In this review, we examine existing radiogenomics literature in clear cell renal cell carcinoma (ccRCC), the predominant renal cancer, and von Hippel-Lindau (VHL) gene mutation, the most frequent genetic mutation in ccRCC. A thorough examination of the literature was conducted through searches on the PubMed, Medline, Cochrane Library, Google Scholar, and Web of Science databases. Inclusion criteria encompassed articles published in English between 2014 and 2022, resulting in 10 articles meeting the criteria out of 39 initially retrieved articles. Most of these studies applied computed tomography (CT) images obtained from open source and institutional databases. This literature review investigates the role of radiogenomics, with and without texture analysis, in predicting VHL gene mutation in ccRCC patients. Radiogenomics leverages imaging modalities such as CT and magnetic resonance imaging (MRI), to analyze macroscopic features and establish connections with molecular elements, providing insights into tumor heterogeneity and biological behavior. The investigations explored diverse mutations, with a specific focus on VHL mutation, and applied CT imaging features for radiogenomic analysis. Moreover, radiomics and machine learning techniques were employed to predict VHL gene mutations based on CT features, demonstrating promising results. Additional studies delved into the relationship between VHL mutation and body composition, revealing significant associations with adipose tissue distribution. The review concludes by highlighting the potential role of radiogenomics in guiding targeted and selective therapies.

LZTFL1 inhibits kidney tumor cell growth by destabilizing AKT through ZNRF1-mediated ubiquitin proteosome pathway

LZTFL1 is a tumor suppressor located in chromosomal region 3p21.3 that is deleted frequently and early in various cancer types including the kidney cancer. However, its role in kidney tumorigenesis remains unknown. Here we hypothesized a tumor suppressive function of LZTFL1 in clear cell renal cell carcinoma (ccRCC) and its mechanism of action based on extensive bioinformatics analysis of patients' tumor data and validated it using both gain- and loss-functional studies in kidney tumor cell lines and patient-derive xenograft (PDX) model systems. Our studies indicated that LZTFL1 inhibits kidney tumor cell proliferation by destabilizing AKT through ZNRF1-mediated ubiquitin proteosome pathway and inducing cell cycle arrest at G1. Clinically, we found that LZTFL1 is frequently deleted in ccRCC. Downregulation of LZTFL1 is associated with a poor ccRCC outcome and may be used as prognostic maker. Furthermore, we show that overexpression of LZTFL1 in PDX via lentiviral delivery suppressed PDX growth, suggesting that re-expression of LZTFL1 may be a therapeutic strategy against ccRCC.

Unilateral fixation utilizing minimally invasive surgery (MIS) system for lumbosacral metastasis in a patient with stage 4 renal cell carcinoma

Introduction and importance

To summarize the clinical manifestations and treatment of a patient with lumbar metastases from renal cell carcinoma who underwent unilateral fixation of lumbosacral spine utilizing minimally invasive surgery systems.

Case presentation

A 71-year-old woman presented to a local hospital with complaints of low back pain. Computed tomography (CT) at the hospital revealed metastases to the lung, occipital bone, right ribs and fifth lumbar vertebrae from a primary left renal cancer. A lumbar Magnetic resonance imaging (MRI) performed at local clinic revealed an enlarged metastatic tumor invading the right body, transverse process and pedicle of fifth lumbar vertebra. Transmyofascial insertion of pedicle screws and connection with rod utilizing minimally invasive surgery (MIS) systems were made on the left L4.5.S1 vertebrae under fluoroscopy. The operating time was 36 min, the intraoperative blood loss was 30 g and fluoroscopic time was 56 s. Postoperative course was uneventful. She could walk with a single cane on the twenty postoperative days but passed away of systemic metastasis approximately10 months after the spinal fixation. An x-ray taken just before death showed no spinal instrumentation failure.

Discussion

Surgery for spinal metastasis from hypervascular tumor may result in profuse intraoperative bleeding that is difficult to control. It might be preferable to operate with MIS if patients with spinal metastases are candidate for either MIS or conventional methods. It has been reported that unilateral fixation could be as effective as bilateral fixation in up to two-segment lumbar spinal fusion.

Conclusion

Unilateral fixation utilizing MIS systems may be effective in cases whom placing an instrumentation on the side with tumor extending posteriorly may cause massive bleeding.

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Transmyofascial insertion of pedicle screws and connection with rod utilizing MIS systems were made on the left L4.5.S1 vertebrae under fluoroscopy.

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Unilateral fixation utilizing MIS systems may be effective in cases whom placing an instrumentation on the side with tumor extending posteriorly may cause massive bleeding.

Key Renal Neoplasms With a Female Predominance

Renal neoplasms largely favor male patients; however, there is a growing list of tumors that are more frequently diagnosed in females. These tumors include metanephric adenoma, mixed epithelial and stromal tumor, juxtaglomerular cell tumor, mucinous tubular and spindle cell carcinoma, Xp11.2 (TFE3) translocation-associated renal cell carcinoma, and tuberous sclerosis complex (somatic or germline) associated renal neoplasms. The latter category is a heterogenous group with entities still being delineated. Eosinophilic solid and cystic renal cell carcinoma is the best-described entity, whereas, eosinophilic vacuolated tumor is a proposed entity, and the remaining tumors are currently grouped together under the umbrella of tuberous sclerosis complex/mammalian target of rapamycin-related renal neoplasms. The entities described in this review are often diagnostic considerations when evaluating renal mass tissue on biopsy or resection. For example, Xp11.2 translocation renal cell carcinoma is in the differential when a tumor has clear cell cytology and papillary architecture and occurs in a young or middle-aged patient. In contrast, tuberous sclerosis complex-related neoplasms often enter the differential for tumors with eosinophilic cytology. This review provides an overview of the clinical, gross, microscopic, immunohistochemical, genetic, and molecular alterations in key renal neoplasms occurring more commonly in females; differential diagnoses are also discussed regardless of sex predilection.

Surgically induced ischemia has no impact on protein expression levels of HIF-1α and related biomarkers in renal cell carcinoma

The increasing demands for personalized targeted therapy directed against renal cell carcinoma have driven a search for predictive markers. Novel therapies targeting HIF-1α in renal cell carcinoma have been developed, and HIF-1α has been suggested as a novel predictive marker of response to therapy. The surgical resection of a kidney tumor induces tissue ischemia, and HIF-1α is an oxygen-sensitive transcription factor, which is known to be upregulated during hypoxia. This study investigated the impact of intra-surgical and post-surgical ischemia on protein expression levels of HIF-1α and three related biomarkers (VEGF, GLUT-1, and CAIX) in 20 patients with renal cell carcinoma with immunohistochemistry and Western blotting. Surgical ischemia did not have a significant impact on protein expression levels of any of the investigated markers. Long-post-surgical ischemia resulted in reduced expression levels of HIF-1α, probably due to autolysis. Our results suggest that HIF-1α is a stable protein, with expression levels not affected by intra-surgical ischemia, and hence, HIF-1α is suited for marker analysis.

The Differential Diagnosis of Medullary-Based Renal Masses

CONTEXT.—

Renal malignancies can be divided into cortical- and medullary-based tumors, the latter of which classically infiltrate the renal parenchyma by extending between nonneoplastic structures. Although high-grade cortical tumors can rarely exhibit the same growth pattern, the infiltrative morphology should elicit a differential diagnosis to be considered in each case. However, these diagnoses can be challenging to distinguish, especially on small renal biopsy samples.

OBJECTIVE.—

To provide an overview of the clinical, gross, and microscopic findings; genetic and molecular alterations; and immunohistochemical evaluation of medullary-based renal tumors and other tumor types with overlapping morphologies and growth patterns.

DATA SOURCES.—

Literature review and personal observations were used to compile the information in this review.

CONCLUSIONS.—

Collecting duct carcinoma is a prototypical medullary-based tumor, and although diagnostic criteria exist, it remains a diagnosis of exclusion, especially with ancillary techniques aiding the recognition of established as well as more recently described neoplasms. Other medullary-based malignancies included in the differential diagnosis include renal medullary carcinoma/renal cell carcinoma unclassified with medullary phenotype, fumarate hydratase-deficient renal cell carcinoma, and upper tract urothelial carcinoma. Moreover, other rare entities should be excluded, including metastatic carcinoma, lymphoma, and melanoma. In addition to potential prognostic differences, accurate diagnoses can have important surgical and clinical management implications.

Carbonic anhydrase IX (CA9) expression in multiple renal epithelial tumour subtypes

AIMS

Renal epithelial neoplasms (RENs) can be difficult to subclassify, owing to overlapping morphological features. Carbonic anhydrase 9 (CA9) is a common biomarker for clear cell renal cell carcinoma (CCRCC); however, the sensitivity and specificity across REN subtypes are less clear. The aim of this study was to investigate CA9 expression in RENs, especially those in the differential diagnosis with CCRCC and less common entities, to determine its reliability as a diagnostic biomarker.

METHODS AND RESULTS

CA9 immunostaining was performed on 262 RENs, including 119 CCRCCs and 143 non-CCRCC. Immunostaining was evaluated as negative (0%), rare (1+, 1-10%), focal (2+, 11-50%), or diffuse (3+, >50%). CCRCCs were 3+ CA9-positive in 93% of cases; 4% were CA9-negative. Sixty-seven percent of papillary renal cell carcinomas (RCCs) were 1+/2+ CA9-positive, whereas 33% were CA9-negative. Chromophobe RCCs were nearly always CA9-negative (93%), with 7% showing rare cell reactivity. Clear cell tubulopapillary RCCs (CCTPRCCs) were consistently 3+ CA9-positive, but with a cup-like staining pattern. Fifty-three percent of Xp11.2 RCCs were CA9-negative; however, 6% were 3+ CA9-positive and 12% were 2+ CA9-positive. Two of eight fumarate hydratase-deficient RCCs were 3+ CA9-positive. A small subset of the remaining RCCs showed rare to focal CA9 expression. All oncocytomas and eosinophilic solid and cystic RCCs were CA9-negative.

CONCLUSIONS

Overall, diffuse CA9 expression was identified in nearly all CCRCCs and in all CCTPRCCs (high sensitivity); however, CA9 was not entirely specific. At least focal CA9 expression can been seen in a subset of many RCCs, and such findings should be taken into consideration with other morphological, immunophenotypic and clinical findings.

Characterization of solid renal neoplasms using MRI-based quantitative radiomics features

PURPOSE

To assess the diagnostic value of magnetic resonance imaging (MRI)-based radiomics features using machine learning (ML) models in characterizing solid renal neoplasms, in comparison/combination with qualitative radiologic evaluation.

METHODS

Retrospective analysis of 125 patients (mean age 59 years, 67% males) with solid renal neoplasms that underwent MRI before surgery. Qualitative (signal and enhancement characteristics) and quantitative radiomics analyses (histogram and texture features) were performed on T2-weighted imaging (WI), T1-WI pre- and post-contrast, and DWI. Mann-Whitney U test and receiver-operating characteristic analysis were used in a training set (n = 88) to evaluate diagnostic performance of qualitative and radiomics features for differentiation of renal cell carcinomas (RCCs) from benign lesions, and characterization of RCC subtypes (clear cell RCC [ccRCC] and papillary RCC [pRCC]). Random forest ML models were developed for discrimination between tumor types on the training set, and validated on an independent set (n = 37).

RESULTS

We assessed 104 RCCs (51 ccRCC, 29 pRCC, and 24 other subtypes) and 21 benign lesions in 125 patients. Significant qualitative and quantitative radiomics features (area under the curve [AUC] between 0.62 and 0.90) were included for ML analysis. Models with best diagnostic performance on validation sets showed AUC of 0.73 (confidence interval [CI] 0.5-0.96) for differentiating RCC from benign lesions (using combination of qualitative and radiomics features); AUC of 0.77 (CI 0.62-0.92) for diagnosing ccRCC (using radiomics features), and AUC of 0.74 (CI 0.53-0.95) for diagnosing pRCC (using qualitative features).

CONCLUSION

ML models incorporating MRI-based radiomics features and qualitative radiologic assessment can help characterize renal masses.

Deceptive Features on Surveillance Imaging of Intraneural Metastatic Deposits in Metastatic Renal Cell Cancer

BACKGROUND

Spinal renal cell metastases are a common insidious pathological manifestation of the oncological process but less common are intramedullary and intraneural spinal metastases. The differential diagnosis of such pathological features can be difficult in the presence of conflicting radiological evidence.

CASE DESCRIPTION

In the present case report, we have detailed the clinical, diagnostic, surgical, and therapeutic progression of a 54-year-old man diagnosed with metastatic renal cell carcinoma. After the initial presentation and treatment, he had presented with symptomatic right lower limb radiculopathy. Magnetic resonance imaging identified a well-defined cystic lesion expanding in the right exit foramina at L5-S1, suggestive of a benign schwannoma. After a multidisciplinary review, he was treated symptomatically and imaging surveillance for a 19-month period, with static lesion findings. Failure of symptomatic management resulted in operative intervention and subsequent histological diagnosis of the metastatic deposit.

CONCLUSION

To the best of our knowledge, the present report is the first documented case of intraneural metastatic deposits from renal cell carcinoma that showed benign radiographic features and demonstrated a stable appearance on surveillance imaging studies for a significant period. These findings suggest that clinicians should have a high index of suspicion for a metastatic process in symptomatic patients with a known renal cell cancer regardless of the lesion's radiographic or temporal characteristics.

Predicting tumor-specific survival in patients with spinal metastatic renal cell carcinoma: which scoring system is most accurate?

OBJECTIVE

Although several prognostic scores for spinal metastatic disease have been developed in the past 2 decades, the applicability and validity of these models to specific cancer types are not yet clear. Most of the data used for model formation are from small population sets and have not been updated or externally validated to assess their performance. Developing predictive models is clinically relevant as prognostic assessment is crucial to optimal decision-making, particularly the decision for or against spine surgery. In this study, the authors investigated the performance of various spinal metastatic disease risk models in predicting prognosis for spine surgery to treat metastatic renal cell carcinoma (RCC).

METHODS

Data of patients who underwent surgery for RCC metastatic to the spine at 2 tertiary centers between 2010 and 2019 were retrospectively retrieved. The authors determined the prognostic value associated with the following scoring systems: the Tomita score, original and revised Tokuhashi scores, original and modified Bauer scores, Katagiri score, the Skeletal Oncology Research Group (SORG) classic algorithm and nomogram, and the New England Spinal Metastasis Score (NESMS). Regression analysis of patient variables in association with 1-year survival after surgery was assessed using Cox proportional hazard models. Calibration and time-dependent discrimination analysis were tested to quantify the accuracy of each scoring system at 3 months, 6 months, and 1 year.

RESULTS

A total of 86 metastatic RCC patients were included (median age 64 years [range 29-84 years]; 63 males [73.26%]). The 1-year survival rate was 72%. The 1-year survival group had a good performance status (Karnofsky Performance Scale [KPS] score 80%-100%) and an albumin level > 3.5 g/dL (p < 0.05). Multivariable-adjusted Cox regression analysis showed that poor performance status (KPS score < 70%), neurological deficit (Frankel grade A-D), and hypoalbuminemia (< 3.5 g/dL) were associated with a higher risk of death before 1 year (p < 0.05). The SORG nomogram, SORG classic, original Tokuhashi, and original Bauer demonstrated fair performance (0.7 < area under the curve < 0.8). The NESMS differentiates survival among the prognostic categories with the highest accuracy (area under the curve > 0.8).

CONCLUSIONS

The present study shows that the most cited and commonly used scoring systems have a fair performance predicting survival for patients undergoing spine surgery for metastatic RCC. The NESMS had the best performance at predicting 1-year survival after surgery.

Clinical Features and Prognostic Outcome of Renal Collecting Duct Carcinoma: 12 Cases from a Single Institution

Purpose

Collecting duct carcinoma (CDC) is extremely rare and has high malignancy and poor prognosis. The purpose of this research is to explore the clinical characteristic, imaging, pathological diagnosis, treatment and prognostic outcome of CDCs.

Materials and Methods

The clinical data of 12 CDC cases who had been surgically treated between August 2007 and August 2017 and verified the diagnosis of CDC by postoperative pathological and/or immunohistochemical staining (IHC) results were retrospectively analyzed, and related works of literature were reviewed. And Kaplan-Meier survival analysis was used to draw the survival curve and to calculate the survival rate and the median survival time.

Results

According to the TNM stage system, 4 cases were in stage I, 2 in stage II,3 in stage III, and 3 in stage IV. On the computed tomograph and magnetic resonance imaging, CDC displayed that various shapes, unclear boundary and invasive growth into the renal parenchyma. Compared with small CDCs which did not change the contour of the kidney, large CDCs presented various imaging features. Microscopically, the typical morphology of CDCs was that collecting ducts or tubules were obviously infiltrated by tumor cells. A tubular, papillary, tubulopapillary or solid architectures with desmoplasia were often presented. And tumor cells had high-grade cytology or an infiltrative growth pattern. Necrosis of tumor cells also was common in many cases. The expression of biomarkers, such as PAX-8, INI-1, 34βE12, CK19, PAX-2, and vimentin, in most patients was detected by IHC. Eleven of all 12 cases received radical surgery, of whom 5 patients died 3–11 months after surgery, and 1 case having undergone interventional embolization therapy died at 6 months after treatment due to multiple metastases. And 1 lost to contact. The overall 1-, 2-, and 5-year survival rates were 45.5%, 36.4%, and 8.8%, respectively, and the median survival time (MST) was 11 months.

Conclusion

CDC has an aggressive clinical course, with a poor prognosis. The best way to treat CDC suspected by imaging examinations is radical surgery which can contribute to confirm the correct histopathological type. And post-operation follow-up is necessary.

Prognostic Significance of Preoperative Inflammatory Biomarkers and Traditional Clinical Parameters in Patients with Spinal Metastasis from Clear Cell Renal Cell Carcinoma: A Retrospective Study of 95 Patients in a Single Center

Purpose

The purpose of this retrospective study was to identify preoperative inflammatory biomarkers and clinical parameters and evaluate their prognostic significance in patients with spinal metastasis from clear cell renal cell carcinoma (CCRCC).

Patients and methods

Correlations of overall survival (OS) with traditional clinical parameters and inflammatory indicators including the neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), lymphocyte–monocyte ratio (LMR), albumin–globulin ratio (AGR), and C-reactive protein to albumin ratio (CRP/Alb ratio) were analyzed in 95 patients with spinal metastasis from CCRCA using the Kaplan–Meier method to identify potential prognostic factors. Factors with P values ≤ 0.1 were subjected to multivariate analysis by Cox regression analysis. P values ≤ 0.05 were considered statistically significant.

Results

The 95 patients included in this study were followed up by a mean of 48.8 months (median 51 months; range 6–132 months), during which 21 patients died, with a death rate of 22.1%. The statistical results indicated that patients with total piecemeal spondylectomy (TPS), targeted therapy, NLR < 3.8 and PLR < 206.9 had a significantly longer OS rate.

Conclusion

TPS and targeted therapy could significantly prolong the OS of patients with spinal metastasis from CCRCC. In addition, NLR and PLR are robust and convenient prognostic indicators that have a discriminatory ability superior to other inflammatory biomarkers.

Collecting ducts carcinoma: An orphan disease. Literature overview and future perspectives

Collecting ducts carcinoma (CDC) is a rare and aggressive histological subtype of renal cancer accounting for only 1% of renal tumors. Usually patients present in bad clinical conditions due to a symptomatic disease with synchronous metastasis. Due to the rarity of CDC, data from prospective trials evaluating the best treatment for these patients are limited. The prognosis is poor with a median overall survival of around 11 months for patients with metastatic disease. The best treatment option today is considered a doublet chemotherapy with platinum salt plus gemcitabine as a result from a prospective phase II trial, but survival outcomes remain unsatisfactory. The interest in the in-depth understanding the biology of this orphan disease is growing, leading to find potential new biological-driven treatment approaches. Here we review the up-to-date literature evidences to address the best management of this rare and unfavorable clinical condition.

Cutaneous metastases of papillary renal cell carcinoma: A case report and review of the literature

Papillary renal cell carcinoma (RCC) is an uncommon subtype of RCC that is typically encountered at early stages and has a high survival rate. Histopathology typically shows well-defined papillary architecture with tumor cells lining fibrovascular cores and can be further subdivided into type 1 and type 2 tumors based on cytology and genetic basis. Type 1 tumors have a single layer of basophilic cells and low nuclear atypia, while type 2 tumors have a pseudostratified layer of eosinophilic cells and high nuclear atypia. Some tumors have overlapping features of both types. We present a unique case of cutaneous metastases of papillary RCC with typical papillary architecture in the dermis and review the literature on this rare entity.

Update on Indications for Percutaneous Renal Mass Biopsy in the Era of Advanced CT and MRI

OBJECTIVE. The objective of this article is to review the burgeoning role of percutaneous renal mass biopsy (RMB). CONCLUSION. Percutaneous RMB is safe, accurate, and indicated for an expanded list of clinical scenarios. The chief scenarios among them are to prevent treatment of benign masses and help select patients for active surveillance (AS). Imaging characterization of renal masses has improved; however, management decisions often depend on a histologic diagnosis and an assessment of biologic behavior of renal cancers, both of which are currently best achieved with RMB.

Microphthalmia family of transcription factors associated renal cell carcinoma

The microphthalmia (MiT) subfamily of transcription factors includes TFE3, TFEB, TFEC, and MITF. In the 2016 World Health Organization classification, MiT family translocation renal cell carcinoma (tRCC) including Xp11 tRCC and t(6;11) RCC, was newly defined as an RCC subtype. Xp11 and t(6;11) RCC are characterized by the rearrangement of the MiT transcription factors TFE3 and TFEB, respectively. Recent studies identified the fusion partner-dependent clinicopathological and immunohistochemical features in TFE3-rearranged RCC. Furthermore, RCC with TFEB amplification, melanotic MiT family translocation neoplasms, was identified may as a unique subtype of MiT family associated renal neoplasms, along with MITF associated RCC. In this review, we will collect available literature of these newly-described RCCs, analyze their clinicopathological and immunohistochemical features, and summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of these rare subtypes of RCCs, and eventually promote clinical management strategies.

Renal Medullary Carcinoma

Renal medullary carcinoma, also referred to as the seventh sickle cell nephropathy, typically affects young African Americans with sickle cell trait, or, less frequently, patients with sickle cell disease. The existence of renal medullary carcinoma without a concomitant hemoglobinopathy is a topic of controversy. The typical patient is a young male of African or Mediterranean descent, with hematuria and/or flank pain. Most patients have metastatic disease at the time of presentation. The tumor is characteristically a poorly circumscribed mass in the medullary region, commonly showing variable amounts of hemorrhage and necrosis. Microscopically, a characteristic reticular or cribriform pattern with a striking desmoplastic stromal response and a robust mixed inflammatory infiltrate is observed. Collecting duct carcinoma, malignant rhabdoid tumor, urothelial carcinoma, and other subtypes of renal cell carcinoma are in the differential diagnosis. Because of the advanced stage of disease at presentation and the aggressive nature of this malignant neoplasm, survival is poor even with chemotherapy; however, isolated reports of prolonged survival have been documented.

Somatic mutations in renal cell carcinomas from Chinese patients revealed by whole exome sequencing

Background

While the somatic mutation profiles of renal cell carcinoma (RCC) have been revealed by several studies worldwide, the overwhelming majority of those were not derived from Chinese patients. The landscape of somatic alterations in RCC from Chinese patients still needs to be elucidated to determine whether discrepancies exist between Chinese patients and sufferers from other countries and regions.

Methods

We collected specimens from 26 Chinese patients with primary RCC, including 15 clear cell renal cell carcinoma (ccRCC) samples, 5 papillary renal cell carcinoma (PRCC) samples and 6 chromophobe renal cell carcinoma (ChRCC) samples. Genomic DNAs were isolated from paired tumor-normal tissues and subjected to whole exome sequencing (WES). Immunohistochemistry analysis was performed to detect the programmed death ligand 1 (PD-L1) expression in tumor tissues.

Results

A total of 1920 nonsynonymous somatic variants in exons and 86 mutations at splice junctions were revealed. The tumor mutation burden of ccRCC was significantly higher than that of ChRCC (P < 0.05). For both ccRCC and PRCC, the most frequent substitution in somatic missense mutations was T:A > A:T, which was different from that recorded in the COSMIC database. Among eight significantly mutated genes in ccRCC in the TCGA database, six genes were verified in our study including VHL (67%), BAP1 (13%), SETD2 (13%), PBRM1 (7%), PTEN (7%) and MTOR (7%). All the mutations detected in those genes had not been reported in ccRCC before, except for alterations in VHL and PBRM1. Regarding the frequently mutated genes in PRCC in our study, DEPDC4 (p.E293A, p.T279A), PNLIP (p.N401Y, p.F342L) and SARDH (p.H554Q, p.M1T) were newly detected gene mutations predicted to be deleterious. As the most recurrently mutated gene in ChRCC in the TCGA dataset, TP53 (p.R81Q) was somatically altered only in one ChRCC case in this study. The HIF-1 signaling pathway was the most affected pathway in ccRCC, while the PI3K-Akt signaling pathway was altered in all of the three RCC types. Membranous PD-L1 expression was positive in tumor cells from 6/26 (23%) RCC specimens. The PD-L1-positive rate was higher in RCC samples with the somatically mutated genes CSPG4, DNAH11, INADL and TMPRSS13 than in specimens without those (P < 0.05).

Conclusions

Using WES, we identified somatic mutations in 26 Chinese patients with RCC, which enriched the racial diversity of the somatic mutation profiles of RCC subjects, and revealed a few discrepancies in molecular characterizations between our study and published datasets. We also identified numerous newly detected somatic mutations, which further supplements the somatic mutation landscape of RCC. Moreover, 4 somatically mutated genes, including CSPG4, DNAH11, INADL and TMPRSS13, might be promising predictive factors of PD-L1-positive expression in RCC tumor cells.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0661-5) contains supplementary material, which is available to authorized users.

CASC2: An emerging tumour-suppressing long noncoding RNA in human cancers and melanoma

Deregulation of long noncoding RNAs (lncRNAs) has been implicated in tumourigenesis. Cancer Susceptibility Candidate 2 (CASC2) is a lncRNA downregulated in multiple cancer types, including endometrial, lung, gastric and colorectal cancers. CASC2 functions as a tumour-suppressive lncRNA though multiple mechanisms, such as sequestration of oncogenic microRNAs and repression of Wnt/β-catenin signalling. Pertinent to clinical practice, the use of CASC2 as a prognostic marker has been demonstrated in sporadic studies. These findings suggested that CASC2 might play an important role in human cancers and melanoma. More efforts are warranted to examine the function role of CASC2 in other cancer types. Further validation is also needed to promote its development to be a clinically utilizable prognostic biomarker.

The Challenges of Renal Cell Carcinoma Metastatic to the Spine: A Systematic Review of Survival and Treatment

STUDY DESIGN

Systematic review.

OBJECTIVES

The objective of this systematic review was to answer 2 key questions: (1) What is the clinical presentation and probability of symptomatic improvement following treatment for patients with renal cell carcinoma (RCC) of the spine? (2) What is the overall survival of patients diagnosed with spinal metastases from RCC?

METHODS

A literature review was performed to identify articles that reported on survival, clinical outcomes, and/or prognostic factors in the RCC population with spinal metastases from 1986 to 2016.

RESULTS

Forty-eight articles (807 patients) were included. The Fuhrman Nuclear Grade has been significantly associated with survival in previous studies but was underpowered in the current study. The Memorial Sloan-Kettering Cancer Center Score (MSKCC/Motzer) was also underpowered in the current study. From the time of spinal metastasis, the mean and median survival for patients with previously diagnosed primary RCC was 8.75 and 11.7 months, respectively, whereas synchronously diagnosed patients (primary RCC and spinal metastasis) had a mean and median survival of 6.75 and 11 months, respectively. Patients with a "low" (0-8), "intermediate" (9-11), or "high" (12-15) revised Tokuhashi score at initial presentation had a median survival of 5.4, 11.7, and 32.9 months, respectively.

CONCLUSION

Patients with either a synchronous or latent diagnosis of RCC survived greater than 6 months from the time of presentation. Initial Furhman grade, Tokuhashi score, and MSKCC/Motzer can be useful tools in informing patient-specific prognosis for those with metastatic RCC of the spine.

Novel imaging in renal cell carcinoma

PURPOSE OF REVIEW

Renal cell carcinoma is a heterogeneous disease with a spectrum of subtypes and clinical behavior. Quantitative and qualitative imaging biomarkers are sought to correlate with genetic and histologic features and complement pathologic analysis.

RECENT FINDINGS

Texture analysis, radiogenomics, and modality-specific advancements have yielded an array of renal cell carcinoma imaging biomarkers in the research domain. Although many techniques are promising, standardization and validation of these procedures are needed prior to implementation into clinical practice.

SUMMARY

We introduce novel imaging techniques and analytic methods which have been shown to contribute to characterization of renal cell carcinoma and its subtypes, aggressiveness, and responsiveness to therapy, including associated advantages and limitations.

Beta-1,4-galactosyltransferase II predicts poor prognosis of patients with non-metastatic clear-cell renal cell carcinoma

Beta-1,4-galactosyltransferase II is found to be associated with the alterations of tumor-related glycosylation. However, the clinical significance of beta-1,4-galactosyltransferase II in non-metastatic clear-cell renal cell carcinoma has not been reported up to now. Herein, our researches suggested that the expression level of beta-1,4-galactosyltransferase II was first found to be positively associated with tumor size, Fuhrman grade, lymphovascular invasion, rhabdoid differentiation, tumor necrosis and poor overall survival and recurrence-free survival of patients with non-metastatic clear-cell renal cell carcinoma, both in training set and validation set. Moreover, beta-1,4-galactosyltransferase II expression was identified as an independent adverse prognosticator for overall survival and recurrence-free survival of patients with non-metastatic clear-cell renal cell carcinoma. Ultimately, prognostic accuracy of the nomogram integrating beta-1,4-galactosyltransferase II with other independent prognostic parameters was dramatically improved for overall survival and recurrence-free survival of patients with non-metastatic clear-cell renal cell carcinoma. Taken together, beta-1,4-galactosyltransferase II is a potential independent adverse prognostic factor for postoperative recurrence and survival, which could be developed as a useful biomarker for non-metastatic clear-cell renal cell carcinoma by a series of further independent and retrospective studies, so as to help the postsurgical management of clear-cell renal cell carcinoma patients.

Intracrine androgen biosynthesis in renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is one of the most lethal genitourinary cancers. The presence of androgen receptor (AR) in RCC has recently been shown to be associated with higher tumour stage irrespective of gender. Because the clinical context of androgens in female RCC patients is similar to that of prostate cancer patients undergoing androgen-deprivation therapy, mechanisms underlying the emergence of castration-resistant prostate cancer (CRPC) may be at play in AR-positive RCC cells. Therefore, we hypothesized that AR-positive RCC has intratumoral steroidogenesis and that anti-androgen therapy may result in tumour suppression.

METHODS

Mice were injected with an AR-positive RCC cell line. When tumours became palpable, surgical castration was performed and tumour volume was measured. Using ELISA, the levels of intracellular testosterone and dihydrotesterone were measured in AR-positive human RCC cell lines. Lastly, male mice containing xenografts were treated with enzalutamide or abiraterone acetate (AA) for 3 weeks to measure tumour volume.

RESULTS

We first observed in vivo that castration retards the growth of AR-positive RCC tumour xenograft in mice. Next, AR-positive human RCC cell lines and tissues were found to have elevated levels of testosterone and dihydrotestosterone and express key enzymes required for intracellular androgen biosynthesis. A mouse xenograft study with AR-positive RCC cell line using the commonly used anti-androgen therapies showed significant tumour suppression (P<0.01).

CONCLUSIONS

Intracrine androgen biosynthesis is a potential source of androgen in AR-positive RCC and that the androgen signaling axis is a potential target of intervention in RCC.

Clinicopathologic and Molecular Pathology of Collecting Duct Carcinoma and Related Renal Cell Carcinomas

Collecting duct carcinoma (CDC) and related tumors [ie, renal medullary carcinoma (RMC)] are rare types of highly aggressive renal cell carcinomas (RCC) with poor prognosis. Because of the rarity and diagnostic uncertainty of them, their molecular pathology and significance have not yet been fully elucidated. CDC, RMC, fumarate hydratase-deficient RCC (including hereditary leiomyomatosis and RCC-associated RCC HLRCC-RCC), and recently reported anaplastic lymphoma kinase (ALK)-rearrangement RCC have significant morphologic overlaps, but they are separately distinct entities having different molecular pathway and clinical settings. CDC is more likely to occur in middle to old age population with immunoreactivity for PAX8 and integrase interactor-1 proteins (INI-1). Various chromosomal and genomic alterations have been reported with inconsistent results. In contrast, RMC is more likely to occur in younger patients with sickle cell trait. In RMC, loss of INI-1 expression and OCT3/4 expression are distinguished compared with other RCCs. Finally, ALK-rearrangement RCC seems to have 2 different clinical settings, one with sickle cell trait (VCL-ALK fusion) and the other without (other fusions such as TPM3-ALK, EML4-ALK, and STRN-ALK fusions). Interestingly, VCL-ALK fusion was found in pediatric patients with sickle cell trait, whereas other fusions were detected in adolescent or adult without sickle cell trait. Taken together, CDC and related tumors such as RMC, fumarate hydratase-deficient RCC (including hereditary leiomyomatosis and RCC-associated RCC), and ALK-rearrangement RCC are the distinct entities and their recognition is important for the development of future personalized therapeutic options. This review updates the clinicopathologic features of these tumors with overlapping morphology and outcome.

Correlating Preoperative Imaging with Histologic Subtypes of Renal Cell Carcinoma and Common Mimickers

Renal cell carcinoma (RCC) consists of distinct subtypes that have unique pathologic and imaging features as well as specific cytogenetic and molecular characteristics. As the prognosis and therapeutic strategies may differ for each subtype, correlation of the preoperative imaging with the pathologic findings is of great clinical relevance. In addition, differentiation of RCC from benign entities is ideal in order to prevent overtreatment. However, a noninvasive diagnosis with imaging alone is not always straightforward due to the overlapping appearance of RCC with benign lesions such as fat-poor angiomyolipoma and oncocytoma. With new imaging modalities, there have been significant improvements in correlating preoperative imaging with pathologic characteristics. These new discoveries are able to aid in a more specific, noninvasive, diagnosis that in turn helps direct patient management.

The spectrum of renal cell carcinoma in adults

The spectrum of renal cell carcinoma (RCC) includes many neoplasms with distinct cytogenetics, biologic behaviors, and imaging appearances. The advent of molecular therapies targeting different tumor types, new insights into the relative roles of biopsy and surveillance for small incidental tumors, and a growing array of nephron-sparing interventions have altered management of RCC. Similarly, the role of the radiologist is changing, and it is becoming increasingly important for radiologists to familiarize themselves with the various types of RCC. This article introduces the reader to the common and uncommon recognized types of renal cell carcinoma and discusses how these neoplasms differ in imaging appearance and behavior.