Subset Of Renal Cell Carcinoma Research Articles

TFE3 -rearranged Head and Neck Neoplasms : Twenty-two Cases Spanning the Morphologic Continuum Between Alveolar Soft Part Sarcoma and PEComa and Highlighting Genotypic Diversity.

TFE3 rearrangements characterize histogenetically, topographically, and biologically diverse neoplasms. Besides being a universal defining feature in alveolar soft part sarcoma (ASPS) and clear cell stromal tumor of the lung, TFE3 fusions have been reported in subsets of renal cell carcinoma, perivascular epithelioid cell tumor (PEComa), epithelioid hemangioendothelioma and ossifying fibromyxoid tumors. TFE3 -related neoplasms are rare in the head and neck and may pose diagnostic challenges. We herein describe 22 TFE3 fusion neoplasms affecting 11 males and 11 females aged 4 to 79 years (median, 25) and involving different head and neck sites: sinonasal cavities (n = 8), tongue (n = 4), oral cavity/oropharynx (n = 3), salivary glands (n = 2), orbit (n = 2), and soft tissue or unspecified sites (n = 3). Based on morphology and myomelanocytic immunophenotype, 10 tumors qualified as ASPS, 7 as PEComas (3 melanotic; all sinonasal), and 5 showed intermediate (indeterminate) histology overlapping with ASPS and PEComa. Immunohistochemistry for TFE3 was homogeneously strongly positive in all cases. Targeted RNA sequencing/FISH testing confirmed TFE3 fusions in 14 of 16 successfully tested cases (88%). ASPSCR1 was the most frequent fusion partner in ASPS (4 of 5 cases); one ASPS had a rare VCP::TFE3 fusion. The 6 successfully tested PEComas had known fusion partners as reported in renal cell carcinoma and PEComas ( NONO, PRCC, SFPQ , and PSPC1 ). The indeterminate tumors harbored ASPSCR1::TFE3 (n = 2) and U2AF2::TFE3 (n = 1) fusions, respectively. This large series devoted to TFE3-positive head and neck tumors illustrates the recently proposed morphologic overlap in the spectrum of TFE3 -associated mesenchymal neoplasms. While all PEComas were sinonasal, ASPS was never sinonasal and occurred in diverse head and neck sites with a predilection for the tongue. The indeterminate (PEComa-like) category is molecularly more akin to ASPS but shows different age, sex, and anatomic distribution compared with classic ASPS. We report VCP as a novel fusion partner in ASPS and PSPC1 as a novel TFE3 fusion partner in PEComa (detected in one PEComa). Future studies should shed light on the most appropriate terminological subtyping of these highly overlapping tumors.

ASPSCR1::TFE3-mediated upregulation of insulin receptor substrate 2 (IRS-2) activates PI3K/AKT signaling and promotes malignant phenotype

The ASPSCR1::TFE3 fusion gene, resulting from chromosomal translocation, is detected in alveolar soft part sarcoma (ASPS) and a subset of renal cell carcinomas (RCC). The ASPSCR1::TFE3 oncoprotein, functioning as an aberrant transcription factor, contributes to tumor development and progression by inappropriately upregulating target genes. Here, we identified insulin receptor substrate 2 (IRS-2), a cytoplasmic adaptor protein, as a novel transcriptional target of ASPSCR1::TFE3. Ectopic expression of ASPSCR1::TFE3 led to increased IRS-2 mRNA and protein levels. Chromatin immunoprecipitation and luciferase assays demonstrated that ASPSCR1::TFE3 bound to the IRS-2 promoter region and enhanced its transcription. Moreover, IRS-2 was highly expressed in the ASPSCR1::TFE3-positive RCC cell line FU-UR1, while small interfering RNA-mediated depletion of ASPSCR1::TFE3 markedly decreased IRS-2 mRNA and protein levels. Functionally, IRS-2 knockdown attenuated activation of the PI3K/AKT pathway and reduced proliferation, migration, invasion, adhesion, and clonogenicity in FU-UR1 cells. Pharmacological inhibition of IRS-2 also reduced AKT activation as well as cell viability, clonogenicity, migration, invasion, and adhesion. These findings suggest that IRS-2, regulated by ASPSCR1::TFE3, promotes tumor progression by activating PI3K/AKT signaling and enhancing the malignant phenotype.

Alteration of Cadherin 3 Expression and DNA Methylation in Association with Aggressive Renal Cell Carcinoma.

Cadherins (calcium-dependent adhesion proteins) are important in cellular adhesion and may play a role in the development and progression of renal cell carcinoma (RCC). This study investigated changes in cadherin 3 (CDH3; P-cadherin) mRNA expression, DNA methylation, and protein expression in RCC and compared the results with the histopathological and clinical characteristics of patients. The possible contribution of CDH3 to tumor cell invasiveness was tested in a functional assay using siRNA-based suppression of CDH3 expression and subsequent real-time impedance analysis using a Matrigel invasion model. Our analyses revealed a tumor-specific loss of CDH3 mRNA expression, CDH3 DNA hypermethylation, and loss of distal tubular and collecting duct CDH3 protein expression in RCC. A relatively higher methylation level in tumors was associated with a loss of cell differentiation and higher clinical stage. siRNA-induced suppression of CDH3 expression modulated the invasion characteristics of tumor cells in the impedance-based real-time cellular analysis. Our results indicate that loss of CDH3 expression is common in RCC and may contribute to the pathogenesis of a subset of RCC. Further studies to reveal the mechanisms of loss of expression and its effects on the invasive behavior of renal tumor cells are required.

Pathogenic Germline Mutational Landscape in Patients With Renal Cell Carcinoma and Associated Clinicopathologic Features.

A subset of renal cell carcinoma (RCC) cases occur because of a hereditary predisposition. However, the prevalence and profiling of germline alterations in RCC have not been fully characterized. Additionally, clinicopathologic factors associated with pathogenic or likely pathogenic (P/LP) germline variants in patients with RCC remain poorly understood. A retrospective analysis of patients with RCC who underwent genetic evaluation was performed. The frequency of P/LP germline variants and genes was evaluated in this cohort. The association between genetic testing outcomes and clinicopathologic features was also assessed. A total of 321 patients with RCC who had germline testing were identified. Within this cohort, 42 patients (13.1%) had P/LP variants. Genes with the most frequent germline mutations were FLCN (n = 10, 3.1%), SDHB (n = 4, 1.2%), VHL (n = 4, 1.2%), MLH1 (n = 3, 0.9%), and CHEK2 (n = 4, 1.2%). Among patients with P/LP variants, 19 (45.2%) had a potentially targetable mutation. The presence of bilateral or multifocal tumors was associated with P/LP variants (P = .0012 and P = .0098, respectively). Patients who had targeted gene testing had higher rates of P/LP variants compared with multigene panel testing (P = .015). Age and family history of cancers (RCC and non-RCC) did not have any statistically significant association with germline testing outcomes. Among patients with RCC, unselected for a known familial predisposition, 13.4% had P/LP variants. Almost half of patients with P/LP variants had a potentially targetable mutation. Targeted gene panel testing is a feasible option for patients, particularly if syndromic features are present. Age and family history were not associated with P/LP variants. Future studies are needed to optimize current genetic evaluation criteria to expand the detection of patients with RCC who may have germline mutations.

Predicting Oncologic Outcomes in Small Renal Tumors

BackgroundMost patients diagnosed with renal cancer today present with small renal masses (SRMs). Although these patients have a low risk of dying from their disease and many are followed with active surveillance protocols, a small subset of renal cell carcinomas (RCCs) behave aggressively. Knowledge regarding features of aggressive behavior would enable better adoption of active surveillance strategies among these patients. ObjectiveWe sought to improve prognostic models to predict metastasis-free survival after nephrectomy through focused analyses of clinicopathologic characteristics of SRMs associated with adverse outcomes. Design, setting, and participantsWe identified consecutive patients with surgically resected SRMs (≤4 cm) at the University of Texas Southwestern Kidney Cancer Program between 1998 and 2020. In addition, we evaluated the ability of SRMs to form tumors when implanted in mice, an indicator of tumor aggressiveness. Outcome measurements and statistical analysisWe examined the clinicopathologic factors associated with metastasis including prospectively performed BAP1 immunohistochemistry at our Clinical Laboratory Improvement Amendments laboratory. Multivariable Cox proportional hazard regression was used to predict metastasis-free survival. Results and limitationsA total of 3900 evaluable nephrectomies (from 3674 ethnically diverse patients) were identified, of which 1984 (51%) were SRMs including 1720 RCC. Of these patients with RCC (SRMRCC), 1576 did not have synchronous or metachronous larger RCCs and among these, 37 (2%) developed metastases. SRMRCC that metastasized were significantly enriched for aggressive morphologic phenotypes and engrafted in mice at comparable rates as larger metastatic tumors. BAP1 loss remained significantly associated with metastasis-free survival after accounting for TNM (tumor-node-metastasis) stage and SSIGN (stage, size, grade, and necrosis) score in multivariable analysis. ConclusionsWe identified clinicopathologic features that influence metastasis-free survival for patients with SRMRCC. If validated independently, these data should assist with patient prognosis and help with active surveillance strategies. Patient summaryWe report the identification of features of aggressiveness in small renal tumors that influence the likelihood of metastases after surgery.

Transcription factor EB controls both motogenic and mitogenic cell activities.

Transcription factor EB (TFEB) belongs to the microphthalmia family of bHLH-leucine zipper transcription factors and was first identified as an oncogene in a subset of renal cell carcinomas. In addition to exhibiting oncogenic activity, TFEB coordinates genetic programs connected with the cellular response to stress conditions, including roles in lysosome biogenesis, autophagy, and modulation of metabolism. As is the case for other transcription factors, the activities of TFEB are not limited to a specific cellular condition such as the response to stress, and recent findings indicate that TFEB has more widespread functions. Here, we review the emerging roles of TFEB in regulating cellular proliferation and motility. The well-established and emerging roles of TFEB suggest that this protein serves as a hub of signaling networks involved in many non-communicable diseases, such as cancer, ischaemic diseases and immune disorders, drug resistance mechanisms, and tissue generation.

PD59-05 COST EFFECTIVENESS OF ADJUVANT PEMBROLIZUMAB AFTER NEPHRECTOMY FOR RCC: INSIGHTS FOR PATIENT SELECTION FROM A MARKOV MODEL

You have accessJournal of UrologyCME1 May 2022PD59-05 COST EFFECTIVENESS OF ADJUVANT PEMBROLIZUMAB AFTER NEPHRECTOMY FOR RCC: INSIGHTS FOR PATIENT SELECTION FROM A MARKOV MODEL Vidit Sharma, Kevin M. Wymer, Daniel D. Joyce, James Moriarty, Bijan J. Borah, R. Houston Thompson, Brian A. Costello, Bradley C. Leibovich, and Stephen A. Boorjian Vidit SharmaVidit Sharma More articles by this author , Kevin M. WymerKevin M. Wymer More articles by this author , Daniel D. JoyceDaniel D. Joyce More articles by this author , James MoriartyJames Moriarty More articles by this author , Bijan J. BorahBijan J. Borah More articles by this author , R. Houston ThompsonR. Houston Thompson More articles by this author , Brian A. CostelloBrian A. Costello More articles by this author , Bradley C. LeibovichBradley C. Leibovich More articles by this author , and Stephen A. BoorjianStephen A. Boorjian More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002644.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: KEYNOTE-564 found that adjuvant pembrolizumab after nephrectomy for high-risk clear cell renal cell carcinoma (RCC) decreased the risk of disease progression and overall mortality–albeit with immature follow-up (2 years). Herein, we used a Markov-model to consider the costs, toxicities, and efficacy of pembrolizumab and investigate its utility at a population level. METHODS: A decision-analytic Markov Model was used to conduct a cost-utility analysis of adjuvant pembrolizumab versus placebo after nephrectomy for high-risk clear cell RCC, using data from KEYNOTE-564 to inform model probabilities. Utility values were extracted from the literature. Base-case analyses were conducted with 5-year and 15-year time horizons (using extrapolations from 2-year outcomes). Primary outcomes were Quality-adjusted life years (QALYs), 2021 US Medicare costs, and Incremental cost-effectiveness ratios (ICERs) evaluated with a willingness-to-pay threshold of $100,000/QALY. One-way sensitivity analyses and probabilistic sensitivity analyses with 100,000 Monte-Carlo simulations were performed on model conclusions. RESULTS: Pembrolizumab had higher QALYs and costs relative to placebo (Table). Pembrolizumab was not cost-effective at a 5-year time horizon but did become cost-effective at 15 years. On one-way sensitivity analysis, pembrolizumab became cost-effective at 5-years if: 1) its cost was less than $5,064 (base = $10,278) or 2) if the 5-year risk of progression was 18.8% higher in placebo vs pembrolizumab (base = 9%). Using pembrolizumab’s reported hazard ratio of 0.68 for progression from KEYNOTE-564, we estimated that pembrolizumab would be cost-effective at 5-years for all patients with a Mayo Progression Free Survival Score of 10 or higher. Probabilistic sensitivity analysis found that pembrolizumab was cost-effective for 29% and 58% of microsimulations at 5 and 15 years, respectively. CONCLUSIONS: At current prices, adjuvant pembrolizumab was not cost-effective for all trial patients at a population level at 5-years after treatment, though it did emerge to be cost-effective at 15 years. At 5-years, adjuvant pembrolizumab was found to be cost-effective only for the highest risk subsets of RCC. Longer term trial data of progression-free survival and overall survival are necessary to confirm these extrapolations. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e1020 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Vidit Sharma More articles by this author Kevin M. Wymer More articles by this author Daniel D. Joyce More articles by this author James Moriarty More articles by this author Bijan J. Borah More articles by this author R. Houston Thompson More articles by this author Brian A. Costello More articles by this author Bradley C. Leibovich More articles by this author Stephen A. Boorjian More articles by this author Expand All Advertisement PDF DownloadLoading ...

Cost effectiveness of adjuvant pembrolizumab after nephrectomy for RCC: Insights for patient selection from a Markov model.

321 Background: KEYNOTE-564 demonstrated that adjuvant pembrolizumab after nephrectomy for high-risk clear cell renal cell carcinoma (RCC) decreased the risk of disease progression and – albeit with immature follow-up (2 years) – found a signal of improved overall survival as well. Herein, we used extrapolations from a Markov-model, accounting for the costs and toxicities of pembrolizumab relative to its efficacy, to investigate its utility at a population level. Methods: A decision-analytic Markov Model was used to conduct a cost-utility analysis of adjuvant pembrolizumab versus placebo after nephrectomy for high risk RCC, using data from KEYNOTE-564 to inform model probabilities. Transition probabilities not found in KEYNOTE-564, in addition to utility values, were extracted from the literature. Base case analyses were conducted with 5-year and 15-year time horizons (using extrapolations from 2-year outcomes), and 3-week time cycles. Primary outcomes were Quality-adjusted life years (QALYs), 2021 US Medicare costs, and Incremental cost-effectiveness ratios (ICERs). The willingness-to-pay threshold was set at $100,000/QALY. One-way sensitivity analyses were used to identify cost-effectiveness thresholds of individual parameters while probabilistic sensitivity analyses with 100,000 Monte-Carlo simulations were used to simultaneously vary all model inputs. Results: Pembrolizumab was associated with higher QALYs and costs relative to placebo (Table). Pembrolizumab was not cost-effective at a 5-year time horizon but was cost-effective at 15 years and beyond. One-way sensitivity analysis noted that pembrolizumab became cost-effective at 5-years if: 1) its administration cost was less than $5,064 (base = $10,278) or 2) if the 5-year risk of progression was 18.8% higher in placebo vs pembrolizumab (base = 9%). Using pembrolizumab’s reported hazard ratio of 0.68 for progression from KEYNOTE-564, we estimated that pembrolizumab would be cost-effective at 5-years for all patients with a Mayo Progression Free Survival Score of 10 or higher. Probabilistic sensitivity analysis found that pembrolizumab was cost-effective for 29% and 58% of microsimulations at 5 and 15 years, respectively. Conclusions: At current prices, adjuvant pembrolizumab was not cost-effective for all trial patients at a population level at 5-years after treatment but may be cost-effective for time horizons over 15 years. Instead, adjuvant pembrolizumab was found to be cost-effective only for the highest risk subsets of RCC at 5-years. Longer term trial data of progression-free survival and overall survival are necessary to confirm these extrapolations.[Table: see text]

Single nucleotide variants of succinate dehydrogenase A gene in renal cell carcinoma.

Succinate dehydrogenase (SDH)‐deficient renal cell carcinoma (RCC) is mainly associated with a mutation in the SDHB gene and sometimes with mutations in the SDHC or SDHD genes. However, only three cases of succinate dehydrogenase A (SDHA)‐deficient RCC have been reported, and the relation between SDHA mutations and RCC has not been clarified. This study assessed the role of SDHA gene mutations in human RCC. We investigated SDHA/B/C/D gene mutations in 129 human RCCs. Targeted next‐generation sequencing and direct Sanger sequencing revealed single nucleotide variants (SNVs) of the SDHA gene with amino acid sequence variations in 11/129 tumors, while no SDHB/C/D gene mutations were found. Tumor cells with SNVs of the SDHA gene were characterized by eosinophilic cytoplasm and various patterns of proliferation. Immunohistochemistry examination found that the 11 tumors with SNVs of the SDHA gene showed significant reduction of SDHA protein and SDHB protein expression compared to the 19 tumors without SDHA or SDHB mutations (both P < .0001). Western blotting showed a greater decrease in the expression of SDHA and SDHB proteins in the 11 tumors with SNVs of the SDHA gene than in the 19 tumors without (both P < .0001). There was a positive correlation between SDHA and SDHB protein levels (P < .0001). On immunohistochemistry and Western blotting, the 11 tumors with SNVs of the SDHA gene had higher protein expression for nuclear factor E2‐related factor 2 (Nrf2) compared to the 19 tumors without the mutation (P < .01). These observations suggest that SDHA gene mutations might be associated with a subset of RCC.

Mechanistic Target of Rapamycin Inhibitors in Renal Cell Carcinoma: Potential, Limitations, and Perspectives.

Several elements highlight the importance of the mechanistic target of rapamycin (mTOR) in the biology of renal cell carcinoma (RCC). mTOR signaling pathway is indeed frequently activated in RCC, inducing cancer cell proliferation and survival. In addition, mTOR promotes tumor angiogenesis and regulates the expression of hypoxia-inducible factors that play an important role in a subset of RCC. Despite mTOR protumorigenic effects, mTOR inhibitors have failed to provide long-lasting anticancer benefits in RCC patients, highlighting the need to readdress their role in the treatment of RCC. This review aims to present the rationale and limitations of targeting mTOR in RCC. Future roles of mTOR inhibitors in the treatment of RCC are also discussed, in particular in the context of immunotherapies.

TFE3 Xp11.2 Translocation Renal Cell Carcinoma Mouse Model Reveals Novel Therapeutic Targets and Identifies GPNMB as a Diagnostic Marker for Human Disease.

Renal cell carcinoma (RCC) associated with Xp11.2 translocation (TFE3-RCC) has been recently defined as a distinct subset of RCC classified by characteristic morphology and clinical presentation. The Xp11 translocations involve the TFE3 transcription factor and produce chimeric TFE3 proteins retaining the basic helix-loop-helix leucine zipper structure for dimerization and DNA binding suggesting that chimeric TFE3 proteins function as oncogenic transcription factors. Diagnostic biomarkers and effective forms of therapy for advanced cases of TFE3-RCC are as yet unavailable. To facilitate the development of molecular based diagnostic tools and targeted therapies for this aggressive kidney cancer, we generated a translocation RCC mouse model, in which the PRCC-TFE3 transgene is expressed specifically in kidneys leading to the development of RCC with characteristic histology. Expression of the receptor tyrosine kinase Ret was elevated in the kidneys of the TFE3-RCC mice, and treatment with RET inhibitor, vandetanib, significantly suppressed RCC growth. Moreover, we found that Gpnmb (Glycoprotein nonmetastatic B) expression was notably elevated in the TFE3-RCC mouse kidneys as seen in human TFE3-RCC tumors, and confirmed that GPNMB is the direct transcriptional target of TFE3 fusions. While GPNMB IHC staining was positive in 9/9 cases of TFE3-RCC, Cathepsin K, a conventional marker for TFE3-RCC, was positive in only 67% of cases. These data support RET as a potential target and GPNMB as a diagnostic marker for TFE3-RCC. The TFE3-RCC mouse provides a preclinical in vivo model for the development of new biomarkers and targeted therapeutics for patients affected with this aggressive form of RCC. IMPLICATIONS: Key findings from studies with this preclinical mouse model of TFE3-RCC underscore the potential for RET as a therapeutic target for treatment of patients with TFE3-RCC, and suggest that GPNMB may serve as diagnostic biomarker for TFE3 fusion RCC.

Abstract 3417: Genomic analyses of clear cell papillary kidney cancers reveal large metabolic alterations and activation of the hypoxia pathway

Abstract Tumors arising from the nephron of the kidney are collectively called renal cell carcinomas (RCCs). Recent high-throughput genomics endeavors, such as the TCGA initiative, have provided a roadmap for a deepened molecular understanding of these tumor types. With the aim to characterize RCCs that do not conform to the most common subtypes of RCC we scrutinized RNA-Seq transcriptomes of kidney tumor samples supplied by the TCGA project. Dimensionality reduction analyses revealed one defined a transcriptional subset of RCCs, which upon re-review of tissue histology could be classified as clear cell papillary RCC (ccpRCC). In line with previous analyses, samples were defined by overexpression of KRT7, CA9, CCND1 and GATA3 and harbored few genomic alterations as well as a limited number of gene mutations; only mTOR was found recurrently mutated. We observed upregulation of the Hypoxia inducible factor (HIF) pathway, possibly caused by VHLinactivation by gene promoter methylation in the majority of ccpRCCs. This may explain the morphological resemblance of ccpRCCs to VHL driven conventional clear cell RCCs. Further, the methylomes of ccpRCCs were distinct from other tumors and transcription factors specific for epithelial cells of the distal nephron were overexpressed, thus suggesting distinct tumor ontogeny of ccpRCCs compared to other renal tumors. Citation Format: David Lindgren, Jonas Sjolund, Helen Nilsson, Borje Ljungberg, Martin Johansson, Hakan Axelson. Genomic analyses of clear cell papillary kidney cancers reveal large metabolic alterations and activation of the hypoxia pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3417.

Exceptional responders to abexinostat (ABX) plus pazopanib (PAZ) in pretreated renal cell carcinoma (RCC) and other solid tumors: Long-term follow-up of a phase 1b study.

3022 Background: We previously reported the initial phase 1b study results of PAZ + ABX, a potent pan-HDAC inhibitor, demonstrating acceptable toxicity profile and encouraging anti-tumor activity (Aggarwal et al. JCO 2017). We report the long-term follow up of exceptional responders and additional correlative analyses associated with clinical outcomes. Methods: Key efficacy endpoints included objective response rate and duration of response. Peripheral blood histone acetylation, HDAC expression, and plasma VEGF levels were analyzed and associated with clinical outcomes. Results: 51 pts (RCC subset; N = 22) were enrolled between June 2012 and October 2015. 10 pts (20%) had experienced disease progression on prior PAZ; 59% had received any prior VEGF-targeting therapy. 9 evaluable pts (18%) (N = 6 RCC; 2 thyroid; 1 mesothelioma) achieved partial tumor response (PR), of which 6 had prior progression on VEGF-targeting therapy. 7/10 (70%) of pts with prior disease progression on PAZ monotherapy had reduction in tumor burden on study. The median duration of response was 9.1 months (range 1.2 to 70+), and clinical benefit rate (PR or stable disease &gt; 6 months) was 33%. Five treatment-refractory pts achieved durable PRs lasting for &gt; 2 years duration, and one previously PAZ-refractory patient with RCC remains on treatment with ongoing PR for &gt; 6 years. Higher HDAC2 expression was associated with prolonged progression-free survival (median PFS 5.9 vs. 3.5 months, log-rank p = 0.02). Induction of histone acetylation on ABX lead-in treatment was associated with subsequent time to progression (p = 0.002). On-treatment plasma VEGF levels were inversely correlated with PBMC histone acetylation (p = 0.02). Conclusions: Markedly durable responses with PAZ + ABX are achievable, including in pts with PAZ- and VEGF-refractory RCC and other solid tumor malignancies. Host factors including HDAC expression and acetylation status may identify those most likely to benefit. A randomized phase 3 study is underway of PAZ + ABX as a first- or second-line therapy in pts with locally advanced or metastatic RCC (RENAVIV; NCT03592472). Clinical trial information: NCT01543763.

TFEB-VEGFA (6p21.1) co-amplified renal cell carcinoma: a distinct entity with potential implications for clinical management.

A subset of renal cell carcinomas shows TFEB overexpression secondary to MALAT1-TFEB gene fusion. As alternate mechanisms of TFEB overexpression are likely to have the same effect, we sought to determine the frequency of amplification of TFEB and the adjacent VEGFA gene at 6p21.1. As patients with metastatic renal cell carcinomas are managed with anti-VEGF therapies, we retrospectively assessed therapeutic response in patients with amplified tumors. Amplification status was analyzed for 875 renal cell carcinomas from our institution, a consultative case and 794 cases from The Cancer Genome Atlas. Cases were classified as having low level (5-10 copies), and high-level amplification (>10 copies), and were further analyzed for adjacent oncogene copy number status (n=6; 3 single-nucleotide polymorphism genomic microarray, 3 The Cancer Genome Atlas) and structural rearrangements (n=1; mate-pair sequencing). These were then reviewed for histopathology, immunophenotype, and response to VEGF-targeted therapy on follow-up. In all, 10/875 (1.1%) institutional cases, 1 consultative case, and 3/794 (0.4%) of The Cancer Genome Atlas cases showed TFEB high-level amplification, while 14/875 (1.6%) cases showed TFEB low-level amplification. All cases had associated VEGFA amplification. This was confirmed with evaluation for copy number changes (n=6). The 6p21.1 high and low-level amplified tumors occurred in adults (mean age: 66), with over half being ≥pT3 (13/25, 52%), and most showed oncocytic, tubulopapillary features and high grade (≥grade 3: 20/22, 91%). These were aggressive tumors with metastasis and death from renal cell carcinoma in 11 (of 24, 46%) cases. Four patients received targeted therapy and had a mean survival of 31 months (range: 17-50) post nephrectomy. In summary, a group of aggressive renal cell carcinomas show genomic amplification of the 6p21.1 region including TFEB and VEGFA genes and share morphologic features. Additional studies are warranted to determine whether these patients respond to anti-VEGF therapy.

Renal Cell Carcinoma Occurring in Patients With Prior Neuroblastoma: A Heterogenous Group of Neoplasms.

Renal cell carcinoma (RCC) associated with neuroblastoma (NB) was included as a distinct entity in the 2004 World Health Organization classification of kidney tumors. A spectrum of RCC subtypes has been reported in NB survivors. We herein describe a series of 8 RCCs diagnosed in 7 patients with a history of NB. Microscopic evaluation, immunohistochemical staining for PAX8, cathepsin K, and succinate dehydrogenase subunit B (SDHB), and fluorescence in situ hybridization (FISH) for TFE3 and TFEB were performed. Four distinct morphologic subtypes were identified: 3 tumors were characterized by cells with abundant oncocytoid cytoplasm and irregular nuclei; 3 showed features of microphthalmia transcription factor family translocation RCC (MiTF-RCC); 1 had features of hybrid oncocytic-chromophobe tumor; 1 had papillary RCC histology. All RCCs expressed PAX8 and retained SDHB expression. Cathepsin K was positive in 2 MiTF-RCCs, 1 was TFEB FISH positive, and the other was indeterminate. Cathepsin K was negative in a third MiTF-RCC with TFE3 rearrangement. TFE3 FISH was negative in 4 and insufficient in 1 of the other 5 RCCs. While a subset of RCCs associated with NB is characterized by cells with prominent oncocytoid cytoplasm, other RCC subtypes also occur in post-NB patients. Renal neoplasms occurring in patients with a history of NB do not represent a single entity but a heterogenous group of RCCs. SDHB mutations do not explain the subset of nontranslocation RCCs with oncocytoid features; therefore, further studies are needed to clarify whether they may represent a distinct entity with unique molecular abnormalities or may belong to other emerging RCC subtypes.

Clinical evaluation of microRNA-145 expression in renal cell carcinoma: a promising molecular marker for discriminating and staging the clear cell histological subtype.

The vast majority of malignancies detected in renal parenchyma are diagnosed as renal cell carcinoma (RCC), whose subtype discrimination and determination of prognosis may contribute to the selection of the adequate therapy. Recently, a new class of small non-coding RNAs, known as microRNAs, has proven to be among the most promising biomarkers for providing this information. Herein, we sought to add up to this knowledge by evaluating the expression levels of microRNA-145 (miR-145) in RCC. For that purpose, total RNA from 58 cancerous and 44 adjacent non-cancerous renal tissues was firstly extracted and then polyadenylated and reverse transcribed to cDNA. MiR-145 levels were finally analyzed by developing and applying a highly sensitive real-time PCR protocol, while their clinical significance was determined via comprehensive statistical analysis. Our data showed that miR-145 was significantly downregulated in cancerous samples and could discriminate between clear cell and non-clear cell subtypes. Moreover, miR-145 expression was found to be correlated with primary tumor staging of cancerous samples, something also noticed in the clear cell RCC subset, in which miR-145 levels were negatively correlated with tumor size as well. Overall, these results indicate that miR-145 might constitute a promising molecular marker for RCC classification and staging.

Eosinophilic, Solid, and Cystic Renal Cell Carcinoma: Clinicopathologic Study of 16 Unique, Sporadic Neoplasms Occurring in Women.

A unique renal neoplasm characterized by eosinophilic cytoplasm and solid and cystic growth was recently reported in patients with tuberous sclerosis complex (TSC). We searched multiple institutional archives and consult files in an attempt to identify a sporadic counterpart. We identified 16 morphologically identical cases, all in women, without clinical features of TSC. The median age was 57 years (range, 31 to 75 y). Macroscopically, tumors were tan and had a solid and macrocystic (12) or only solid appearance (4). Average tumor size was 50 mm (median, 38.5 mm; range, 15 to 135 mm). Microscopically, the tumors showed solid areas admixed with variably sized macrocysts and microcysts that were lined by cells with a pronounced hobnail arrangement. The cells had voluminous eosinophilic cytoplasm with prominent granular cytoplasmic stippling and round to oval nuclei with prominent nucleoli. Scattered histiocytes and lymphocytes were invariably present. Thirteen of 16 patients were stage pT1; 2 were pT2, and 1 was pT3a. The cells demonstrated a distinct immunoprofile: nuclear PAX8 expression, predominant CK20-positive/CK7-negative phenotype, patchy AMACR staining, but no CD117 reactivity. Thirteen of 14 patients with follow-up were alive and without disease progression after 2 to 138 months (mean: 53 mo; median: 37.5 mo); 1 patient died of other causes. Although similar to a subset of renal cell carcinomas (RCCs) seen in TSC, we propose that sporadic "eosinophilic, solid, and cystic RCC," which occurs predominantly in female individuals and is characterized by distinct morphologic features, predominant CK20-positive/CK7-negative immunophenotype, and indolent behavior, represents a novel subtype of RCC.

Highlights of This Issue

An analysis by Sowalsky and colleagues of metastatic castration-resistant prostate cancer (mCRPC) specimens using paired-end RNA-seq identified a series of likely driver mutations, genomic fusions, and lncRNAs. The authors also found an unexpectedly high level of sequence reads mapping to introns, the result of inefficient splicing at canonical splice junctions, which were more abundant in the mCRPC samples than in normal prostate or primary prostate cancer. Inefficient splicing in advanced prostate cancer may provide a selective advantage through effects on microRNA networks, but it may also render tumors vulnerable to agents that target steps in RNA splicing.Lukin and colleagues show that in response to transient treatment with DNA damaging agents, wild-type p53 cells reversibly arrest and repair the damage. In contrast, p53-null cells undergo cell death, suggesting that acute treatments can exploit differences between wild-type and p53-null cells. Although p53 status has been implicated as a clinical predictor of chemotherapeutic efficacy, studies have not always aligned. These data support the use of transient treatment paradigms to exploit the reversibility of the p53-dependent checkpoint and justify the use of p53 status in clinical decision making. The molecular basis for this appears to involve the temporal regulation of p53-dependent gene expression.ATM loss-of-function has been described in hematologic malignancies such as mantle cell lymphoma (MCL). Given the importance of ATM to genome integrity, small-molecule ATR inhibitors may have therapeutic utility in MCL. Here, a focused siRNA screen by Menezes and colleagues not only confirmed ATM but also identified additional replication checkpoint proteins that are synthetically lethal with ATR inhibition. In both in vitro and in vivo models, ATR inhibition enhanced efficacy in ATM loss-of-function compared with wild-type MCL cells. These data indicate that ATR inhibitors, as a monotherapy, have therapeutic potential and that ATR utilizes a complex set of proteins to maintain genomic stability that could be further exploited.Sarcomatoid tumors are a rare and aggressive histologic subset of renal cell carcinoma (RCC), and one that is generally refractory to current treatments. Little is known about the molecular biology of this disease; therefore, Pal and colleagues performed RNA-seq on metastatic RCC (mRCC) patient samples. Importantly, follow-up analysis of a large cohort revealed changes in cell proliferation pathways, including altered expression of Aurora kinase (AURKA) and mTOR signaling. These results not only warrant further preclinical workup and analysis of a larger clinical cohort but also suggest that combined or individual therapeutic targeting of AURKA and mTOR in patients with sarcomatoid mRCC should be explored.

Evaluation of EGFR, KRAS and BRAF gene mutations in renal cell carcinoma.

A subset of renal cell carcinoma (RCC) patients has been shown to respond to anti-EGFR therapy. As KRAS and BRAF mutations are associated with poor response to anti-EGFR therapy in some cancers, it has been suggested that screening for KRAS and BRAF mutations in RCC may be a promising strategy to identify patients who might respond to EGFR-targeted therapy. The aim of this study was to investigate the mutation status of EGFR, KRAS and BRAF in RCC patients. Renal tumors and normal renal samples from forty-eight patients who underwent radical or partial nephrectomy for kidney cancer were used in this study. Histological classification of the tumors was performed according to International Union against Cancer (UICC) / American Joint Committee on Cancer (AJCC) classification. Seventeen patients (48%) had clear-cell RCC, 7 (20%) had chromophobe RCC, and 11 patients (32%) had papillary RCC. DNA isolated from the samples was subjected to melting curve mutation analysis for EGFR, BRAF and KRAS using ABI-3130 DNA sequencer. DNA sequencing analysis of RCC samples, when compared with morphologically normal matched regions, did not show any exon mutations. Our results do not support the notion that EGFR, KRAS and BRAF might be mutated in RCC.

NY-ESO-1 as a potential immunotherapeutic target in renal cell carcinoma.

Novel immune therapies targeting tumor specific antigens are being developed. Our purpose was to determine expression of the cancer testes antigen NY-ESO-1 in renal cell carcinoma (RCC), as NY-ESO-1 targeting approaches, particularly adoptive cell therapy, have not been evaluated in this disease. We employed tissue microarrays containing >300 unique RCC cases and adjacent benign renal tissue to determine NY-ESO-1 expression using a quantitative immunofluorescence method. In addition, we studied NY-ESO-1 expression in 35 matched primary and metastatic RCC specimens to assess concordance between different tumor sites. NY-ESO-1 was highly expressed in a subset of RCCs. Expression in primary RCC specimens was significantly higher than adjacent normal renal tissue (P<0.0001) and higher in clear cell carcinomas than papillary RCC (P<0.0001). Expression levels in metastatic specimens were higher than in matched primary samples (P=0.0018), and the correlation between the two sites was modest (χ2=3.5, p=0.06). Aberrant NY-ESO-1 expression seen in clear cell RCC suggests that NY-ESO-1 targeting approaches should be studied in this disease. Expression is higher in metastatic sites, and discordance between primary and metastatic sites in some patients suggests that patient selection for these therapies should be based on expression in metastatic rather than nephrectomy specimens.