Non-Clear Cell Renal Cell Carcinomas: From Shadow to Light

Clinical features and response to immune combinations in patients with renal cell carcinoma and sarcomatoid de-differentiation (ARON-1 study)

Metastatic renal cell carcinoma (mRCC) carrying sarcomatoid features (sRCC) has aggressive biology and poor prognosis. First-line immunotherapy (IO)-based combinations have improved the outcome of clear cell RCC patients, including that of sRCC. Real-world data confirming the adequate first-line management of sRCC is largely lacking. We investigated the clinical features and the outcome of sRCC patients treated with IO-based combinations within the ARON-1 study population (NCT05287464). The primary objective was to define the incidence and baseline clinical characteristics of sRCC compared with non-sRCC patients. The secondary objective was to describe the outcome of sRCC patients based on type of first-line treatment (IO + IO vs. IO + tyrosin kinase inhibitor [TKI]). We identified 1362 mRCC patients with IMDC intermediate or poor risk, 226 sRCC and 1136 non-sRCC. These two subgroups did not differ in terms of baseline characteristics. The median overall survival (OS) was 26.8 months (95%CI 21.6-44.2) in sRCC and 35.3 months (95%CI 30.2-40.4) in non-sRCC patients (p = .013). The median progression-free survival (PFS) was longer in non-sRCC patients compared to sRCC (14.5 vs. 12.3 months, p = .064). In patients treated with first-line IO + TKI the median OS was 34.4 months compared to 26.4 months of those who received IO + IO (p = .729). The median PFS was 12.4 months with IO + TKI and 12.3 months with IO + IO (p = .606). In conclusion, we confirm that sRCC are aggressive tumors with poor prognosis. IO-based combinations improve survival outcomes of sRCC patients, regardless from the type of strategy (IO + IO versus IO + TKI) adopted.

A Multi-Omics Prognostic Model Capturing Tumor Stemness and the Immune Microenvironment in Clear Cell Renal Cell Carcinoma

Background: Cancer stem-like cells (CSCs), a distinct subset recognized for their stem cell-like abilities, are intimately linked to the resistance to radiotherapy, metastatic behaviors, and self-renewal capacities in tumors. Despite their relevance, the definitive traits and importance of CSCs in the realm of oncology are still not fully comprehended, particularly in the context of clear cell renal cell carcinoma (ccRCC). A comprehensive understanding of these CSCs' properties in relation to stemness, and their impact on the efficacy of treatment and resistance to medication, is of paramount importance. Methods: In a meticulous research effort, we have identified new molecular categories designated as CRCS1 and CRCS2 through the application of an unsupervised clustering algorithm. The analysis of these subtypes included a comprehensive examination of the tumor immune environment, patterns of metabolic activity, progression of the disease, and its response to immunotherapy. In addition, we have delved into understanding these subtypes' distinctive clinical presentations, the landscape of their genomic alterations, and the likelihood of their response to various pharmacological interventions. Proceeding from these insights, prognostic models were developed that could potentially forecast the outcomes for patients with ccRCC, as well as inform strategies for the surveillance of recurrence after treatment and the handling of drug-resistant scenarios. Results: Compared with CRCS1, CRCS2 patients had a lower clinical stage/grading and a better prognosis. The CRCS2 subtype was in a hypoxic state and was characterized by suppression and exclusion of immune function, which was sensitive to gefitinib, erlotinib, and saracatinib. The constructed prognostic risk model performed well in both training and validation cohorts, helping to identify patients who may benefit from specific treatments or who are at risk of recurrence and drug resistance. A novel therapeutic target, SAA2, regulating neutrophil and fibroblast infiltration, and, thus promoting ccRCC progression, was identified. Conclusions: Our findings highlight the key role of CSCs in shaping the ccRCC tumor microenvironment, crucial for therapy research and clinical guidance. Recognizing tumor stemness helps to predict treatment efficacy, recurrence, and drug resistance, informing treatment strategies and enhancing ccRCC patient outcomes.

Targeting HIF-2α and anemia: A therapeutic breakthrough for clear-cell renal cell carcinoma

Renal cell carcinoma (RCC) is a heterogenous disease which the incidence is increasing worldwide. The identification and understanding of the role of the Von Hipple Lindau (VHP) in regulating the hypoxia-inducible factor signaling pathway has revolutionized the treatment of this disease. Belzutifan is an oral hypoxia-inducible factor (HIF)-2α inhibitor, which has demonstrated efficacy in treating von Hippel-Lindau (VHL) disease and for the treatment of adults with RCC who experienced disease progression after PD-1/PD-L1- and VEGFR-targeted therapies. One of the most common adverse effect of this drug is anemia; however, it is treatment is not well known. This review summarizes role of the VHL-HIF pathway in ccRCC aroused the interest of targeting HIF activity, the history of belzutifan development and their relationship to anemia as well as propose a management algorithm.

FDG-Avid Metastatic Non-Clear Cell Renal Cell Carcinoma Presenting as Intussusception

ABSTRACT

A 47-year-old man with a history of metastatic non-clear cell left renal cell carcinoma, unclassified subtype, status post left radical nephrectomy 4 years prior, and treated with immunotherapy for approximately 2½ years, presented for 18 F-FDG PET/CT exam 7 months after immunotherapy was stopped. A contrast-enhanced CT exam performed 3 weeks prior demonstrated a new small bowel intussusception in the left upper quadrant. The PET/CT demonstrated focal FDG uptake in the segment of small bowel involved in the intussusception. Pathology from small bowel resection demonstrated metastatic renal cell carcinoma.

First-Line Immune Combination Therapies for Nonclear Cell Versus Clear Cell Metastatic Renal Cell Carcinoma: Real-World Multicenter Data From Germany

INTRODUCTION

The aim was to compare treatment outcomes of clear cell metastatic renal cell carcinoma (ccmRCC) versus non-ccmRCC (nccmRCC) patients who received first-line immune combination therapies.

MATERIALS AND METHODS

Within our retrospective multi-institutional consecutive database of eight tertiary-care centers, we identified mRCC patients treated with first-line immune combination therapies between 11/2017 and 12/2022. Using log-rank analysis and multivariable Cox regression, we tested for differences in overall survival (OS) and progression-free survival (PFS) of nccmRCC versus ccmRCC patients. Covariables consisted of age at diagnosis, sex, International Metastatic Renal Cell Carcinoma Database Consortium risk groups, Eastern Cooperative Oncology Group status, and sarcomatoid feature.

RESULTS

Of 289 study patients, 39 (13%) patients harbored nccmRCC. Median OS was 37 months versus not reached for ccmRCC versus nccmRCC patients (P = .6). Median PFS was 13 versus 15 months (P = .9). Multivariable Cox regression models did not identify nccmRCC as an independent predictor of higher overall mortality in mRCC patients (hazard ratio [HR]: 1.23; P = .6) or a higher progression rate (HR: 1.0; P = 1.0).

CONCLUSION

In our real-world multi-institutional study, no differences in OS and PFS between ccmRCC and nccmRCC patients receiving first-line immune combination treatment were observed, even after adjustment for important patient and tumor characteristics. More prospective trials in nccmRCC patients are needed.

Comprehensive analyses of immune tumor microenvironment in papillary renal cell carcinoma

BACKGROUND

Papillary renal cell carcinoma (pRCC) is the most common non-clear cell RCC, and associated with poor outcomes in the metastatic setting. In this study, we aimed to comprehensively evaluate the immune tumor microenvironment (TME), largely unknown, of patients with metastatic pRCC and identify potential therapeutic targets.

METHODS

We performed quantitative gene expression analysis of TME using Microenvironment Cell Populations-counter (MCP-counter) methodology, on two independent cohorts of localized pRCC (n=271 and n=98). We then characterized the TME, using immunohistochemistry (n=38) and RNA-sequencing (RNA-seq) (n=30) on metastatic pRCC from the prospective AXIPAP trial cohort.

RESULTS

Unsupervised clustering identified two "TME subtypes", in each of the cohorts: the "immune-enriched" and the "immune-low". Within AXIPAP trial cohort, the "immune-enriched" cluster was significantly associated with a worse prognosis according to the median overall survival to 8 months (95% CI, 6 to 29) versus 37 months (95% CI, 20 to NA, p=0.001). The two immune signatures, Teff and JAVELIN Renal 101 Immuno signature, predictive of response to immune checkpoint inhibitors (CPI) in clear cell RCC, were significantly higher in the "immune-enriched" group (adjusted p<0.05). Finally, five differentially overexpressed genes were identified, corresponding mainly to B lymphocyte populations.

CONCLUSION

For the first time, using RNA-seq and immunohistochemistry, we have highlighted a specific immune TME subtype of metastatic pRCC, significantly more infiltrated with T and B immune population. This "immune-enriched" group appears to have a worse prognosis and could have a potential predictive value for response to immunotherapy, justifying the confirmation of these results in a cohort of metastatic pRCC treated with CPI and in combination with targeted therapies.

TRIAL REGISTRATION NUMBER

NCT02489695.

Development and External Validation of a Novel Nomogram Predicting Cancer-specific Mortality-free Survival in Surgically Treated Papillary Renal Cell Carcinoma Patients

BACKGROUND

Accurate prediction of cancer control outcomes in renal cell carcinoma (RCC) patients is important for counselling, follow-up planning, and selection of appropriate adjuvant trial designs.

OBJECTIVE

To develop and externally validate a novel contemporary population-based model for predicting cancer-specific mortality-free survival (CSM-FS) in surgically treated papillary RCC (papRCC) patients and to compare it with established risk categories (Leibovich 2018).

DESIGN, SETTING, AND PARTICIPANTS

Within the Surveillance, Epidemiology, and End Results database (2004-2019), we identified surgically treated papRCC patients (n = 3978). The population was randomly divided into development (50%, n = 1989) and external validation (50%, n = 1989) cohorts. Of the external validation cohort, 97% (n = 1930) of patients were included in a head-to-head comparison of the Leibovich 2018 risk categories addressing nonmetastatic patients.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Univariable Cox regression models tested the statistical significance in the prediction of CSM-FS. The most parsimonious model with the best validation metrics was selected as the multivariable nomogram. Accuracy, calibration, and decision curve analyses (DCAs) tested the Cox regression-based nomogram, as well as the Leibovich 2018 risk categories in the external validation cohort.

RESULTS AND LIMITATIONS

Age at diagnosis, grade, T stage, N stage, and M stage qualified for inclusion in the novel nomogram. In external validation, the accuracy of the novel nomogram was 0.83 at 5 yr and 0.80 at 10 yr. In nonmetastatic patients, 5- and 10-yr accuracy of the novel nomogram was 0.77 and 0.76, respectively. Conversely, 5- and 10-yr accuracy of the Leibovich 2018 risk categories was 0.70 and 0.66, respectively. The novel nomogram exhibited smaller departures from ideal predictions in calibration plots and higher net benefit in DCAs, when it was compared with the Leibovich 2018 risk categories. Limitations include the retrospective nature of the study, absence of a central pathological review, and inclusion of only North American patients.

CONCLUSIONS

The novel nomogram may represent a valuable clinical aid, when papRCC CSM-FS predictions are required.

PATIENT SUMMARY

We developed an accurate tool to predict death due to papillary kidney cancer in a North American population.

Assessment of the VENUSS and GRANT Models for Individual Prediction of Cancer-specific Survival in Surgically Treated Nonmetastatic Papillary Renal Cell Carcinoma

Background

Guidelines recommend VENUSS and GRANT models for the prediction of cancer control outcomes after nephrectomy for nonmetastatic papillary renal cell carcinoma (pRCC).

Objective

To test the ability of VENUSS and GRANT models to predict 5-yr cancer-specific survival in a North American population.

Design setting and participants

For this retrospective study, we identified 4184 patients with unilateral surgically treated nonmetastatic pRCC in the Surveillance, Epidemiology, and End Results database (2004-2019).

Outcome measurements and statistical analysis

The original VENUSS and GRANT risk categories were applied to predict 5-yr cancer-specific survival. A cross-validation method was used to test the accuracy and calibration of the models and to conduct decision curve analyses for the study cohort.

Results and limitations

The VENUSS and GRANT categories represented independent predictors of cancer-specific mortality. On cross-validation, the accuracy of the VENUSS and GRANT risk categories was 0.73 and 0.65, respectively. Both models showed good calibration and performed better than random predictions in decision curve analysis. Limitations include the retrospective nature of the study and the absence of a central pathological review.

Conclusion

VENUSS risk categories fulfilled prognostic model criteria for predicting cancer-specific survival 5 yr after surgery in North American patients with nonmetastatic pRCC as recommended by guidelines. Conversely, GRANT risk categories did not. Thus, VENUSS risk categories represent an important tool for counseling, follow-up planning, and patient selection for appropriate adjuvant trials in pRCC.

Patient summary

We tested the ability of two validated methods (VENUSS and GRANT) to predict death due to papillary kidney cancer in a North American population. The VENUSS risk categories showed good performance in predicting 5-year cancer-specific survival.

Cancer-specific mortality free survival rates in non-metastatic non-clear cell renal carcinoma patients at intermediate/high risk of recurrence

BACKGROUND

To date, five trials testing the effect of adjuvant systemic therapy in surgically treated non-metastatic renal cell carcinoma included patients with non-clear cell histology. We tested the effect of papillary vs. chromophobe histological subtype, stage, and grade on 10-year cancer-specific survival, in patients eligible for ≥1 such trial.

METHODS

We identified patients meeting ASSURE, SORCE, EVEREST, PROSPER, or RAMPART trial inclusion criteria in the SEER (2000-2018) database. Kaplan-Meier analyses estimated 10-year survival rates and multivariable Cox regression models tested for the independent predictor status of histological subtype, stage, and grade.

RESULTS

We identified 5465 (68%) papillary and 2562 (32%) chromophobe renal cell carcinoma patients. Cancer-specific survival rates at 10 years were 77% in papillary vs. 90% in chromophobe. In multivariable Cox regression models applied to papillary patients, cancer-specific mortality independent predictor status was reached for T3G3-4 (HR 2.9), T4Gany (HR 3.4), TanyN1G1-2 (HR 3.1), and TanyN1G3-4 (HR 8.0, P<0.001), relative to T1/2Gany. In multivariable Cox regression models applied to chromophobe patients, mortality independent predictor status was reached for T3G3-4 (HR 3.6), T4Gany (HR 14.0), TanyN1G1-2 (HR 5.7), and TanyN1G3-4 (HR 15.0, P<0.001), relative to T1/2Gany.

CONCLUSIONS

In surgically treated non-metastatic intermediate/high-risk renal cell carcinoma patients, papillary histologic subtype exhibited worse cancer-specific survival than chromophobe histologic subtype. Although stage and grade represented independent predictors in both histological subtype groups, the magnitude of their effect was invariably worse in chromophobe than in papillary patients. In consequence, papillary and chromophobe patients should be considered separate entities instead of being combined under the non-clear cell designation.

Critical Appraisal of Leibovich 2018 and GRANT Models for Prediction of Cancer-Specific Survival in Non-Metastatic Chromophobe Renal Cell Carcinoma

Within the Surveillance, Epidemiology, and End Results database (2000–2019), we identified 5522 unilateral surgically treated non-metastatic chromophobe kidney cancer (chRCC) patients. This population was randomly divided into development vs. external validation cohorts. In the development cohort, the original Leibovich 2018 and GRANT categories were applied to predict 5- and 10-year cancer-specific survival (CSS). Subsequently, a novel multivariable nomogram was developed. Accuracy, calibration and decision curve analyses (DCA) tested the Cox regression-based nomogram as well as the Leibovich 2018 and GRANT risk categories in the external validation cohort. The accuracy of the Leibovich 2018 and GRANT models was 0.65 and 0.64 at ten years, respectively. The novel prognostic nomogram had an accuracy of 0.78 at ten years. All models exhibited good calibration. In DCA, Leibovich 2018 outperformed the novel nomogram within selected ranges of threshold probabilities at ten years. Conversely, the novel nomogram outperformed Leibovich 2018 for other values of threshold probabilities. In summary, Leibovich 2018 and GRANT risk categories exhibited borderline low accuracy in predicting CSS in North American non-metastatic chRCC patients. Conversely, the novel nomogram exhibited higher accuracy. However, in DCA, all examined models exhibited limitations within specific threshold probability intervals. In consequence, all three examined models provide individual predictions that might be suboptimal and be affected by limitations determined by the natural history of chRCC, where few deaths occur within ten years from surgery. Further investigations regarding established and novel predictors of CSS and relying on large sample sizes with longer follow-up are needed to better stratify CSS in chRCC.

WHO 2022 landscape of papillary and chromophobe renal cell carcinoma

The 5th edition of the WHO Classification of Tumours of the Urinary and Male Genital Systems contains relevant revisions and introduces a group of molecularly defined renal tumour subtypes. Herein we present the World Health Organization (WHO) 2022 perspectives on papillary and chromophobe renal cell carcinoma with emphasis on their evolving classification, differential diagnosis, and emerging entities. The WHO 2022 classification eliminated the type 1/2 papillary renal cell carcinoma (pRCC) subcategorization, given the recognition of frequent mixed tumour phenotypes and the existence of entities with a different molecular background within the type 2 pRCC category. Additionally, emerging entities such as biphasic squamoid alveolar RCC, biphasic hyalinising psammomatous RCC, papillary renal neoplasm with reverse polarity, and Warthin-like pRCC are included as part of the pRCC spectrum, while additional morphological and molecular data are being gathered. In addition to oncocytomas and chromophobe renal cell carcinoma (chRCC), a category of 'other oncocytic tumours' with oncocytoma/chRCC-like features has been introduced, including emerging entities, most with TSC/mTOR pathway alterations (eosinophilic vacuolated tumour and so-called 'low-grade' oncocytic tumour), deserving additional research. Eosinophilic solid and cystic RCC was accepted as a new and independent tumour entity. Finally, a highly reproducible and clinically relevant universal grading system for chRCC is still missing and is another niche of ongoing investigation. This review discusses these developments and highlights emerging morphological and molecular data relevant for the classification of renal cell carcinoma.

Impact of MET status on treatment outcomes in papillary renal cell carcinoma: A pooled analysis of historical data

BACKGROUND

Papillary renal cell carcinoma (PRCC) represents 15% of RCCs but has no indicated therapies, with limited biomarker-based data to inform targeted treatment. MET alterations may be key; > 80% of PRCC tumours show MET upregulation. The objective of this study was to assess MET status in PRCC and its impact on clinical outcomes.

METHODS

This retrospective, observational study included patients with locally advanced/metastatic PRCC from three international registries. MET status was determined retrospectively by next generation sequencing (NGS) of archival tissue. MET-driven was defined as MET and/or hepatocyte growth factor amplification, chromosome 7 gain, and/or MET kinase domain mutations. Objectives included progression-free survival (PFS) and overall survival (OS) by MET status using a Cox proportional hazards model.

RESULTS

Of 308 patients, 305 received first-line treatment; most commonly sunitinib (n = 208; 68%), then everolimus (n = 40; 13%). Of 179 patients with valid NGS results, 38% had MET-driven and 49% MET-independent tumours (13% unevaluable). In the MET-driven versus MET-independent subgroups, respectively, of sunitinib-treated patients, median PFS was numerically longer, though not statistically significantly; PFS: 9.2 months (95% confidence interval [CI]: 5.4-13.2) versus 5.7 months (95% CI: 4.3-7.4), hazard ratio (HR) = 0.67; 95% CI: 0.41-1.08. There was no difference between the OS of each subgroup.

CONCLUSIONS

MET-driven PRCC may respond to targeted agents. However, the presence of MET alterations did not appear to be predictive for outcomes in response to current therapies, which are not biomarker-driven, compared with MET-independent tumours.

From Basic Science to Clinical Translation in Kidney Cancer: A Report from the Second Kidney Cancer Research Summit

The second Kidney Cancer Research Summit was held virtually in October 2020. The meeting gathered worldwide experts in the field of kidney cancer, including basic, translational, and clinical scientists as well as patient advocates. Novel studies were presented, addressing areas of unmet need related to different topics. These include novel metabolic targets, promising immunotherapeutic regimens, predictive genomic and transcriptomic biomarkers, and variant histologies of renal cell carcinoma (RCC). With the development of pioneering technologies, and an unprecedented commitment to kidney cancer research, the field has tremendously evolved. This perspective aims to summarize the different sessions of the conference, outline major advances in the understanding of RCC and discuss current challenges faced by the field.

Patient Characteristics and Survival Outcomes of Non-Metastatic, Non-Clear Cell Renal Cell Carcinoma

Background

Non-clear cell renal cell carcinoma (ccRCC) includes histologically and molecularly distinct subtypes such as papillary, chromophobe, collecting duct, and sarcomatoid RCC, with an incidence ranging from 20% to 25%. Oncologic outcomes and the role of adjuvant systemic therapy [vascular endothelial growth factor inhibitor (VEGFi) or immunotherapy] for non-ccRCC are not well-described.

Objective

To assess the incidence and survival outcomes of non-ccRCC subtypes in comparison to ccRCC.

Methods

The National Cancer Database was utilized to identify patients with non-metastatic RCC (T1–T4, N0–N1) between 2004 and 2015. The non-ccRCC cohort was further stratified by histologic subtype: papillary, chromophobe, sarcomatoid, and collecting duct RCC. Multivariable Cox regression models were used to compare overall survival (OS).

Results

The 5-year OS for chromophobe, papillary, clear cell, collecting duct, and sarcomatoid RCC was 91%, 82%, 81%, 44%, and 40%, respectively. After adjusting for clinicopathologic and treatment characteristics, there was no significant difference in OS between papillary RCC and ccRCC (p = 0.17). Patients with collecting duct and sarcomatoid subtypes were at over two times increased risk of death compared to patients with clear cell (p < 0.01 and p < 0.01, respectively). Conversely, patients with chromophobe RCC were at 36% decreased risk of death compared to ccRCC (p < 0.01).

Conclusions

This hospital-based analysis confirms that collecting duct and sarcomatoid histologic subtypes are uncommon and associated with poor survival after surgery when compared to the other RCC subtypes. Further studies are needed to evaluate the role of neoadjuvant and adjuvant systemic therapies in these subtypes to improve oncologic outcomes.

How to individualise oncological treatment of patients with metastatic non-clear cell renal cell carcinoma by using gene sequencing and Patient-Reported Outcomes: INDIGO study protocol (Preprint)

Background

No phase 3 studies have yet been conducted for patients with non–clear cell (CC) renal cell carcinoma (RCC) exclusively due to the rare occurrence of the disease and the heterogenicity in tumor morphology. Consequently, there is no evidence of the optimal treatment, and new approaches are needed. One approach is individualizing treatment based on the gene sequencing of tumor tissue. Additionally, recent studies involving the patient-reported outcomes (PROs) of patients treated for metastatic cancer have shown significant benefits for quality of life, median overall survival, and overall survival. The use of gene sequencing and PROs can be of great importance to patients with rare cancer types, including patients with non-CC RCC, and should be investigated in clinical trials, especially for cases where evidence based on phase 3 studies is difficult to obtain.

Objective

We describe the INDIGO study, in which patients, based on gene analyses, will be allocated into 4 treatment arms containing 14 treatments and use electronic PROs. We aim to improve the treatment of patients with non-CC RCC. The end points in the study will be the overall response rate (complete and partial) in the total patient population, which will be based on the RECIST (Response Evaluation Criteria in Solid Tumors) version 1.1 criteria, and the time to treatment failure.

Methods

INDIGO is a prospective phase 2 trial, and 30 patients will be enrolled. The patients will receive systemic treatment based on genetic analyses of their tumor tissue. All patients will receive electronic questionnaires in a dedicated app—a questionnaire regarding symptoms and side effects and another regarding health-related quality of life. Depending on the treatment regimen, the patients will be seen by a medical doctor every third, fourth, or sixth week, and the effect of the systemic treatment will be evaluated every 6 weeks via a computed tomography scan. The study has been approved by the Danish Medicines Agency and the National Committee on Health Research Ethics (approval number: H-19041833), complies with good clinical practice guidelines, follows the General Data Protection Regulation, and is registered at the Capital Region of Denmark.

Results

Recruitment started in March 2020, and at the time of submitting this paper (June 2022), a total of 9 patients have been enrolled.

Conclusions

We aim to explore methods for improving the treatment outcomes of patients with non-CC RCC, and the INDIGO study will contribute further data on personalized medicine for rare types of RCC and provide new knowledge on the active use of electronic PROs.

Trial Registration

ClinicalTrials.gov NCT04644432, https://clinicaltrials.gov/ct2/show/NCT04644432 ; European Union Drug Regulating Authorities Clinical Trials Database 2019-001316-38, https://tinyurl.com/2p8mb4aw

International Registered Report Identifier (IRRID)

DERR1-10.2196/36632

Cabozantinib in Combination With Atezolizumab for Advanced Renal Cell Carcinoma: Results From the COSMIC-021 Study

[Figure: see text].

Pathology and systemic therapy of non-clear cell renal cell carcinoma: an overview

Introduction: Non-clear cell renal cell carcinoma (nccRCC) represents a highly heterogenous group of kidney cancer entities. As most clinical trials predominantly include patients with clear cell RCC (ccRCC), nccRCC treatment guidelines are mainly extrapolated from recommendations in ccRCC. Here, we review and elucidate current data on the pathologic classification and treatment of nccRCC.Areas covered: This article gives an overview of the WHO classification of RCC, showing the histological diversity of nccRCC and focusing particularly on entities first characterized since 2016, their specific molecular behavior and their role as indicators for hereditary cancer syndromes. In this context, we discuss the available data on nccRCC treatment oprtions such as tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, cytotoxic chemotherapy, and immune checkpoint inhibitors.Expert opinion: Although nccRCCs are relatively uncommon, entities of this type account for a subgroup of up to 20-25% of all RCCs. Advances in histopathology and molecular genetics, together with evidence gained from retrospective and prospective clinical data, have improved understanding of these tumors in recent years. Nevertheless, selective trials of current and novel therapies including new targeted agents in patients with nccRCC are urgently needed to further improve treatment guidelines.

The Molecular Characteristics of Non-Clear Cell Renal Cell Carcinoma: What's the Story Morning Glory?

Non-clear cell renal cell carcinomas are a miscellaneous group of tumors that include different histological subtypes, each one characterized by peculiarity in terms of genetic alteration, clinical behavior, prognosis, and treatment response. Because of their low incidence and poor enrollment in clinical trials, alongside their heterogeneity, additional efforts are required to better unveil the pathogenetic mechanisms and, consequently, to improve the treatment algorithm. Nowadays, tyrosine kinase inhibitors, mTOR and MET inhibitors, and even cisplatin-based chemotherapy and immunotherapy are potential weapons that are still under evaluation in this setting. Various biomarkers have been evaluated for detecting progression and monitoring renal cell carcinoma, but more studies are necessary to improve this field. In this review, we provide an overview on the molecular characteristics of this group of tumors and the recently published trials, giving an insight into what might become the future therapeutic standard in this complex world of non-clear cell kidney cancers.

Checkpoint inhibitors in metastatic papillary renal cell carcinoma

Papillary Renal Cell Carcinoma (pRCC) is the most common non-clear cell RCC (nccRCC) and a distinct entity, although heterogenous, associated with poor outcomes. The treatment landscape of metastatic pRCC (mpRCC) relied so far on targeted therapies, mimicking previous developments in metastatic clear-cell renal cell carcinoma. However, antiangiogenics as well as mTOR inhibitors retain only limited activity in mpRCC. As development of immune checkpoint inhibitors (ICI) is now underway in patients with mpRCC, we aimed at discussing early activity data and potential for future therapeutic strategies in monotherapy or combination. Expression of immune checkpoints such as PD-L1 and infiltrative immune cells in pRCC could provide insights into their potential immunogenicity, although this is currently poorly described. Based on retrospective and prospective data, efficacy of ICI as single agent remains limited. Combinations with tyrosine-kinase inhibitors, notably with anti-MET inhibitors, harbor promising response rates and may enter the standard of care in untreated patients. Collaborative work is needed to refine the molecular and immune landscape of pRCC, and pursue efforts to set up predictive biomarker-driven clinical trials in these rare tumors.

Systemic Therapies for the Management of Non-Clear Cell Renal Cell Carcinoma: What Works, What Doesn't, and What the Future Holds

Non-clear cell renal cell carcinoma (nccRCC) is a broad term that refers to a diverse group of tumors, each with its own distinct biologic and therapeutic profile. The management of nccRCCs is often based on extrapolating data from clinical trials in the more common clear cell renal cell carcinoma, but our emerging prospective and retrospective clinical experience in nccRCC allows us to make more precise recommendations tailored to each histology. The systemic therapy options for metastatic nccRCC include targeted therapies such as tyrosine kinase inhibitors, immune checkpoint inhibitors, and, for specific rare subtypes, cytotoxic chemotherapy. Each nccRCC histology may respond differently to these regimens, which makes accurate pathologic diagnosis imperative. In the present review, we discuss the available clinical and biological data that can help guide systemic therapy recommendations for specific nccRCC subtypes.

Beyond conventional immune-checkpoint inhibition - novel immunotherapies for renal cell carcinoma

The management of advanced-stage renal cell carcinoma (RCC) has been transformed by the development of immune-checkpoint inhibitors (ICIs). Nonetheless, most patients do not derive durable clinical benefit from these agents. Importantly, unlike other immunotherapy-responsive solid tumours, most RCCs have only a moderate mutational burden, and paradoxically, high levels of tumour CD8+ T cell infiltration are associated with a worse prognosis in patients with this disease. Building on the successes of antibodies targeting the PD-1 and CTLA4 immune checkpoints, multiple innovative immunotherapies are now in clinical development for the treatment of patients with RCC, including ICIs with novel targets, co-stimulatory pathway agonists, modified cytokines, metabolic pathway modulators, cell therapies and therapeutic vaccines. However, the successful development of such novel immune-based treatments and of immunotherapy-based combinations will require a disease-specific framework that incorporates a deep understanding of RCC immunobiology. In this Review, using the structure provided by the well-described cancer-immunity cycle, we outline the key steps required for a successful antitumour immune response in the context of RCC, and describe the development of promising new immunotherapies within the context of this framework. With this approach, we summarize and analyse the most encouraging targets of novel immune-based therapies within the RCC microenvironment, and review the landscape of emerging antigen-directed therapies for this disease.

Broad spectrum mutational analysis of chromophobe renal cell carcinoma using next-generation sequencing

BACKGROUND

Chromophobe renal cell carcinoma (ChRCC) is a rare subtype of non-clear cell renal cell carcinoma. Due to its rarity, its molecular characterization as well as therapeutic targets are still not fully understood.

METHODS

We performed a next-generation sequencing analysis using the platform Ion PGM System on 20 retrospectively collected ChRCC cases with the aim of identify molecular biomarkers with potential prognostic value or that could have therapeutic implications.

RESULTS

We identified mutation onTP53, SMARCB1, RB1 and JAK3. The most frequently altered gene was TP53 (6/20, 30 % of cases). SMARCB1 mutation was found in 3 (15 %) patients and in all cases the mutational variant was p.T72 K, with known pathogenenic meaning. One (5%) patient presented a pathogenetic mutation of RB1. JAK3 was mutated in 1 (5%) patient and this mutation resulted to have uncertain pathogenetic significance.

CONCLUSION

ChRCC is a rare disease still not fully molecularly characterized. Next-generation sequencing analysis could be useful to identify potential mutation with prognostic value or that could be potential therapeutic targets.

Evaluation of Clear Cell, Papillary, and Chromophobe Renal Cell Carcinoma Metastasis Sites and Association With Survival

IMPORTANCE

There exists considerable biological and clinical variability between histologic variants of metastatic renal cell carcinoma (mRCC). Data reporting on patterns of metastasis in histologic variants of mRCC are sparse.

OBJECTIVE

To characterize sites of metastasis and their association with survival across the 3 most common histologic variants of mRCC: clear cell (ccRCC), papillary (pRCC), and chromophobe (chrRCC).

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter, international cohort study, the International mRCC Database Consortium (IMDC) database was used to identify consecutive patients starting systemic therapy for mRCC between 2002 and 2019. Patients with mixed histologic subtype were excluded. Statistical analysis was performed from February to June 2020.

EXPOSURES

Data regarding histologic subtype and sites of metastatic involvement at the time of first systemic therapy initiation were collected.

MAIN OUTCOMES AND MEASURES

The primary outcomes were prevalence of metastatic site involvement and overall survival (OS) from time of systemic therapy initiation. Patients with multiple sites of metastatic involvement were included in analyses of all groups to which they had metastases.

RESULTS

A total of 10 105 patients were eligible for analysis. Median (interquartile range) age at diagnosis was 60 (53-67) years, 7310 (72.4%) were men and 8526 (84.5%) underwent nephrectomy. Of these, 9252 (92%) had ccRCC, 667 (7%) had pRCC, and 186 (2%) had chrRCC. The median number of sites of metastasis was 2 (range, 0-7). In ccRCC, the most common sites of metastasis were lung (70%; 6189 of 8804 patients [448 missing]), lymph nodes (45%; 3874 of 8655 patients [597 missing]), bone (32%; 2847 of 8817 patients [435 missing]), liver (18%; 1560 of 8804 [448 missing]), and adrenal gland (10%; 678 of 6673 patients [2579 missing]). Sites of metastasis varied between subtypes. Lung, adrenal, brain, and pancreatic metastases were more frequent in ccRCC, lymph node involvement was more common in pRCC, and liver metastases were more frequent in chrRCC. Median OS for ccRCC varied by site of metastatic involvement, ranging between 16 months (95% CI, 13.7-18.8 months) for the pleura and 50 months (95% CI, 41.1-55.5 months) for the pancreas. Compared with ccRCC, patients with pRCC tended to have lower OS, regardless of metastatic site.

CONCLUSIONS AND RELEVANCE

Sites of metastatic involvement differ according to histologic subtype in mRCC and are associated with OS. These data highlight the clinical and biological variability between histologic subtypes of mRCC. Patterns of metastatic spread may reflect differences in underlying disease biology. Further work to investigate differences in immune, molecular, and genetic profiles between metastatic sites and histologic subtypes is encouraged.

Immunotherapy in metastatic sarcomatoid renal cell carcinoma: A single institution experience

INTRODUCTION

Immune checkpoint inhibitors (CPIs) were recently approved in advanced clear cell renal cell carcinoma (RCC) and could be a promising option for metastatic RCC with sarcomatoid differentiation (sRCC) which otherwise carry a poor prognosis. We sought to compare outcomes between patients who received immunotherapy (IO) including CPIs or high dose interleukin-2 (HD IL2) for metastatic sRCC versus those who did not.

PATIENTS AND METHODS

We performed a single-center retrospective data analysis of 44 consecutive sRCC patients with any percentage of sarcomatoid differentiation from our institutional RCC database of whom 34 received IO and 10 patients did not.

RESULTS

Baseline variables between the two groups were not significantly different except for a greater percentage of patients with ≥40% sarcomatoid differentiation in the non-IO cohort. At a median follow-up of 27.6 months, patients treated with IO had a median overall survival of 57.6 months compared to 6.6 months in patients not treated with IO (p = 0.0002). Overall response rates (ORR) between the IO and non-IO group were 35.3% and 0% respectively (p = 0.06). When IO was given in the 1st line setting, the ORR was 25.0%, as compared to 44.4% in the 2nd line setting and beyond though limitations of small sample sizes apply. Immune-related adverse events (IRAE) occurred in 38.2% of patients in the IO group, with grade 3 events (mostly gastrointestinal) in 20.6% with no grade 4 or 5 events. IRAEs led to interruption or discontinuation of immunotherapy in 26.5%.

CONCLUSION

Our results support IO as an effective therapeutic option for patients with metastatic sarcomatoid RCC. Further study of various IO regimens, including those affecting the interleukin-2 signaling pathway, and their efficacy in neoadjuvant and adjuvant settings are warranted in sRCC.

Tumor contour irregularity on preoperative imaging: a practical and useful prognostic parameter for papillary renal cell carcinoma

OBJECTIVES

To illustrate tumor contour irregularity on preoperative imaging with a practical method and further determine its value in predicting disease-free survival (DFS) in patients with pRCC (papillary renal cell carcinoma).

METHODS

We performed a retrospective single-institution review of 267 Chinese pRCC patients between March 2009 and May 2019. Contour irregularity on cross-section was classified into smooth but distorted margin, unsmooth and sharply nodular margin, and blurred margin. Then, the ratio of the cross-section numbers of irregularity and the total tumor was defined as the contour irregular degree (CID). Cox regression and Kaplan-Meier analysis were performed to analyze the impact of CID on DFS. Then, the prognostic performance of CID was compared with pRCC risk stratification published by Leibovich et al. RESULTS: The median follow-up was 45 months (IQR: 23-69), in which 27 (10%) patients had metastasis or recurrence. Observed DFS rates were 95%, 90%, and 88% at 1, 3, and 5 years. The CID was an independent prognostic factor of DFS (HR = 1.048, 95% CI = 1.029-1.068, p < 0.001). The Kaplan-Meier plot showed that high-risk patients (CID ≥ 50%) tended to have a significantly shorter DFS (p < 0.001). The CID and Leibovich's pRCC model for DFS prediction had a C-index of 0.934 (95% CI = 0.907-0.961) and 0.833 (95% CI = 0.739-0.927) respectively.

CONCLUSIONS

With our standard and practical method, the CID can be a reliable imaging marker for DFS prediction in patients with pRCC.

KEY POINTS

• The updated contour irregularity was an independent parameter for predicting disease-free survival in patients with pRCC. • High-risk pRCC patients (contour irregular degree ≥ 50%) tended to have a shorter disease-free survival. • Tumor contour irregularity in pRCC risk stratification outperformed Leibovich's model from our cohort.

Efficacy of Savolitinib vs Sunitinib in Patients With MET-Driven Papillary Renal Cell Carcinoma: The SAVOIR Phase 3 Randomized Clinical Trial

Importance

Papillary renal cell carcinoma (PRCC) is the most common type of non-clear cell RCC. Because some cases of PRCC are MET-driven, MET inhibition could be a targeted treatment approach. In previous studies, savolitinib (AZD6094, HMPL-504, volitinib), a highly selective MET-tyrosine kinase inhibitor, demonstrated antitumor activity in this patient group.

Objective

To determine whether savolitinib is a better treatment option for this patient population, vs standard of care, sunitinib.

Design, Setting, and Participants

The SAVOIR phase 3, open-label, randomized clinical trial was a multicenter study carried out in 32 centers in 7 countries between July 2017 and the data cutoff in August 2019. Overall, 360 to 450 patients were to be screened to randomize approximately 180 patients. Patients were adults with MET-driven (centrally confirmed), metastatic PRCC, with 1 or more measurable lesions. Exclusion criteria included prior receipt of sunitinib or MET inhibitor treatment. Overall, 254 patients were screened.

Interventions

Patients received 600 mg of savolitinib orally once daily (qd), or 50 mg of sunitinib orally qd for 4 weeks, followed by 2 weeks without treatment.

Main Outcomes and Measures

The primary end point was progression-free survival (PFS, assessed by investigator and confirmed by blinded independent central review). Secondary end points included overall survival (OS), objective response rate (ORR), duration of response, and safety/tolerability.

Results

At data cutoff, 60 patients were randomized (savolitinib n = 33; sunitinib n = 27); most patients had chromosome 7 gain (savolitinib, 30 [91%]; sunitinib, 26 [96%]) and no prior therapy (savolitinib, 28 [85%]; sunitinib, 25 [93%]). For savolitinib and sunitinib, 4 (12%) and 10 (37%) patients were women, and the median (range) age was 60 (23-78) and 65 (31-77) years, respectively. Following availability of external data on PFS with sunitinib in patients with MET-driven disease, study enrollment was closed. Progression-free survival, OS, and ORR were numerically greater with savolitinib vs sunitinib. Median PFS was not statistically different between the 2 groups: 7.0 months (95% CI, 2.8-not calculated) for savolitinib and 5.6 months (95% CI, 4.1-6.9) for sunitinib (hazard ratio [HR], 0.71; 95% CI, 0.37-1.36; P = .31). For savolitinib and sunitinib respectively, grade 3 or higher adverse events (AEs) were reported in 14 (42%) and 22 (81%) of patients and AE-related dose modifications in 10 (30%) and 20 (74%). After discontinuation, 12 (36%) and 5 (19%) of patients on savolitinib and sunitinib respectively, received subsequent anticancer therapy.

Conclusions and Relevance

Although patient numbers and follow-up were limited, savolitinib demonstrated encouraging efficacy vs sunitinib, with fewer grade 3 or higher AEs and dose modifications. Further investigation of savolitinib as a treatment option for MET-driven PRCC is warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT03091192.

Patients with sarcomatoid renal cell carcinoma - re-defining the first-line of treatment: A meta-analysis of randomised clinical trials with immune checkpoint inhibitors

BACKGROUND

Sarcomatoid renal cell carcinoma (sRCC) represents a rare form of renal cell carcinoma marked by an aggressive biology, poor prognosis and little benefit from anti-angiogenic targeted therapy. More promising results come from the recent therapeutic strategy based on immune checkpoint inhibitor (ICI) combinations.

MATERIALS AND METHODS

For this meta-analysis, we searched MEDLINE/PubMed, the Cochrane Library and American Society of Medical Oncology (ASCO) Meeting abstracts for phase II or III randomised clinical trials. Data extraction was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. The hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) with the relative 95% confidence intervals were extracted from studies. Summary HRs were calculated using random- or fixed-effects models, depending on the heterogeneity of the included studies.

RESULTS

Four studies were selected for final analysis, including 467 patients (226 treated in with ICI combinations and 241 received sunitinib in the control arms). ICI-based combinations were associated with an improved PFS and OS compared with sunitinib, with a reduction of more than 40% of progression (HR = 0.56; p < 0.0001) and mortality (HR = 0.56; p = 0.001) risk. Moreover, ICI-based combinations are associated with a objective response rate (ORR) of more than 50% (versus 20% with sunitinib), corresponding to a doubled risk of achieving an ORR compared with controls (relative risk [RR] = 2.15; p < 0.00001). Finally, immunotherapy significantly increased the possibility to obtain complete responses (RR = 8.15, p = 0.0002) with an incidence of 11%.

CONCLUSION

Our data support the efficacy of ICI-based combinations for sRCC therapy, redefining the first-line treatment.

Are immune checkpoint inhibitors a valid option for papillary renal cell carcinoma? A multicentre retrospective study

BACKGROUND

Papillary renal cell carcinoma (pRCC) is the most common non-clear cell RCC (nccRCC). Pivotal studies evaluating immune checkpoint inhibitors mostly excluded nccRCC. The aim of this retrospective and multicentre study was to evaluate the activity of programmed death-1 (PD-1)/ programmed death-ligand 1 (PD-L1) inhibitors specifically in metastatic pRCC.

METHODS

The primary end-point was time to treatment failure (TTF). Secondary endpoints included objective response rate (ORR), overall survival (OS) and treatment-related adverse events (TRAEs).

RESULTS

From 02/2016 to 01/2019, 57 patients with pRCC were included. Histology included 16 (28%) type 1 pRCC, 34 (60%) type 2 pRCC and 7 (12%) unclassified pRCC. Treatment with immune checkpoint inhibitors was used in the first-line setting in 4 patients (7%), in the second-line setting in 32 patients (56%) and in the third-line setting or more in 21 patients (37%). With a median follow-up of 12 months (95% confidence interval [CI]: 9.9-21.0), the median TTF was 3.1 months (95% CI: 2.7-5.0). Among the 55 patients evaluable for ORR, best response was complete response/partial response in 6 patients (11%), stable disease in 18 patients (33%) and progressive disease in 31 patients (56%). The median OS was 14.6 months (95% CI: 9.0- not reached). TRAEs of grade III-IV were noted in 6 patients (10%) leading to treatment discontinuation, and no grade V TRAEs were observed.

CONCLUSION

PD-1/PD-L1 inhibitors exhibit limited activity as monotherapy in this pRCC population, which remains an unmet need. Our findings underline the need for further prospective clinical trials evaluating immune checkpoint inhibitor combinations in patients with pRCC.

A Randomized Phase IIa Trial with Temsirolimus versus Sunitinib in Advanced Non-Clear Cell Renal Cell Carcinoma: An Intergroup Study of the CESAR Central European Society for Anticancer Drug Research-EWIV and the Interdisciplinary Working Group on Renal Cell Cancer (IAGN) of the German Cancer Society

BACKGROUND

Non-clear cell renal cell cancers (nccRCC) are rare entities, and the optimal therapy in metastatic disease has still to be defined.

METHODS

In this small prospectively randomized phase IIa multicenter trial, we investigated temsirolimus (TEM) versus sunitinib (SUN) as first-line therapy in patients with metastatic nccRCC. The patients were randomized 1:1 to either TEM in a dose of 25 mg i.v. once a week or SUN with 50 mg p.o. daily for 4 weeks on and 2 weeks off. Primary endpoint was progression-free survival (PFS). In total, 22 patients were included with predominantly papillary RCC (16/22) followed by chromophobe RCC and others.

RESULTS

The male to female ratio was 16:6. The tumor control rate (CR + PR + SD) was 58% for TEM and 90% for SUN-treated patients. There was also a trend for improved PFS with 9.3 versus 13.2 months (HR 1.64; 95% CI 0.65-4.18) in favor of SUN. There was no trend for overall survival.

CONCLUSIONS

Despite this trial had to be terminated earlier due to low recruitment, the results match the other studies published so far with the mTOR inhibitor everolimus and SUN, which show a trend in favor of SUN for ORR and PFS.

Management of Metastatic Renal Cell Carcinoma with Variant Histologies

Variant histology renal cell carcinoma (vRCC) encompasses rare non-clear cell subtypes that have long been associated with poor prognosis and minimal response to therapies targeting vascular endothelial growth factor and its receptor. Molecular advances have helped classify vRCC into distinct entities and identify putative targetable driver alterations, such as MET in papillary subtypes. More have since been identified in other vRCC subtypes, including alterations of tumor metabolism, chromatin remodeling genes, cell-cycle genes, and inactivation of tumor suppressors such as TP53 or NF2. New targeted therapies, as well as immune checkpoint inhibitors, have been in development and yielded encouraging results. Collaborative clinical trials will be an essential step toward better implementation of these regimens in clinical practice.

Safety and efficacy of CDX-014, an antibody-drug conjugate directed against T cell immunoglobulin mucin-1 in advanced renal cell carcinoma

CDX-014 is an antibody-drug conjugate directed against TIM-1, a surface marker highly expressed in renal cell carcinoma (RCC) and ovarian carcinoma. This phase I, first-in-human trial was conducted to evaluate the safety and preliminary activity of CDX-014 in patients with advanced refractory RCC, following a dose-escalation and dose expansion design. CDX-014 was administered intravenously at doses ranging from 0.15 to 2.0 mg/kg every 2 or 3 weeks until progression or unacceptable toxicity. Sixteen patients received at least one dose of CDX-014. The maximum tolerated dose was not identified. Most frequent adverse grade 1 or 2 adverse events included nausea (38%), fatigue, alopecia, elevation of AST and decreased appetite (25% each). Adverse events of grade 3 or more included hyperglycemia (19%), urosepsis (6%), and one multi-organ failure (6%) responsible for one treatment-related death. Two patients discontinued therapy for adverse events including fatigue grade 2 and urosepsis grade 4. CDX-014 showed antitumor activity with one prolonged partial response and a clinical benefit rate (objective response or stable disease >6 months) of 31%. The two patients that exhibited the most marked tumor shrinkage had high TIM-1 expression on tumor tissue. Overall, CDX-014 exhibited a manageable toxicity profile and early signs of activity, supporting further evaluation of antibody-drug conjugates in patients with advanced RCC and potentially other TIM-1 expressing cancers. Trial registration https://clinicaltrials.gov/ct2/show/NCT02837991 NCT02837991; July 20, 2016.

Latest progress in molecular biology and treatment in genitourinary tumours

The management of genitourinary cancer, including bladder, prostate, renal and testicular cancer, has evolved dramatically in recent years due to a better understanding of tumour genetic mutations, alterations in molecular pathways, and to the development of new kinds of drugs such as targeted therapies and immunotherapies. In the field of immunotherapy, new drugs focused on stimulating, enhancing and modulating the immune system to detect and destroy cancer, have been recently discovered. Research in oncology moves quickly and new data of great relevance for clinical practice are communicated every year. For this reason, a group of experts, focused exclusively on the treatment of genitourinary tumours and who get together every year in the BestGU conference to assess the latest progress in this field have summarized the most important advances in a single review, along with a critical assessment of whether these results should alter daily clinical practice.

Assessing Genomic Copy Number Alterations as Best Practice for Renal Cell Neoplasia: An Evidence-Based Review from the Cancer Genomics Consortium Workgroup

Renal cell neoplasia are heterogeneous with diverse histology, genetic alterations, and clinical behavior that are diagnosed mostly on morphologic features. The Renal Cell Neoplasia Workgroup of the Cancer Genomics Consortium systematically evaluated peer-reviewed literature on genomic studies of renal cell carcinoma (RCC), including clear cell RCC, papillary RCC, chromophobe RCC, and the translocation RCC involving TFE3, TFEB and MITF rearrangements, as well as benign oncocytoma, which together comprise about 95% of all renal cell neoplasia. The Workgroup curated recurrent copy number alterations (CNAs), copy-neutral loss-of-heterozygosity (cnLOH), rearrangements, and mutations, found in each subtype and assigned clinical relevance according to established criteria. In clear cell RCC, loss of 3p has a disease-initiating role and most likely also in progression with mutations detected in VHL and other genes mapped to this arm, and loss of 9p and/or 14q has well-substantiated prognostic utility. Gain of chromosomes 7 and 17 are hallmark CNAs of papillary RCC, but patterns of other CNAs as detected by chromosomal microarray analysis (CMA) afford sub-classification into Type 1 and 2 with prognostic value, and for further sub-stratification of Type 2. Inherent chromosome loss in chromophobe RCC as detected by CMA is useful for distinguishing the eosinophilic variant from benign oncocytoma which in contrast exhibits few CNAs or rearranged CCND1, but share mitochondrial DNA mutations. In morphologically atypical RCCs, rearrangement of TFE3 and TFEB should be considered in the differential diagnosis, portending an aggressive RCC subtype. Overall, this evidence-based review provides a validated role for assessment of CNAs in renal cell neoplasia in the clinical setting to assist in renal cell neoplasm diagnosis and sub-classification within subtypes that is integral to the management of patients, from small incidentally found renal masses to larger surgically resected specimens, and simultaneously identify the presence of key alterations portending outcome in malignant RCC subtypes.

Sarcomatoid Dedifferentiation in Renal Cell Carcinoma: From Novel Molecular Insights to New Clinical Opportunities

Sarcomatoid features in renal cell carcinoma (RCC) have long been associated with dismal prognosis and poor response to therapy, while biological mechanisms underpinning sarcomatoid dedifferentiation remained obscure. Several efforts have been conducted to break down the molecular profile of sarcomatoid RCC and investigate different targeted therapeutic approaches. Mutations enriched for in sarcomatoid RCC involve, notably, TP53, BAP1, cell cycle, and chromatin-remodeling genes. The immunological landscape of these tumors is also gradually being uncovered, showing frequent expression of programmed cell death ligand-1 (PD-L1) and high levels of tumor-infiltrating lymphocytes. These features may be major determinants for the activity of immune checkpoint inhibitors in this population, which has been confirmed by retrospective studies and subgroup analyses of large randomized phase 3 trials. Combinations based on PD-1/PD-L1 inhibition have demonstrated response rates and complete responses in >50% and >10% of patients in the first-line metastatic setting, respectively, with median overall survival exceeding two years. This remarkable improvement in outcomes effectively establishes immune checkpoint inhibitor combinations as a new standard of care in patients with sarcomatoid RCC. New research fields, including epigenetic regulations and tumor-microenvironment interactions, may further sharpen understanding of sarcomatoid RCC and advance therapeutic developments.

MDM2-positive papillary sarcomatoid renal cell carcinoma: a potential diagnostic pitfall

Sarcomatoid renal cell carcinoma is a highly aggressive form of carcinoma, histologically showing both carcinomatous and mesenchymal component in different proportions. We present a case of advanced type 1 papillary sarcomatoid renal cell carcinoma infiltrating adjacent organs and showing positivity for MDM2 by immunohistochemistry and MDM2 amplification by fluorescence in situ hybridization. This finding, together with sarcomatoid morphology, poses a potential pitfall for diagnosis with dedifferentiated liposarcoma. MDM2 is known to be altered in various human sarcomas. Only recently, MDM2 alterations have been reported in carcinomas. The presented case illustrates the need of thorough sampling with clinic-pathological correlation before making a final diagnosis in sarcomatoid retroperitoneal tumours. Additionally, the potential clinical implications of MDM2 amplification in renal cell carcinoma are discussed.

Evolving Systemic Treatment Landscape for Patients With Advanced Renal Cell Carcinoma

PURPOSE

To outline current practices and challenges in the systemic management of patients with advanced renal cell carcinoma (RCC).

DESIGN

We conducted a focused review of hallmark randomized controlled trials informing the systemic treatment of patients with RCC. We concentrated on trials informing the use of combination therapies, therapy in both treatment-naïve and previously treated patients, sequential treatment strategies, and schedules.

RESULTS

The systemic treatment of advanced RCC has experienced tremendous progress over the past 15 years. An improved understanding of the canonical pathways implicated in RCC pathogenesis has resulted in the development of molecularly targeted and immunotherapy options for patients. These therapies have replaced cytokine-based treatments as the standard of care for patients with advanced RCC. Until recently, sequential vascular endothelial growth factor (VEGF)-targeted therapy or VEGF-targeted therapy followed by mammalian target of rapamycin inhibition has been the prevailing treatment paradigm for patients. However, newer agents such as cabozantinib and nivolumab have challenged this traditional approach. In addition, combination treatments including nivolumab plus ipilimumab and atezolizumab plus bevacizumab have transformed the RCC treatment landscape, and other doublet combinations in clinical testing will likely continue to alter the treatment paradigm in RCC. Currently, factors that inform treatment selection between different therapy options include performance status, comorbidities, prognostic risk stratification, treatment adverse event profile, and mode of administration, with no Level I evidence for predictive biomarker use in clinic.

CONCLUSIONS

The treatment options for advanced RCC are rapidly evolving since the introduction of VEGF-targeted therapy, immunotherapy with checkpoint blockade and, more recently, combination regimens. Despite the success of these regimens, advanced RCC remains a largely incurable disease, and additional strategies are warranted.