Contemporary Renal Tumor Categorization With Biomarker and Translational Updates: A Practical Review

NMRK2 is an efficient diagnostic indicator for Xp11.2 translocation renal cell carcinoma

Xp11.2 translocation renal cell carcinomas (tRCC) are a rare and highly malignant type of renal cancer, lacking efficient diagnostic indicators and therapeutic targets. Through the analysis of public databases and our cohort, we identified NMRK2 as a potential diagnostic marker for distinguishing Xp11.2 tRCC from kidney renal clear cell carcinoma (KIRC) and kidney renal papillary cell carcinoma (KIRP) due to its specific upregulation in Xp11.2 tRCC tissues. Mechanistically, we discovered that TFE3 fusion protein binds to the promoter of the NMRK2 gene, leading to its upregulation. Importantly, we established RNA- and protein-based diagnostic methods for identifying Xp11.2 tRCC based on NMRK2 expression levels, and the diagnostic performance of our methods was comparable to a dual-color break-apart fluorescence in situ hybridization assay. Moreover, we successfully identified fresh Xp11.2 tRCC tissues after surgical excision using our diagnostic methods and established an immortalized Xp11.2 tRCC cell line for further research purposes. Functional studies revealed that NMRK2 promotes the progression of Xp11.2 tRCC by upregulating the NAD+/NADH ratio, and supplementation with β-nicotinamide mononucleotide (NMN) or nicotinamide riboside chloride (NR), effectively rescued the phenotypes induced by the knockdown of NMRK2 in Xp11.2 tRCC. Taken together, these data introduce a new diagnostic indicator capable of accurately distinguishing Xp11.2 tRCC and highlight the possibility of developing novel targeted therapeutics. © 2024 The Pathological Society of Great Britain and Ireland.

Perioperative, functional and oncologic outcomes of percutaneous ablation versus minimally invasive partial nephrectomy for clinical T1 renal tumors: outcomes from a pooled analysis

The objective of this study was to perform a comprehensive pooled analysis aimed at comparing the efficacy and safety of percutaneous ablation (PCA) versus minimally invasive partial nephrectomy (MIPN), including robotic and laparoscopic approaches, in patients diagnosed with cT1 renal tumors. We conducted a comprehensive search across four major electronic databases: PubMed, Embase, Web of Science, and the Cochrane Library, targeting studies published in English up to April 2024. The primary outcomes evaluated in this analysis included perioperative outcomes, functional outcomes, and oncological outcomes. A total of 2449 patients across 17 studies were included in the analysis. PCA demonstrated superior outcomes compared to MIPN in terms of shorter hospital stays (WMD: - 2.13 days; 95% Confidence Interval [CI]: - 3.29, - 0.97; p = 0.0003), reduced operative times (WMD: - 109.99 min; 95% CI: - 141.40, - 78.59; p < 0.00001), and lower overall complication rates (OR: 0.54; 95% CI: 0.40, 0.74; p = 0.0001). However, PCA was associated with a higher rate of local recurrence when compared to MIPN (OR: 3.81; 95% CI: 2.45, 5.92; p < 0.00001). Additionally, no significant differences were observed in major complications, estimated glomerular filtration rate decline, creatinine variation, overall survival, recurrence-free survival, and disease-free survival between the two treatment modalities. PCA presents a notable disadvantage regarding local recurrence rates in comparison to MIPN. However, PCA offers several advantages over MIPN, including shorter durations of hospital stay, reduced operative times, and lower complication rates, while achieving similar outcomes in other oncologic metrics.

Comparison between minimally invasive partial nephrectomy and open partial nephrectomy for complex renal tumors: a systematic review and meta-analysis

BACKGROUND

The present study aimed to conduct a pooled analysis to compare the efficacy and safety of minimally invasive partial nephrectomy (MIPN) with open partial nephrectomy (OPN) in patients with complex renal tumors (defined as PADUA or RENAL score ≥7).

METHODS

The present study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, Supplemental Digital Content 1, http://links.lww.com/JS9/A394 . We conducted a systematic search of the PubMed, Embase, Web of Science, and Cochrane Library databases until October 2022. MIPN and OPN-controlled trials for complex renal tumors were included. The primary outcomes were perioperative results, complications, renal function, and oncologic outcomes.

RESULTS

A total of 2405 patients were included in 13 studies. MIPN outperformed OPN in terms of hospital stay [weighted mean difference (WMD) -1.84 days, 95% CI -2.35 to -1.33; P <0.00001], blood loss (WMD -52.42 ml, 95% CI -71.43 to -33.41; P <0.00001), transfusion rates [odds ratio (OR) 0.34, 95% CI 0.17-0.67; P =0.002], major complications (OR 0.59, 95% CI 0.40-0.86; P =0.007) and overall complications (OR 0.43, 95% CI 0.31-0.59; P <0.0001), while operative time, warm ischemia time, conversion to radical nephrectomy rates, estimated glomerular decline, positive surgical margins, local recurrence, overall survival, recurrence-free survival, and cancer-specific survival were not significantly different.

CONCLUSIONS

The present study demonstrated that MIPN was associated with a shorter length of hospital stay, less blood loss, and fewer complications in treating complex renal tumors. MIPN may be considered a better treatment for patients with complex tumors when technically feasible.

Computed Tomography Image under Three-Dimensional Reconstruction Algorithm Based in Diagnosis of Renal Tumors and Retroperitoneal Laparoscopic Partial Nephrectomy

This study was to explore the clinical application value of computed tomography (CT) images based on a three-dimensional (3D) reconstruction algorithm for laparoscopic partial nephrectomy (LPN) in patients with renal tumors. 30 cases of renal cell carcinoma (RCC) patients admitted to the hospital were selected as the research objects and were rolled into two groups using a random table method. The patients who received PLN under the three-dimensional reconstruction and laparoscopic technique were included in the experimental group (group A), and the patients who received LPN using CT images only were included in the control group (group B). In addition, the treatment results of the two groups of patients were compared and analyzed. Results. The effective rate of the established model was 93.3%; the total renal arteriovenous variability of group A (13.3%) was higher than that of group B (6.7%), and the operation time (131.5 ± 32.1 minutes) was much lower than that of group B (158.7 ± 36.2 minutes), showing statistical significance (P < 0.05). Conclusion. CT images based on 3D reconstruction algorithms had high clinical application value for LPN in patients with renal tumors, which could improve the efficiency and safety of LPN.

TRIM63 is a sensitive and specific biomarker for MiT family aberration-associated renal cell carcinoma

Microphthalmia-associated transcription factor (MiT) family aberration-associated renal cell carcinoma (MiTF-RCC) is a subtype of renal cell carcinoma harboring recurrent chromosomal rearrangements involving TFE3 or TFEB genes. MiTF-RCC is morphologically diverse, can histologically resemble common RCC subtypes like clear cell RCC and papillary RCC, and often poses a diagnostic challenge in genitourinary clinical and pathology practice. To characterize the MiTF-RCC at the molecular level and identify biomarker signatures associated with MiTF-RCC, we analyzed RNAseq data from MiTF-RCC, other RCC subtypes and benign kidney. Upon identifying TRIM63 as a cancer-specific biomarker in MiTF-RCC, we evaluated its expression independently by RNA in situ hybridization (RNA-ISH) in whole tissue sections from 177 RCC cases. We specifically included 31 cytogenetically confirmed MiTF-RCC cases and 70 RCC cases suspicious for MiTF-RCC in terms of clinical and morphological features, to evaluate and compare TRIM63 RNA-ISH results with the results from TFE3/TFEB fluorescence in situ hybridization (FISH), which is the current clinical standard. We confirmed that TRIM63 mRNA was highly expressed in all classes of MiTF-RCC compared to other renal tumor categories, where it was mostly absent to low. While the TRIM63 RNA-ISH and TFE3/TFEB FISH results were largely concordant, importantly, TRIM63 RNA-ISH was strongly positive in TFE3 FISH false-negative cases with RBM10-TFE3 inversion. In conclusion, TRIM63 can serve as a diagnostic marker to distinguish MiTF-RCC from other renal tumor subtypes with overlapping morphology. We suggest a combination of TFE3/TFEB FISH and TRIM63 RNA-ISH assays to improve the accuracy and efficiency of MiTF-RCC diagnosis. Accurate diagnosis of MiTF-RCC and other RCC subtypes would enable effective targeted therapy and avoid poor therapeutic response due to tumor misclassification.

Impact of Laparoscopic Partial Nephrectomy and Open Partial Nephrectomy on Outcomes of Clear Cell Renal Cell Carcinoma

Objective: To analyze the impact of laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) on outcomes of complex clear cell renal cell carcinoma (ccRCC).

Methods: A total of 132 high-complex ccRCC patients with a Radius Exophytic Nearness Anterior Location (R.E.N.A.L) score ≥7 enrolled in our hospital between January 2018 and June 2020 were matched and assigned to an LPN group (given LPN treatment) and an OPN group (given OPN treatment), with 66 cases in each group. Two weeks and 3 months after the operation, the renal indexes, inflammatory factors, basic perioperative conditions, and incidence of complications were compared.

Results: Two weeks after the operation, the levels of SCr and CysC were elevated, with higher levels observed in the LPN group (all P < 0.05), and the eGFR levels were reduced, with a lower result in the LPN group. Three months after the operation, the two groups observed decreased levels of SCr and CysC, and an increased level of eGFR; moreover, the decreased SCr and CysC levels were still higher, and the increased eGFR was lower than those before the operation (P < 0.05). The levels of CRP and TNF-α in the two groups increased after the operation, with a lower outcome in the LPN group (P < 0.05). Moreover, the LPN group had less intraoperative blood loss and shorter postoperative length of hospital stay but longer blocking time compared to the OPN group (P < 0.05). Patients in the LPN group were recorded with a lower complication incidence compared with the OPN group (3.03 vs. 15.15%, P < 0.05).

Conclusion: Both LPN and OPN enjoy significant efficacy in the treatment of complex ccRCC and effectively protect renal function. Moreover, LPN is a more acceptable option for complex ccRCC due to its numerous benefits in postoperative stress response, complications, recovery. which is worthy of promotion with safety and feasibility.

Single-cell analyses of renal cell cancers reveal insights into tumor microenvironment, cell of origin, and therapy response

Renal cell carcinomas (RCCs) are heterogeneous malignancies thought to arise from kidney tubular epithelial cells, and clear cell RCC is the most common entity. This study demonstrates that cell atlases generated from benign kidney and two common RCCs using single-cell RNA sequencing can predict putative cells of origin for more than 10 RCC subtypes. A focused analysis of distinct cell-type compartments reveals the potential role of tumor epithelia in promoting immune infiltration and other molecular attributes of the tumor microenvironment. Finally, an observed association between the lack of immunotherapy response and endothelial cell fraction has important clinical implications. The current study, therefore, significantly contributes toward understanding disease ontogenies and the molecular dynamics of tumor epithelia and the microenvironment.

Diverse subtypes of renal cell carcinomas (RCCs) display a wide spectrum of histomorphologies, proteogenomic alterations, immune cell infiltration patterns, and clinical behavior. Delineating the cells of origin for different RCC subtypes will provide mechanistic insights into their diverse pathobiology. Here, we employed single-cell RNA sequencing (scRNA-seq) to develop benign and malignant renal cell atlases. Using a random forest model trained on this cell atlas, we predicted the putative cell of origin for more than 10 RCC subtypes. scRNA-seq also revealed several attributes of the tumor microenvironment in the most common subtype of kidney cancer, clear cell RCC (ccRCC). We elucidated an active role for tumor epithelia in promoting immune cell infiltration, potentially explaining why ccRCC responds to immune checkpoint inhibitors, despite having a low neoantigen burden. In addition, we characterized an association between high endothelial cell types and lack of response to immunotherapy in ccRCC. Taken together, these single-cell analyses of benign kidney and RCC provide insight into the putative cell of origin for RCC subtypes and highlight the important role of the tumor microenvironment in influencing ccRCC biology and response to therapy.

Renal Cell Tumors: Molecular Findings Reshaping Clinico-pathological Practice

Over the past 20 years, the number of subtypes of renal epithelial cell neoplasia has grown. This growth has resulted from detailed histological and immunohistochemical characterization of these tumors and their correlation with clinical outcomes. Distinctive molecular phenotypes have validated the unique nature of many of these tumors. This growth of unique renal neoplasms has continued after the 2016 World Health Organization (WHO) Classification of Tumours. A consequence is that both the pathologists who diagnose the tumors and the clinicians who care for these patients are confronted with a bewildering array of renal cell carcinoma variants. Many of these variants have important clinical features, i.e. familial or syndromic associations, genomics alterations that can be targeted with systemic therapy, and benignancy of tumors previously classified as carcinomas. Our goal in the review is to provide a practical guide to help recognize these variants, based on small and distinct sets of histological features and limited numbers of immunohistochemical stains, supplemented, as necessary, with molecular features.

Next-generation RNA Sequencing-based Biomarker Characterization of Chromophobe Renal Cell Carcinoma and Related Oncocytic Neoplasms

BACKGROUND

Renal cell carcinomas (RCCs) are a heterogeneous group of neoplasms. Recent sequencing studies revealed various molecular features associated with histologic RCC subtypes, including chromophobe renal cell carcinoma (ChRCC).

OBJECTIVE

To characterize the gene expression and biomarker signatures associated with ChRCC.

DESIGN, SETTING, AND PARTICIPANTS

We performed integrative analysis on RNA sequencing data available from 1049 RCC specimens from The Cancer Genome Atlas and in-house studies. Our workflow identified genes relatively enriched in ChRCC, including Forkhead box I1 (FOXI1), Rh family C glycoprotein (RHCG), and LINC01187. We assessed the expression pattern of FOXI1 and RHCG protein by immunohistochemistry (IHC) and LINC01187 mRNA by RNA in situ hybridization (RNA-ISH) in whole tissue sections representing a cohort of 197 RCC cases, including both primary and metastatic tumors.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The FOXI1 and RHCG IHC staining, as well as the LINC01187 RNA-ISH staining, was evaluated in each case for intensity, pattern, and localization of expression.

RESULTS AND LIMITATIONS

All primary and metastatic classic ChRCCs demonstrated homogeneous positive labeling for FOXI1, RHCG proteins, and LINC01187 transcript. Unclassified RCC with oncocytic features, oncocytoma, and hybrid oncocytic tumor, as well as all but two cases of eosinophilic ChRCC also stained positive. Importantly, metastatic and primary RCC of all other subtypes did not demonstrate any unequivocal staining for FOXI1, RHCG, or LINC01187. In normal kidney, FOXI1, RHCG, and LINC01187 were detected in the distal nephron segment, specifically in intercalated cells. Two cases of eosinophilic ChRCC with focal expression of FOXI1 and LINC01187, and Golgi-like RHCG staining were found to contain MTOR gene mutations upon DNA sequencing.

CONCLUSIONS

We demonstrate a pipeline for the identification and validation of RCC subtype-specific biomarkers that can aid in the confirmation of cell of origin and may facilitate accurate classification and diagnosis of renal tumors.

PATIENT SUMMARY

FOXI1, RHCG, and LINC01187 are lineage-specific signature genes for chromophobe renal cell carcinoma.