Renal Cell Carcinoma Subtypes Research Articles

An epidemiological and clinicopathological study of type 1 vs. type 2 morphological subtypes of papillary renal cell carcinoma– results from a nation-wide study covering 50 years in Iceland

IntroductionPapillary renal cell carcinoma (pRCC) is the second most common histology of renal cell carcinoma (RCC), accounting for 10–15% of cases. Traditionally, pRCC is divided into type 1 and type 2, although this division is currently debated as a prognostic factor of survival. Our aim was to investigate the epidemiology and survival of the pRCC subtypes in a whole nation cohort of patients during a 50-year period.Materials and methodsA Population based retrospective study including consecutive cases of RCC in Iceland from 1971–2020. Comparisons were made between histological classifications of RCC, with emphasis on pRCC subtypes (type 1 vs. 2) for outcome estimation. Changes in RCC incidence were analyzed in 5-year intervals after age standardization. The Kaplan–Meier method and Cox regression were used for outcome analysis.ResultsA total of 1.725 cases were identified, with 74.4%, 2.1% and 9.2% having clear cell (ccRCC), chromophobe (chRCC), and pRCC, respectively. The age standardized incidence (ASI) of pRCC was 1.97/100.000 for males and 0.5/100.000 for females, and the proportion of pRCC increased from 3.7% to 11.5% between the first and last intervals of the study (p < 0.001). Age standardized cancer specific mortality (ASCSM) of pRCC was 0.6/100.000 and 0.19/100.000 for males and females, respectively. The annual average increase in ASI was 3.6% for type 1 pRCC, but the ASI for type 2 pRCC and ASCSM for both subtypes did not change significantly. Male to female ratio was 4.4 for type 1 pRCC and 2.3 for type 2. The average tumor size for type 1 and 2 was 58.8 and 73.7 mm, respectively. Metastasis at diagnosis was found in 8.7% in the type 1 pRCC, compared to 30.0% of patients with type 2 pRCC (p < 0.001). Estimated 5-year cancer-specific survival (CSS) were 94.4%, 80.7%, and 69.3% for chRCC, pRCC and ccRCC, respectively (p < 0.001). For the pRCC subtypes, type 1 was associated with better 5-year CSS than type 2 (86.3% vs. 66.0%, p < 0.001), although this difference was not significant after adjusting for cancer stage and grading.ConclusionspRCC histology was slightly less common in Iceland than in other countries. Males are more than three times more likely to be diagnosed with pRCC, compared to other RCC histologies. The subtype of pRCC was not found to be an independent risk factor for worse survival, and as suggested by the most recent WHO Classification of Urinary Tumors, grade and TNM-stage seem to be the most important factors for estimation of survival for pRCC patients.

A rare case of TFEB/6p21/VEGFA-amplified renal cell carcinoma diagnosed by whole-exome sequencing: clinicopathological and genetic feature report and literature review

BackgroundTFEB/6p21/VEGFA-amplified renal cell carcinoma (RCC) is rare and difficult to diagnose, with diverse histological patterns and immunohistochemical and poorly defined molecular genetic characteristics.Case presentationWe report a case of a 63-year-old male admitted in 2017 with complex histomorphology, three morphological features of clear cell, eosinophilic and papillary RCC and resembling areas of glomerular and tubular formation. The immunophenotype also showed a mixture of CD10 and P504s. RCC with a high suspicion of collision tumors was indicated according to the 2014 WHO classification system; no precise diagnosis was possible. The patient was diagnosed at a different hospital with poorly differentiated lung squamous cell carcinoma one year after RCC surgery. We exploited molecular technology advances to retrospectively investigate the patient’s molecular genetic alterations by whole-exome sequencing. The results revealed a 6p21 amplification in VEGFA and TFEB gene acquisition absent in other RCC subtypes. Clear cell, papillary, chromophobe, TFE3-translocation, eosinophilic solid and cystic RCC were excluded. Strong TFEB and Melan-A protein positivity prompted rediagnosis as TFEB/6p21/VEGFA-amplified RCC as per 2022 WHO classification. TMB-L (low tumor mutational load), CCND3 gene acquisition and MRE11A and ATM gene deletion mutations indicated sensitivity to PD-1/PD-L1 inhibitor combinations and the FDA-approved targeted agents Niraparib (Grade C), Olaparib (Grade C), Rucaparib (Grade C) and Talazoparib (Class C). GO (Gene Ontology) and KEGG enrichment analyses revealed major mutations and abnormal CNVs in genes involved in biological processes such as the TGF-β, Hippo, E-cadherin, lysosomal biogenesis and autophagy signaling pathways, biofilm synthesis cell adhesion substance metabolism regulation and others. We compared TFEB/6p21/VEGFA-amplified with TFEB-translocated RCC; significant differences in disease onset age, histological patterns, pathological stages, clinical prognoses, and genetic characteristics were revealed.ConclusionWe clarified the patient’s challenging diagnosis and discussed the clinicopathology, immunophenotype, differential diagnosis, and molecular genetic information regarding TFEB/6p21/VEGFA-amplified RCC via exome analysis and a literature review.

A pediatric and young adult case of unclassified renal cell carcinoma with medullary phenotype (RCCU-MP): Clinical course and treatment

Renal cell carcinoma (RCC) is the most common kidney tumor in adults. RCC is rare in children, although its incidence increases in the second decade of life. Renal medullary carcinoma (RMC) is a rare and often aggressive RCC subtype characterized by complete loss of SMARCB1/INI1, predominantly diagnosed in patients with sickle cell disease or -trait. Here, we describe a pediatric and a young adult patient with clinicopathological characteristics similar to RMC but without hemoglobinopathies. These tumors are currently classified as “RCC unclassified with medullary phenotype” (RCCU-MP). Both our patients had an infiltrating, rather small kidney tumor with SMARCB1/INI1 deficiency. Remarkably, the aggressiveness and clinical course and treatment differed greatly between these two cases. So far, only nine patients, predominantly adults, have been reported. In a literature overview, most cases were metastatic and progressed or relapsed after varying treatment approaches, with low survival. Whereas the classification of these tumors remains a topic of debate, case reports add to the current knowledge of RMCs without hemoglobinopathies, stressing the importance of sharing experience concerning rare renal neoplasms with often poor outcomes, also concerning younger age categories.

The role of natural products versus miRNA in renal cell carcinoma: implications for disease mechanisms and diagnostic markers.

Natural products are chemical compounds produced by living organisms. They are isolated and purified to determine their function and can potentially be used as therapeutic agents. The ability of some bioactive natural products to modify the course of cancer is fascinating and promising. In the past 50years, there have been advancements in cancer therapy that have increased survival rates for localized tumors. However, there has been little progress in treating advanced renal cell carcinoma (RCC), which is resistant to radiation and chemotherapy. Oncogenes and tumor suppressors are two roles played by microRNAs (miRNAs). They are involved in important pathogenetic mechanisms like hypoxia and epithelial-mesenchymal transition (EMT); they control apoptosis, cell growth, migration, invasion, angiogenesis, and proliferation through target proteins involved in various signaling pathways. Depending on their expression pattern, miRNAs may identify certain subtypes of RCC or distinguish tumor tissue from healthy renal tissue. As diagnostic biomarkers of RCC, circulating miRNAs show promise. There is a correlation between the expression patterns of several miRNAs and the prognosis and diagnosis of patients with RCC. Potentially high-risk primary tumors may be identified by comparing original tumor tissue with metastases. Variations in miRNA expression between treatment-sensitive and therapy-resistant patients' tissues and serum allow for the estimation of responsiveness to target therapy. Our knowledge of miRNAs' function in RCC etiology has a tremendous uptick. Finding and validating their gene targets could have an immediate effect on creating anticancer treatments based on miRNAs. Several miRNAs have the potential to be used as biomarkers for diagnosis and prognosis. This review provides an in-depth analysis of the current knowledge regarding natural compounds and their modes of action in combating cancer. Also, this study aims to give information about the diagnostic and prognostic value of miRNAs as cancer biomarkers and their involvement in the pathogenesis of RCC.

Can 18F FDG PET/CT metabolic parameters be used to noninvasively differentiate between different histopathological subtypes and Fuhrman grades of renal cell cancer?

To evaluate relationship between metabolic PET metabolic parameters and size of the primary tumor, various histopathological subtypes of renal cell carcinoma (RCC) and Fuhrman grade of the tumors. Retrospective analysis of 93 biopsy-proven RCC patients who underwent pretreatment flourine 18 flourodeoxyglucose PET/computed tomography (18F FDG PET/CT) was performed. Quantitative PET parameters, size of the primary tumor, histopathological subtypes and Fuhrman grades of the tumor were extracted. We tried to assess if there was any significant difference in the metabolic patterns of various histopathological subtypes of RCCs, Fuhrman grade of the tumors and size of the primary tumor. A significant correlation was noted between the size of primary tumor and maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) (P < 0.01, P < 0.001 and P < 0.001, respectively). SUVmax values correlated significantly with the histopathological subtype (P < 0.001). Further sub-analyses was also done by segregating the patients into Low grade (Fuhrman grade 1 and 2) vs. High grade (Fuhrman grade 3 and 4). SUVmax, MTV and TLG were significantly different between high grade vs. low grade tumors. ROC analysis yielded cut off values for SUVmax, MTV and TLG to differentiate between high grade from low grade tumors. FDG PET/CT with the use of metabolic PET parameters can differentiate between different histopathological subtypes of RCC. Incorporation of metabolic parameters into clinical practice can potentially noninvasively identify patients with low-grade vs. high-grade RCC.

Collecting duct (Bellini duct) renal cell carcinoma: a clinical case and literature review

A rare subtype of renal cell carcinoma (RCC) is Bellini collecting duct carcinoma, also known as medullary renal carcinoma or distal nephron carcinoma, which accounts for 0.4-2.0% of all RCC cases. This subtype has the poorest prognosis of all RCC subtypes, typically presenting as a low-grade tumor at the pT3 or higher stage. Consequently, many patients have distant metastases at diagnosis and 60% develop metastases following radical treatment. There have been approximately 400 literature-reported cases of Bellini ductal carcinoma to date. We present a case report of a patient with early-stage Bellini duct cancer and a literature review of published reports on this condition.

A Review of the Paradigmatic Role of Adipose Tissue in Renal Cancer: Fat Measurement and Tumor Behavior Features.

(1) Background: Renal-cell carcinoma (RCC) incidence has been steadily rising, with obesity identified as a potential risk factor. However, the relationship between obesity and RCC prognosis remains unclear. This systematic review aims to investigate the impact of different adipose tissue measurements on RCC behavior and prognosis. (2) Methods: A search of MEDLINE databases identified 20 eligible studies focusing on various fat measurements, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), perirenal adipose tissue (PRAT), and the Mayo adhesive probability (MAP) score. (3) Results: The review revealed conflicting findings regarding the association between adipose tissue measurements and RCC outcomes. While some studies suggested a protective role of certain fat deposits, particularly VAT, against disease progression and mortality, others reported contradictory results across different adipose metrics and RCC subtypes. (4) Conclusions: Methodological variations and limitations, such as retrospective designs and sample size constraints, pose challenges to standardization and generalizability. Further research is needed to understand these associations better and establish standardized approaches for adiposity assessment in RCC patients, which could inform clinical practice and therapeutic decision-making.

Collecting Duct Carcinoma in the Kidneys: A Rare Case Report

Background: Collecting duct carcinoma (CDC) is one of the rare pathological subtypes of renal cell carcinoma, with high malignancy and poor prognosis. Pathological examination is the gold standard in confirming the diagnosis of CDC. CDC is described as a tumor that has a tubulopapillary architecture and forms a hobnail pattern along the glandular tube. Case presentation: A 56-year-old woman with the main complaint of a lump in the right abdomen for 1.5 months before entering the hospital. The lump in the stomach is getting bigger, complaints are accompanied by intermittent pain, nausea, vomiting, body feeling weak, and decreased appetite. The patient then underwent a CT-Scan examination of the abdomen and concluded that fluid/water was found next to the right kidney, and a hypodense lesion appeared in segment 6 of the right lobe of the liver. Histopathological examination of large tissue shows pieces of kidney tissue with a connective tissue capsule on the outside containing glomeruli and tubules lined by cuboidal epithelium as well as a proliferation of tumor cells that grow infiltratively in the connective tissue stroma which is partly desmoplastic and fatty tissue between the glomeruli and tubules. Tumor cells are arranged to form tubulopapillary and tubulocystic structures. These cells with pleomorphic nuclei, some hyperchromatic, some vesicular, coarse chromatin, clear nuclei, and atypical mitoses can be found and tumor cell embolism in the blood vessels and perineural invasion can be seen. There were spots and clusters of lymphocytes and plasma cells as well as areas of bleeding and necrosis. Conclusion: The patient was diagnosed with collecting duct carcinoma (CDC).

Von Hippel Lindau tumor suppressor controls m6A-dependent gene expression in renal tumorigenesis.

N6-Methyladenosine (m6A) is the most abundant posttranscriptional modification, and its contribution to cancer evolution has recently been appreciated. Renal cancer is the most common adult genitourinary cancer, approximately 85% of which is accounted for by the clear cell renal cell carcinoma (ccRCC) subtype characterized by VHL loss. However, it is unclear whether VHL loss in ccRCC affects m6A patterns. In this study, we demonstrate that VHL binds and promotes METTL3/METTL14 complex formation while VHL depletion suppresses m6A modification, which is distinctive from its canonical E3 ligase role. m6A RNA immunoprecipitation sequencing (RIP-Seq) coupled with RNA-Seq allows us to identify a selection of genes whose expression may be regulated by VHL-m6A signaling. Specifically, PIK3R3 is identified to be a critical gene whose mRNA stability is regulated by VHL in a m6A-dependent but HIF-independent manner. Functionally, PIK3R3 depletion promotes renal cancer cell growth and orthotopic tumor growth while its overexpression leads to decreased tumorigenesis. Mechanistically, the VHL-m6A-regulated PIK3R3 suppresses tumor growth by restraining PI3K/AKT activity. Taken together, we propose a mechanism by which VHL regulates m6A through modulation of METTL3/METTL14 complex formation, thereby promoting PIK3R3 mRNA stability and protein levels that are critical for regulating ccRCC tumorigenesis.

Cellular senescence and metabolic reprogramming model based on bulk/single-cell RNA sequencing reveals PTGER4 as a therapeutic target for ccRCC

Clear cell renal cell carcinoma (ccRCC) is the prevailing histological subtype of renal cell carcinoma and has unique metabolic reprogramming during its occurrence and development. Cell senescence is one of the newly identified tumor characteristics. However, there is a dearth of methodical and all-encompassing investigations regarding the correlation between the broad-ranging alterations in metabolic processes associated with aging and ccRCC. We utilized a range of analytical methodologies, such as protein‒protein interaction network analysis and least absolute shrinkage and selection operator (LASSO) regression analysis, to form and validate a risk score model known as the senescence-metabolism-related risk model (SeMRM). Our study demonstrated that SeMRM could more precisely predict the OS of ccRCC patients than the clinical prognostic markers in use. By utilizing two distinct datasets of ccRCC, ICGC-KIRC (the International Cancer Genome Consortium) and GSE29609, as well as a single-cell dataset (GSE156632) and real patient clinical information, and further confirmed the relationship between the senescence-metabolism-related risk score (SeMRS) and ccRCC patient progression. It is worth noting that patients who were classified into different subgroups based on the SeMRS exhibited notable variations in metabolic activity, immune microenvironment, immune cell type transformation, mutant landscape, and drug responsiveness. We also demonstrated that PTGER4, a key gene in SeMRM, regulated ccRCC cell proliferation, lipid levels and the cell cycle in vivo and in vitro. Together, the utilization of SeMRM has the potential to function as a dependable clinical characteristic to increase the accuracy of prognostic assessment for patients diagnosed with ccRCC, thereby facilitating the selection of suitable treatment strategies.

Artificial Intelligence-Based Non-invasive Differentiation of Distinct Histologic Subtypes of Renal Tumors With Multiphasic Multidetector Computed Tomography.

With rising cases of renal cell carcinoma (RCC), precise identification of tumor subtypes is essential, particularly for detecting small, heterogenous lesions often overlooked in traditional histopathological examinations. This study demonstrates the non-invasive use of deep learning for Histopathological differentiation of renal tumors through quadriphasic multidetector computed tomography (MDCT). This prospective longitudinal study includes 50 subjects (32 males, 18 females) with suspected renal tumors. A deep neural network (DNN) is developed to predict RCC subtypes using peak attenuation values measured in Hounsfield Units (HUs) obtained from quadriphasic MDCT scans. The network then generates confidence scores for each of the four primary subtypes of renal tumors, effectively distinguishing between benign oncocytoma and various malignant subtypes. Our neural network accurately distinguishes Renal tumor subtypes, including clear cell, papillary, chromophobe, and benign oncocytoma, with a confidence score of 68% with the network's diagnosis aligning with Histopathological examinations. Our network was also able to accurately classify RCC subtypes on a synthetically generated dataset with 20,000 samples. We developed an artificial intelligence-based RCC subtype classification technique. Our approach is non-invasive and has the potential to transform the methodology in Renal oncology by providing accurate and timely diagnostic information and enhancing clinical decisions.

Boosting Clear Cell Renal Carcinoma-Specific Drug Discovery Using a Deep Learning Algorithm and Single-Cell Analysis.

Clear cell renal carcinoma (ccRCC), the most common subtype of renal cell carcinoma, has the high heterogeneity of a highly complex tumor microenvironment. Existing clinical intervention strategies, such as target therapy and immunotherapy, have failed to achieve good therapeutic effects. In this article, single-cell transcriptome sequencing (scRNA-seq) data from six patients downloaded from the GEO database were adopted to describe the tumor microenvironment (TME) of ccRCC, including its T cells, tumor-associated macrophages (TAMs), endothelial cells (ECs), and cancer-associated fibroblasts (CAFs). Based on the differential typing of the TME, we identified tumor cell-specific regulatory programs that are mediated by three key transcription factors (TFs), whilst the TF EPAS1/HIF-2α was identified via drug virtual screening through our analysis of ccRCC's protein structure. Then, a combined deep graph neural network and machine learning algorithm were used to select anti-ccRCC compounds from bioactive compound libraries, including the FDA-approved drug library, natural product library, and human endogenous metabolite compound library. Finally, five compounds were obtained, including two FDA-approved drugs (flufenamic acid and fludarabine), one endogenous metabolite, one immunology/inflammation-related compound, and one inhibitor of DNA methyltransferase (N4-methylcytidine, a cytosine nucleoside analogue that, like zebularine, has the mechanism of inhibiting DNA methyltransferase). Based on the tumor microenvironment characteristics of ccRCC, five ccRCC-specific compounds were identified, which would give direction of the clinical treatment for ccRCC patients.

The Necroptotic Process-Related Signature Predicts Immune Infiltration and Drug Sensitivity in Kidney Renal Papillary Cell Carcinoma.

It remains controversial whether the current subtypes of kidney renal papillary cell carcinoma (KIRP) can be used to predict the prognosis independently. This observational study aimed to identify a risk signature based on necroptotic pro-cess-related genes (NPRGs) in KIRP. In the training cohort, LASSO regression was applied to construct the risk signature from 158 NPRGs, followed by the analysis of Overall Survival (OS) using the Kaplan-Meier method. The signature accuracy was evaluated by the Receiver Operating Characteristic (ROC) curve, which was further validated by the test cohort. Wilcoxon test was used to compare the expressions of immune-related genes, neoantigen genes, and immune infiltration between differ-ent risk groups, while the correlation test was performed between NPRGs expressions and drug sensitivity. Gene set enrichment analysis was used to investigate the NPRGs' signature's biologi-cal functions. We finally screened out 4-NPRGs (BIRC3, CAMK2B, PYGM, and TRADD) for con-structing the risk signature with the area under the ROC curve (AUC) reaching about 0.8. The risk score could be used as an independent OS predictor. Consistent with the enriched signaling, the NPRGs signature was found to be closely associated with neoantigen, immune cell infiltration, and immune-related functions. Based on NPRGs expressions, we also predicted multiple drugs potentially sensitive or resistant to treatment. The novel 4-NPRGs risk signature can predict the prognosis, immune infiltration, and therapeutic sensitivity of KIRP.

Association of Elevated C-Reactive Protein with Worsened Outcomes in Different Histologies of Renal Cortical Tumors: Analysis of the INMARC Registry

Background: To evaluate relationship between histological subtypes of renal cell carcinoma (RCC) and preoperative c-reactive protein (CRP). Patients and Methods: We queried the International Marker Consortium for Renal Cancer (INMARC) database for patients affected by RCC. Patients were classified according to their histology: benign tumors, clear cell (ccRCC), chromophobe (chRCC), papillary (pRCC), and variant histology RCC (vhRCC); and according to CRP (mg/L): low CRP ≤5 and high CRP >5. Primary outcome was all-cause mortality (ACM). Secondary outcomes were cancer-specific mortality (CSM), recurrence and association between CRP and histology. Multivariable analysis (MVA) via Cox regression and multivariable logistic regression (MLR) were fitted to elucidate predictors of outcomes. Results: 3,902 patients (high CRP n=1,266) were analyzed; median follow up 51 (IQR 20-91) months. On MVA elevated CRP was an independent risk factor associated with increased risk of ACM in benign tumors (HR 5.98, p<0.001), ccRCC (HR 2.69, p<0.001), chRCC (HR 3.99, p<0.001), pRCC (HR 1.76, p=0.009) and vhRCC (HR 2.97, p=0.007). MVA for CSM showed CRP as risk factor in ccRCC (HR 2.77, p<0.001), chRCC (HR 6.16, p=0.003) and pRCC (HR 2.29, p=0.011), while in vhRCC was not (p=0.27). MVA for recurrence reported CRP as risk factor for ccRCC (HR 1.30, p=0.013), while in chRCC (p=0.33), pRCC (p=0.34) and vhRCC (p=0.52) was not. On MLR CRP was a predictor of pRCC (OR 1.003, p=0.002), while decreasing CRP was associated with benign tumors (OR 0.994, p=0.048). Conclusion: Elevated CRP was a robust predictor of worsened ACM in all renal cortical neoplasms. While most frequently observed in pRCC patients, elevated CRP was independently associated with worsened CSM in non vhRCC. Conversely, elevated CRP was least likely to be noted in benign tumors, and elevation in this subgroup of patients should prompt further consideration for surveillance given increased risk of ACM. Further investigation is requisite.

Clinical Characteristics and Outcomes of TFE3-Rearranged/TFEB-Altered Renal Cell Carcinoma with Systemic Therapies, Including Tyrosine Kinase Inhibitors or Immune Checkpoint Inhibitors: An Observational Study

Purpose: &lt;i&gt;TFE3&lt;/i&gt;-rearranged/&lt;i&gt;TFEB&lt;/i&gt;-altered renal cell carcinoma (RCC) is a rare subtype of RCC. Due to its rarity, there is an unmet medical need for effective therapies in advanced settings. The study aims to investigate the clinical and histopathological characteristics of patients with microphthalmia transcription factor family/ transcription factor E (MiTF/TFE) translocation RCC and the clinical outcomes of systemic therapies, including tyrosine kinase inhibitors (TKIs) or immune checkpoint inhibitors (ICIs).Materials and Methods: This was a single-center, retrospective study. We identified 32 eligible patients among a total of 37 patients diagnosed with MiTF/TFE translocation RCC between January 2004 and September 2021, and the study included 9 patients who were treated with systemic therapies. We collected data on clinical characteristics, targeted sequencing, and clinical outcomes.Results: The median age of the 32 patients was 45.5 years. Histologically, 26 patients (81.3%) had &lt;i&gt;TFE3&lt;/i&gt;-rearranged RCC, and only 1 patient (3.1%) had &lt;i&gt;TFEB&lt;/i&gt;-altered RCC. Curative or cytoreductive nephrectomy was performed in all 27 patients (84.4%), and 4 patients (12.6%) were diagnosed with metastatic disease at the time of the initial diagnosis. Nine patients (28.1%) were treated with systemic therapy with TKIs, 2 (6.3%) of whom received simultaneous TKI and ICI treatment. The response to systemic therapy (TKI or ICI) and duration of response ranged from complete response to progressive disease. Excluding 1 patient who was treated with a TKI in the adjuvant setting, the overall response rate in 8 metastatic patients was 50% and the complete response rate was 37.5%. The median follow-up period was 29 months. The median progressionfree survival was 21 months, median overall survival was not achieved, and 2 deaths occurred.Conclusions: Our findings suggest that TKI for treatment for metastatic &lt;i&gt;TFE3&lt;/i&gt;-rearranged RCC is efficacious, with an overall response rate of 50% and a median progression-free survival of 21 months.

Unlocking Precision Medicine: Liquid Biopsy Advancements in Renal Cancer Detection and Monitoring.

Renal cell carcinoma (RCC) remains a formidable diagnostic challenge, especially in the context of small renal masses. The quest for non-invasive screening tools and biomarkers has steered research towards liquid biopsy, focusing on microRNAs (miRNAs), exosomes, and circulating tumor cells (CTCs). MiRNAs, small non-coding RNAs, exhibit notable dysregulation in RCC, offering promising avenues for diagnosis and prognosis. Studies underscore their potential across various biofluids, including plasma, serum, and urine, for RCC detection and subtype characterization. Encouraging miRNA signatures show correlations with overall survival, indicative of their future relevance in RCC management. Exosomes, with their diverse molecular cargo, including miRNAs, emerge as enticing biomarkers, while CTCs, emanating from primary tumors into the bloodstream, provide valuable insights into cancer progression. Despite these advancements, clinical translation necessitates further validation and standardization, encompassing larger-scale studies and robust evidence generation. Currently lacking approved diagnostic assays for renal cancer, the potential future applications of liquid biopsy in follow-up care, treatment selection, and outcome prediction in RCC patients are profound. This review aims to discuss and highlight recent advancements in liquid biopsy for RCC, exploring their strengths and weaknesses in the comprehensive management of this disease.

Cystic Features in Renal Epithelial Neoplasms and Their Increasing Clinical and Pathologic Significance.

Most cystic renal tumors after resection (Boniak IIF to IV cysts) have an indolent course despite the significantly higher proportion of malignant [ie, renal cell carcinoma (RCC)] diagnosis. Most cystic renal tumors have clear cell histology that include cystic clear cell RCC and multilocular cystic renal neoplasm of low malignant potential (MCNLMP). There is growing evidence to suggest that MCNLMP, cystic clear cell RCC, and noncystic clear cell RCC form a cystic-to-solid biological spectrum with MCNLMP representing the most indolent form and with cystic clear cell RCC behaving better than noncystic (solid) clear cell RCC. Extensively (>75%) cystic clear cell RCC also has an excellent outcome similar to MCNLMP stressing the need to reevaluate the histologic criteria that separate these 2 cystic clear cell tumors. Other tumors with clear cells that can be extensively cystic such as the recently reclassified noncancerous clear cell papillary renal tumor and the newly described MED15::TFE3 RCC also have indolent course and may mimic MCNLMP. Cystic features occur also in renal tumors with nonclear cell histology including tumors capable of metastasis such as acquired cystic disease-associated, tubulocystic, fumarate hydratase-deficient, and eosinophilic solid and cystic RCCs. Cystic imaging presentation of some renal tumors such as papillary RCC can be attributed in part to pseudocystic necrosis and hemorrhage. It is important to know that tubulocystic RCC may have a lower Bosniak class presentation that overlaps with benign renal cysts (Bosniak I to IIF) that are managed conservatively. This review highlights the cystic renal tumors with clear cell and nonclear cell morphologies including some novel RCC subtypes that may have cystic features. The presence of cystic features and their extent may aid in the classification and prognostication of renal neoplasms underscoring its increasing importance in the pathologic diagnosis and reporting of renal neoplasia.

Abstract 5670: CRISPR-Mediated knockout of Ceruloplasmin (CP) and UCHL1 reveals angiogenic role in renal cell carcinoma (RCC) cell survival and proliferation

Abstract Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cell carcinoma, accounting for approximately 70% of all cases. Therapeutic treatment for metastatic ccRCC involve tyrosine kinase inhibitors or mTOR inhibiters. While these drugs extend patient survival, it also introduces a range of adverse side effects. Utilizing snRNA sequencing, snATACseq, and spatial transcriptomics, two potential ccRCC tumor specific markers have been identified: ceruloplasmin (CP) and UCHL1. These markers are notably overexpressed in a majority of ccRCC tumor cells and elevated CP levels have been correlated with reduced patient survival. To investigate the roles of CP and UCHL1 in ccRCC, CRISPR-based knockout experiments were conducted on two RCC cell lines, namely RCC4-VHL- and Caki-1. Through cell line characterization assays, we find that the absence of CP and UCHL1 impairs the cells' capabilities to migrate, proliferate, and adhere. Additionally, Cell-Derived Xenografts (CDX) of the knockout cell lines in nude mice revealed that cells lacking UCHL1 exhibited slower tumor growth compared to their parental lines. Bulk RNA sequencing further suggested a potential interrelationship between CP and UCHL1, as CP knockout cells showed increased UCHL1 expression relative to the parental line. These findings open new avenues for potential therapeutic strategies and biomarkers in the treatment and screening of ccRCC and further elevates our understandings of the roles of CP and UCHL1 in RCC tumor progression. Citation Format: Wagma Caravan, Yige Wu, Preet Lal, Kazu Sato, Yize Li, Nataly Naser Al Deen, Siqi Chen, Ateih Abedin, Feng Chen, Li Ding. CRISPR-Mediated knockout of Ceruloplasmin (CP) and UCHL1 reveals angiogenic role in renal cell carcinoma (RCC) cell survival and proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5670.

Abstract 5673: Transposable element expression patterns in epigenetic mutational subtypes of clear cell renal cell carcinoma

Abstract Background: Clear cell renal cell carcinoma (ccRCC) is characterized by mutations in epigenetic modulators and by aberrant transposable element (TE) expression, each of which have been separately associated with immunotherapy (IO) benefit in specific clinical contexts. However, the relationship between mutations in epigenetic regulators and TE expression, and the potential effect of both somatic mutations and TE expression on clinical outcomes, has not been fully investigated. Methods: We utilized RNA sequencing from ccRCC patients’ tumors and cell lines to quantify TE subfamily expression with TEtranscripts (n=123 metastatic IO-treated; CheckMate-009, 010, 025, n=355 all stage TCGA untreated, n=8 CCLE). Locus-specific endogenous retrovirus (ERV) expression was quantified using hervQuant. Differential TE and ERV expression was determined using DESeq2. Samples were stratified by mutations in PBRM1, SETD2, BAP1 and KDM5C, four of the top five mutated genes in ccRCC. Multivariable CoxPH models and the log-rank test were used to compare overall (OS) and progression-free survival (PFS). Two validation metastatic ccRCC cohorts were employed: the everolimus arm of CheckMate-025 (n=78, CM025e) and IMmotion150 (n=146, IM150). Results: Global TE expression (LTR, LINE, SINE and DNA transposons) did not differ significantly across mutational and clinical subtypes. However, 29 of 795 TE subfamilies were differentially expressed in &amp;gt;1 mutational subtype across datasets, and 22 of 29 were ERVs. At locus-specific resolution, 52 of 3173 ERVs were differentially expressed in &amp;gt;1 mutational subtype across datasets. Additionally, 6 of the 52 ERVs nominally associated with PFS, and 4 nominally associated with OS, in the IO cohort. Among them, only ERVs 544 and 2014 associated with improved PFS (multivariable CoxPH p = 0.03 and 0.02, respectively) and were expressed across all datasets. Both ERVs also exhibited increased expression in PBRM1 mutant and decreased expression in BAP1 mutant vs. wildtype samples, in discovery (IO, TCGA, CCLE) and validation (CM025e, IM150) cohorts. Lastly, PBRM1 mutant patients with high ERV 544 or 2014 expression had improved PFS in the IO (log-rank p = 0.04 and 0.03, multivariable CoxPH p = 0.008 and 0.009, respectively, HR = 0.43 both), but not in the CM025e cohort, compared to other patients regardless of PBRM1 mutations. Conclusion: ERVs 544 and 2014 were upregulated in PBRM1 mutant and downregulated in BAP1 mutant samples. Coupled with PBRM1 inactivation, their expression served as a candidate biomarker of improved PFS in IO-treated ccRCC that may have additional biological relevance. Expanded functional and clinicogenomic studies of epigenetic mutational subtype-specific patterns of TE expression, and their relation to selective IO response, may guide additional discovery and therapeutic development strategies in ccRCC. Citation Format: Kevin Meli, Cora A. Ricker, Sabrina Y. Camp, Christof C. Smith, Chris Labaki, Eddy Saad, Hanna Soulati, Brendan Reardon, Jihye Park, Natalie I. Vokes, Benjamin G. Vincent, Toni K. Choueiri, David A. Braun, Eliezer M. Van Allen. Transposable element expression patterns in epigenetic mutational subtypes of clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5673.

Abstract 3500: Refining diagnosis of renal cell carcinoma subtypes through single-cell resolution transcriptomic signatures

Abstract A remaining challenge in the field of renal cell carcinoma (RCC) is diagnosis of rare or mixed subtypes, which hampers the delivery of the most effective healthcare to patients. While a new classification scheme, integrating molecular characteristics of tumors, is emerging, it requires a deep understanding of the tumor heterogeneity and etiopathogenesis of each subtype. We have generated and analyzed single-cell transcriptome profiles of 38 human RCCs and normal kidneys 16 RCCs with diverse histological subtypes and established gene signatures specific to each cell type. We have applied these gene signatures to bulk RNA-sequencing data of 1000 RCC tumors with different histological subtypes and normal kidneys from The Cancer Genome Atlas (TCGA) to characterize different cancer types and cellular origins. Unsupervised clustering analysis of TCGA data shows diagnostic discrepancies for 9.3% cases and subclassifies each major subtype (clear cell, papillary and chromophobe) into clusters with differential clinical outcomes.[KM1]. The pathological marker expression in misdiagnosed tumors is consistent with clustering-based classification, not their original diagnosis. Notably, using unique and subtype-specific gene signature patterns, we identified clear cell papillary renal cell tumor (ccpRCT), which is a newly classified benign entity and the main tumor type representing the mis-diagnosed tumors. These observations have further been confirmed by reviewing histological images of the tumors by an experienced genitourinary pathologist. Interestingly, our gene signatures reveal that ccpRCT does not originate from proximal tubule cells unlike clear cell and papillary RCCs. Taken together, our approach suggests a potential new classification method connected to clinical behaviors and drug responses based on overall transcriptomic differences. Citation Format: Minjun Kim, Ariel Madrigal, Zohreh Mehrjoo, Kate I. Glennon, Madeleine Arseneault, Morag Park, Fadi Brimo, Simon Tanguay, Hamed S. Najafabadi, Yasser Riazalhosseini. Refining diagnosis of renal cell carcinoma subtypes through single-cell resolution transcriptomic signatures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3500.