Pathological Response and Outcomes in Patients With Metastatic Renal Cell Carcinoma (mRCC) Receiving Immunotherapy-Based Therapies and Undergoing Deferred Cytoreductive Nephrectomy (CN).

In this study we evaluated outcomes of patients with metastatic renal cell carcinoma who received immunotherapy before surgery. We found that receiving immunotherapy combinations before surgery can offer patients benefits in reducing tumor size and improving disease control. BACKGROUND: Immunotherapy (IO) has improved outcomes for patients with metastatic renal cell carcinoma (mRCC). However, the timing of surgical intervention for cytoreductive nephrectomy (CN) is still controversial for this group of patients. PATIENTS AND METHODS: We identified patients with mRCC receiving IO-based therapies and undergoing CN. Patients were divided into 2 cohorts: those who underwent upfront CN and those who underwent deferred CN. Pathologic and radiographic features along with clinical outcomes were systematically collected. Comparisons were performed using Chi-square test, paired t-Test or Mann-Whitney-U test. Progression Free survival (PFS) and Overall Survival (OS) were estimated using the Kaplan-Meier method. RESULTS: Fifty-one patients with mRCC were included, with a median follow-up of 21 months. 38 (74.5%) patients received IO-based therapies prior to CN, while 13 (25.5%) patients underwent up-front CN. IO-based therapies reduced median tumor size from pretreatment 10 cm to 8.6 cm post-treatment when given prior to CN. IO-TKI had a trend toward higher tumor shrinkage (-2.3 vs -1.2 cm). Pathologic T downstaging occurred in 42% (n=16) of patients, 11% (n=4) of whom had pT0 disease. Thrombus downstaging occurred in 13% (n=6) of patients, all with either partial response (PR) or complete response (CR) in metastases. PFS (HR=0.7, 95% CI 0.29-1.98, p=0.58) and OS (HR 0.4, 95% CI 0.13-1.57, p=0.21) were not statistically significant between 2 cohorts. CONCLUSIONS: IO-based therapies, particularly IO-TKIs, resulted in pathologic necrosis and reductions in tumor size prior to deferred CN. PFS and OS were similar for patients who received either upfront IO-based therapy or after CN.

An ultraconserved snoRNA-like element in long noncoding RNA CRNDE promotes ribosome biogenesis and cell proliferation.

Cancer cells frequently upregulate ribosome production to support tumorigenesis. While small nucleolar RNAs (snoRNAs) are critical for ribosome biogenesis, the roles of other classes of noncoding RNAs in this process remain largely unknown. Here we performed CRISPRi screens to identify essential long noncoding RNAs (lncRNAs) in renal cell carcinoma (RCC) cells. This revealed that an alternatively-spliced isoform of lncRNA Colorectal Neoplasia Differentially Expressed containing an ultraconserved element (UCE), referred to as CRNDE UCE, is required for RCC cell proliferation. CRNDE UCE localizes to the nucleolus and promotes 60S ribosomal subunit biogenesis. The UCE of CRNDE functions as an unprocessed C/D box snoRNA that directly interacts with ribosomal RNA precursors. This facilitates delivery of eIF6, a key 60S biogenesis factor, which binds to CRNDE UCE through a sequence element adjacent to the UCE. These findings highlight the functional versatility of snoRNA sequences and expand the known mechanisms through which noncoding RNAs orchestrate ribosome biogenesis.

Molecular analysis of primary and metastatic sites in patients with renal cell carcinoma.

BACKGROUNDMetastases are the hallmark of lethal cancer, though underlying mechanisms that drive metastatic spread to specific organs remain poorly understood. Renal cell carcinoma (RCC) is known to have distinct sites of metastases, with lung, bone, liver, and lymph nodes being more common than brain, gastrointestinal tract, and endocrine glands. Previous studies have shown varying clinical behavior and prognosis associated with the site of metastatic spread; however, little is known about the molecular underpinnings that contribute to the differential outcomes observed by the site of metastasis.METHODSWe analyzed primary renal tumors and tumors derived from metastatic sites to comprehensively characterize genomic and transcriptomic features of tumor cells as well as to evaluate the tumor microenvironment at both sites.RESULTSWe included a total of 657 tumor samples (340 from the primary site [kidney] and 317 from various sites of metastasis). We show distinct genomic alterations, transcriptomic signatures, and immune and stromal tumor microenvironments across metastatic sites in a large cohort of patients with RCC.CONCLUSIONWe demonstrate significant heterogeneity among primary tumors and metastatic sites and elucidate the complex interplay between tumor cells and the extrinsic tumor microenvironment that is vital for developing effective anticancer therapies.

Histopathology Based AI Model Predicts Anti-Angiogenic Therapy Response in Renal Cancer Clinical Trial.

Background: Predictive biomarkers of treatment response are lacking for metastatic clearcell renal cell carcinoma (ccRCC), a tumor type that is treated with angiogenesis inhibitors, immune checkpoint inhibitors, mTOR inhibitors and a HIF2 inhibitor. The Angioscore, an RNA-based quantification of angiogenesis, is arguably the best candidate to predict anti-angiogenic (AA) response. However, the clinical adoption of transcriptomic assays faces several challenges including standardization, time delay, and high cost. Further, ccRCC tumors are highly heterogenous, and sampling multiple areas for sequencing is impractical. Approach: Here we present a novel deep learning (DL) approach to predict the Angioscore from ubiquitous histopathology slides. In order to overcome the lack of interpretability, one of the biggest limitations of typical DL models, our model produces a visual vascular network which is the basis of the model's prediction. To test its reliability, we applied this model to multiple cohorts including a clinical trial dataset. Results: Our model accurately predicts the RNA-based Angioscore on multiple independent cohorts (spearman correlations of 0.77 and 0.73). Further, the predictions help unravel meaningful biology such as association of angiogenesis with grade, stage, and driver mutation status. Finally, we find our model is able to predict response to AA therapy, in both a real-world cohort and the IMmotion150 clinical trial. The predictive power of our model vastly exceeds that of CD31, a marker of vasculature, and nearly rivals the performance (c-index 0.66 vs 0.67) of the ground truth RNA-based Angioscore at a fraction of the cost. Conclusion: By providing a robust yet interpretable prediction of the Angioscore from histopathology slides alone, our approach offers insights into angiogenesis biology and AA treatment response.

Unconventional mechanism of action and resistance to rapalogs in renal cancer.

mTORC1 is aberrantly activated in renal cell carcinoma (RCC) and is targeted by rapalogs. As for other targeted therapies, rapalogs clinical utility is limited by the development of resistance. Resistance often results from target mutation, but mTOR mutations are rarely found in RCC. As in humans, prolonged rapalog treatment of RCC tumorgrafts (TGs) led to resistance. Unexpectedly, explants from resistant tumors became sensitive both in culture and in subsequent transplants in mice. Notably, resistance developed despite persistent mTORC1 inhibition in tumor cells. In contrast, mTORC1 became reactivated in the tumor microenvironment (TME). To test the role of the TME, we engineered immunocompromised recipient mice with a resistance mTOR mutation (S2035T). Interestingly, TGs became resistant to rapalogs in mTORS2035T mice. Resistance occurred despite mTORC1 inhibition in tumor cells and could be induced by coculturing tumor cells with mutant fibroblasts. Thus, enforced mTORC1 activation in the TME is sufficient to confer resistance to rapalogs. These studies highlight the importance of mTORC1 inhibition in nontumor cells for rapalog antitumor activity and provide an explanation for the lack of mTOR resistance mutations in RCC patients.

De novo and salvage purine synthesis pathways across tissues and tumors.

Purine nucleotides are vital for RNA and DNA synthesis, signaling, metabolism, and energy homeostasis. To synthesize purines, cells use two principal routes: the de novo and salvage pathways. Traditionally, it is believed that proliferating cells predominantly rely on de novo synthesis, whereas differentiated tissues favor the salvage pathway. Unexpectedly, we find that adenine and inosine are the most effective circulating precursors for supplying purine nucleotides to tissues and tumors, while hypoxanthine is rapidly catabolized and poorly salvaged in vivo. Quantitative metabolic analysis demonstrates comparative contribution from de novo synthesis and salvage pathways in maintaining purine nucleotide pools in tumors. Notably, feeding mice nucleotides accelerates tumor growth, while inhibiting purine salvage slows down tumor progression, revealing a crucial role of the salvage pathway in tumor metabolism. These findings provide fundamental insights into how normal tissues and tumors maintain purine nucleotides and highlight the significance of purine salvage in cancer.

PML restrains p53 activity and cellular senescence in clear cell renal cell carcinoma.

Clear-cell renal cell carcinoma (ccRCC), the major subtype of RCC, is frequently diagnosed at late/metastatic stage with 13% 5-year disease-free survival. Functional inactivation of the wild-type p53 protein is implicated in ccRCC therapy resistance, but the detailed mechanisms of p53 malfunction are still poorly characterized. Thus, a better understanding of the mechanisms of disease progression and therapy resistance is required. Here, we report a novel ccRCC dependence on the promyelocytic leukemia (PML) protein. We show that PML is overexpressed in ccRCC and that PML depletion inhibits cell proliferation and relieves pathologic features of anaplastic disease in vivo. Mechanistically, PML loss unleashed p53-dependent cellular senescence thus depicting a novel regulatory axis to limit p53 activity and senescence in ccRCC. Treatment with the FDA-approved PML inhibitor arsenic trioxide induced PML degradation and p53 accumulation and inhibited ccRCC expansion in vitro and in vivo. Therefore, by defining non-oncogene addiction to the PML gene, our work uncovers a novel ccRCC vulnerability and lays the foundation for repurposing an available pharmacological intervention to restore p53 function and chemosensitivity.

Molecular underpinnings of dedifferentiation and aggressiveness in chromophobe renal cell carcinoma.

Sarcomatoid dedifferentiation is common to multiple renal cell carcinoma (RCC) subtypes, including chromophobe RCC (ChRCC), and is associated with increased aggressiveness, resistance to targeted therapies, and heightened sensitivity to immunotherapy. To study ChRCC dedifferentiation, we performed multiregion integrated paired pathological and genomic analyses. Interestingly, ChRCC dedifferentiates not only into sarcomatoid but also into anaplastic and glandular subtypes, which are similarly associated with increased aggressiveness and metastases. Dedifferentiated ChRCC shows loss of epithelial markers, convergent gene expression, and whole genome duplication from a hypodiploid state characteristic of classic ChRCC. We identified an intermediate state with atypia and increased mitosis but preserved epithelial markers. Our data suggest that dedifferentiation is initiated by hemizygous mutation of TP53, which can be observed in differentiated areas, as well as mutation of PTEN. Notably, these mutations become homozygous with duplication of preexisting monosomes (i.e., chromosomes 17 and 10), which characterizes the transition to dedifferentiated ChRCC. Serving as potential biomarkers, dedifferentiated areas become accentuated by mTORC1 activation (phospho-S6) and p53 stabilization. Notably, dedifferentiated ChRCC share gene enrichment and pathway activation features with other sarcomatoid RCC, suggesting convergent evolutionary trajectories. This study expands our understanding of aggressive ChRCC, provides insight into molecular mechanisms of tumor progression, and informs pathologic classification and diagnostics.

Glycosaminoglycan-mediated lipoprotein uptake protects cancer cells from ferroptosis.

Lipids are essential for tumours because of their structural, energetic, and signaling roles. While many cancer cells upregulate lipid synthesis, growing evidence suggests that tumours simultaneously intensify the uptake of circulating lipids carried by lipoproteins. Which mechanisms promote the uptake of extracellular lipids, and how this pool of lipids contributes to cancer progression, are poorly understood. Here, using functional genetic screens, we find that lipoprotein uptake confers resistance to lipid peroxidation and ferroptotic cell death. Lipoprotein supplementation robustly inhibits ferroptosis across numerous cancer types. Mechanistically, cancer cells take up lipoproteins through a pathway dependent on sulfated glycosaminoglycans (GAGs) linked to cell-surface proteoglycans. Tumour GAGs are a major determinant of the uptake of both low and high density lipoproteins. Impairment of glycosaminoglycan synthesis or acute degradation of surface GAGs decreases the uptake of lipoproteins, sensitizes cells to ferroptosis and reduces tumour growth in mice. We also find that human clear cell renal cell carcinomas, a distinctively lipid-rich tumour type, display elevated levels of lipoprotein-derived antioxidants and the GAG chondroitin sulfate than non-malignant human kidney. Altogether, our work identifies lipoprotein uptake as an essential anti-ferroptotic mechanism for cancer cells to overcome lipid oxidative stress in vivo, and reveals GAG biosynthesis as an unexpected mediator of this process.

A First-in-Human Phase 1 Study of a Tumor-Directed RNA-Interference Drug against HIF2α in Patients with Advanced Clear Cell Renal Cell Carcinoma.

PURPOSE: ARO-HIF2 is an siRNA drug designed to selectively target hypoxia-inducible factor-2α (HIF2α) interrupting downstream pro-oncogenic signaling in clear cell renal cell carcinoma (ccRCC). The aims of this Phase 1 study (AROHIF21001) were to evaluate safety, tolerability, pharmacokinetics, and establish a recommended Phase 2 dose. PATIENTS AND METHODS: Subjects with ccRCC and progressive disease after at least 2 prior therapies that included VEGF and immune checkpoint inhibitors were progressively enrolled into dose-escalation cohorts of ARO-HIF2 administered intravenously at 225, 525, or 1,050 mg weekly. RESULTS: Twenty-six subjects received ARO-HIF2. The most common treatment emergent adverse events (AE) irrespective of causality were fatigue (50.0%), dizziness (26.9%), dyspnea (23.1%), and nausea (23.1%). Four subjects (15.4%) had treatment-related serious AEs. AEs of special interest included neuropathy, hypoxia, and dyspnea. ARO-HIF2 was almost completely cleared from plasma circulation within 48 hours with minimal renal clearance. Reductions in HIF2α were observed between pre- and post-dosing tumor biopsies, but the magnitude was quite variable. The objective response rate was 7.7% and the disease control rate was 38.5%. Responses were accompanied by ARO-HIF2 uptake in tumor cells, HIF2α downregulation, as well as rapid suppression of tumor produced erythropoietin (EPO) in a patient with paraneoplastic polycythemia. CONCLUSIONS: ARO-HIF2 downregulated HIF2α in advanced ccRCC-inhibiting tumor growth in a subset of subjects. Further development was hampered by off-target neurotoxicity and low response rate. This study provides proof of concept that siRNA can target tumors in a specific manner.

GPR1 and CMKLR1 Control Lipid Metabolism to Support the Development of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC), the most common type of kidney cancer, is largely incurable in the metastatic setting. ccRCC is characterized by excessive lipid accumulation that protects cells from stress and promotes tumor growth, suggesting that the underlying regulators of lipid storage could represent potential therapeutic targets. Here, we evaluated the regulatory roles of GPR1 and CMKLR1, two G protein-coupled receptors of the protumorigenic adipokine chemerin that is involved in ccRCC lipid metabolism. Both genetic and pharmacologic suppression of either receptor suppressed lipid formation and induced multiple forms of cell death, including apoptosis, ferroptosis, and autophagy, thereby significantly impeding ccRCC growth in cell lines and patient-derived xenograft models. Comprehensive lipidomic and transcriptomic profiling of receptor competent and depleted cells revealed overlapping and unique signaling of the receptors granting control over triglyceride synthesis, ceramide production, and fatty acid saturation and class production. Mechanistically, both receptors enforced suppression of adipose triglyceride lipase, but each receptor also demonstrated distinct functions, such as the unique ability of CMKLR1 to control lipid uptake through regulation of sterol regulatory element-binding protein 1c and the CD36 scavenger receptor. Treating patient-derived xenograft models with the CMKLR1-targeting small molecule 2-(α-naphthoyl) ethyltrimethylammonium iodide (α-NETA) led to a dramatic reduction in tumor growth, lipid storage, and clear-cell morphology. Together, these findings provide mechanistic insights into lipid regulation in ccRCC and identify a targetable axis at the core of the histologic definition of this tumor that could be exploited therapeutically. Significance: Extracellular control of lipid accumulation via G protein receptor-mediated cell signaling is a metabolic vulnerability in clear cell renal cell carcinoma, which depends on lipid storage to avoid oxidative toxicity.

Comparative genomics incorporating translocation renal cell carcinoma mouse model reveals molecular mechanisms of tumorigenesis.

Translocation renal cell carcinoma (tRCC) most commonly involves an ASPSCR1-TFE3 fusion, but molecular mechanisms remain elusive and animal models are lacking. Here, we show that human ASPSCR1-TFE3 driven by Pax8-Cre (a credentialed clear cell RCC driver) disrupted nephrogenesis and glomerular development, causing neonatal death, while the clear cell RCC failed driver, Sglt2-Cre, induced aggressive tRCC (as well as alveolar soft part sarcoma) with complete penetrance and short latency. However, in both contexts, ASPSCR1-TFE3 led to characteristic morphological cellular changes, loss of epithelial markers, and an epithelial-mesenchymal transition. Electron microscopy of tRCC tumors showed lysosome expansion, and functional studies revealed simultaneous activation of autophagy and mTORC1 pathways. Comparative genomic analyses encompassing an institutional human tRCC cohort (including a hitherto unreported SFPQ-TFEB fusion) and a variety of tumorgraft models (ASPSCR1-TFE3, PRCC-TFE3, SFPQ-TFE3, RBM10-TFE3, and MALAT1-TFEB) disclosed significant convergence in canonical pathways (cell cycle, lysosome, and mTORC1) and less established pathways such as Myc, E2F, and inflammation (IL-6/JAK/STAT3, interferon-γ, TLR signaling, systemic lupus, etc.). Therapeutic trials (adjusted for human drug exposures) showed antitumor activity of cabozantinib. Overall, this study provides insight into MiT/TFE-driven tumorigenesis, including the cell of origin, and characterizes diverse mouse models available for research.

Kinome-wide siRNA screen identifies a DCLK2-TBK1 oncogenic signaling axis in clear cell renal cell carcinoma.

TANK-binding kinase 1 (TBK1) is a potential therapeutic target in multiple cancers, including clear cell renal cell carcinoma (ccRCC). However, targeting TBK1 in clinical practice is challenging. One approach to overcome this challenge would be to identify an upstream TBK1 regulator that could be targeted therapeutically in cancer specifically. In this study, we perform a kinome-wide small interfering RNA (siRNA) screen and identify doublecortin-like kinase 2 (DCLK2) as a TBK1 regulator in ccRCC. DCLK2 binds to and directly phosphorylates TBK1 on Ser172. Depletion of DCLK2 inhibits anchorage-independent colony growth and kidney tumorigenesis in orthotopic xenograft models. Conversely, overexpression of DCLK2203, a short isoform that predominates in ccRCC, promotes ccRCC cell growth and tumorigenesis in vivo. Mechanistically, DCLK2203 elicits its oncogenic signaling via TBK1 phosphorylation and activation. Taken together, these results suggest that DCLK2 is a TBK1 activator and potential therapeutic target for ccRCC.

Recent Advances in Renal Tumors with TSC/mTOR Pathway Abnormalities in Patients with Tuberous Sclerosis Complex and in the Sporadic Setting.

A spectrum of renal tumors associated with frequent TSC/mTOR (tuberous sclerosis complex/mechanistic target of rapamycin) pathway gene alterations (in both the germline and sporadic settings) have recently been described. These include renal cell carcinoma with fibromyomatous stroma (RCC FMS), eosinophilic solid and cystic renal cell carcinoma (ESC RCC), eosinophilic vacuolated tumor (EVT), and low-grade oncocytic tumor (LOT). Most of these entities have characteristic morphologic and immunohistochemical features that enable their recognition without the need for molecular studies. In this report, we summarize recent advances and discuss their evolving complexity.

Metastatic renal cell carcinoma to the pancreas and other sites-a multicenter retrospective study.

Background: Metastatic renal cell carcinoma (mRCC) is a heterogenous disease with poor 5-year overall survival (OS) at 14%. Patients with mRCC to endocrine organs historically have prolonged OS. Pancreatic metastases are uncommon overall, with mRCC being the most common etiology of pancreatic metastases. In this study, we report the long-term outcomes of patients with mRCC to the pancreas in two separate cohorts. Methods: We performed a multicenter, international retrospective cohort study of patients with mRCC to the pancreas at 15 academic centers. Cohort 1 included 91 patients with oligometastatic disease to the pancreas. Cohort 2 included 229 patients with multiples organ sites of metastases including the pancreas. The primary endpoint for Cohorts 1 and 2 was median OS from time of metastatic disease in the pancreas until death or last follow up. Findings: In Cohort 1, the median OS (mOS) was 121 months with a median follow up time of 42 months. Patients who underwent surgical resection of oligometastatic disease had mOS of 100 months with a median follow-up time of 52.5 months. The mOS for patients treated with systemic therapy was not reached. In Cohort 2, the mOS was 90.77 months. Patients treated with first-line (1L) VEGFR therapy had mOS of 90.77 months; patients treated with IL immunotherapy (IO) had mOS of 92 months; patients on 1L combination VEGFR/IO had mOS of 74.9 months. Interpretations: This is the largest retrospective cohort of mRCC involving the pancreas. We confirmed the previously reported long-term outcomes in patients with oligometastatic pancreas disease and demonstrated prolonged survival in patients with multiple RCC metastases that included the pancreas. In this retrospective study with heterogeneous population treated over 2 decades, mOS was similar when stratified by first-line therapy. Future research will be needed to determine whether mRCC patients with pancreatic metastases require a different initial treatment strategy. Funding: Statistical analyses for this study were supported in part by the University of Colorado Cancer Center Support Grant from the NIH/NCI, P30CA046934-30.

Reporting on FH-deficient renal cell carcinoma using circulating succinylated metabolites.

Fumarate hydratase-deficient (FH-deficient) renal cell carcinoma (RCC) represents a particularly aggressive form of kidney cancer. FH-deficient RCC arises in the setting of germline, or solely somatic, mutations in the FH gene, a two-hit tumor suppressor gene. Early detection can be curative, but there are no biomarkers, and in the sporadic setting, establishing a diagnosis of FH-deficient RCC is challenging. In this issue of the JCI, Zheng, Zhu, and co-authors report untargeted plasma metabolomic analyses to identify putative biomarkers. They discovered two plasma metabolites directly linked to fumarate overproduction by tumor cells, succinyl-adenosine and succinic-cysteine, which correlate with tumor burden. The identification of circulating biomarkers of FH-deficient RCC may aid in the diagnosis of FH-deficient RCC and provide a means for longitudinal follow-up.

Life-threatening hemoptysis in patients with metastatic kidney cancer.

Hemoptysis is a complication of intrathoracic tumors, both primary and metastatic, and the risk may be increased by procedural interventions as well as Stereotactic Ablative Radiation (SAbR). The risk of hemoptysis with SAbR for lung cancer is well characterized, but there is a paucity of data about intrathoracic metastases. Here, we sought to evaluate the incidence of life-threatening/fatal hemoptysis (LTH) in patients with renal cell carcinoma (RCC) chest metastases with a focus on SAbR. We systematically evaluated patients with RCC at UT Southwestern Medical Center (UTSW) Kidney Cancer Program (KCP) from July 2005 to March 2020. We queried Kidney Cancer Explorer (KCE), a data portal with clinical, pathological, and experimental genomic data. Patients were included in the study based on mention of "hemoptysis" in clinical documentation, if they had a previous bronchoscopy, or had undergone SAbR to any site within the chest. Two hundred and thirty four patients met query criteria and their records were individually reviewed. We identified 10 patients who developed LTH. Of these, 4 had LTH as an immediate procedural complication whilst the remaining 6 had prior SAbR to ultra-central (UC; abutting the central bronchial tree) metastases. These 6 patients had a total of 10 lung lesions irradiated (UC, 8; central 1, peripheral 1), with a median total cumulative SAbR dose of 38 Gray (Gy/ lesion) (range: 25-50 Gy). Other risk factors included intrathoracic disease progression (n = 4, 67%), concurrent anticoagulant therapy (n = 1, 17%) and concurrent systemic therapy (n = 4, 67%). Median time to LTH from first SAbR was 26 months (range: 8-61 months). Considering that 130 patients received SAbR to a chest lesion during the study period, the overall incidence of LTH following SAbR was 4.6% (6/130). The patient population that received SAbR (n = 130) was at particularly high risk for complications, with 67 (52%) having two or more chest metastaes treated, and 29 (22%) receiving SAbR to three or more lesions. Overall, the risk of LTH following SAbR to a central or UC lesion was 10.5% (6/57). In conclusion, SAbR of RCC metastases located near the central bronchial tree may increase the risk of LTH.

Erratum to: Extended Disease Control with Unconventional Cabozantinib Dose Increase in Metastatic Renal Cell Carcinoma.

[This corrects the article DOI: 10.3233/KCA-210117.].

Navigating and adapting care integrating immunotherapy, antiangiogenic therapy, and combinations in patients with advanced renal cell carcinoma.

Advanced renal cell carcinoma is a biologically heterogeneous disease with multiple treatment options that largely involve immunotherapy and/or anti-angiogenic therapies. The choice of initial and subsequent therapy depends on both clinical and biological considerations. Here, we describe the application of recent data to clinical practice.

Phase 2 Trial of Stereotactic Ablative Radiotherapy for Patients with Primary Renal Cancer.

BACKGROUND: Most renal cell carcinomas (RCCs) are localized and managed by active surveillance, surgery, or minimally invasive techniques. Stereotactic ablative radiation (SAbR) may provide an innovative non-invasive alternative although prospective data are limited. OBJECTIVE: To investigate whether SAbR is effective in the management of primary RCCs. DESIGN, SETTING, AND PARTICIPANTS: Patients with biopsy-confirmed radiographically enlarging primary RCC (≤5 cm) were enrolled. SAbR was delivered in either three (12 Gy) or five (8 Gy) fractions. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was local control (LC) defined as a reduction in tumor growth rate (compared with a benchmark of 4 mm/yr on active surveillance) and pathologic evidence of tumor response at 1 yr. Secondary endpoints included LC by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1), safety, and preservation of kidney function. Exploratory tumor cell-enriched spatial protein and gene expression analysis were conducted on pre- and post-treatment biopsy samples. RESULTS AND LIMITATIONS: Target accrual was reached with the enrollment of 16 ethnically diverse patients. Radiographic LC at 1 yr was observed in 94% of patients (15/16; 95% confidence interval: 70, 100), and this was accompanied by pathologic evidence of tumor response (hyalinization, necrosis, and reduced tumor cellularity) in all patients. By RECIST, 100% of the sites remained without progression at 1 yr. The median pretreatment growth rate was 0.8 cm/yr (interquartile range [IQR]: 0.3, 1.4), and the median post-treatment growth rate was 0.0 cm/yr (IQR: -0.4, 0.1, p < 0.002). Tumor cell viability decreased from 4.6% to 0.7% at 1 yr (p = 0.004). With a median follow-up of 36 mo for censored patients, the disease control rate was 94%. SAbR was well tolerated with no grade ≥2 (acute or late) toxicities. The average glomerular filtration rate declined from a baseline of 65.6 to 55.4 ml/min at 1 yr (p = 0.003). Spatial protein and gene expression analyses were consistent with the induction of cellular senescence by radiation. CONCLUSIONS: This clinical trial adds to the growing body of evidence suggesting that SAbR is effective for primary RCC supporting its evaluation in comparative phase 3 clinical trials. PATIENT SUMMARY: In this clinical trial, we investigated a noninvasive treatment option of stereotactic radiation therapy for the treatment of primary kidney cancer and found that it was safe and effective.