Chromophobe Renal Cell Carcinoma Research Articles

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.

Comprehensive proteogenomic characterization of rare kidney tumors.

Non-clear cell renal cell carcinomas (non-ccRCCs) encompass diverse malignant and benign tumors. Refinement of differential diagnosis biomarkers, markers for early prognosis of aggressive disease, and therapeutic targets to complement immunotherapy are current clinical needs. Multi-omics analyses of 48 non-ccRCCs compared with 103 ccRCCs reveal proteogenomic, phosphorylation, glycosylation, and metabolic aberrations in RCC subtypes. RCCs with high genome instability display overexpression of IGF2BP3 and PYCR1. Integration of single-cell and bulk transcriptome data predicts diverse cell-of-origin and clarifies RCC subtype-specific proteogenomic signatures. Expression of biomarkers MAPRE3, ADGRF5, and GPNMB differentiates renal oncocytoma from chromophobe RCC, and PIGR and SOSTDC1 distinguish papillary RCC from MTSCC. This study expands our knowledge of proteogenomic signatures, biomarkers, and potential therapeutic targets in non-ccRCC.

Comparison of conventional DWI and intravoxel incoherent motion in differentiating between chromophobe renal cell carcinoma and renal oncocytoma: a preliminary study.

Quantitative comparison of the diagnostic efficacy of conventional diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) in differentiating between chromophobe renal cell carcinoma(ChRCC) from renal oncocytoma(RO). A total of 48 patients with renal tumors who had undergone DWI and IVIM were divided into two groups-ChRCC (n = 28) and RO (n = 20) groups, and the apparent diffusion coefficient (ADC), true diffusivity (D), pseudo-diffusion coefficient (D*), perfusion fraction (f) and their diagnostic efficacy were compared between the two groups. The D* values were higher in the ChRCCs group compared to the RO groups (0.019 ± 0.003mm2/s vs.0.008 ± 0.002 mm2/s, p < 0.05). Moreover, the ADC, D and f values were higher in ROs compared to ChRCCs (0.61 ± 0.08 × 10-3mm2/s vs. 0.51 ± 0.06 × 10-3mm2/s, 1.02 ± 0.15 × 10-3mm2/s vs. 0.86 ± 0.07 × 10-3mm2/s, 0.41 ± 0.05 vs. 0.28 ± 0.02, p < 0.05). The areas of the ADC, D, D* and f values under the ROC curves in differentiating ChRCCs from ROs were 0.713, 0.839, 0.856 and 0.906, respectively. The cut-off values of ADC, D, D* and f were 0.54, 0.91, 0.013 and 0.31, respectively. The AUC, sensitivity, specificity and accuracy of the f values were 0.906, 89.3%, 80.0% and 89.6%, respectively. For pairwise comparisons of ROC curves and diagnostic efficacy, IVIM parameters, ie, D, D*and f offered better diagnostic accuracy than ADC in differentiating ChRCCs from ROs(p = 0.013, 0.016 and 0.008) with f having the highest diagnostic accuracy. IVIM parameters presented better performance than ADC in differentiating ChRCCs from ROs.

Radiomics and machine learning for renal tumor subtype assessment using multiphase computed tomography in a multicenter setting.

To distinguish histological subtypes of renal tumors using radiomic features and machine learning (ML) based on multiphase computed tomography (CT). Patients who underwent surgical treatment for renal tumors at two tertiary centers from 2012 to 2022 were included retrospectively. Preoperative arterial (corticomedullary) and venous (nephrogenic) phase CT scans from these centers, as well as from external imaging facilities, were manually segmented, and standardized radiomic features were extracted. Following preprocessing and addressing the class imbalance, a ML algorithm based on extreme gradient boosting trees (XGB) was employed to predict renal tumor subtypes using 10-fold cross-validation. The evaluation was conducted using the multiclass area under the receiver operating characteristic curve (AUC). Algorithms were trained on data from one center and independently tested on data from the other center. The training cohort comprised n = 297 patients (64.3% clear cell renal cell cancer [RCC], 13.5% papillary renal cell carcinoma (pRCC), 7.4% chromophobe RCC, 9.4% oncocytomas, and 5.4% angiomyolipomas (AML)), and the testing cohort n = 121 patients (56.2%/16.5%/3.3%/21.5%/2.5%). The XGB algorithm demonstrated a diagnostic performance of AUC = 0.81/0.64/0.8 for venous/arterial/combined contrast phase CT in the training cohort, and AUC = 0.75/0.67/0.75 in the independent testing cohort. In pairwise comparisons, the lowest diagnostic accuracy was evident for the identification of oncocytomas (AUC = 0.57-0.69), and the highest for the identification of AMLs (AUC = 0.9-0.94) CONCLUSION: Radiomic feature analyses can distinguish renal tumor subtypes on routinely acquired CTs, with oncocytomas being the hardest subtype to identify. Radiomic feature analyses yield robust results for renal tumor assessment on routine CTs. Although radiologists routinely rely on arterial phase CT for renal tumor assessment and operative planning, radiomic features derived from arterial phase did not improve the accuracy of renal tumor subtype identification in our cohort.

Chromophobe Renal Cell Carcinoma With Extensive Retraction Artifact: A Potential Diagnostic Pitfall From Micropapillary Urothelial Carcinoma.

In addition to "classic" and eosinophilic subtype, chromophobe renal cell carcinoma (RCC) is well-known to demonstrate various morphological patterns including adenomatoid, microcystic, pigmented, multicystic, papillary, neuroendocrine-like, and small cell-like, all of which are important to appreciate for accurate diagnosis. Herein, we expand on a unique chromophobe RCC morphology not previously described consisting of tumor cells with extensive stromal retraction, mimicking upper urothelial tract micropapillary carcinoma (MPC). Twelve MPC-like chromophobe RCC nephrectomies were reviewed with clinicopathological features recorded; molecular testing was performed on 7 of 12 tumors. Patients were mostly men (n=10) with a mean age of 65 years. Mean tumor size was 6.4 cm with pathological stage distribution as follows: 4 (33%) T1a, 2 (17%) T1b, 1 (8%) T2b, and 3 (25%) T3a. The extent of MPC-like chromophobe RCC foci ranged from 10% to 40% (mean=26%; there was no correlation between the extent of MPC-like chromophobe RCC foci and tumor stage). Other chromophobe RCC morphological patterns were not identified. When performed, all (100%) tumors depicted prototypic chromophobe RCC staining pattern of KIT positivity/KRT7 positivity. Molecular showed 6 of 7 (86%) with multiple chromosomal losses. Clinically significant mutations were identified in NF1, TP53, FLCN (likely somatic), CHEK2, and ZFHX3 genes. Follow up available in 9 patients showed no evidence of disease (mean=23 months). Although the etiology behind the extensive stromal retraction in our tumors is unknown, this may likely be artifactual in nature. Nonetheless, it is important to include MPC-like chromophobe RCC in the spectrum of "variant" morphologies to avoid diagnostic pitfalls from micropapillary carcinoma.

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.

Association between PD-L1 Expression and the Prognosis and Clinicopathologic Features of Non-Clear Cell Renal Cell Carcinoma.

PD-L1 is one of the two programmed cell death 1 (PD-1) ligands and a part of an immune checkpoint system (PD-1/PD-L1) with widespread clinical application. The aim of this study was to investigate PD-L1 expression and its association with clinicopathological and prognostic significance in non-clear cell renal cell carcinoma (non-ccRCC) patients. A total of 41 papillary (pRCC) and 20 chromophobe (chRCC) RCC tumors were examined for PD-L1 expression by immunohistochemistry in the cancer cells and tumor-infiltrating mononuclear cells (TIMCs). PD-L1 positivity was detected in 36.6% pRCC and 85.0% chRCC cancer cells, while PD-L1 positivity was observed in 73.2% pRCC and 50.0% chRCC TIMCs. PD-L1 positivity in both pRCC and chRCC tumor cells was not correlated with any of the examined clinicopathological features, while PD-L1 positivity in TIMCs was associated with the age of patients with pRCC. During follow-up, the death was documented among 6 patients with pRCC. Papillary RCC patients with PD-L1-positive tumor cells were significantly associated with an increased risk of death compared with patients with PD-L1-negative cancer cells. A similar trend was observed when comparing PD-L1 expression in TIMCs. However, no differences in overall survival for PD-L1-positive pRCC patients with compared to PD-L1-negative patients were observed in tumor cells or TIMCs.

External validation of a four-tiered grading system for chromophobe renal cell carcinoma

This study aimed to validate the prognostic value of a four-tiered grading system recently proposed by Avulova et al. and to explore the prognostic ability of another four-tiered classification grading system in which there is a separate Grade 3 for tumor necrosis. Grading of chromophobe renal cell carcinoma (ChRCC) by the Fuhrman system is not feasible because of the inherent nuclear atypia in ChRCC. We collected relevant data of 263 patients with ChRCC who had undergone surgery in our hospital from 2008 to 2020. The Kaplan–Meier method was used to calculate the survival rate and Cox proportional hazard regression models to assess associations with cancer-specific survival and distant metastasis-free survival by hazard ratios (HRs) and 95% confidence intervals (CIs). Ten patients died from ChRCC, and 12 developed metastases. The 5 year CSS rates were 95.9%. Grades 2 (HR = 10.9; CI 1.11–106.4; P = 0.04), 3 (HR = 33.6, CI 3.32–339.1; P = 0.003), and 4 (HR = 417.4, CI 35.0–4976.2; P < 0.001) in a four-tiered grading system were significantly associated with CSS in a multivariate setting. However, the difference in CSS between Grades 2 and 3 was not significant (HR = 2.14, 95% CI 0.43–10.63; P = 0.35). The HRs of the associations between an exploratory grading system that includes a separate Grade 3 for tumor necrosis and CSS were as follows: Grade 2, 10.2 (CI 1.06–97.9, P = 0.045); Grade 3, 11.4 (CI 1.18–109.6, P = 0.04); and Grade 4, 267.9 (CI 27.6–2603.3, P < 0.001). Similarly, Grades 2 and 3 did not differ significantly. The four-tiered grading system studied is useful for predicting death from ChRCC and metastasis. However, Grade 3 did not more accurately predict risk of death and metastasis than did Grade 2. This was also true for the novel exploratory grading system that classifies tumors with necrosis into a separate Grade 3.

Abstract 4357: Examining the role of end-stage kidney as a potential intermediate stage in the development of renal cell carcinomas; understanding the pathogenesis allowing for early detection

Abstract Introduction: Clear cell renal cell carcinoma (CCRCC) and papillary renal cell carcinoma (PRCC) are both thought to arise from the renal proximal tubules. End stage renal disease (ESRD) patients have an increased incidence of developing PRCC and CCRCC. Some studies showed a progenitor cell population that is inherently present in renal tubules, and is significantly increased after renal injury. The studies have also illustrated similarities between these progenitor cells and PRCC &amp; CCRCC; hypothesizing that they are the cell of origin of these tumors. This trend was not observed in other renal cell carcinomas such as chromophobe renal cell carcinoma (chRCC). This study aims to further examine the possible role of ESRD in the development of PRCC and CCRCC to understand this initial step of renal cell carcinoma pathogenesis. Methods: A cohort of n = 39 PRCC, 25 CCRCC, 63 normal, 10 end-stage and 18 chRCC cases were selected. RNA sequencing was performed and differential-gene-expression analysis was conducted between normal, ESRD and tumor using DESeq2 software. Pathway analysis was performed using GSEA. Genes from oncogenic pathways that have been studied to be involved in renal cancer development were selected to perform consensus clustering analysis on Genepattern. Results: Oncogenic and developmental pathways enriched in ESRD are consistently overlapping with that of CCRCC and PRCC tumors. 50% of end-stage developmental pathways are found in both CCRCC and PRCC but only 4.5% in chRCC. 62.4% and 46.4% of end-stage oncogenic pathways are found in CCRCC and PRCC respectively but only 16% in chRCC. Clustering analysis showed ESRD cases clustered together with CCRCC and PRCC groups and not with chRCC. Overall, the ESRD cases exhibited a gene expression profile more closely resembling that of CCRCC and PRCC than chRCC. Conclusion: Our findings support the hypothesis that ESRD provides a favorable environment for tumor growth promoting pathogenesis of both PRCC and CCRCC. The enrichment of the same developmental pathways in both ESRD and the tumors suggests that the progenitor cell population in the renal tubules, mentioned above, could be the origin of both PRCC and CCRCC lesions. Further analysis would allow the uncovering of the pathways that lead to tumor progression from these cells of origin, and can be used to determine biomarkers for early detection of CCRCC and PRCC. This is of particular benefit for those with increased risk as the ESRD patients. Citation Format: Mingyuan Wan, Vincent Castillo, Rola Saleeb. Examining the role of end-stage kidney as a potential intermediate stage in the development of renal cell carcinomas; understanding the pathogenesis allowing for early detection [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 4357.

Abstract 1049: Prevalence of KDM6A expression loss in human cancer: A tissue microarray study on 6,560 cancers from 114 different tumor types

Abstract KDM6A, also known as UTX (ubiquitously transcribed X chromosome tetratricopeptide repeat protein) is an epigenetic regulator constituting a critical part of the COMPASS-like complex. KDM6A mutations occur commonly in cancer. These are of interest because KDM6A loss results in a dependency on EZH2, a potential therapeutic target. Most data on KDM6A have been obtained by next generation sequencing (NGS). However, since most KDM6A mutations are truncating and KDM6A is located on the X chromosome, many mutations result in a complete expression loss which can be detected by immunohistochemistry (IHC). To learn more on the prevalence of KDM6A expression loss and its role in cancer, a tissue microarray containing 6,560 samples from 114 different tumor entities and 608 samples of 76 different normal tissue types was analyzed. In normal tissues, KDM6A staining was rather ubiquitously seen in nuclei. In cancer, KDM6A staining was considered weak (1+) in 581 (11.2%), moderate in 1,927 (37%), and strong in 2,362 (45.4%) of 5,206 interpretable tumors. A complete loss of KDM6A staining occurred in 336 (6.5%) of tumors. At least one case with a complete KDM6A expression loss was observed in 51 of 114 tumor categories. KDM6A staining was most commonly lost in different categories of urothelial carcinomas (19.5-39.2%), squamous cell carcinomas of the esophagus (27.1%), hepatocellular carcinoma (18.4%), gastric carcinoma (3.2-12.5%), papillary renal cell carcinoma (9.5%), adenocarcinoma of the prostate (5.9-9.4%), chromophobe renal cell carcinoma (8.9%), Ewing sarcoma (8.3%), pheochromocytoma (8.3%), and metastatic malignant melanoma (8%). A KDM6A expression loss in less than 8% of cases was observed in 32 further tumor entities. KDM6A expression loss was more than twice as frequent in tumors from male (8.4% of 2,526) than in tumors from female patients (3.9% of 2,024; p&amp;lt;0.0001). It is concluded that KDM6A IHC is a suitable method for the detection of truncating KDM6A mutations, especially in males. These make up for about 2/3 of all KDM6A mutations and may exert specific biological effects than differ from the various KDM6A missense mutations known to also occur. Citation Format: Florian Viehweger, Natalia Gorbokon, Maximilian Lennartz, Viktor Reiswich, Florian Lutz, Till Krech, Andreas M. Luebke, Claudia Hube-Magg, Guido Sauter, Ronald Simon, Stefan Steurer, Andreas H. Marx, Christian Bernreuther, Martina Kluth, Sarah Minner. Prevalence of KDM6A expression loss in human cancer: A tissue microarray study on 6,560 cancers from 114 different tumor types [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 1049.

A Case of Metastatic Chromophobe Renal Cell Carcinoma Masked as Suspected Hepatic Abscesses

A Case of Metastatic Chromophobe Renal Cell Carcinoma Masked as Suspected Hepatic Abscesses

L1 Cell Adhesion Molecule (L1CAM) Expression and Molecular Alterations Distinguish Low-Grade Oncocytic Tumor From Eosinophilic Chromophobe Renal Cell Carcinoma

Renal low-grade oncocytic tumor (LOT) is a recently recognized renal cell neoplasm designated within the “other oncocytic tumors” category in the 2022 World Health Organization classification system. Although the clinicopathologic, immunohistochemical, and molecular features reported for LOT have been largely consistent, the data are relatively limited. The morphologic overlap between LOT and other low-grade oncocytic neoplasms, particularly eosinophilic chromophobe renal cell carcinoma (E-chRCC), remains a controversial area in renal tumor classification. To address this uncertainty, we characterized and compared large cohorts of LOT (n = 67) and E-chRCC (n = 69) and revealed notable differences between the 2 entities. Clinically, LOT predominantly affected women, whereas E-chRCC showed a male predilection. Histologically, although almost all LOTs were dominated by a small-nested pattern, E-chRCC mainly showed solid and tubular architectures. Molecular analysis revealed that 87% of LOT cases harbored mutations in the tuberous sclerosis complex (TSC)-mTOR complex 1 (mTORC1) pathway, most frequently in MTOR and RHEB genes; a subset of LOT cases had chromosomal 7 and 19q gains. In contrast, E-chRCC lacked mTORC1 mutations, and 60% of cases displayed chromosomal losses characteristic of chRCC. We also explored the cell of origin for LOT and identified L1 cell adhesion molecule (L1CAM), a collecting duct and connecting tubule principal cell marker, as a highly sensitive and specific ancillary test for differentiating LOT from E-chRCC. This distinctive L1CAM immunohistochemical labeling suggests the principal cells as the cell of origin for LOT, unlike the intercalated cell origin of E-chRCC and oncocytoma. The ultrastructural analysis of LOT showed normal-appearing mitochondria and intracytoplasmic lumina with microvilli, different from what has been described for chRCC. Our study further supports LOT as a unique entity with a benign clinical course. Based on the likely cell of origin and its clinicopathologic characteristics, we propose that changing the nomenclature of LOT to “Oncocytic Principal Cell Adenoma of the Kidney” may be a better way to define and describe this entity.

Identification of PANoptosis-related signature reveals immune infiltration characteristics and immunotherapy responses for renal cell carcinoma

PANoptosis is a specific type of inflammatory programmed cell death (PCD) modality that can be involved in three key modes of cellular programmed cell death-pyroptosis, apoptosis and necroptosis. We analyzed PANoptosis activity in three common renal cell carcinoma subtypes (Clear cell renal cell carcinoma, Papillary renal cell carcinoma, and Chromophobe renal cell carcinoma) separately and constructed a new PANoptosis immunity index (PANII). In three renal cell carcinomas, we found that PANII was an effective predictor of immunotherapy efficacy in KIRC, KIRP and KICH, and the high PANII group was characterized by high immune infiltration and sensitivity to immunotherapy, while the low PANII group was prone to immune escape and immunotherapy resistance. We performed molecular docking prediction of each core protein comprising PANII and identified natural small molecule compounds with the highest affinity to target proteins. In addition, we found that down-regulation of PYCARD inhibited the proliferation and migration of renal clear cell carcinoma cells by in vitro functional assays, suggesting that PYCARD could be a novel target for renal clear cell carcinoma therapy. Our findings that the PANoptosis characterization-based index (PANII) helps to elucidate the tumor microenvironmental features of three common renal cell carcinoma subtypes and identify patient populations that will benefit from immunotherapy, providing a new tool for the clinical diagnosis and treatment of patients with intermediate- and advanced-stage renal cell carcinoma.

High-Grade, Nonsarcomatoid Chromophobe Renal Cell Carcinoma: A Series of 22 Cases With Novel Molecular Features on a Subset

Chromophobe renal cell carcinoma (ChRCC) is the third most common subtype of renal cell carcinoma, and typically exhibits indolent behavior, though a rare subset can exhibit high-grade morphological features and are associated with a poor prognosis. Although there is limited data on the molecular characteristics of metastatic and sarcomatoid ChRCC, the molecular features of high-grade non-sarcomatoid ChRCC remain unexplored. Herein, we characterize 22 cases of ChRCC with high-grade, non-sarcomatoid components. High-grade ChRCC frequently demonstrated advanced stage at diagnosis (64% ≥pT3a or N1), with regions of extrarenal extension, nodal metastases, and vascular invasion consisting solely of high-grade ChRCC morphologically. We performed spatially guided panel-based DNA sequencing on 11 cases, comparing high- and low-grade regions (n = 22 samples). We identified recurring somatic alterations emblematic of ChRCC, including deletions of chromosomes 1, 2, 6, 10, 13, 17, and 21 in 91% (10/11) of cases and recurring mutations in TP53 (81.8%, n = 9/11) and PTEN (36.4%, n = 4/11). Notably, though PTEN and TP53 alterations were found in both high- and low- grade regions, private mutations were identified in 3 cases, indicating convergent evolution. Finally, we identified recurring RB1 mutations in 27% (n = 3) of high-grade regions leading to selective protein loss by immunohistochemistry not observed in adjacent low-grade regions. This finding was confirmed in the TCGA cohort where 2/66 cases contained RB1 mutations and demonstrated unequivocal high-grade, non-sarcomatoid morphology. We also detected multiple chromosomal gains confined to the high-grade regions, consistent with imbalanced chromosome duplication. These findings broaden our understanding of the molecular pathogenesis of ChRCC and suggest that subclonal RB1 mutations can drive the evolution to high-grade, non-sarcomatoid ChRCC.

Implications of MTHFD2 expression in renal cell carcinoma aggressiveness.

Renal cell carcinoma (RCC) is the most common type of cancer in kidney and is often diagnosed in advanced stages. Until now, there is no reliable biomarker to assess tumor prognosis during histopathological diagnosis. The Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) overexpression has been suggested as prognostic indicator for RCC, however, its protein profile needs to be clarified. This study investigated the MTHFD2 expression in different RCC cohorts, associating it with tumor characteristics and prognostic factors. Gene expression comparisons between non-neoplastic (NN) and tumor samples, as well as patients' survival analysis, were assessed using KM-Plotter tool. MTHFD2 protein pattern was evaluated in 117 RCC by immunohistochemistry and associations with prognosis, clinical and pathological data were investigated. The tumors exhibited higher MTHFD2 transcript levels than NN, being even higher in the metastatic group. Opposite gene expression patterns were found among clear cell renal cell carcinoma (ccRCC) and pappilary renal cell carcinoma (pRCC) subtypes, showing higher and lower expressions compared to NN samples respectively. Overexpression was associated with shorter overall survival for ccRCC and pRCC subtypes, and shorter recurrence-free survival for pRCC. The immunolabeling profile varied according to tumor subtypes, with lower intensity and expression scores in ccRCC compared to pRCC and to chromophobe renal cell carcinoma (chRCC). MTHFD2 protein expression was associated with larger tumors and higher Fuhrman grades. Although prognostic value of protein immunostaining was not confirmed, patients with higher MTHFD2 tended to have lower survival rates in the pRCC group. The results highlight MTHFD2 different patterns according to RCC histological subtypes, revealing marked variations at both the genetic and protein levels. The mRNA indicated tumor prognosis, and greater expression in the tumor samples. Although MTHFD2 immunolabeling suggests tumor aggressiveness, it needs to be validated in other cohorts as potential prognostic factor.

Metastasis suppressor kisspeptin (KISS1) in serum of patients with renal cell carcinoma

Background. The most important problems in improvement of treatment outcomes in patients with renal cell carcinoma (RCC) are search and validation of molecular markers for its early diagnosis and prognosis. Genes suppressing distant metastasizing but not affecting the primary tumor are called metastasis suppressors. Study of these genes and their products not only improves understanding of the mechanisms of tumor progression, but has practical value for diagnosis, prognosis, and establishment of new molecular targets for antitumor therapy. One of such genes is KISS1 with its product kisspeptin (KISS1) protein.Aim: comparative evaluation of KISS1 concentration in blood serum of practically healthy persons and patients with renal cancer; analysis of correlations between the marker’s level and clinical and morphological characteristics of the disease.Materials and methods. 140 patients with RCC (88 men, 52 women) aged between 29 and 82 years were included in the study. Among them, clear cell RCC was diagnosed in 84 patients, papillary in 38, chromophobe in 18. The control group was comprised of 40 healthy persons of matched age and sex. Pre-treatment KISS1 concentration in blood serum was measured using a direct enzyme immunoassay kit (Kisspeptin 1 – KISS1, Cloud-Clone Corp., USA).Results. Median serum KISS1 concentration in the control group was 51.7 pg/mL which was significantly lower than in the total RCC patient group – 243.6 pg/mL (p &lt;0.0001). ROC analysis of diagnostic value of serum KISS1 level was performed both for the total RCC group and for each of its three histological types. In the total group the sensitivity of the test was 75 %, specificity – 80 % (AUC 0.877; 95 % confidence interval (CI) 0.827–0.927; optimal cut-off level 130.8 pg/mL; р &lt;0.0001). For clear cell RCC, both sensitivity and specificity were 85 % (AUC 0.941; 95 % CI 0.902– 0.979; cut-off 141.8 pg/mL; p &lt;0.0001). In non-clear cell RCC types, sensitivity of this marker was only 58 % while the specificity remained 80 % (for papillary RCC AUC 0.787; 95 % CI 0.684–0.889; cut-off level 135.5 pg/mL; p &lt;0.0001, and for chromophobe RCC AUC 0.774; 95 % CI 0.617–0.929; cut-off level 132.1 pg/mL; p &lt;0.001). KISS1 level increased with disease progression: it is significantly higher at more advanced stages above stage I, and in patients with distant metastases compared to those without metastases. Higher serum KISS1 level is also observed in patients with poorly differentiated high-grade (per Furhman) clear cell RCC and papillary RCC (G3–G4) than in those with well differentiated low-grade (G1–G2) tumors.Conclusion. KISS1 level is significantly increased in patients with RCC compared to healthy controls and is a stagedependent marker of this disease. It has relatively high diagnostic sensitivity and specificity (both 85 %) for the most frequent histological type of RCC – clear cell RCC. Thus, clinical significance of kisspeptin in RCC requires further investigation.

VDRA downregulate β-catenin/Smad3 and DNA damage and repair associated with improved prognosis in ccRCC patients

The clear cell renal cell carcinoma (ccRCC) spotlighted the poorest survival, while chromophobe renal cell carcinoma (chRCC) was associated with the best survival. Earlier studies corroborated vitamin D receptor (VDR) was a promising molecular for improving the prognosis of RCC. In contrast to VDRA, the one of VDR isoforms, VDRB1 (VDR isoform B1) has an N-terminal extension of 50 amino acids and is less ligand-dependent. However, the functional differences between VDRA and VDRB1, and their roles in the prognosis of ccRCC and chRCC, have not been investigated. In the present study, we uncovered that the transcripts related to vitamin D pathway and cellular calcium signaling were effectively decreased in the context of ccRCC, yet failed to exert a comparable effect within chRCC. Specially, minimally levels of VDRA wherein kidneys of patients suffering from ccRCC predict shorter survival time. In addition, the protein expressions for β-catenin/Smad3 pathway and DNA damage and repair pathways were obviously impeded in VDRA-overexpressed ccRCC cells, yet this inhibitory effect was conspicuously absent in enable VDRB1 cells. Our results provide a new idea to improve the prognosis of ccRCC via VDRA upregulation.

Elevated Plasma Concentration of 4-Pyridone-3-carboxamide-1-β-D-ribonucleoside (4PYR) Highlights Malignancy of Renal Cell Carcinoma.

Nicotinamide (NA) derivatives play crucial roles in various biological processes, such as inflammation, regulation of the cell cycle, and DNA repair. Recently, we proposed that 4-pyridone-3-carboxamide-1-β-D-ribonucleoside (4PYR), an unusual derivative of NA, could be classified as an oncometabolite in bladder, breast, and lung cancer. In this study, we investigated the relations between NA metabolism and the progression, recurrence, metastasis, and survival of patients diagnosed with different histological subtypes of renal cell carcinoma (RCC). We identified alterations in plasma NA metabolism, particularly in the clear cell RCC (ccRCC) subtype, compared to papillary RCC, chromophobe RCC, and oncocytoma. Patients with ccRCC also exhibited larger tumor sizes and elevated levels of diagnostic serum biomarkers, such as hsCRP concentration and ALP activity, which were positively correlated with the plasma 4PYR. Notably, 4PYR levels were elevated in advanced stages of ccRCC cancer and were associated with a highly aggressive phenotype of ccRCC. Additionally, elevated concentrations of 4PYR were related to a higher likelihood of mortality, recurrence, and particularly metastasis in ccRCC. These findings are consistent with other studies, suggesting that NA metabolism is accelerated in RCC, leading to abnormal concentrations of 4PYR. This supports the concept of 4PYR as an oncometabolite and a potential prognostic factor in the ccRCC subtype.

Optimized reconstruction of the absorption spectra of kidney tissues from the spectra of tissue components using the least squares method.

With the objective of developing new methods to acquire diagnostic information, the reconstruction of the broadband absorption coefficient spectra (μa [λ]) of healthy and chromophobe renal cell carcinoma kidney tissues was performed. By performing a weighted sum of the absorption spectra of proteins, DNA, oxygenated, and deoxygenated hemoglobin, lipids, water, melanin, and lipofuscin, it was possible to obtain a good match of the experimental μa (λ) of both kidney conditions. The weights used in those reconstructions were estimated using the least squares method, and assuming a total water content of 77% in both kidney tissues, it was possible to calculate the concentrations of the other tissue components. It has been shown that with the development of cancer, the concentrations of proteins, DNA, oxygenated hemoglobin, lipids, and lipofuscin increase, and the concentration of melanin decreases. Future studies based on minimally invasive spectral measurements will allow cancer diagnosis using the proposed approach.

Intratumoral metastasis of sigmoid colon cancer to chromophobe renal cell carcinoma: a case report

We herein report an extremely rare case of intratumoral metastasis of colon cancer to chromophobe renal cell carcinoma. A 71-year-old woman was diagnosed with lung metastasis of sigmoid colon cancer and underwent sigmoid colon resection with D3 lymph node dissection. Preoperative contrast-enhanced computed tomography (CT) revealed a left renal tumor; however, colon resection was prioritized, and the renal tumor was placed under observation. Two years later, CT revealed enlargement of the left renal tumor, and laparoscopic partial left nephrectomy was performed 1 month later. Histopathologic examination showed that the resected renal tumor was a chromophobe renal cell carcinoma with intratumoral metastasis of colon cancer to the renal tumor center, and adjuvant chemotherapy with bevacizumab plus SOX (L-OHP + S-1) was initiated. Because of severe chemotherapy-induced fatigue and nausea, the patient was switched to bevacizumab + S-1. However, the patient’s nausea did not improve after this change, and postoperative adjuvant chemotherapy was discontinued at the patient’s request 4 months after the partial nephrectomy. Two months after discontinuation of chemotherapy, CT showed no renal recurrence; however, increased lung metastases and a new bone metastasis in the left sciatic bone were observed. Palliative treatment was then initiated because of severe adverse events that made it difficult to continue treatment. In patients who have multiple cancers and an increase in renal tumor size, the possibility of intratumoral metastasis to the renal tumor should be considered.