Integrative molecular characterization of sarcomatoid and rhabdoid renal cell carcinoma

Contemporary Management of Renal Cell Carcinoma: A Review for General Practitioners in Oncology

Renal cell carcinoma accounts for a significant proportion of cancer diagnoses in Canadians. Over the past several years, the management of renal cell cancers has undergone rapid changes in all prognostic risk categories, resulting in improved oncologic outcomes. Novel strategies for metastatic disease make use of the synergy between checkpoints and angiogenesis inhibition. Moreover, combination checkpoint inhibition has demonstrated durable efficacy in some patients. Adjuvant immunotherapy has recently shown a survival benefit for the first time in select cases. Significant efforts are underway to explore new compounds or combinations for later-line diseases, such as inhibitors of hypoxia-inducible factors and radiolabeled biomolecules targeting tumor antigens within the neoplastic microenvironment for precise payload delivery. In this manuscript, we provide a comprehensive review of the available data addressing key therapeutic areas pertaining to systemic therapy for metastatic and localized disease, review the most relevant prognostic tools, describe local therapies and management of CNS disease, and discuss practice-changing trials currently underway. Finally, we focus on some of the practical aspects for general practitioners in oncology caring for patients with renal cell carcinoma.

Advancements in Radiogenomics for Clear Cell Renal Cell Carcinoma: Understanding the Impact of BAP1 Mutation

Recent advancements in understanding clear cell renal cell carcinoma (ccRCC) have underscored the critical role of the BAP1 gene in its pathogenesis and prognosis. While the von Hippel-Lindau (VHL) mutation has been extensively studied, emerging evidence suggests that mutations in BAP1 and other genes significantly impact patient outcomes. Radiogenomics with and without texture analysis based on CT imaging holds promise in predicting BAP1 mutation status and overall survival outcomes. However, prospective studies with larger cohorts and standardized imaging protocols are needed to validate these findings and translate them into clinical practice effectively, paving the way for personalized treatment strategies in ccRCC. This review aims to summarize the current knowledge on the role of BAP1 mutation in ccRCC pathogenesis and prognosis, as well as the potential of radiogenomics in predicting mutation status and clinical outcomes.

Sarcomatoid and Rhabdoid Renal Cell Carcinoma: Clinical, Pathologic, and Molecular Genetic Features

Renal cell carcinoma (RCC) with sarcomatoid and rhabdoid morphologies has an aggressive biological behavior and a typically poor prognosis. The current 2022 WHO classification of renal tumors does not include them as distinct histologic entities but rather as transformational changes that may arise in a background of various distinct histologic types of RCC. The sarcomatoid component shows malignant spindle cells that may grow as intersecting fascicles, which is reminiscent of pleomorphic undifferentiated sarcoma. The rhabdoid cells are epithelioid cells with eccentrically located vesicular nuclei with prominent nucleoli and large intracytoplasmic eosinophilic inclusions. Studies have shown that RCCs with sarcomatoid and rhabdoid differentiation have distinctive molecular features. Sarcomatoid RCC harbors shared genomic alterations in carcinomatous and rhabdoid components, but also enrichment of specific genomic alterations in the sarcomatoid element, suggesting molecular pathways for development of sarcomatoid growth from a common clonal ancestor. Rhabdoid differentiation also arises through clonal evolution although less is known of specific genomic alterations in rhabdoid cells. Historically, treatment has lacked efficacy, although recently immunotherapy with PD-1/PD-L1/CTLA-4 inhibitors has produced significant clinical responses. Reporting of sarcomatoid and rhabdoid features in renal cell carcinoma is required by the College of American Pathologists and the International Collaboration on Cancer Reporting. This manuscript reviews the clinical, pathologic, and molecular features of sarcomatoid RCC and rhabdoid RCC with emphasis on the morphologic features of these tumors, significance of diagnostic recognition, the molecular mechanisms of tumorigenesis and differentiation along sarcomatoid and rhabdoid lines, and advances in treatment, particularly immunotherapy.

Epigenomic signatures of sarcomatoid differentiation to guide the treatment of renal cell carcinoma

Renal cell carcinoma with sarcomatoid differentiation (sRCC) is associated with poor survival and a heightened response to immune checkpoint inhibitors (ICIs). Two major barriers to improving outcomes for sRCC are the limited understanding of its gene regulatory programs and the low diagnostic yield of tumor biopsies due to spatial heterogeneity. Herein, we characterized the epigenomic landscape of sRCC by profiling 107 epigenomic libraries from tissue and plasma samples from 50 patients with RCC and healthy volunteers. By profiling histone modifications and DNA methylation, we identified highly recurrent epigenomic reprogramming enriched in sRCC. Furthermore, CRISPRa experiments implicated the transcription factor FOSL1 in activating sRCC-associated gene regulatory programs, and FOSL1 expression was associated with the response to ICIs in RCC in two randomized clinical trials. Finally, we established a blood-based diagnostic approach using detectable sRCC epigenomic signatures in patient plasma, providing a framework for discovering epigenomic correlates of tumor histology via liquid biopsy.

Treatment options in first-line metastatic renal carcinoma: A meta-analysis of 2556 patients treated with immune checkpoint inhibitors-based combinations in randomised controlled trials

BACKGROUND & AIMS

The average five-year survival of metastatic renal cell carcinoma (mRCC) is 71%. However, there is significant variability in patient prognosis. Immune checkpoint inhibitors (ICIs) have been introduced into the treatment landscape of mRCC. This meta-analysis aimed to estimate progression-free and overall survival probabilities and identify possible outcome predictors of mRCC patients treated with ICI combination as first-line treatment.

METHODS

Studies comparing the combination of ICI combinations versus standard of therapy for first-line treatment of advanced renal-cell carcinoma were searched in MEDLINE, CANCERLIT, the Cochrane Controlled Trials Register, and the Cochrane Library from inception through September 2023. Data on patient populations and outcomes were extracted from each study by three independent observers and combined using the DerSimonian and Laird methods.

RESULTS

Six studies met the inclusion criteria. Globally, 5121 patients were included in this meta-analysis: 2556 patients treated with immune checkpoint inhibitors and 2565 with sunitinib as control. The ICI combination was associated with improved PFS (hazard ratio (HR) 0.68; 95 % confidence interval (CI), 0.56-0.81, p < 0.0001). Furthermore, ICI combination was also associated with OS improvement (HR 0.85; 95 % CI, 0.78-0.92, p = 0.001). There is no statistical increase in adverse events.

CONCLUSIONS

Our findings show that PFS and OS are statistically increased in mRCC with ICI combination treatment by 32% and 15%, respectively.

Renal Cell Carcinoma of Variant Histology: New Biologic Understanding Leads to Therapeutic Advances

Renal cell carcinoma (RCC) is one of the 10 most commonly diagnosed solid tumors. Most RCCs are histologically defined as clear cell, comprising approximately 75% of diagnoses. However, the remaining RCC cases are composed of a heterogeneous combination of diverse histopathologic subtypes, each with unique pathogeneses and clinical features. Although the therapeutic approach to both localized and metastatic RCCs has dramatically changed, first with the advent of antiangiogenic targeted therapies and more recently with the approval of immune checkpoint inhibitor (ICI)-based combinations, these advances have primarily benefited the clear cell RCC patient population. As such, there remains critical gaps in the optimization of treatment regimens for patients with non-clear cell, or variant, RCC histologies. Herein, we detail recent advances in understanding the biology of RCC with variant histology and how such findings have guided novel clinical studies investigating precision oncology approaches for these rare subtypes. Among the most common variant histology RCCs are papillary RCC, comprising approximately 15%-20% of all diagnoses. Although a histopathologically diverse subset of tumors, papillary RCC is canonically associated with amplification of the MET protooncogene; recently completed and ongoing trials have investigated MET-directed therapies for this patient population. Finally, we discuss the unique biology of RCC with sarcomatoid dedifferentiation and the recent clinical findings detailing its paradoxical sensitivity to ICIs.

Efficacy Assessment of Post-nephrectomy Adjuvant Therapies in Patients with Renal Cell Carcinoma

OBJECTIVE

The objective of our study was to integrate the efficacy results of post-nephrectomy adjuvant therapies in renal cell carcinoma (RCC) patients with risk of recurrence, and attempt to determine the optimal intervention choice.

METHODS

We performed standard meta-analysis procedures in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Embase, and Cochrane Library databases were searched from inception to 22 September 2022. Randomized controlled trials reporting overall survival (OS) or disease-free survival (DFS) of adjuvant therapies, including immune checkpoint inhibitors (ICIs) and targeted therapies, in adult post-nephrectomy RCC patients were eligible for inclusion.

RESULTS

Seven studies involving 7548 participants were included in our analyses. In contrast with placebo, DFS benefit with ICIs was only observed in female RCC patients and RCC patients with high programmed death-ligand 1 (PD-L1) expression (≥ 1%), sarcomatoid features, and M0 intermediate-high risk. Network meta-analyses demonstrated that pembrolizumab exhibited both DFS and OS benefit compared with placebo, sunitinib, sorafenib, and girentuximab, and only DFS benefit compared with atezolizumab and nivolumab plus ipilimumab.

CONCLUSIONS

Our results suggest that post-nephrectomy RCC patients with sarcomatoid differentiation and high PD-L1 expression were more responsive to ICIs. Furthermore, pembrolizumab monotherapy exhibited superior DFS and OS results over other adjuvant therapies.

The Evolving Landscape of Biomarkers for Immune Checkpoint Blockade in Genitourinary Cancers

In the past decade, immune checkpoint inhibitors (ICI) have been approved for treatment of genitourinary malignancies and have revolutionized the treatment landscape of these tumors. However, despite the remarkable success of these therapies in some GU malignancies, many patients' tumors do not respond to these therapies, and others may experience significant side effects, such as immune-related adverse events (iRAEs). Accordingly, biomarkers and improved prognostic tools are critically needed to help predict which patients will respond to ICI, predict and mitigate risk of developing immune-related adverse events, and inform personalized choice of therapy for each patient. Ongoing clinical and preclinical studies continue to provide an increasingly robust understanding of the mechanisms of the response to immunotherapy, which continue to inform biomarker development and validation. Herein, we provide a comprehensive review of biomarkers of the response to immunotherapy in GU tumors and their role in selection of therapy and disease monitoring.

Tumor microenvironment and clinical efficacy of first line immunotherapy-based combinations in metastatic renal cell carcinoma

The impact of tumor microenvironment (TME) in influencing clinical response to first-line immune checkpoint inhibitor (ICI)-based treatment in advanced renal cell carcinoma (RCC) is unclear. Immunohistochemistry (IHC) could identify biomarkers related to immune checkpoints and immune cell population. This study retrospectively characterized TME from 28 RCC patients who received first line ICI-based therapy through IHC assessment of selected markers and explored preliminary evidence about their possible correlation with treatment efficacy. We found a significantly higher count of CD80+, CD163+ cells and their ratio in RCC with clear cell component compared to those without clear cell features; additionally, patients with metastatic disease at diagnosis were associated with higher expression of CD163+ cells, while higher count of CD4+ cells and CD4+/CD8+ ratio were found in RCC with sarcomatoid features. Patients achieving partial or complete response were associated with lower expression of CD163+ cells (median 28 vs 47; p = 0.049). Furthermore, lower expression of CD163+ was associated with better PFS (median PFS 20.0 vs 4.7 months; HR 0.22 p = 0.011) and OS (median OS NR vs 14.4 months; HR 0.28 p = 0.036). A longer OS was reported in PD-L1 CPS negative patients (median OS NR vs 11.8 months; HR 0.20 p = 0.024). High infiltration of CD163+ macrophages, who typically present "anti-inflammatory" M2-like phenotype, could identify a subgroup of patients with poor survival after receiving first-line ICI.

Genetic study of the CDKN2A and CDKN2B genes in renal cell carcinoma patients

Objectives

While recent studies have demonstrated several genetic alterations are associated with pathogenesis of RCC, the significance of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase inhibitor 2B (CDKN2B) in tumorigenesis of RCC is less clear. We investigate the distribution of CDKN2A and CDKN2B mutations in patients with RCC and analyze the impact of CDKN2A and CDKN2B mutations on RCC.

Methods

A pathological examination was conducted using thirty fresh renal tissue samples with renal masses that had undergone partial or radical nephrectomy. Multiplex ligation-dependent probe amplification (MLPA) was used to detect genetic aberrations of CDKN2A and CDKN2B in genomic DNA isolated from samples. Subsequently, CDKN2A and CDKN2B mutations were confirmed using chromosomal microarray technique.

Results

Twenty-one patients were diagnosed with RCC, eight with benign diseases, including angiomyolipoma (AML) and oncocytoma, and one with mucinous adenocarcinoma of renal pelvis. Two of twenty-one patients (9.5 %) with clear-cell RCC were positive for CDKN2A and CDKN2B gene deletions. Interestingly, patients with CDKN2A and CDKN2B mutations were associated with sarcomatoid patterns of RCC (2 out of 4, 50 %). In contrast, no CDKN2A or CDKN2B deletions were detected in samples from benign renal tumors, papillary RCC, or other kidney cancers.

Conclusions

This study demonstrated the potential use of CDKN2A and CDKN2B as biomarkers for the prognostic and molecular classification of renal cancer. CDKN2A and CDKN2B mutations may be associated with RCC development and sarcomatoid changes. Further research is needed to understand the underlying molecular mechanisms of CDKN2A and CDKN2B in the pathogenesis of RCC.

Special populations in metastatic renal cell carcinoma

PURPOSE OF REVIEW

This review focuses on special populations poorly represented in current evidence-based practice for metastatic renal cell carcinoma (mRCC). This includes the elderly and frail, patients on immunosuppression or with autoimmune diseases, patients with brain, liver, and/or bone metastases, and RCC with sarcomatoid features.

RECENT FINDINGS

Certain populations are poorly represented in current trials for mRCC. Patients with central nervous system (CNS) metastases are often excluded from first-line therapy trials. Modern doublet systemic therapy appears to benefit patients with bone or liver metastases, but data supporting this conclusion is not robust. Post-hoc analyses on patients with sarcomatoid differentiation have shown improved response to modern doublet therapy over historical treatments. The elderly are underrepresented in current clinical trials, and most trials exclude all but high-performing (nonfrail) patients, though true frailty is likely poorly captured using the current widely adopted indices. It is difficult to make conclusions about the efficacy of modern therapy in these populations from subgroup analyses. Data from trials on other malignancies in patients with autoimmune diseases or solid organ transplant recipients on immunosuppression suggest that immune checkpoint inhibitors (ICIs) may still have benefit, though at the risk of disease flare or organ rejection. The efficacy of ICIs has not been demonstrated specifically for RCC in this group of patients.

SUMMARY

The elderly, frail, and immunosuppressed, those with tumors having aggressive histologic features, and patients with brain, bone, and/or liver metastases represent the populations least understood in the modern era of RCC treatment.

Renal cell carcinoma histologic subtypes exhibit distinct transcriptional profiles

Molecular profiling of clear cell renal cell carcinoma (ccRCC) tumors of patients in a clinical trial has identified distinct transcriptomic signatures with predictive value, yet data in non-clear cell variants (nccRCC) are lacking. We examined the transcriptional profiles of RCC tumors representing key molecular pathways, from a multi-institutional, real-world patient cohort, including ccRCC and centrally reviewed nccRCC samples. ccRCC had increased angiogenesis signature scores compared with the heterogeneous group of nccRCC tumors, while cell cycle, fatty acid oxidation/AMPK signaling, and fatty acid synthesis/pentose phosphate signature scores were increased in one or more nccRCC subtypes. Among both ccRCC and nccRCC tumors, T effector scores statistically correlated with increased immune cell infiltration and were more commonly associated with immunotherapy-related markers (PD-L1+/TMBhi/MSIhi). In conclusion, this study provides evidence of differential gene transcriptional profiles among ccRCC versus nccRCC tumors, providing insights for optimizing personalized and histology-specific therapeutic strategies for patients with advanced RCC.

Predictive and prognostic biomarkers in urological tumours

Advancements in cutting-edge molecular profiling techniques, such as next-generation sequencing and bioinformatic analytic tools, have allowed researchers to examine tumour biology in detail and stratify patients based on factors linked with clinical outcome and response to therapy. This manuscript highlights the most relevant prognostic and predictive biomarkers in kidney, bladder, prostate and testicular cancers with recognised impact in clinical practice. In bladder and prostate cancer, new genetic acquisitions concerning the biology of tumours have modified the therapeutic scenario and led to the approval of target directed therapies, increasing the quality of patient care. Thus, it has become of paramount importance to choose adequate molecular tests, i.e., FGFR screening for urothelial cancer and BRCA1-2 alterations for prostate cancer, to guide the treatment plan for patients. While no tissue or blood-based biomarkers are currently used in routine clinical practice for renal cell carcinoma and testicular cancers, the field is quickly expanding. In kidney tumours, gene expression signatures might be the key to identify patients who will respond better to immunotherapy or anti-angiogenic drugs. In testicular germ cell tumours, the use of microRNA has outperformed conventional serum biomarkers in the diagnosis of primary tumours, prediction of chemoresistance, follow-up monitoring, and relapse prediction.

Understanding Factors that Influence Prognosis and Response to Therapy in Clear Cell Renal Cell Carcinoma

In this review, we highlight and contextualize emerging morphologic prognostic and predictive factors in renal cell carcinoma. We focus on clear cell renal cell carcinoma (ccRCC), the most common histologic subtype. Our understanding of the molecular characterization of ccRCC has dramatically improved in the last decade. Herein, we highlight how these discoveries have laid the foundation for new approaches to prognosis and therapeutic decision-making for patients with ccRCC. We explore the clinical relevance of common mutations, established gene expression signatures, intratumoral heterogeneity, sarcomatoid/rhabdoid morphology and PD-L1 expression, and discuss their impact on predicting response to therapy.

Surgical Management and Oncologic Outcomes of Renal Cell Carcinoma and Inferior Vena Caval Thrombi With Aggressive Histologic Variants

OBJECTIVE

To characterize the surgical management, perioperative, and cancer-specific outcomes, and the influence of aggressive histologic variants (AHV) on operative management among patients with renal cell carcinoma (RCC) and inferior vena cava (IVC) thrombus. RCC with rhabdoid and/or sarcomatoid differentiation, which we defined as AHV, portends a worse prognosis. AHV can be associated with a desmoplastic reaction which may complicate resection.

METHODS

We reviewed patients undergoing radical nephrectomy and IVC thrombectomy between 1990 and 2020. Comparative statistics were employed as appropriate. Survival analysis was performed according to the Kaplan-Meier method, and intergroup analysis performed with log-rank statistics. Multivariable cox proportional hazards regression was used to assess the effect of AHV, age, thrombus level, vena cavectomy, metastases, and medical comorbidities on recurrence and overall survival (OS).

RESULTS

Ninety-four of 403 (23.3%) patients had AHV, including 43 (46%) rhabdoid, 39 (41%) sarcomatoid, and 12 (13%) with both. AHV were more likely to present with advanced disease; however, increased perioperative complications or decreased OS were not observed. Median (IQR) survival was 16.7 (4.8-47) months without AHV and 12.6 (4-29) months with AHV (P = .157). Sarcomatoid differentiation was independently associated with worse OS (HR = 2.016, CI 1.38-2.95, P <.001), whereas rhabdoid alone or with sarcomatoid demonstrated similar OS (P = 0.063).

CONCLUSION

RCC and IVC thrombus with AHV are more likely to present with metastatic disease, and sarcomatoid differentiation is associated with a worse OS. Resection of tumors with and without AHV have similar perioperative complications, suggesting that surgery can be safely accomplished in patients with RCC and IVC thrombus with AHV.

The incidence, pathogenesis, and management of non-clear cell renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and is divided into two distinct subtypes, clear cell renal cell carcinoma (ccRCC) and non-clear cell renal cell carcinoma (nccRCC). Although many treatments exist for RCC, these are largely based on clinical trials performed in ccRCC and there are limited studies on the management of nccRCC. Non-clear cell RCC consists of multiple histological subtypes: papillary, chromophobe, translocation, medullary, collecting duct, unclassified, and other rare histologies. Due to variations in pathogenesis and therapeutic response, therapy should be tailored to specific variant histologies. For patients with localized nccRCC, surgical resection remains the gold standard. In the metastatic setting, the standard of care has yet to be clearly defined, and most guidelines recommend clinical trial participation. General therapeutic options include immunotherapy, either as monotherapy or in combination, targeted therapies such as vascular endothelial growth factor tyrosine kinase inhibitors and MET inhibitors, and chemotherapy in certain subtypes. Here we present a review of the incidence and pathogenesis of the various subtypes, as well as available clinical data to support therapeutic recommendations for these subtypes. We also highlight currently available clinical trials in nccRCC and future directions in investigating novel treatment modalities tailored to patients with variant histology.

Update on Biomarkers in Renal Cell Carcinoma

Immune checkpoint inhibitors have significantly transformed the treatment paradigm for metastatic renal cell carcinoma (RCC), offering prolonged overall survival and achieving remarkable deep and durable responses. However, given the multiple ICI-containing, standard-of-care regimens approved for RCC, identifying biomarkers that predict therapeutic response and resistance is of critical importance. Although tumor-intrinsic features such as pathological characteristics, genomic alterations, and transcriptional signatures have been extensively investigated, they have yet to provide definitive, robust predictive biomarkers. Current research is exploring host factors through in-depth characterization of the immune system. Additionally, innovative technological approaches are being developed to overcome challenges presented by existing techniques, such as tumor heterogeneity. Promising avenues in biomarker discovery include the study of the microbiome, radiomics, and spatial transcriptomics.

Immune checkpoint inhibitors in non-conventional histologies of renal-cell carcinoma

For years, prospective randomized clinical trials excluded patients with non-conventional histologies of renal cell carcinoma (RCC). The paucity of data has led to adopting the same treatment strategies used for clear-cell RCC (ccRCC). In the present narrative review, we explored state of the art about use of immune checkpoint inhibitors (ICIs) in variant histologies of RCC. According to the results collected, ICIs as monotherapy showed promising antitumor activity in advanced non-clear cell (ncc)RCC. The objective response rate (ORR) was similar to that observed with single-agent anti-PD-1 in the ccRCC population, either in the first-line or the second-line setting, and responder patients experienced an early and durable benefit. Combined ICI-based strategies have shown increasing evidence in nccRCC and robust results in the sarcomatoid variants of RCC. A definitive recommendation about treating non-conventional histologies, either in adjuvant or metastatic settings, should be supported by more extensive dedicated trials.

Common clinicopathological and immunological features of sarcomatoid carcinoma across organs: A histomorphology-based cross-organ study

Sarcomatoid carcinoma (SC), which can occur in any organ, is a rare disease. To elucidate common characteristics of SC beyond organs, we evaluated clinicopathological and immunological features of SC defined by the single histological criterion beyond organs compared to randomly matched conventional carcinoma (non-SC) adjusted for the disease stage. Immunological features were assessed by multiplex immunohistochemistry, comparing immune cell density in tumor tissues and tumor programmed death-ligand 1 (PD-L1) expression. A total of 101 patients with SC or non-SC (31 lung, 19 esophagus, 22 pancreas, 15 liver, 4 bile duct, 6 kidney, 2 uterus and 2 ovary) were identified among 7197 patients who underwent surgery at our institute (1997-2020). SC was significantly associated with worse survival (HR: 1.571; 95% CI: 1.084-2.277; P = .017). The frequency of postoperative progression within 6 months was significantly higher for SC patients (54% vs 28%; P = .002). The immune profiling revealed the densities of CD8+ T cells (130 vs 72 cells/mm2 ; P = .004) and tumor-associated macrophages (566 vs 413 cells/mm2 ; P < .0001) and the tumor PD-L1 expression score (40% vs 5%; P < .0001) were significantly higher in SCs than in non-SCs. Among 73 SC patients with postoperative progression, multivariate Cox regression analysis showed that immunotherapy tended to be associated with favorable survival (HR: 0.256; 95% CI: 0.062-1.057; P = .060). Collectively, SCs shared clinicopathological and immunological features across organs. Our study can initiate to standardize the pathological definition of SC and provide a rationale for the investigation and development for this rare disease in a cross-organ manner.

Outcomes of Patients With Advanced Renal Cell Carcinoma With Non-Clear Cell Histology Treated With Systemic Therapy

BACKGROUND

Patients with nonclear cell renal cell carcinoma (RCC) and RCC with sarcomatoid differentiation have been under-represented in clinical trials. This study evaluates the outcomes and treatment patterns of patients with non-clear cell RCC and RCC with sarcomatoid features compared to those with clear cell RCC receiving systemic therapy.

METHODS

A single-center retrospective analysis of patients with advanced or metastatic RCC receiving systemic therapy was conducted. Patients were divided into groups based on histology: nonclear cell RCC, clear cell RCC, and RCC with and without sarcomatoid features. The primary endpoint was overall survival (OS) for each group calculated from the date of diagnosis of advanced or metastatic RCC to the date of last follow-up or death. Additionally, an exploratory analysis was conducted by nonclear cell type and type of first-line treatment.

RESULTS

Overall, 251 patients were included, with most treated before 2018. First-line therapies included vascular endothelial growth factor monotherapy (68.5%), immunotherapy monotherapy (7.6%), immunotherapy combination therapy (16.7%), or other treatments (7.2%). Overall survival was shorter for patients with nonclear cell RCC compared to clear cell RCC (39.2 months vs. 81.1 months, hazard ratio (HR), 1.60, 95% Confidence Interval 1.0, 2.6, P = .04). Additionally, OS for patients with sarcomatoid differentiation was shorter compared to patients without sarcomatoid differentiation (43.4 vs. 75.0 months, HR 1.5, 95% CI 0.8, 2.6, P = .20).

CONCLUSION

We demonstrate inferior outcomes among patients with advanced or metastatic nonclear cell RCC and RCC with sarcomatoid differentiation receiving systemic treatment. Further prospective studies are warranted testing immunotherapy combinations and novel treatments in patients with nonclear cell RCC.

Silencing of genes by promoter hypermethylation shapes tumor microenvironment and resistance to immunotherapy in clear-cell renal cell carcinomas

The efficacy of immune checkpoint inhibitors varies in clear-cell renal cell carcinoma (ccRCC), with notable primary resistance among patients. Here, we integrate epigenetic (DNA methylation) and transcriptome data to identify a ccRCC subtype characterized by cancer-specific promoter hypermethylation and epigenetic silencing of Polycomb targets. We develop and validate an index of methylation-based epigenetic silencing (iMES) that predicts primary resistance to immune checkpoint inhibition (ICI) in the BIONIKK trial. High iMES is associated with VEGF pathway silencing, endothelial cell depletion, immune activation/suppression, EZH2 activation, BAP1/SETD2 deficiency, and resistance to ICI. Combination therapy with hypomethylating agents or tyrosine kinase inhibitors may benefit patients with high iMES. Intriguingly, tumors with low iMES exhibit increased endothelial cells and improved ICI response, suggesting the importance of angiogenesis in ICI treatment. We also develop a transcriptome-based analogous system for extended applicability of iMES. Our study underscores the interplay between epigenetic alterations and tumor microenvironment in determining immunotherapy response.

Increased spatial coupling of integrin and collagen IV in the immunoresistant clear cell renal cell carcinoma tumor microenvironment

Background

Immunotherapy (IO) has improved survival for patients with advanced clear cell renal cell carcinoma (ccRCC), but resistance to therapy develops in most patients. We use cellular-resolution spatial transcriptomics in patients with IO naïve and IO exposed primary ccRCC tumors to better understand IO resistance. Spatial molecular imaging (SMI) was obtained for tumor and adjacent stroma samples. Spatial gene set enrichment analysis (GSEA) and autocorrelation (coupling with high expression) of ligand-receptor transcript pairs were assessed. Multiplex immunofluorescence (mIF) validation was used for significant autocorrelative findings and the cancer genome atlas (TCGA) and the clinical proteomic tumor analysis consortium (CPTAC) databases were queried to assess bulk RNA expression and proteomic correlates.

Results

21 patient samples underwent SMI. Viable tumors following IO harbored more stromal CD8+ T cells and neutrophils than IO naïve tumors. YES1 was significantly upregulated in IO exposed tumor cells. The epithelial-mesenchymal transition pathway was enriched on spatial GSEA and the associated transcript pair COL4A1-ITGAV had significantly higher autocorrelation in the stroma. Fibroblasts, tumor cells, and endothelium had the relative highest expression. More integrin αV+ cells were seen in IO exposed stroma on mIF validation. Compared to other cancers in TCGA, ccRCC tumors have the highest expression of both COL4A1 and ITGAV. In CPTAC, collagen IV protein was more abundant in advanced stages of disease.

Conclusions

On spatial transcriptomics, COL4A1 and ITGAV were more autocorrelated in IO-exposed stroma compared to IO-naïve tumors, with high expression amongst fibroblasts, tumor cells, and endothelium. Integrin represents a potential therapeutic target in IO treated ccRCC.

Establishment and validation of a nomogram to select patients with metastatic sarcomatoid renal cell carcinoma suitable for cytoreductive radical nephrectomy

Introduction

Metastatic renal cell carcinoma (mRCC) with sarcomatoid features has a poor prognosis. Cytoreductive radical nephrectomy (CRN) can improve prognosis, but patient selection is unclear. This study aimed to develop a prediction model for selecting patients suitable for CRN.

Materials and methods

Patients with a diagnosis of mRCC with sarcomatoid features in the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015 were retrospectively reviewed. CRN benefit was defined as a survival time longer than the median overall survival (OS) in patients who did not receive CRN. A prediction nomogram was established and validated using the SEER cohort (training and internal validation) and an external validation cohort.

Results

Of 900 patients with sarcomatoid mRCC, 608 (67.6%) underwent CRN. OS was longer in the CRN group than in the non-CRN group (8 vs. 6 months, hazard ratio (HR) = 0.767, p = 0.0085). In the matched CRN group, 124 (57.7%) patients survived >6 months after the surgery and were considered to benefit from CRN. Age, T-stage, systematic therapy, metastatic site, and lymph nodes were identified as independent factors influencing OS after CRN, which were included in the prediction nomogram. The monogram performed well on the training set (area under the receiver operating characteristic (AUC) curve = 0.766, 95% confidence interval (CI): 0.687-0.845), internal validation set (AUC = 0.796, 95% CI: 0.684-0.908), and external validation set (AUC = 0.911, 95% CI: 0.831-0.991).

Conclusions

A nomogram was constructed and validated with good accuracy for selecting patients with sarcomatoid mRCC suitable for CRN.

The Role of the Pathologist in Renal Cell Carcinoma Management

Recent advances in our understanding of the molecular alterations underlying different types of renal cell carcinoma (RCC), as well as the implementation of immune checkpoint inhibitors in the treatment of patients with advanced disease, have significantly expanded the role of pathologists in the management of RCC patients and in the identification of predictive biomarkers that can guide patient treatment. In this chapter, we examine pathologists' evolving role in patient care and the development of precision medicine strategies for RCC.

Immunobiology and Metabolic Pathways of Renal Cell Carcinoma

The treatment of advanced renal cell carcinoma (RCC) has changed dramatically with immune checkpoint inhibitors, yet most patients do not have durable responses. There is consequently a tremendous need for novel therapeutic development. RCC, and particularly the most common histology clear cell RCC, is an immunobiologically and metabolically distinct tumor. An improved understanding of RCC-specific biology will be necessary for the successful identification of new treatment targets for this disease. In this review, we discuss the current understanding of RCC immune pathways and metabolic dysregulation, with a focus on topics important for future clinical development.

First-Line Treatment for Intermediate and Poor Risk Advanced or Metastatic Clear Cell Renal Cell Carcinoma

Combination therapies with immune checkpoint blockers have shown improvements in overall response rate, progression free survival, and overall survival over monotherapy with sunitinib in intermediate and poor risk subgroups. Identification of best upfront therapy may be guided by future clinical trials utilizing adaptive strategies, triplet therapy, or novel biomarkers.

Early detection of genotoxic hepatocarcinogens in rats using γH2AX and Ki-67: prediction by machine learning

Direct DNA double-strand breaks result in phosphorylation of H2AX, a variant of the histone H2 protein. Phosphorylated H2AX (γH2AX) may be a potential indicator in the evaluation of genotoxicity and hepatocarcinogenicity. In this study, γH2AX and Ki-67 were detected in the short-term responses (24 h after chemical administration) to classify genotoxic hepatocarcinogens (GHs) from non-GH chemicals. One hundred and thirty-five 6-week-old Crl: CD(SD) (SPF) male rats were treated with 22 chemicals including 11 GH and 11 non-GH, sacrificed 24 h later, and immunostained with γH2AX and Ki-67. Positivity rates of these markers were measured in the 3 liver ZONEs 1-3; portal, lobular, and central venous regions. These values were input into 3 machine learning models-Naïve Bayes, Random Forest, and k-Nearest Neighbor to classify GH and non-GH using a 10-fold cross-validation method. All 11 and 10 out of 11 GH caused significant increase in γH2AX and Ki-67 levels, respectively (P < .05). Of the 3 machine learning models, Random Forest performed the best. GH were identified with 95.0% sensitivity (76/80 GH-treated rats), 90.9% specificity (50/55 non-GH-treated rats), and 90.0% overall correct response rate using γH2AX staining, and 96.2% sensitivity (77/80), 81.8% specificity (45/55), and 90.4% overall correct response rate using Ki-67 labeling. Random Forest model using γH2AX and Ki-67 could independently predict GH in the early stage with high accuracy.

Evolutionary fingerprints of EMT in pancreatic cancers

Mesenchymal plasticity has been extensively described in advanced and metastatic epithelial cancers; however, its functional role in malignant progression, metastatic dissemination and therapy response is controversial. More importantly, the role of epithelial mesenchymal transition (EMT) and cell plasticity in tumor heterogeneity, clonal selection and clonal evolution is poorly understood. Functionally, our work clarifies the contribution of EMT to malignant progression and metastasis in pancreatic cancer. We leveraged ad hoc somatic mosaic genome engineering, lineage tracing and ablation technologies and dynamic genetic reporters to trace and ablate tumor-specific lineages along the phenotypic spectrum of epithelial to mesenchymal plasticity. The experimental evidences clarify the essential contribution of mesenchymal lineages to pancreatic cancer evolution and metastatic dissemination. Spatial genomic analysis combined with single cell transcriptomic and epigenomic profiling of epithelial and mesenchymal lineages reveals that EMT promotes with the emergence of chromosomal instability (CIN). Specifically tumor lineages with mesenchymal features display highly conserved patterns of genomic evolution including complex structural genomic rearrangements and chromotriptic events. Genetic ablation of mesenchymal lineages robustly abolished these mutational processes and evolutionary patterns, as confirmed by cross species analysis of pancreatic and other human epithelial cancers. Mechanistically, we discovered that malignant cells with mesenchymal features display increased chromatin accessibility, particularly in the pericentromeric and centromeric regions, which in turn results in delayed mitosis and catastrophic cell division. Therefore, EMT favors the emergence of high-fitness tumor cells, strongly supporting the concept of a cell-state, lineage-restricted patterns of evolution, where cancer cell sub-clonal speciation is propagated to progenies only through restricted functional compartments. Restraining those evolutionary routes through genetic ablation of clones capable of mesenchymal plasticity and extinction of the derived lineages completely abrogates the malignant potential of one of the most aggressive form of human cancer.

Spatially aware deep learning reveals tumor heterogeneity patterns that encode distinct kidney cancer states

Clear cell renal cell carcinoma (ccRCC) is molecularly heterogeneous, immune infiltrated, and selectively sensitive to immune checkpoint inhibition (ICI). However, the joint tumor-immune states that mediate ICI response remain elusive. We develop spatially aware deep-learning models of tumor and immune features to learn representations of ccRCC tumors using diagnostic whole-slide images (WSIs) in untreated and treated contexts (n = 1,102 patients). We identify patterns of grade heterogeneity in WSIs not achievable through human pathologist analysis, and these graph-based "microheterogeneity" structures associate with PBRM1 loss of function and with patient outcomes. Joint analysis of tumor phenotypes and immune infiltration identifies a subpopulation of highly infiltrated, microheterogeneous tumors responsive to ICI. In paired multiplex immunofluorescence images of ccRCC, microheterogeneity associates with greater PD1 activation in CD8+ lymphocytes and increased tumor-immune interactions. Our work reveals spatially interacting tumor-immune structures underlying ccRCC biology that may also inform selective response to ICI.

Cytoreductive Nephrectomy for Patients with Metastatic Sarcomatoid and/or Rhabdoid Renal Cell Carcinoma Treated with Immune Checkpoint Therapy

BACKGROUND

Renal cell carcinoma (RCC) with sarcomatoid and/or rhabdoid (S/R) dedifferentiation is a highly aggressive tumor with a poor prognosis. Immune checkpoint therapy (ICT) has shown significant treatment efficacy in this subtype. There remains uncertainly regarding the role of cytoreductive nephrectomy (CN) for patients with metastatic RCC (mRCC) with S/R who received ICT.

OBJECTIVE

Here, we report the outcomes with ICT for patients with mRCC and S/R dedifferentiation by CN status.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review was conducted of 157 patients with sarcomatoid, rhabdoid, or sarcomatoid plus rhabdoid dedifferentiation who received an ICT-based regimen at two cancer centers.

INTERVENTION

CN performed at any time point; nephrectomy with curative intent was excluded.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

ICT treatment duration (TD) and overall survival (OS) from ICT initiation were recorded. To address the immortal time bias, a time-dependent Cox regression model was generated that accounted for confounders identified by a directed acyclic graph as well as a time-dependent nephrectomy variable.

RESULTS AND LIMITATIONS

A total of 118 patients underwent CN, and of them, 89 underwent upfront CN. The results did not contradict the supposition that CN does not improve ICT TD (hazard ratio [HR] 0.98, 95% confidence interval [CI] 0.65-1.47, p = 0.94) or OS from ICT initiation (HR 0.79, 95% CI 0.47-1.33, p = 0.37). In patients who underwent upfront CN compared with those who did not undergo CN, there was no association with ICT duration or OS (HR 0.61, 95% CI 0.35-1.06, p = 0.08). A detailed clinical summary of 49 patients with mRCC and rhabdoid dedifferentiation is provided.

CONCLUSIONS

In this multi-institutional cohort of mRCC with S/R dedifferentiation treated with ICT, CN was not significantly associated with improved TD or superior OS when accounting for the lead time bias. There appears to be a subset of patients who derive meaningful benefit from CN, so improved tools for stratification prior to CN are needed to optimize outcomes.

PATIENT SUMMARY

Immunotherapy has improved outcomes for patients with metastatic renal cell carcinoma (mRCC) who have sarcomatoid and/or rhabdoid (S/R) dedifferentiation, which is an aggressive and uncommon feature; yet, the utility of a nephrectomy in this setting is unclear. We found that nephrectomy did not significantly improve survival or time on immunotherapy for these patients with mRCC and S/R dedifferentiation; yet, there may be a subset of patients who benefit from this surgical approach.

The SWI/SNF complex member SMARCB1 supports lineage fidelity in kidney cancer

Lineage switching can induce therapy resistance in cancer. Yet, how lineage fidelity is maintained and how it can be lost remain poorly understood. Here, we have used CRISPR-Cas9-based genetic screening to demonstrate that loss of SMARCB1, a member of the SWI/SNF chromatin remodeling complex, can confer an advantage to clear cell renal cell carcinoma (ccRCC) cells upon inhibition of the renal lineage factor PAX8. Lineage factor inhibition-resistant ccRCC cells formed tumors with morphological features, but not molecular markers, of neuroendocrine differentiation. SMARCB1 inactivation led to large-scale loss of kidney-specific epigenetic programs and restoration of proliferative capacity through the adoption of new dependencies on factors that represent rare essential genes across different cancers. We further developed an analytical approach to systematically characterize lineage fidelity using large-scale CRISPR-Cas9 data. An understanding of the rules that govern lineage switching could aid the development of more durable lineage factor-targeted and other cancer therapies.

Circulating and Intratumoral Immune Determinants of Response to Atezolizumab plus Bevacizumab in Patients with Variant Histology or Sarcomatoid Renal Cell Carcinoma

Renal cell carcinoma (RCC) of variant histology comprises approximately 20% of kidney cancer diagnoses, yet the optimal therapy for these patients and the factors that impact immunotherapy response remain largely unknown. To better understand the determinants of immunotherapy response in this population, we characterized blood- and tissue-based immune markers for patients with variant histology RCC, or any RCC histology with sarcomatoid differentiation, enrolled in a phase II clinical trial of atezolizumab and bevacizumab. Baseline circulating (plasma) inflammatory cytokines were highly correlated with one another, forming an "inflammatory module" that was increased in International Metastatic RCC Database Consortium poor-risk patients and was associated with worse progression-free survival (PFS; P = 0.028). At baseline, an elevated circulating vascular endothelial growth factor A (VEGF-A) level was associated with a lack of response (P = 0.03) and worse PFS (P = 0.021). However, a larger increase in on-treatment levels of circulating VEGF-A was associated with clinical benefit (P = 0.01) and improved overall survival (P = 0.0058). Among peripheral immune cell populations, an on-treatment decrease in circulating PD-L1+ T cells was associated with improved outcomes, with a reduction in CD4+PD-L1+ [HR, 0.62; 95% confidence interval (CI), 0.49-0.91; P = 0.016] and CD8+PD-L1+ T cells (HR, 0.59; 95% CI, 0.39-0.87; P = 0.009) correlated with improved PFS. Within the tumor itself, a higher percentage of terminally exhausted (PD-1+ and either TIM-3+ or LAG-3+) CD8+ T cells was associated with worse PFS (P = 0.028). Overall, these findings support the value of tumor and blood-based immune assessments in determining therapeutic benefit for patients with RCC receiving atezolizumab plus bevacizumab and provide a foundation for future biomarker studies for patients with variant histology RCC receiving immunotherapy-based combinations.

Interferon signaling promotes tolerance to chromosomal instability during metastatic evolution in renal cancer

Molecular routes to metastatic dissemination are critical determinants of aggressive cancers. Through in vivo CRISPR-Cas9 genome editing, we generated somatic mosaic genetically engineered models that faithfully recapitulate metastatic renal tumors. Disruption of 9p21 locus is an evolutionary driver to systemic disease through the rapid acquisition of complex karyotypes in cancer cells. Cross-species analysis revealed that recurrent patterns of copy number variations, including 21q loss and dysregulation of the interferon pathway, are major drivers of metastatic potential. In vitro and in vivo genomic engineering, leveraging loss-of-function studies, along with a model of partial trisomy of chromosome 21q, demonstrated a dosage-dependent effect of the interferon receptor genes cluster as an adaptive mechanism to deleterious chromosomal instability in metastatic progression. This work provides critical knowledge on drivers of renal cell carcinoma progression and defines the primary role of interferon signaling in constraining the propagation of aneuploid clones in cancer evolution.

Cystic Clear Cell Renal Cell Carcinoma: A Morphological and Molecular Reappraisal

A wide variety of renal neoplasms can have cystic areas. These can occur for different reasons: some tumors have an intrinsic cystic architecture, while others exhibit pseudocystic degeneration of necrotic foci or they have cystically dilated renal tubules constrained by stromal neoplastic cells. Clear cell renal cell carcinoma (CCRCC), either solid or cystic, is the most frequent type of renal cancer. While pseudocysts are found in high-grade aggressive CCRCC, cystic growth is associated with low-grade indolent cases. The latter also form through a cyst-dependent molecular pathway, and they are more frequent in patients suffering from VHL disease. The differential diagnosis of multilocular cystic renal neoplasm of low malignant potential and clear cell papillary renal cell tumor can be especially hard and requires a focused macroscopical and microscopical pathological analysis. As every class of renal tumor includes cystic forms, knowledge of the criteria required for a differential diagnosis is mandatory.

Comparison of tyrosine kinase inhibitors in the treatment of metastatic renal cell carcinoma with rhabdoid and sarcomatoid differentiations

OBJECTIVE

To investigate the efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of metastatic renal cell carcinoma (mRCC) with rhabdoid (mRCC-R) and sarcomatoid (mRCC-S) differentiations.

MATERIALS AND METHODS

In this single-institutional cohort study, we included patients with RCC with rhabdoid (RCC-R) and sarcomatoid (RCC-S) differentiation, who were treated with TKIs after metastasis at our institute from 2013 to 2021. Patient characteristics, treatments, and clinical outcomes were recorded and analyzed.

RESULTS

We identified 111 patients with RCC-R or RCC-S differentiations, of which 23 patients were included in the final analysis. Of the 23 patients, 10 (43.5%) were grouped as mRCC-R and 13 (56.5%) as mRCC-S. At a median follow-up of 40 months, mRCC-R and mRCC-S progressed in 7 of 10 and 12 of 13 patients, respectively. In addition, four and eight patients died in the mRCC-R and mRCC-S groups, respectively. The median progression-free survival (PFS) of the two groups was 19 months (mRCC-R: 95% confidence interval [CI] 4.08-33.92) and 7 months (mRCC-S: 95% CI 2.03-11.96), while the median overall survival (OS) was 32 months and 21 months, respectively. mRCC-S had a worse prognosis than mRCC-R. Based on the univariate Cox regression model, single metastasis or multiple metastasis of tumor, rhabdoid differentiation, and sarcomatoid differentiation were predictors of PFS but not OS.

CONCLUSION

The efficacy of TKIs in the treatment of mRCC-R and mRCC-S may be different.

The components of tumor microenvironment as biomarker for immunotherapy in metastatic renal cell carcinoma

Substantial improvement in prognosis among metastatic renal cell carcinoma (mRCC) patients has been achieved, owing to the rapid development and utilization of immunotherapy. In particular, immune checkpoint inhibitors (ICIs) have been considered the backbone of systemic therapy for patients with mRCC alongside multi-targeted tyrosine kinase inhibitors (TKIs) in the latest clinical practice guidelines. However, controversies and challenges in optimal individualized treatment regarding immunotherapy remains still About 2/3 of the patients presented non-response or acquired resistance to ICIs. Besides, immune-related toxicities, namely immune-related adverse events, are still elusive and life-threatening. Thus, reliable biomarkers to predict immunotherapeutic outcomes for mRCC patients are needed urgently. Tumor microenvironment (TME), consisting of immune cells, vasculature, signaling molecules, and extracellular matrix and regulates tumor immune surveillance and immunological evasion through complex interplay, plays a critical role in tumor immune escape and consequently manipulates the efficacy of immunotherapy. Various studied have identified the different TME components are significantly associated with the outcome of mRCC patients receiving immunotherapy, making them potential valuable biomarkers in therapeutic guidance. The present review aims to summarize the latest evidence on the associations between the components of TME including immune cells, cytokines and extracellular matrix, and the therapeutic responses among mRCC patients with ICI-based treatment. We further discuss the feasibility and limitation of these components as biomarkers.

Robotic-assisted cytoreductive partial nephrectomy for metastatic sarcomatoid renal cell carcinoma following dramatic response to combination immunotherapy in a young female

Novel immune checkpoint inhibitors (ICI) have yielded remarkable response rates in metastatic renal cell carcinoma (RCC), including sarcomatoid RCC (sRCC). Here, we show the feasibility and efficacy of robotic-assisted cytoreductive partial nephrectomy (cPN) following a remarkable response to combination ICI for metastatic sRCC in a young female. A female in her late 40s presented with poor-risk, metastatic sRCC emanating from a 6.5 cm left renal mass including pulmonary involvement, retroperitoneal lymphadenopathy, and a scalp metastasis. She received 4 cycles of combination ipilimumab and nivolumab followed by maintenance nivolumab with a remarkable and durable response. Given the apparent downstaging of her primary tumor, a robotic cPN was pursued for residual ypT1aNoRo sRCC and found to be both feasible and safe with exceptional perioperative outcomes. She has since done well clinically and oncologically. Our unique case of metastatic sRCC in a young female highlights several aspects pertinent to the contemporary management of metastatic RCC including the role for cytoreductive nephrectomy in selected patients, the safety and feasibility of a nephron-sparing and minimally-invasive approach to cytoreduction after downstaging with ICI, and remarkable sensitivity of sRCC-a classically aggressive entity-to ICI.

Adjuvant immunotherapy in renal cell carcinoma: a systematic review and meta-analysis

OBJECTIVES

To synthesise available data regarding the disease-free survival (DFS) benefit of adjuvant immune checkpoint inhibitors (ICIs) for patients with renal cell carcinoma (RCC) and evaluate the overall safety profile of ICIs in this setting.

MATERIALS AND METHODS

We utilised PubMed, Embase, and relevant conference proceedings to identify phase III randomised controlled trials comparing adjuvant ICIs vs placebo/observation for RCC. The primary outcome of interest was DFS. Variables for subgroup analyses were programmed death-ligand 1 (PD-L1) expression, sarcomatoid features, nephrectomy type, and disease-risk category. Secondary outcomes included Grade ≥3 adverse events (AEs), immune-related AEs, and treatment discontinuation due to AEs. All outcomes were analysed using random-effects models owing to inter-study heterogeneity.

RESULTS

Among the four included studies, one demonstrated a significant DFS benefit. There was considerable clinical and statistical heterogeneity (I2  = 64%) due to differences in inclusion criteria and interventions. While pooled results across the four studies did not demonstrate a significant benefit in DFS overall (hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.69-1.04) there was significant benefit among patients with positive PD-L1 expression (HR 0.72, 95% CI 0.55-0.94) and sarcomatoid features (HR 0.59, 95% CI 0.38-0.91).

CONCLUSION

The evidence base to date regarding ICIs as adjuvant therapy in RCC is mixed - conclusions are limited by considerable heterogeneity between studies. However, pooled analyses suggest that patients with positive PD-L1 expression or sarcomatoid features are most likely to benefit from adjuvant immunotherapy.

The Changing Landscape of Immunotherapy for Advanced Renal Cancer

The management of advanced renal cell carcinoma has advanced tremendously over the past decade, but most patients still do not receive durable clinical benefit from current therapies. Renal cellcarcinoma is an immunogenic tumor, historically with conventional cytokine therapies, such as interleukin-2 and interferon-α, and contemporarily with the introduction of immune checkpoint inhibitors. Now the central therapeutic strategy in renal cell carcinoma is combination therapies including immunecheckpoint inhibitors. In this Review, we look back on the historical changes in systemic therapy for advanced renal cell carcinoma, and focus on the latest developments and prospects in this field.

Prognostic and predictive biomarkers for immunotherapy in advanced renal cell carcinoma

The therapeutic algorithm of renal cell carcinoma has been revolutionized by the approval of immunotherapy agents by regulatory agencies. However, objective and durable responses are still not observed in a large number of patients, and prognostic and predictive biomarkers for immunotherapy response are urgently needed. Prognostic models used in clinical practice are based on clinical and laboratory factors (such as hypercalcaemia, neutrophil count or Karnofsky Performance Status), but, with progress in molecular biology and genome sequencing techniques, new renal cell carcinoma molecular features that might improve disease course and outcomes prediction have been highlighted. An implementation of current models is needed to improve the accuracy of prognosis in the immuno-oncology era. Moreover, several potential biomarkers are currently under evaluation, but effective markers to select patients who might benefit from immunotherapy and to guide therapeutic strategies are still far from validation.

Spatially aware deep learning reveals tumor heterogeneity patterns that encode distinct kidney cancer states

Clear cell renal cell carcinoma (ccRCC) is molecularly heterogeneous, immune infiltrated, and selectively sensitive to immune checkpoint inhibition (ICI). Established histopathology paradigms like nuclear grade have baseline prognostic relevance for ccRCC, although whether existing or novel histologic features encode additional heterogeneous biological and clinical states in ccRCC is uncertain. Here, we developed spatially aware deep learning models of tumor- and immune-related features to learn representations of ccRCC tumors using diagnostic whole-slide images (WSI) in untreated and treated contexts (n = 1102 patients). We discovered patterns of nuclear grade heterogeneity in WSI not achievable through human pathologist analysis, and these graph-based "microheterogeneity" structures associated with PBRM1 loss of function, adverse clinical factors, and selective patient response to ICI. Joint computer vision analysis of tumor phenotypes with inferred tumor infiltrating lymphocyte density identified a further subpopulation of highly infiltrated, microheterogeneous tumors responsive to ICI. In paired multiplex immunofluorescence images of ccRCC, microheterogeneity associated with greater PD1 activation in CD8+ lymphocytes and increased tumor-immune interactions. Thus, our work reveals novel spatially interacting tumor-immune structures underlying ccRCC biology that can also inform selective response to ICI.

The Natural History of Renal-Cell Carcinoma with Sarcomatoid Differentiation, a Stage-by-Stage Analysis

BACKGROUND

Sarcomatoid differentiation in patients diagnosed with renal cell carcinoma (sRCC) imply aggressive behavior and often metastatic disease at the time of diagnosis. We aim to examine the overall survival (OS) in patients with sRCC using the National Cancer Database (NCDB).

MATERIALS AND METHODS

We identified patients diagnosed with sRCC between 2010-2015. We employed Kaplan-Meier curves and multivariable Cox proportional hazards regression models to examine the impact of several potential risk factors on OS in patients diagnosed with sRCC.

RESULTS

In total, 8582 patients with renal cancer were found to have sarcomatoid differentiation, with 4105 patients (47.8%) being diagnosed with AJCC stage IV disease. The median OS was 17.2 months (IQR 5.4, 68.7 months). Compared to patients who did not undergo surgery, OS was significantly longer in patients undergoing partial or total nephrectomy across all stages. This result remained consistent on multivariable Cox proportional hazards regression adjusting for patient and tumor characteristics (Surgery: Hazard ratio 0.54, 95%Confidence interval 0.43 - 0.68, P < .001).

CONCLUSION

In our cohort sRCC was found to have an unfavorable median OS, which was mainly caused by the high number of cases diagnosed with late-stage disease. Additionally, surgery was associated with favorable OS across all stages. This study supports the notion that surgical therapy, even in the setting of cytoreductive surgery, provides a survival benefit in patients with sRCC.

Adjuvant Therapy for Renal Cell Carcinoma: End Points, Outcomes, and Risk Assessments

PURPOSE

Targeted tyrosine kinase inhibitors (TKIs) and immune-checkpoint inhibitors (ICIs) revolutionized the treatment of metastatic renal cell carcinoma (RCC). Efforts to translate these therapies into the adjuvant setting for local and locoregional RCC have been pursued over the past decade. We sought to provide an updated review of the literature regarding adjuvant therapy in RCC, as well as an analysis of patient characteristics that may portend the most favorable responses.

MATERIALS AND METHODS

Using PubMed, Google Scholar, and Wiley Online Library, we reviewed articles between 2000 and 2022. Search terms included "tyrosine kinase inhibitors," "adjuvant," "immunotherapy," and "renal cell carcinoma." The articles included were original and published in English. Information on clinical trials was collected from ClinicalTrials.gov, accessed in June 2022.

RESULTS

Landmark trials investigating adjuvant vascular endothelial growth factor (VEGF) inhibitors produced conflicting results, with only a single trial of sunitinib (S-TRAC) resulting in US Food and Drug Administration-approval on the basis of a slightly prolonged progression-free survival (PFS). Subsequent meta-analyses failed to show a benefit for adjuvant VEGF inhibitors. Several trials evaluating ICIs are currently ongoing, with pembrolizumab (KEYNOTE-564) earning US Food and Drug Administration-approval for a prolonged PFS, although overall survival data are not yet mature. Preliminary results from other adjuvant ICI trials have been conflicting.

CONCLUSION

There remains a lack of clear benefit for the use of adjuvant VEGF inhibitors in local and locoregional RCC. Adjuvant ICI investigations are ongoing, with promising results from KEYNOTE-564. It remains to be seen if PFS is an adequate surrogate end point for overall survival. Selection of patients at greatest risk for recurrence, and identification of those at greatest risk of rare but serious adverse events, may improve outcomes.

The role of immune checkpoint inhibitors (ICI) as adjuvant treatment in renal cell carcinoma (RCC): A systematic review and meta-analysis

Pembrolizumab, a PD-1 ICI is approved for the adjuvant treatment of postnephrectomy patients with clear cell RCC in some countries worldwide. However, recent negative data from randomized clinical trials (RCT) with another ICIs makes the benefit of this treatment uncertain. A systematic review and study-level meta-analysis was performed to evaluate the benefit of disease-free survival (DFS) with adjuvant ICI treatment for patients with localized and/or metastatic resected RCC. Using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement, a systematic search was performed in PUBMED/MEDLINE, Scopus and EMBASE up to September 15, 2022. The statistical analysis was performed by ProMeta 3 software in intention-to-treat (ITT) population and in predetermined subgroups. Four RCT totalizing 3407 patients were included in this analysis. Systemic immunotherapy was pembrolizumab, atezolizumab, nivolumab, and ipilimumab plus nivolumab in 496, 390, 404, and 405 patients, respectively. In the ITT population there was a nonstatistically significant DFS benefit with adjuvant ICI (HR: 0.85, 95% CI: 0.69-1.04). Regarding the subgroups, there was a DFS benefit for PD-L1 positive (HR: 0.72; 95% CI: 0.55-0.94), intermediate-high risk patients (HR: 0.77; 95% CI: 0.63-0.94), and patients with sarcomatoid component (HR: 0.66; 95% CI: 0.43-0.99). This meta-analysis did not demonstrate a statistically significant DFS benefit in overall population, however considering the heterogeneity between the RCTs the use of adjuvant ICI should be individualized.

Histopathologic and proteogenomic heterogeneity reveals features of clear cell renal cell carcinoma aggressiveness

Clear cell renal cell carcinomas (ccRCCs) represent ∼75% of RCC cases and account for most RCC-associated deaths. Inter- and intratumoral heterogeneity (ITH) results in varying prognosis and treatment outcomes. To obtain the most comprehensive profile of ccRCC, we perform integrative histopathologic, proteogenomic, and metabolomic analyses on 305 ccRCC tumor segments and 166 paired adjacent normal tissues from 213 cases. Combining histologic and molecular profiles reveals ITH in 90% of ccRCCs, with 50% demonstrating immune signature heterogeneity. High tumor grade, along with BAP1 mutation, genome instability, increased hypermethylation, and a specific protein glycosylation signature define a high-risk disease subset, where UCHL1 expression displays prognostic value. Single-nuclei RNA sequencing of the adverse sarcomatoid and rhabdoid phenotypes uncover gene signatures and potential insights into tumor evolution. In vitro cell line studies confirm the potential of inhibiting identified phosphoproteome targets. This study molecularly stratifies aggressive histopathologic subtypes that may inform more effective treatment strategies.

Navigating the Current Landscape of Non-Clear Cell Renal Cell Carcinoma: A Review of the Literature

Non-clear cell renal cell carcinoma (nccRCC) is an entity comprised of a heterogeneous constellation of RCC subtypes. Genomic profiling has broadened our understanding of molecular pathogenic mechanisms unique to individual nccRCC subtypes. To date, clinical trials evaluating the use of immunotherapies and targeted therapies have predominantly been conducted in patients with clear cell histology. A comprehensive review of the literature has been undertaken in order to describe molecular pathogenic mechanisms pertaining to each nccRCC subtype, and concisely summarise findings from therapeutic trials conducted in the nccRCC space.

ANGPTL8 links inflammation and poor differentiation, which are characteristics of malignant renal cell carcinoma

Inflammation is observed in many tumors, which affects metastasis, infiltration, and immune escape and causes poor differentiation of the cancer cells. However, the molecular basis underlying the relationship between inflammation and poor differentiation in tumors has not been identified. In this study, we demonstrate that angiopoietin-like protein-8 (ANGPTL8), which is induced by stress stimuli such as inflammation, is involved in the maintenance of the undifferentiated state of clear cell renal cell carcinoma (ccRCC) cells. ANGPTL8 is also involved in the production of chemokines that attract immune suppressor cells to the tumor microenvironment. ANGPTL8 sustains the continuous production of chemokines by activating the NF-κB signaling pathway and maintains the undifferentiated state of ccRCC cells. Finally, ANGPTL8 is induced by STAT3 signaling, which is activated by immune cells in the tumor microenvironment. These results support a role for ANGPTL8 in determining the properties of ccRCC by hampering tumor cell differentiation and establishing the tumor microenvironment.

"Collecting duct carcinoma of the kidney: diagnosis and implications for management"

Collecting duct carcinoma of the kidney is a rare and aggressive subtype of renal cell carcinoma (RCC) arising from the distal convoluted tubules. At the time of diagnosis, patients are more frequently symptomatic, with advanced locoregional stage, and have metastatic disease. The 2016 WHO Classification of Tumours of the Urinary System defined diagnostic criteria for this entity. However, the diagnostic features continue to evolve, with typical, but not entirely specific, histologic and immunophenotypic characteristics. In addition, the lack of consistent molecular alterations makes collecting duct carcinoma a diagnosis of exclusion, with historical cases being re-classified as fumarate hydratase deficient RCC, ALK rearranged RCC, renal medullary carcinoma or high-grade urothelial carcinoma. The rarity and poor prognosis of the tumor makes it difficult to reach consensus guidelines to guide therapy. In this manuscript we review the clinicopathologic features of collecting duct carcinoma including pathologic diagnostic criteria, molecular characteristics and differential diagnosis, and their possible implications for management.

Hot topics in renal cancer pathology: implications for clinical management

INTRODUCTION

The updated European Association of Urology (EAU) Guidelines issued a weak recommendation for adjuvant pembrolizumab for patients with high-risk operable clear cell Renal Cell Carcinoma (ccRCC). High risk of recurrence was defined, as per protocol-criteria, as T2 with nuclear grade 4 or sarcomatoid differentiation, T3 or higher, regional lymph node metastasis, or stage M1 with no evidence of disease. Considering the heterogeneous population included in the recommendation, it has been questioned if adjuvant pembrolizumab may lead to overtreatment of some patients as well as undertreatment of patients with worse prognosis.

AREAS COVERED

In this review, we discuss the issues related to the assessment of pathological features required to identify those patients harboring a high-risk tumor, highlighting the issue related to interobserver variability and discuss the currently available prognostic scoring systems in ccRCC.

EXPERT OPINION

PPathologist assessment of prognostic features suffers from interobserver variability which may depend on gross sampling and the pathologist's expertise. The presence of clear cell feature is not sufficient criteria by itself to define ccRCC since clear cell can be also found in other histotypes. Application of molecular biomarkers may be useful tools in the near future to help clinicians identify patients harboring tumors with worse prognosis.