Epigenetic and transcriptomic characterization reveals progression markers and essential pathways in clear cell renal cell carcinoma

Identifying tumor-cell-specific markers and elucidating their epigenetic regulation and spatial heterogeneity provides mechanistic insights into cancer etiology. Here, we perform snRNA-seq and snATAC-seq in 34 and 28 human clear cell renal cell carcinoma (ccRCC) specimens, respectively, with matched bulk proteogenomics data. By identifying 20 tumor-specific markers through a multi-omics tiered approach, we reveal an association between higher ceruloplasmin (CP) expression and reduced survival. CP knockdown, combined with spatial transcriptomics, suggests a role for CP in regulating hyalinized stroma and tumor-stroma interactions in ccRCC. Intratumoral heterogeneity analysis portrays tumor cell-intrinsic inflammation and epithelial-mesenchymal transition (EMT) as two distinguishing features of tumor subpopulations. Finally, BAP1 mutations are associated with widespread reduction of chromatin accessibility, while PBRM1 mutations generally increase accessibility, with the former affecting five times more accessible peaks than the latter. These integrated analyses reveal the cellular architecture of ccRCC, providing insights into key markers and pathways in ccRCC tumorigenesis.

SETD2 regulates chromatin accessibility and transcription to suppress lung tumorigenesis

SETD2, a H3K36 trimethyltransferase, is the most frequently mutated epigenetic modifier in lung adenocarcinoma, with a mutation frequency of approximately 9%. However, how SETD2 loss of function promotes tumorigenesis remains unclear. Using conditional Setd2-KO mice, we demonstrated that Setd2 deficiency accelerated the initiation of KrasG12D-driven lung tumorigenesis, increased tumor burden, and significantly reduced mouse survival. An integrated chromatin accessibility and transcriptome analysis revealed a potentially novel tumor suppressor model of SETD2 in which SETD2 loss activates intronic enhancers to drive oncogenic transcriptional output, including the KRAS transcriptional signature and PRC2-repressed targets, through regulation of chromatin accessibility and histone chaperone recruitment. Importantly, SETD2 loss sensitized KRAS-mutant lung cancer to inhibition of histone chaperones, the FACT complex, or transcriptional elongation both in vitro and in vivo. Overall, our studies not only provide insight into how SETD2 loss shapes the epigenetic and transcriptional landscape to promote tumorigenesis, but they also identify potential therapeutic strategies for SETD2 mutant cancers.

Tumor-associated macrophages expressing the transcription factor IRF8 promote T cell exhaustion in cancer

Tumors are populated by antigen-presenting cells (APCs) including macrophage subsets with distinct origins and functions. Here, we examined how cancer impacts mononuclear phagocytic APCs in a murine model of breast cancer. Tumors induced the expansion of monocyte-derived tumor-associated macrophages (TAMs) and the activation of type 1 dendritic cells (DC1s), both of which expressed and required the transcription factor interferon regulatory factor-8 (IRF8). Although DC1s mediated cytotoxic T lymphocyte (CTL) priming in tumor-draining lymph nodes, TAMs promoted CTL exhaustion in the tumor, and IRF8 was required for TAMs' ability to present cancer cell antigens. TAM-specific IRF8 deletion prevented exhaustion of cancer-cell-reactive CTLs and suppressed tumor growth. Tumors from patients with immune-infiltrated renal cell carcinoma had abundant TAMs that expressed IRF8 and were enriched for an IRF8 gene expression signature. Furthermore, the TAM-IRF8 signature co-segregated with CTL exhaustion signatures across multiple cancer types. Thus, CTL exhaustion is promoted by TAMs via IRF8.

Multiregional single-cell proteogenomic analysis of ccRCC reveals cytokine drivers of intratumor spatial heterogeneity

Intratumor heterogeneity (ITH) represents a major challenge for anticancer therapies. An integrated, multidimensional, multiregional approach dissecting ITH of the clear cell renal cell carcinoma (ccRCC) tumor microenvironment (TME) is employed at the single-cell level with mass cytometry (CyTOF), multiplex immunofluorescence (MxIF), and single-nucleus RNA sequencing (snRNA-seq) and at the bulk level with whole-exome sequencing (WES), RNA-seq, and methylation profiling. Multiregional analyses reveal unexpected conservation of immune composition within each individual patient, with profound differences among patients, presenting patient-specific tumor immune microenvironment signatures despite underlying genetic heterogeneity from clonal evolution. Spatial proteogenomic TME analysis using MxIF identifies 14 distinct cellular neighborhoods and, conversely, demonstrated architectural heterogeneity among different tumor regions. Tumor-expressed cytokines are identified as key determinants of the TME and correlate with clinical outcome. Overall, this work signifies that spatial ITH occurs in ccRCC, which may drive clinical heterogeneity and warrants further interrogation to improve patient outcomes.

Precise reconstruction of the TME using bulk RNA-seq and a machine learning algorithm trained on artificial transcriptomes

Cellular deconvolution algorithms virtually reconstruct tissue composition by analyzing the gene expression of complex tissues. We present the decision tree machine learning algorithm, Kassandra, trained on a broad collection of >9,400 tissue and blood sorted cell RNA profiles incorporated into millions of artificial transcriptomes to accurately reconstruct the tumor microenvironment (TME). Bioinformatics correction for technical and biological variability, aberrant cancer cell expression inclusion, and accurate quantification and normalization of transcript expression increased Kassandra stability and robustness. Performance was validated on 4,000 H&E slides and 1,000 tissues by comparison with cytometric, immunohistochemical, or single-cell RNA-seq measurements. Kassandra accurately deconvolved TME elements, showing the role of these populations in tumor pathogenesis and other biological processes. Digital TME reconstruction revealed that the presence of PD-1-positive CD8⁺ T cells strongly correlated with immunotherapy response and increased the predictive potential of established biomarkers, indicating that Kassandra could potentially be utilized in future clinical applications.

Telaglenastat plus Everolimus in Advanced Renal Cell Carcinoma: A Randomized, Double-Blinded, Placebo-Controlled, Phase II ENTRATA Trial

PURPOSE

Glutaminase is a key enzyme, which supports elevated dependency of tumors on glutamine-dependent biosynthesis of metabolic intermediates. Dual targeting of glucose and glutamine metabolism by the mTOR inhibitor everolimus plus the oral glutaminase inhibitor telaglenastat showed preclinical synergistic anticancer effects, which translated to encouraging safety and efficacy findings in a phase I trial of 2L+ renal cell carcinoma (RCC). This study evaluated telaglenastat plus everolimus (TelaE) versus placebo plus everolimus (PboE) in patients with advanced/metastatic RCC (mRCC) in the 3L+ setting (NCT03163667).

PATIENTS AND METHODS

Eligible patients with mRCC, previously treated with at least two prior lines of therapy [including ≥1 VEGFR-targeted tyrosine kinase inhibitor (TKI)] were randomized 2:1 to receive E, plus Tela or Pbo, until disease progression or unacceptable toxicity. Primary endpoint was investigator-assessed progression-free survival (PFS; one-sided α <0.2).

RESULTS

Sixty-nine patients were randomized (46 TelaE, 23 PboE). Patients had a median three prior lines of therapy, including TKIs (100%) and checkpoint inhibitors (88%). At median follow-up of 7.5 months, median PFS was 3.8 months for TelaE versus 1.9 months for PboE [HR, 0.64; 95% confidence interval (CI), 0.34-1.20; one-sided P = 0.079]. One TelaE patient had a partial response and 26 had stable disease (SD). Eleven patients on PboE had SD. Treatment-emergent adverse events included fatigue, anemia, cough, dyspnea, elevated serum creatinine, and diarrhea; grade 3 to 4 events occurred in 74% TelaE patients versus 61% PboE.

CONCLUSIONS

TelaE was well tolerated and improved PFS versus PboE in patients with mRCC previously treated with TKIs and checkpoint inhibitors.

Association between biomarkers and clinical outcomes of lenvatinib + pembrolizumab in advanced renal cell carcinoma (RCC): Results from Study 111/KEYNOTE-146

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Background: In the Study 111/KEYNOTE-146 trial (NCT02501096; N=147), lenvatinib (lenva) + pembrolizumab (pembro) showed encouraging antitumor activity and a manageable safety profile in treatment-naive (n=23) or previously treated metastatic RCC (n=105, previously treated with immune checkpoint inhibitor [ICI]; n=19, previously treated ICI naive); 145 had clear cell RCC and 2 had non-clear cell RCC. In this exploratory analysis, we evaluated the association between clinical outcomes and gene expression signatures and DNA variants for individual RCC-specific driver genes of interest based on published reports. Methods: Patients (pts) with metastatic RCC were treated with lenva 20 mg orally once daily + pembro 200 mg intravenously once every 3 weeks. The analysis population included pts with treatment-naive (n=10) and ICI pretreated (n=70) disease with evaluable RNA-sequencing data for the 18-gene T-cell–inflamed gene expression profile (TcellinfGEP) and for 11 other signatures (angiogenesis; glycolysis; gMDSC; hypoxia; mMDSC; MVD; MYC; proliferation; RAS; stroma/EMT/TGFβ; WNT) and whole exome sequencing (WES) data for DNA variants for individual genes ( VHL, PBRM1, BAP1, and SETD2). Specimens were collected prior to the start of treatment. The associations between each signature score and ORR and PFS per immune-related RECIST were evaluated using logistic regression and Cox proportional hazards, respectively. One-sided P values for TcellinfGEP (hypothesized positive association) and two-sided P values for all other signatures (no hypothesized association) were adjusted for multiplicity using the Hochberg step-up procedure; significance was prespecified at α=0.05. The association between DNA variants for individual genes and ORR was evaluated descriptively. Clinical data cutoff was August 18, 2020. Results: Of 147 treated pts, RNA sequencing and WES data were available for 80 (54%) and 60 (41%), respectively. TcellinfGEP was not associated with ORR ( P=0.827) or PFS ( P=0.741), nor were the other 11 signatures before or after adjustment for TcellinfGEP. ORR for DNA variants reported in the table. Conclusions: In this exploratory analysis of pts with metastatic RCC enrolled in Study 111/KEYNOTE-146 treated with lenva + pembro, responses were observed regardless of biomarker status. There were no statistically significant associations between gene signatures and clinical outcomes. Clinical benefit was observed regardless of VHL, PBRM1, BAP1, or SETD2 mutation status. Analyses in larger randomized datasets will provide additional information on the role of biomarkers in RCC. Clinical trial information: NCT02501096. [Table: see text]

Targeting Aurora B kinase prevents and overcomes resistance to EGFR inhibitors in lung cancer by enhancing BIM- and PUMA-mediated apoptosis

The clinical success of EGFR inhibitors in EGFR-mutant lung cancer is limited by the eventual development of acquired resistance. We hypothesize that enhancing apoptosis through combination therapies can eradicate cancer cells and reduce the emergence of drug-tolerant persisters. Through high-throughput screening of a custom library of ∼1,000 compounds, we discover Aurora B kinase inhibitors as potent enhancers of osimertinib-induced apoptosis. Mechanistically, Aurora B inhibition stabilizes BIM through reduced Ser87 phosphorylation, and transactivates PUMA through FOXO1/3. Importantly, osimertinib resistance caused by epithelial-mesenchymal transition (EMT) activates the ATR-CHK1-Aurora B signaling cascade and thereby engenders hypersensitivity to respective kinase inhibitors by activating BIM-mediated mitotic catastrophe. Combined inhibition of EGFR and Aurora B not only efficiently eliminates cancer cells but also overcomes resistance beyond EMT.

Taspase1 orchestrates fetal liver hematopoietic stem cell and vertebrae fates by cleaving TFIIA

Taspase1, a highly conserved threonine protease encoded by TASP1, cleaves nuclear histone-modifying factors and basal transcription regulators to orchestrate diverse transcription programs. Hereditary loss-of-function mutation of TASP1 has recently been reported in humans as resulting in an anomaly complex syndrome, which manifests with hematological, facial, and skeletal abnormalities. Here, we demonstrate that Taspase1-mediated cleavage of TFIIAα-β, rather than of MLL1 or MLL2, in mouse embryos was required for proper fetal liver hematopoiesis and correct segmental identities of the axial skeleton. Homozygous genetic deletion of Taspase1 disrupted embryonic hematopoietic stem cell self-renewal and quiescence states and axial skeleton fates. Strikingly, mice carrying knockin noncleavable mutations of TFIIAα-β, a well-characterized basal transcription factor, displayed more pronounced fetal liver and axial skeleton defects than those with noncleavable MLL1 and MLL2, 2 trithorax group histone H3 trimethyl transferases. Our study offers molecular insights into a syndrome in humans that results from loss of TASP1 and describes an unexpected role of TFIIAα-β cleavage in embryonic cell fate decisions.

Diagnostic Utility of RNA-Seq for Evaluation of PD-L1 Expression in Clear Cell Renal Cell Carcinoma

BACKGROUND

Although there are immune checkpoint inhibitors (ICIs) available for the treatment of renal cell carcinoma (RCC), the utility of PD-L1 detection by immunohistochemistry (IHC) as a predictive biomarker in clear cell RCC (ccRCC) remains controversial. Nevertheless, alternative methods for PD-L1 detection, such as RNA sequencing (RNA-Seq), may be clinically useful in ccRCC; therefore, we sought to determine the ability of RNA-Seq to accurately and sensitively detect PD-L1 expression across different ccRCC clinical samples in comparison with IHC.

PATIENTS AND METHODS

Patients with ccRCC (n=127) who received treatment from Washington University in St. Louis between 2018 and 2020 were identified. Tumors from these patients were analyzed using RNA-Seq and IHC.

RESULTS

PD-L1 detection by RNA-Seq strongly correlated with IHC (P < .001), which was further validated using two independent datasets. Furthermore, RNA-Seq analysis identified an immune-enriched (higher PD-L1 positivity) and an immune-desert (lower PD-L1 positivity) microenvironment of ccRCC, which also correlated with IHC (P < .00001).

CONCLUSION

The results demonstrate the ability of RNA-Seq to detect PD-L1 in various ccRCC clinical samples compared to IHC. Ultimately, these findings suggest that PD-L1 detection by RNA-Seq can be further developed to determine the clinical utility of this methodology in ccRCC.

Abstract 2742: Integrated multiregional transcriptomic and multi-parameter single-cell imaging analysis of clear cell renal cell carcinoma elucidates diverse cellular communities present within the tumor microenvironment

Although genomic analyses of clear cell renal cell carcinoma (ccRCC) patients have revealed targetable pathways that have led to FDA-approved therapies, the responses to these therapies remain limited. The significant success of immune checkpoint inhibitors and anti-angiogenic agents suggest that ccRCC has a unique tumor microenvironment composition and tumor behavior that influences therapeutic response. Here, we describe an integrated proteogenomic method to study intratumoral heterogeneity (ITH), microenvironment composition, tumor spatial behavior, and cellular communities in ccRCC.

A unique AI-based segmentation platform for multiplex immunofluorescence (MxIF) was developed to analyze an entire tissue slide at single-cell resolution, including 70 regions of interest per slide, providing significant information regarding spatial architecture. Primary ccRCC tumors collected from patients were biopsied at multiple locations and subjected to MxIF (20 markers, n = 10 sites, 4 pts, ~1,000,000 cells), RNA-seq (n = 8 sites, 3 pts) and CyTOF (n = 21 sites, 6 pts), allowing integrated multi-omics analysis at the single-cell level.

Integrated analysis showed that genomic intratumor heterogeneity (ITH) was remarkably similar across all regions biopsied from the same patient, and the cellular populations present within each region of the same patient were alike. However, some cell types such as TCM CD4 T cells and Tem CD38 and Tem PD1+CD69+CD38- CD8 T cells, and CD163+PDL1+LAMP+ showed great inter-patient differences in the proportion of these cell populations. Notably, 14 CD4 T cell, 13 CD8 T cell, and 10 macrophage subpopulations were identified across the ccRCC tumors. Moreover, 14 microenvironment proximity communities based on MxIF imaging analysis of ~1 million cells were identified. The presence of B cell- and T cell-enriched communities (e.g., CD8 T cell enrichment and T-cell enrichment at the tumor border) correlated with the expression of interferon-gamma, PD1, IL-6, IL-10, PD-L1, CXCL13, and others. Macrophage-enriched communities correlated with the expression of CXCL12 and PDGFRB. Finally, tertiary lymphoid structures within the “B cell-enriched” communities correlating with the expression of CXCL13 were found in two tumors collected from one patient, with subsequent validation via H&E staining. Further, B cell repertoire (BCR) analysis of RNA-seq of the tumors from this patient showed the presence of a large B cell clone in the tumors.

In conclusion, via MxIF, 14 distinct spatial microenvironment communities with unique cytokine expression patterns were identified in ccRCC. Uncovering the spatial behavior of tumors can lead to the development of effective therapies personalized for each patient based on microenvironment composition and architecture.

Citation Format: Natalia Miheecheva, Akshaya Ramachandran, Yang Lyu, Ekaterina Postovalova, Viktor Svekolkin, Ilia Galkin, Pavel Ovcharov, Diana Shamsutdinova, Vladimir Zyrin, Alexander Bagaev, Krystle Nomie, Felix Frenkel, Ravshan Ataullakhanov, James J. Hsieh. Integrated multiregional transcriptomic and multi-parameter single-cell imaging analysis of clear cell renal cell carcinoma elucidates diverse cellular communities present within the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2742.

Abstract 161: Evaluating the clinical utility of RNA-seq-based PD-L1 expression and cellular deconvolution as alternatives to conventional immunohistochemistry in clear cell renal cell carcinoma

The emergence of immune checkpoint inhibitors (ICI) have revolutionized treatment of many cancer types, including renal cell carcinoma (RCC). Although there are currently three ICI combination regimens approved as standard of care for the first-line treatment of advanced RCC, the utility of PD-L1 detected by immunohistochemistry (IHC) as a predictive biomarker remains somewhat controversial. In this study, we sought to determine the ability to detect PD-L1 expression accurately and sensitively in comparison with IHC as well as whether RNA-seq-based cellular deconvolution potentially correlates with PD-L1 IHC for the development of a deconvolution-based biomarker. Tumors from 103 clear cell RCC (ccRCC) patients were collected to compare sensitivity and clinical utility of RNA-seq and IHC in PD-L1 detection. Additionally, we used gene expression signatures to comprehensively characterize the ccRCC tumor microenvironments (TMEs) from RNA-seq to examine PD-L1 expression levels across varied TMEs. This classification system revealed that the ccRCC samples clustered into an immune-enriched microenvironment with high lymphocyte infiltration and an immune desert microenvironment predominantly composed of malignant cells. For RNA-seq-based cellular deconvolution, a unique and robust machine learning algorithm, named Kassandra, was developed using over 8,000 RNA profiles of sorted cells that outperformed all current cellular deconvolution algorithms. The RNA-seq of ccRCC clinical tumors (n =89) were analyzed by Kassandra. Our RNA-seq analysis identified ccRCC tumors with high (maximum), intermediate and low (minimum) PD-L1 expression, which were then validated with IHC. Among these, 5/5, 10/10 and 87/88 ccRCC tumors with high, medium and low expression, respectively, detected via RNA-seq matched with the PD-L1 levels detected with IHC, suggesting a high degree of concordance (p &lt; 0.01) between the two methods. Notably, the immune-enriched ccRCC clusters had a higher percentage of PD-L1-positive malignant and immune cells. PD1+ CD8 T cells, identified via RNAseq-based cellular deconvolution (Kassandra), most strongly correlated with PD-L1 IHC (p &lt; 0.05). PD-L1 status was predicted with an 0.82 AUC performance score using a regression model. In conclusion, our results indicated that PD-L1 expression detected by RNA-seq as well as the presence of PD1+ CD8 T cells determined by applying Kassandra strongly correlated with the PD-L1 values obtained via IHC, potentially providing a less costly and more robust alternative to the conventional methods. In addition, an increased number of PD-L1-positive tumor and immune cells within the immune-enriched TME may suggest the significance of the TME composition as a predictive factor in response to ICIs.

Citation Format: Natalia Miheecheva, Maria Sorokina, Akshaya Ramachandran, Yang Lyu, Danil Stupichev, Alexander Bagaev, Ekaterina Postovalova, Krystle Nomie, Felix Frenkel, Maria Tsiper, Nathan Fowler, Ravshan Ataullakhanov, James J. Hsieh. Evaluating the clinical utility of RNA-seq-based PD-L1 expression and cellular deconvolution as alternatives to conventional immunohistochemistry in clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 161.

Lenvatinib plus pembrolizumab in patients with either treatment-naive or previously treated metastatic renal cell carcinoma (Study 111/KEYNOTE-146): a phase 1b/2 study

BACKGROUND

Despite advances in the first-line treatment of metastatic renal cell carcinoma (RCC), there is an unmet need for options to address disease progression during or after treatment with immune checkpoint inhibitors (ICIs). Pembrolizumab and lenvatinib are active as monotherapies in RCC; thus, we aimed to evaluate the combination of lenvatinib plus pembrolizumab in these patients.

METHODS

We report results of the metastatic RCC cohort from an open-label phase 1b/2 study of lenvatinib plus pembrolizumab in patients aged at least 18 years with selected solid tumours and an Eastern Cooperative Oncology Group performance status of 0-1. Oral lenvatinib at 20 mg was given once daily along with intravenous pembrolizumab at 200 mg once every 3 weeks. Patients remained on study drug treatment until disease progression, development of unacceptable toxicity, or withdrawal of consent. Efficacy was analysed in patients with clear cell metastatic RCC receiving study drug by previous therapy grouping: treatment naive, previously treated ICI naive (previously treated with at least one line of therapy but not with an anti-PD-1 or anti-PD-L1 ICI), and ICI pretreated (ie, anti-PD-1 or anti-PD-L1) patients. Safety was analysed in all enrolled and treated patients. The primary endpoint was the objective response rate at week 24 per immune-related Response Evaluation Criteria In Solid Tumors (irRECIST) by investigator assessment. This trial is registered with ClinicalTrials.gov (NCT02501096) and with the EU Clinical Trials Register (EudraCT2017-000300-26), and is closed to new participants.

FINDINGS

Between July 21, 2015, and Oct 16, 2019, 145 patients were enrolled in the study. Two patients had non-clear cell RCC and were excluded from the efficacy analysis (one in the treatment-naive group and one in the ICI-pretreated group); thus, the population evaluated for efficacy comprised 143 patients (n=22 in the treatment-naive group, n=17 in the previously treated ICI-naive group, and n=104 in the ICI-pretreated group). All 145 enrolled patients were included in the safety analysis. The median follow-up was 19·8 months (IQR 14·3-28·4). The number of patients with an objective response at week 24 by irRECIST was 16 (72·7%, 95% CI 49·8-89·3) of 22 treatment-naive patients, seven (41·2%, 18·4-67·1) of 17 previously treated ICI-naive patients, and 58 (55·8%, 45·7-65·5) of 104 ICI-pretreated patients. Of 145 patients, 82 (57%) had grade 3 treatment-related adverse events and ten (7%) had grade 4 treatment-related adverse events. The most common grade 3 treatment-related adverse event was hypertension (30 [21%] of 145 patients). Treatment-related serious adverse events occurred in 36 (25%) patients, and there were three treatment-related deaths (upper gastrointestinal haemorrhage, sudden death, and pneumonia).

INTERPRETATION

Lenvatinib plus pembrolizumab showed encouraging antitumour activity and a manageable safety profile and might be an option for post-ICI treatment of metastatic RCC.

FUNDING

Eisai and Merck Sharp & Dohme.

Resource-efficient pooled sequencing expands translational impact in solid tumors

Intratumoral genetic heterogeneity (ITH) poses a significant challenge to utilizing sequencing for decision making in the management of cancer. Although sequencing of multiple tumor regions can address the pitfalls of ITH, it does so at a significant increase in cost and resource utilization. We propose a pooled multiregional sequencing strategy, whereby DNA aliquots from multiple tumor regions are mixed prior to sequencing, as a cost-effective strategy to boost translational value by addressing ITH while preserving valuable residual tissue for secondary analysis. Focusing on kidney cancer, we demonstrate that DNA pooling from as few as two regions significantly increases mutation detection while reducing clonality misattribution. This leads to an increased fraction of patients identified with therapeutically actionable mutations, improved patient risk stratification, and improved inference of evolutionary trajectories with an accuracy comparable to bona fide multiregional sequencing. The same approach applied to non-small-cell lung cancer data substantially improves tumor mutational burden (TMB) detection. Our findings demonstrate that pooled DNA sequencing strategies are a cost-effective alternative to address intrinsic genetic heterogeneity in clinical settings.

Nivolumab plus cabozantinib (N+C) versus sunitinib (S) for advanced renal cell carcinoma (aRCC): Outcomes by baseline disease characteristics in the phase 3 CheckMate 9ER trial

4553

Background: First-line N+C significantly improved progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) vs S in aRCC patients (pts) in the phase 3 CheckMate 9ER trial, leading to FDA approval of N+C in this setting. A deeper understanding of how baseline disease characteristics may impact clinical outcomes with N+C vs S may inform clinical decision making. Methods: Pts with clear cell aRCC were randomized to N 240 mg IV Q2W + C 40 mg PO QD vs S 50 mg PO QD (4 weeks of 6-week cycles). In this post hoc exploratory analysis, PFS, OS, and ORR were evaluated across pt subgroups defined by baseline IMDC risk status, organ sites of metastases (mets), number of organs with any lesions, or target lesion size. Consistent with primary/secondary efficacy endpoints in ITT pts, PFS and ORR were evaluated per RECIST v1.1 by blinded independent central review in subgroups. Results: Median follow-up in ITT pts was 23.5 months. PFS, OS, and ORR (including complete response [CR]) outcomes are summarized in the table across subgroups: IMDC risk (favorable [FAV], intermediate [I], poor [P]); number of organs with ≥ 1 target/nontarget lesion (T/NT; 1 and ≥ 2); sum of diameters of target lesions (sDTL; < and ≥ median [72.1 mm]), and in pts with liver, bone, or lung mets. The PFS HR favored N+C vs S and median (m) PFS was longer with N+C vs S across all subgroups. The OS HR also favored N+C vs S across most subgroups. ORR ranged from 38%–66% (N+C) vs 10%–44% (S) across subgroups, and CR benefits were seen with N+C in most subgroups. Additional outcomes including landmark OS and response details in subgroups will be reported. Conclusions: Consistent with outcomes in ITT pts, efficacy benefits with N+C vs S were observed regardless of IMDC risk status, organ site of mets, or extent of tumor burden at baseline. These results support N+C as a new first-line treatment option for pts with aRCC. Clinical trial information: NCT03141177. [Table: see text]

Lenvatinib (LEN) + pembrolizumab (PEMBRO) treatment in patients (pts) with metastatic clear cell renal cell carcinoma (RCC): Final results of a phase 1b/2 trial

e16542

Background: Immune checkpoint inhibitors (ICIs) are commonly used as first-line treatment for pts with advanced RCC. In the recent phase 3 CLEAR trial, LEN + PEMBRO showed improved objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) vs sunitinib in first-line treatment of advanced RCC (Motzer R et al. NEJM. 2021). Additional treatment options are needed for pts with disease progression on ICIs. A phase 1b trial of LEN + PEMBRO was performed in multiple tumor types and included an expansion part into a phase 2 cohort of ICI-pretreated, treatment-naïve, or previously treated ICI-naïve pts with metastatic RCC (NCT02501096). We report the final results of the RCC cohort with an extended follow-up. Methods: Eligible pts were ≥18 years old and had measurable disease. Efficacy analyses were conducted by prior therapy grouping. The primary endpoint was ORR at week 24 (ORRwk24) per immune-related (ir) RECIST by investigator assessment. Secondary endpoints included ORR, duration of response (DOR), PFS, OS, and safety. Exploratory endpoints included tumor response assessed per RECIST v1.1 by independent review committee (IRC). Subgroup analyses of the ICI-pretreated group will be included in the poster. Results: The recommended doses determined in phase 1b were LEN 20 mg daily + PEMBRO 200 mg once every 3 weeks (Taylor M et al. JCO. 2020). The study enrolled 145 pts (efficacy analysis, n=143; safety analysis, n=145). At data cutoff (August 18, 2020), the median follow-up time was 19.8 months. The ORRwk24 was 55.8% (95% CI 45.7–65.5) for ICI-pretreated pts (n=104), 72.7% (95% CI 49.8–89.3) for treatment-naïve pts (n=22), and 41.2% (95% CI 18.4–67.1) for previously treated ICI-naïve pts (n=17). The median OS for the previously treated ICI-naïve pts was 30.3 months and was not reached in the other groups. Additional efficacy analyses are shown in the table. Treatment-related adverse events occurred in 99.3% of pts; the most common were fatigue (58.6%), diarrhea (55.2%), and hypertension (40.0%). Most pts (69%) maintained the LEN starting dose or were reduced to LEN 14 mg daily (dose level −1). Conclusions: LEN + PEMBRO demonstrated promising antitumor activity with a manageable safety profile in pts with metastatic RCC, including pts who were ICI-pretreated. Clinical trial information: NCT02501096. [Table: see text]

The Therapeutic Landscape of Renal Cell Carcinoma: From the Dark Age to the Golden Age

Oncologic treatments for renal cell carcinoma (RCC) have undergone a major revolution in the past 2 decades, moving away from the pre-2004 Dark Age during which interleukin 2 and interferon-α were the only therapeutic options and induced treatment responses in only 5% to 10% of patients with metastatic disease. The development of anti-angiogenic tyrosine kinase inhibitors against vascular endothelial growth factor receptor 2 and inhibitors of mammalian target of rapamycin complex 1 in 2005 introduced the Modern Age with better overall and progression-free survival and a greater number of patients (30%-40%) responding to and (∼80%) benefiting from these targeted therapeutic agents. The coming of age of the immuno-oncology era with the use of immune checkpoint inhibitors (ICIs) have ushered us into the Golden Age of metastatic RCC care, in which combined administrations of two ICIs (anti-programmed cell death protein 1/programmed death-ligand 1 and anti-cytotoxic T-lymphocyte-associated protein 4 or one tyrosine kinase inhibitor plus one ICI (anti-programmed cell death protein 1/programmed death-ligand 1) have recast the treatment landscape of clear cell RCC, the most common RCC subtype, with an approximately 60% response rate and an approximately 90% disease control rate that further improves metastatic RCC survival. Exciting clinical trials are in the pipeline investigating complementary/synergistic molecular mechanisms, based on studies investigating the biology, pathology, and genomics of renal carcinoma and the respective treatment outcome. This will enable us to enter the Diamond Age of precision medicine in which a specific treatment can be tailored to the specific biological and pathologic circumstance of an individual kidney tumor to offer more effective yet less toxic therapy.

A Single-arm, Multicenter, Phase 2 Study of Lenvatinib Plus Everolimus in Patients with Advanced Non-Clear Cell Renal Cell Carcinoma

BACKGROUND

Non-clear cell renal cell carcinoma (nccRCC) accounts for ≤20% of RCC cases. Lenvatinib (a multitargeted tyrosine kinase inhibitor) in combination with everolimus (an mTOR inhibitor) is approved for the treatment of advanced RCC after one prior antiangiogenic therapy.

OBJECTIVE

To determine the safety and efficacy of lenvatinib plus everolimus as a first-line treatment for patients with advanced nccRCC.

DESIGN, SETTING, AND PARTICIPANTS

This open-label, single-arm, multicenter, phase 2 study enrolled patients with unresectable advanced or metastatic nccRCC and no prior anticancer therapy for advanced disease.

INTERVENTION

Lenvatinib (18 mg) plus everolimus (5 mg) orally once daily.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the objective response rate (ORR) as assessed by investigators according to Response Evaluation Criteria in Solid Tumors version 1.1. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety assessments. The 95% confidence intervals (CIs) for ORRs were calculated using the two-sided Clopper-Pearson method. Median PFS and median OS were estimated using the Kaplan-Meier product-limit method and their 95% CIs were estimated via a generalized Brookmeyer and Crowley method.

RESULTS AND LIMITATIONS

The study (start date: February 20, 2017) enrolled 31 patients with nccRCC (papillary, n = 20; chromophobe, n = 9; unclassified, n = 2). At the data cutoff date (July 17, 2019), the best overall response was a partial response (eight patients: papillary, n = 3; chromophobe, n = 4; unclassified, n = 1) for an overall ORR of 26% (95% CI 12-45). Median PFS was 9.2 mo (95% CI 5.5-not estimable), and median OS was 15.6 mo (95% CI 9.2-not estimable). The most common treatment-emergent adverse events were fatigue (71%), diarrhea (58%), decreased appetite (55%), nausea (55%), and vomiting (52%). Limitations include the small sample size and single-arm design.

CONCLUSIONS

Lenvatinib plus everolimus showed promising anticancer activity in patients with advanced nccRCC with an ORR of 26% and is worthy of further study. The safety profile was consistent with the established profile of the study-drug combination.

PATIENT SUMMARY

We examined the combination of lenvatinib plus everolimus as the first therapy for 31 patients who had advanced nccRCC. We found that this treatment seemed effective, because most patients had a decrease in tumor size and manageable treatment-related side effects.

CLINICAL REGISTRATION

This trial is registered at ClinicalTrials.Gov as NCT02915783.

Structural insights into the function of the catalytically active human Taspase1

Taspase1 is an Ntn-hydrolase overexpressed in primary human cancers, coordinating cancer cell proliferation, invasion, and metastasis. Loss of Taspase1 activity disrupts proliferation of human cancer cells in vitro and in mouse models of glioblastoma. Taspase1 is synthesized as an inactive proenzyme, becoming active upon intramolecular cleavage. The activation process changes the conformation of a long fragment at the C-terminus of the α subunit, for which no full-length structural information exists and whose function is poorly understood. We present a cloning strategy to generate a circularly permuted form of Taspase1 to determine the crystallographic structure of active Taspase1. We discovered that this region forms a long helix and is indispensable for the catalytic activity of Taspase1. Our study highlights the importance of this element for the enzymatic activity of Ntn-hydrolases, suggesting that it could be a potential target for the design of inhibitors with potential to be developed into anticancer therapeutics.

Single-cell Spatial Proteomic Revelations on the Multiparametric MRI Heterogeneity of Clinically Significant Prostate Cancer

PURPOSE

Multiparametric MRI (mpMRI) has become an indispensable radiographic tool in diagnosing prostate cancer. However, mpMRI fails to visualize approximately 15% of clinically significant prostate cancer (csPCa). The molecular, cellular, and spatial underpinnings of such radiographic heterogeneity in csPCa are unclear.

EXPERIMENTAL DESIGN

We examined tumor tissues from clinically matched patients with mpMRI-invisible and mpMRI-visible csPCa who underwent radical prostatectomy. Multiplex immunofluorescence single-cell spatial imaging and gene expression profiling were performed. Artificial intelligence-based analytic algorithms were developed to examine the tumor ecosystem and integrate with corresponding transcriptomics.

RESULTS

More complex and compact epithelial tumor architectures were found in mpMRI-visible than in mpMRI-invisible prostate cancer tumors. In contrast, similar stromal patterns were detected between mpMRI-invisible prostate cancer and normal prostate tissues. Furthermore, quantification of immune cell composition and tumor-immune interactions demonstrated a lack of immune cell infiltration in the malignant but not in the adjacent nonmalignant tissue compartments, irrespective of mpMRI visibility. No significant difference in immune profiles was detected between mpMRI-visible and mpMRI-invisible prostate cancer within our patient cohort, whereas expression profiling identified a 24-gene stromal signature enriched in mpMRI-invisible prostate cancer. Prostate cancer with strong stromal signature exhibited a favorable survival outcome within The Cancer Genome Atlas prostate cancer cohort. Notably, five recurrences in the 8 mpMRI-visible patients with csPCa and no recurrence in the 8 clinically matched patients with mpMRI-invisible csPCa occurred during the 5-year follow-up post-prostatectomy.

CONCLUSIONS

Our study identified distinct molecular, cellular, and structural characteristics associated with mpMRI-visible csPCa, whereas mpMRI-invisible tumors were similar to normal prostate tissue, likely contributing to mpMRI invisibility.

Nivolumab plus Cabozantinib versus Sunitinib for Advanced Renal-Cell Carcinoma

BACKGROUND

The efficacy and safety of nivolumab plus cabozantinib as compared with those of sunitinib in the treatment of previously untreated advanced renal-cell carcinoma are not known.

METHODS

In this phase 3, randomized, open-label trial, we randomly assigned adults with previously untreated clear-cell, advanced renal-cell carcinoma to receive either nivolumab (240 mg every 2 weeks) plus cabozantinib (40 mg once daily) or sunitinib (50 mg once daily for 4 weeks of each 6-week cycle). The primary end point was progression-free survival, as determined by blinded independent central review. Secondary end points included overall survival, objective response as determined by independent review, and safety. Health-related quality of life was an exploratory end point.

RESULTS

Overall, 651 patients were assigned to receive nivolumab plus cabozantinib (323 patients) or sunitinib (328 patients). At a median follow-up of 18.1 months for overall survival, the median progression-free survival was 16.6 months (95% confidence interval [CI], 12.5 to 24.9) with nivolumab plus cabozantinib and 8.3 months (95% CI, 7.0 to 9.7) with sunitinib (hazard ratio for disease progression or death, 0.51; 95% CI, 0.41 to 0.64; P<0.001). The probability of overall survival at 12 months was 85.7% (95% CI, 81.3 to 89.1) with nivolumab plus cabozantinib and 75.6% (95% CI, 70.5 to 80.0) with sunitinib (hazard ratio for death, 0.60; 98.89% CI, 0.40 to 0.89; P = 0.001). An objective response occurred in 55.7% of the patients receiving nivolumab plus cabozantinib and in 27.1% of those receiving sunitinib (P<0.001). Efficacy benefits with nivolumab plus cabozantinib were consistent across subgroups. Adverse events of any cause of grade 3 or higher occurred in 75.3% of the 320 patients receiving nivolumab plus cabozantinib and in 70.6% of the 320 patients receiving sunitinib. Overall, 19.7% of the patients in the combination group discontinued at least one of the trial drugs owing to adverse events, and 5.6% discontinued both. Patients reported better health-related quality of life with nivolumab plus cabozantinib than with sunitinib.

CONCLUSIONS

Nivolumab plus cabozantinib had significant benefits over sunitinib with respect to progression-free survival, overall survival, and likelihood of response in patients with previously untreated advanced renal-cell carcinoma. (Funded by Bristol Myers Squibb and others; CheckMate 9ER ClinicalTrials.gov number, NCT03141177.).

Nivolumab + cabozantinib (NIVO+CABO) versus sunitinib (SUN) for advanced renal cell carcinoma (aRCC): Outcomes by sarcomatoid histology and updated trial results with extended follow-up of CheckMate 9ER

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Background: First-line NIVO+CABO met primary and secondary efficacy endpoints by improving progression-free survival (PFS; HR 0.51, P < 0.0001), overall survival (OS; HR 0.60, P = 0.0010), and objective response rate (ORR; 55.7% vs 27.1%; P < 0.0001) vs SUN in patients (pts) with aRCC in CheckMate 9ER (Choueiri et al. ESMO 2020). Efficacy benefits with NIVO+CABO vs SUN were consistent across prespecified subgroups including by IMDC risk group, and regardless of tumor PD-L1 expression (database lock for primary analysis, March 30, 2020). Updated analyses are needed to establish durability of benefit with first-line NIVO+CABO and assess outcomes in aRCC pts with sarcomatoid features (sRCC)—an aggressive histologic subtype associated with poor prognoses. Methods: In this phase III open-label trial, adults with confirmed aRCC (with a clear cell component including those with sRCC) were randomized 1:1 (stratified by IMDC risk score, tumor PD-L1 expression, geographic region) to NIVO 240 mg IV Q2W + CABO 40 mg PO QD vs SUN 50 mg PO (4 weeks of 6-week cycles). The primary endpoint was RECIST v1.1-defined PFS by blinded independent central review (BICR) in all randomized (intent-to-treat [ITT]) pts; secondary endpoints included OS, ORR by BICR, and safety. Pts with and without sRCC were identified by local pathology report, and outcomes in these pts were evaluated via prespecified supportive subset analyses. Results: The presence of sRCC was assessed in ITT pts (N = 651) at enrollment. Overall, 75 (11.5%) pts had sRCC and 557 (85.6%) did not; sRCC status was not reported in 19 pts (2.9%). Overall, 34 vs 41 pts with sRCC were randomized to NIVO+CABO vs SUN, respectively. At a median follow-up of 18.1 months, NIVO+CABO improved PFS, OS, and ORR in sRCC pts vs SUN (Table). Notable PFS, OS, and ORR benefits were observed with NIVO+CABO vs SUN in the subgroup of pts without sRCC. Median PFS was doubled, the risk of death was lower, and ORR was consistently higher with NIVO+CABO vs SUN regardless of sarcomatoid status. Key updated PFS, OS, response, and safety outcomes in the ITT population and in pts with and without sRCC will be reported with additional follow-up based on a September 10, 2020 database lock. Conclusions: NIVO+CABO demonstrated improved efficacy and prolonged survival vs SUN in previously untreated aRCC pts regardless of sarcomatoid status. Updated results with extended follow-up will assess the durability of outcomes in this trial. Clinical trial information: NCT03141177 . [Table: see text]

Laparoscopic cytoreductive nephrectomy is associated with significantly improved survival compared with open cytoreductive nephrectomy or targeted therapy alone

The aim of the present study was to compare the survival outcomes for patients with metastatic renal cell carcinoma (mRCC) who underwent laparoscopic cytoreductive nephrectomy (CN) vs. open CN vs. targeted therapy (TT) alone at our institution. A retrospective chart review was performed at our institution for patients who underwent CN prior to TT (laparoscopic, n=48; open, n=48) or who were deemed unfit for surgery and received TT alone (n=36), between January 2007 and December 2012. Kaplan-Meier estimated survival and Cox proportional hazards analyses were performed. Laparoscopic CN was associated with significantly longer survival compared with open CN or TT alone (median survival 24 vs. <12 months, respectively; P<0.01). On multivariate analysis, laparoscopic CN was an independent predictor of survival [hazard ratio (HR)=0.48, P<0.01), controlling for preoperative risk factors, while survival was similar between open CN and TT alone (HR=0.85, P=0.54). In our experience, laparoscopic CN appears to be a significant predictor of survival in mRCC. Selection bias of the surgeon for patients with improved survival may account for clinical variables that were otherwise difficult to quantify. For patients who were not candidates for laparoscopic CN, open CN did not confer a survival benefit over TT alone, while it was associated with increased morbidity.

The Pan-Omics Landscape of Renal Cell Carcinoma and Its Implication on Future Clinical Practice

Renal cell carcinoma has traditionally been classified based on histological features. Contemporary studies have identified genomic, transcriptomic, epigenomic, and metabolomic signatures that correspond to or even transcend histological subtypes. Much remains to be learned about improving the algorithm of pan-omics integration for precision oncology, which will not only advance our understanding of RCC pathobiology and treatment response but also result in novel therapeutic opportunities. Accordingly, this review focuses on recent RCC multi-omics literature. Encouragingly, a few reports on omics integration into routinely employed prognostic risk models have shown early promise that could lay the foundation for future development of precision kidney cancer therapies. Hence, this article serves as a primer on what we have learned and how we might better realize the clinical potential of the burgeoning pan-omics data.

Exploiting the circuit breaker cancer evolution model in human clear cell renal cell carcinoma

The incessant interactions between susceptible humans and their respective macro/microenvironments registered throughout their lifetime result in the ultimate manifestation of individual cancers. With the average lifespan exceeding 50 years of age in humans since the beginning of 20th century, aging - the "time" factor - has played an ever-increasing role alongside host and environmental factors in cancer incidences. Cancer is a genetic/epigenetic disease due to gain-of-function mutations in cancer-causing genes (oncogene; OG) and/or loss-of-function mutations in tumor-suppressing genes (tumor suppressor genes; TSG). In addition to their integral relationship with cancer, a timely deployment of specific OG and/or TSG is in fact needed for higher organisms like human to cope with respective physiological and pathological conditions. Over the past decade, extensive human kidney cancer genomics have been performed and novel mouse models recapitulating human kidney cancer pathobiology have been generated. With new genomic, genetic, mechanistic, clinical and therapeutic insights accumulated from studying clear cell renal cell carcinoma (ccRCC)-the most common type of kidney cancer, we conceived a cancer evolution model built upon the OG-TSG signaling pair analogous to the electrical circuit breaker (CB) that permits necessary signaling output and at the same time prevent detrimental signaling overdrive. Hence, this viewpoint aims at providing a step-by-step mechanistic explanation/illustration concerning how inherent OG-TSG CBs intricately operate in concert for the organism's wellbeing; and how somatic mutations, the essential component for genetic adaptability, inadvertently triggers a sequential outage of specific sets of CBs that normally function to maintain and protect and individual tissue homeostasis.

Phase II trial of lenvatinib (LEN) plus pembrolizumab (PEMBRO) for disease progression after PD-1/PD-L1 immune checkpoint inhibitor (ICI) in metastatic clear cell renal cell carcinoma (mccRCC)

5008

Background: LEN, a multikinase VEGFR inhibitor, plus everolimus is approved for advanced RCC after prior VEGF-targeted therapy. PEMBRO, an anti-PD-1 antibody, plus axitinib is approved as first-line therapy of advanced RCC. We report phase 2 results of the RCC cohort of a phase 1b/2 trial (Study 111/KEYNOTE-146) of LEN + PEMBRO in patients (pts) who progressed after ICI therapy. Methods: We performed a multicenter, open-label study of pts with mccRCC, who previously had disease progression by RECIST (confirmed ≥ 4 weeks later) during or following ICI therapy. Pts had measurable disease by immune-related RECIST, and ≥ 1 prior therapy. Pts received LEN 20 mg orally once daily plus PEMBRO 200 mg IV every 3 weeks until disease progression or toxicity. Tumor assessments were performed every 6 weeks (until week 24), then every 9 weeks. The primary endpoint was objective response rate (ORR) at Week 24 by irRECIST. Results: 104 pts were enrolled. At data cutoff (January 12, 2020), 71 (69%) pts were still on study treatment. Most pts had ≥2 prior anticancer regimens (58%). 91 of 104 pts were evaluable for response at Week 12 (13 pts NE at Week 12); 46 of 91 pts achieved a confirmed partial response for an ORR of 51% (Table). Median progression-free survival (PFS) was 11.7 months and median duration of response (DOR) was 9.9 months. The most common treatment-related adverse events (TRAEs) were fatigue (49%), diarrhea (44%), proteinuria (37%), hypertension (31%), nausea (31%), dysphonia (29%), stomatitis (29%), and arthralgia (27%). There was 1 grade 5 TRAE (upper gastrointestinal hemorrhage). 43% of pts required dose reduction and 12% of pts discontinued treatment due to TRAEs. Response and safety data will be updated to include all pts evaluable at an April 9, 2020 cut-off. Conclusions: LEN + PEMBRO demonstrated promising antitumor activity in pts with mccRCC with disease progression following ICI therapy. No new safety signals were detected. Efficacy outcomes by investigator review per irRECIST. Clinical trial information: NCT02501096 . [Table: see text]

Integrated-omics of MRI-visible and -invisible prostate cancer identifies molecular correlations with clinical outcome

e17506

Background: The inclusion of multiparametric MRI (mpMRI) to prostate cancer (PCa) diagnostics has increased the detection rate and has improved the prediction rate of clinically significant PCa. Yet, mpMRI has a false negative rate of 12.6%, missing 6-13% of clinically significant PCa. The mechanisms underlying MRI visibility are poorly understood; therefore, to probe the molecular and cellular underpinnings of PCa MRI visibility, we profiled tissue from Gleason score and clinically matched patients with MRI-visible and MRI-invisible PCa who underwent radical prostatectomy. Methods: MRI-invisible (n = 7) and MRI-visible (n = 8) PCa tumors were evaluated with multiplex immunofluorescence (MxIF; 14 markers) and were subjected to gene expression profiling using the HTG EdgeSeq Oncology Biomarker Panel (2,549 genes). Gene expression analysis was also performed using The Cancer Genome Atlas (TCGA), including normal prostate (n = 52) and PCa (n = 387) tissue. Analyses were performed using the BostonGene automated pipeline. Results: MpMRI-visible PCa tumors (62.5%) displayed compact epithelial tumor architecture compared with mpMRI-invisible PCa tumors (28.5%). mpMRI-visible PCa had higher malignant cell density (p = 0.04) and increased neighboring malignant cells (p = 0.07), correlating with MRI-visible PCa complex tumor architecture (r = 0.49 for neighboring malignant cells vs tumor cell density). Tumor stromal organization differences were determined by measuring Wasserstein distances between distributions, and mpMRI-invisible PCa stroma appeared more similar to normal tissue. The visible group exhibited lower expression of stroma-enriched genes such as filamin C (FLNC) (FDR < 0.1) and cellular adhesion-related genes (FDR < 0.4), with gene expression signatures markedly different compared to normal prostate tissue. Higher malignant cell density, neighboring malignant cells, and Wasserstein distances, and low FLNC expression – all mpMRI visibility characteristics – were associated with patient relapse (p = 0.02). Low stroma signature expression in the TCGA cohort correlated with inferior PCa PFS (p = 0.005). Conclusions: This is the first integrated multi-omics analysis of clinically matched mpMRI-visible and -invisible PCa. mpMRI-invisible tumors exhibited molecular, cellular, and structural characteristics more akin to normal prostate tissue, which may render them undetectable by imaging. A stroma-associated gene signature, a mpMRI-invisible tumor feature, correlated with better PCa clinical outcomes.

Integrated single-cell spatial multi-omics of intratumor heterogeneity in renal cell carcinoma

e17106

Background: Clear cell renal cell carcinoma (ccRCC) exhibits conspicuous intratumor heterogeneity (ITH) - a driver of tumor evolution and metastasis. ITH in RCC has been studied extensively with bulk tumor DNA sequencing, which lacks the ability to integrate single cell resolution data, spatial architecture, and microenvironment composition. Therefore, we analyzed primary ccRCC tumors at multiple biopsy sites with CyTOF, multiplex immunofluorescence (MxIF), whole exome sequencing (WES), RNA sequencing (RNA-seq), single nuclei RNA-seq (snRNA-seq), and whole genome bisulfite sequencing (WGBS). Methods: Primary ccRCC tumors collected from 6 patients (pts) were biopsied at multiple locations and subjected to CyTOF (n = 21 sites, 6 pts), MxIF (20 markers, n = 8 sites, 3 pts), WES (n = 8 sites, 3 pts), RNA-seq (n = 8 sites, 3 pts), snRNA-seq (n = 8 sites, 3 pts), and WGBS (n = 8 sites, 3 pts), enabling integrated multi-omics analysis. MxIF, CyTOF, and genomic/transcriptomic analyses were performed by BostonGene. Results: Genomic intratumor (IT) evolution of ccRCC cells was tracked with WES, and subclonal distribution of SETD2, STAG2, TSC2 and PBRM1 mutations was observed in different IT regions. Different regions of the same tumor were similar, whereas individual patient tumors were distinct according to tumor microenvironment cellular composition measured by CyTOF or deconvoluted from RNA-seq. The cellular deconvolution of the ccRCC tumors reconstructed from RNA-seq correlated with CyTOF, snRNA-seq and WGBS, showing high concordance among the methods. The promoter CpG island methylation levels, averaged across all genes, positively correlated with ccRCC grade. MxIF revealed spatial IT heterogeneity in the distribution of immune infiltrate components. Macrophages and T cells dispersed among malignant cells; whereas, T cells formed clusters at unique tumor margins. Conclusions: The utilization of multi-omics methods produced a high-resolution portrait of the ccRCC tumor composition and identified differential ITH among regions within the primary tumors or among individual primary tumors. This study demonstrated strong concordance among the different technologies, suggesting that tumor deconvolution by bulk RNA-seq might be clinically applicable for ccRCC tumors. MxIF analysis enabled a fine elucidation of the spatial relationships among the tumor and the immune and stromal cells, missed by common omic platforms. Integrated single cell multi-omics could render specific pathobiological and therapeutic insights that impact treatment decisions.

Modeling biological and genetic diversity in upper tract urothelial carcinoma with patient derived xenografts

Treatment paradigms for patients with upper tract urothelial carcinoma (UTUC) are typically extrapolated from studies of bladder cancer despite their distinct clinical and molecular characteristics. The advancement of UTUC research is hampered by the lack of disease-specific models. Here, we report the establishment of patient derived xenograft (PDX) and cell line models that reflect the genomic and biological heterogeneity of the human disease. Models demonstrate high genomic concordance with the corresponding patient tumors, with invasive tumors more likely to successfully engraft. Treatment of PDX models with chemotherapy recapitulates responses observed in patients. Analysis of a HER2 S310F-mutant PDX suggests that an antibody drug conjugate targeting HER2 would have superior efficacy versus selective HER2 kinase inhibitors. In sum, the biological and phenotypic concordance between patient and PDXs suggest that these models could facilitate studies of intrinsic and acquired resistance and the development of personalized medicine strategies for UTUC patients.

A phase II study of lenvatinib plus everolimus in patients with advanced non-clear cell renal cell carcinoma (nccRCC)

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Background: Non-clear cell renal cell carcinoma (nccRCC) is an umbrella term that encompasses multiple RCC histological subtypes, including papillary, chromophobe, and undetermined RCC. Both increased expression of the vascular endothelial growth factor (VEGF) and dysregulation of the mammalian target of rapamycin (mTOR) pathway occur in nccRCC. Lenvatinib (LEN) is a multitarget tyrosine kinase inhibitor that inhibits the VEGF receptor and other targets; everolimus (EVE) is a mTOR inhibitor. LEN + EVE is approved for the treatment of patients with advanced RCC following 1 prior antiangiogenic therapy. This phase 2 study examined the efficacy and tolerability of LEN + EVE in patients with nccRCC. Methods: This single-arm, multicenter, phase 2 trial assessed the safety and efficacy of LEN (18 mg once daily) + EVE (5 mg once daily) in patients with unresectable advanced or metastatic nccRCC who had not received any chemotherapy for advanced disease. The primary objective was objective response rate (ORR) as assessed by investigators using RECIST v1.1. Secondary objectives included progression-free survival (PFS), overall survival (OS), and safety assessments. Results: At the time of data cutoff (July 17, 2019), 31 patients with nccRCC (papillary, n = 20; chromophobe, n = 9; unclassified, n = 2) were enrolled and treated. The ORR was 25.8% (95% confidence interval [CI]: 11.9–44.6%); 8 patients achieved a partial response (PR; papillary, n = 3; chromophobe, n = 4; unclassified, n = 1) and no patients had a complete response (CR). The median duration of response was not reached. Additionally, 18 patients (58.1%) had stable disease (SD) and the clinical benefit rate (CR + PR + durable SD [duration ≥ 23 weeks]) was 61.3% (95% CI: 42.2–78.2%). The median PFS was 9.23 months (95% CI: 5.49- not estimable [NE]) and median OS was 15.64 months (95% CI: 9.23–NE). The safety profile observed in this study was similar to the established profile of the study drug combination (LEN + EVE). Conclusions: The combination of LEN + EVE showed promising antitumor activity as first-line therapy in patients with advanced nccRCC. The ORR was 25.8%, which compares favorably to historical reports with EVE monotherapy. Clinical trial information: NCT02915783.

Molecular characterization of sarcomatoid clear cell renal cell carcinoma unveils new candidate oncogenic drivers

Sarcomatoid clear-cell renal cell carcinomas (sRCC) are associated with dismal prognosis. Genomic alterations associated with sarcomatoid dedifferentiation are poorly characterized. We sought to define the genomic landscape of sRCC and uncover potentially actionable therapeutic targets. We assessed the genomic landscape of sRCC using targeted panel sequencing including patients with microdissected sarcomatoid and epithelial components. Along with common genomic alterations associated with clear-cell histology, we found that Hippo was one of the most frequently altered pathways in these tumours. Hippo alterations were differentially enriched in sRCC compared to non-sRCC. Functional analysis showed that Hippo members mutations were associated with higher nuclear accumulation of YAP/TAZ, core effectors of the Hippo pathway. In a NF2-mutant sRCC model, YAP1 knockdown and NF2 reconstitution suppressed cell proliferation, tumour growth and invasion, both in vitro and in vivo. Overall, we show that Hippo pathway alterations are a feature of sRCC, and enable the exploration of the Hippo pathway as a novel potential therapeutic target.

Integrated Proteogenomic Characterization of Clear Cell Renal Cell Carcinoma

To elucidate the deregulated functional modules that drive clear cell renal cell carcinoma (ccRCC), we performed comprehensive genomic, epigenomic, transcriptomic, proteomic, and phosphoproteomic characterization of treatment-naive ccRCC and paired normal adjacent tissue samples. Genomic analyses identified a distinct molecular subgroup associated with genomic instability. Integration of proteogenomic measurements uniquely identified protein dysregulation of cellular mechanisms impacted by genomic alterations, including oxidative phosphorylation-related metabolism, protein translation processes, and phospho-signaling modules. To assess the degree of immune infiltration in individual tumors, we identified microenvironment cell signatures that delineated four immune-based ccRCC subtypes characterized by distinct cellular pathways. This study reports a large-scale proteogenomic analysis of ccRCC to discern the functional impact of genomic alterations and provides evidence for rational treatment selection stemming from ccRCC pathobiology.

Abstract 698: Enhancing apoptosis to improve the therapy of EGFR-mutant lung cancer

EGFR-TKIs have shown clinical efficacy in EGFR-mutant lung cancer patients, but most of the cases eventually develop resistance to the drugs, including the third-generation EGFR-TKI. Here, we develop a cell death mechanism-based combination strategy to enhance the therapeutic effect of EGFR-TKIs as well as to overcome the acquired resistance to EGFT-TKI in EGFR-mutant lung cancer. Through high-throughput screening of a custom pathway inhibitor library (-1000 drugs), we discovered Aurora kinase inhibitors that synergized with a third-generation EGFR-TKI (AZD9291) to induce apoptosis in EGFR-mutant lung cancer cells. Aurora kinase inhibitors enhanced AZD9291-mediated induction of BIM and PUMA, two important sentinels interconnecting the EGFR signal transduction pathway and the mitochondrial apoptotic machinery BAX and BAK. Combined inhibition of Aurora kinases and EGFR prevented the emergence of EGFR-TKI resistant clones in clonogenic assays. Interestingly, AZD9291 resistant lung cancer cells exhibited greater sensitivity to Aurora kinase inhibitors compared with parental cells. In conclusion, we found that the combination of AZD9291 and Aurora kinase inhibitors synergistically induced BIM and PUMA-mediated apoptosis, which may render a promising strategy to improve the therapy of EGFR-mutant lung cancer. &lt;!–EndFragment–&gt;

Citation Format: Kosuke Tanaka, Song Han, Yogesh T. Ganesan, James J. Hsieh, Emily H. Cheng. Enhancing apoptosis to improve the therapy of EGFR-mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 698.

Chromophobe Renal Cell Carcinoma: Results From a Large Single-Institution Series

BACKGROUND

The purpose of the study was to evaluate clinical features and prognostic factors in a large single institutional cohort of chromophobe renal cell carcinoma (ChRCC) patients for identification of tumors with the highest metastatic potential.

PATIENTS AND METHODS

Clinicopathological parameters of all patients with ChRCC diagnosed and surgically treated at Memorial Sloan Kettering Cancer Center between 1990 and 2016 were identified and compared with patients treated for clear-cell renal cell carcinoma (ccRCC) in the same study period using Wilcoxon test for continuous variables and Fisher exact test for categorical variables. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method, log rank test, and Cox proportional hazards regression.

RESULTS

Four hundred ninety-six patients with ChRCC (10-year RFS, 91.7% and OS, 82.1%) and 3312 patients with ccRCC (10-year RFS, 79.4% and OS, 63.6%) were included in the analysis. Patients with ChRCC were younger (median 59 vs. 61 years; P = .0015), less frequently male (54.8% vs. 66.3%; P < .0001), showed more favorable T stages (T1-2 in 78% vs. 67%; P < .0001) and less frequent sarcomatoid differentiation (1.2 % vs. 4%; P = .0008) and showed lower rates of metastatic development compared with ccRCC patients. Larger tumor size, sarcomatoid differentiation, and higher T-stage are significantly associated with adverse RFS and OS in chromophobe tumors.

CONCLUSION

ChRCC is more commonly diagnosed in female and younger patients and is associated with a more favorable clinical outcome and a lower propensity for metastatic development than ccRCC. Larger tumors and sarcomatoid differentiation of ChRCC might be considered as risk factors for metastatic development.

Abnormal oxidative metabolism in a quiet genomic background underlies clear cell papillary renal cell carcinoma

While genomic sequencing routinely identifies oncogenic alterations for the majority of cancers, many tumors harbor no discernable driver lesion. Here, we describe the exceptional molecular phenotype of a genomically quiet kidney tumor, clear cell papillary renal cell carcinoma (CCPAP). In spite of a largely wild-type nuclear genome, CCPAP tumors exhibit severe depletion of mitochondrial DNA (mtDNA) and RNA and high levels of oxidative stress, reflecting a shift away from respiratory metabolism. Moreover, CCPAP tumors exhibit a distinct metabolic phenotype uniquely characterized by accumulation of the sugar alcohol sorbitol. Immunohistochemical staining of primary CCPAP tumor specimens recapitulates both the depletion of mtDNA-encoded proteins and a lipid-depleted metabolic phenotype, suggesting that the cytoplasmic clarity in CCPAP is primarily related to the presence of glycogen. These results argue for non-genetic profiling as a tool for the study of cancers of unknown driver.

Hyperpolarized MRI Visualizes Warburg Effects and Predicts Treatment Response to mTOR Inhibitors in Patient-Derived ccRCC Xenograft Models

The ever-changing tumor microenvironment constantly challenges individual cancer cells to balance supply and demand, presenting tumor vulnerabilities and therapeutic opportunities. Everolimus and temsirolimus are inhibitors of mTOR (mTORi) approved for treating metastatic renal cell carcinoma (mRCC). However, treatment outcome varies greatly among patients. Accordingly, administration of mTORi in mRCC is diminishing, which could potentially result in missing timely delivery of effective treatment for select patients. Here, we implemented a clinically applicable, integrated platform encompassing a single dose of [1-¹³C] pyruvate to visualize the in vivo effect of mTORi on the conversion of pyruvate to lactate using hyperpolarized MRI. A striking difference that predicts treatment benefit was demonstrated using two preclinical models derived from patients with clear cell RCC (ccRCC) who exhibited primary resistance to VEGFRi and quickly succumbed to their diseases within 6 months after the diagnosis of metastasis without receiving mTORi. Our findings suggest that hyperpolarized MRI could be further developed to personalize kidney cancer treatment. SIGNIFICANCE: These findings demonstrate hyperpolarized ^[1-13C]pyruvate MRI as a tool for accurately assessing the clinical success of mTOR inhibition in patients with ccRCC.

Genomically annotated risk model for advanced renal-cell carcinoma: a retrospective cohort study

BACKGROUND

The Memorial Sloan Kettering Cancer Center (MSKCC) risk model is an established prognostic tool for metastatic renal-cell carcinoma that integrates clinical and laboratory data, but is agnostic to tumour genomics. Several mutations, including BAP1 and PBRM1, have prognostic value in renal-cell carcinoma. Using two independent clinical trial datasets of patients with metastatic renal-cell carcinoma, we aimed to study whether the addition of the mutation status for several candidate prognostic genes to the MSKCC model could improve the model's prognostic performance.

METHODS

In this retrospective cohort study, we used available formalin-fixed paraffin-embedded tumour tissue and clinical outcome data from patients with metastatic renal-cell carcinoma assigned to treatment with tyrosine kinase inhibitors in the COMPARZ trial (training cohort; n=357) and RECORD-3 trial (validation cohort; n=258). Eligible patients in both trials were treatment-naive; had histologically confirmed, advanced, or metastatic renal-cell carcinoma; and a Karnofsky performance status score of at least 70. For each cohort, data from patients in all treatment groups (sunitinib and pazopanib in the training cohort, and everolimus and sunitinib in the validation cohort) were pooled for this analysis. In the training cohort, tumour tissue was used to evaluate somatic mutations by next-generation sequencing, and the association between cancer-specific outcomes (overall survival, progression-free survival, and overall response) and the mutation status of six genes of interest (BAP1, PBRM1, TP53, TERT, KDM5C, and SETD2) was tested. Only those genes with prognostic value in this setting were added to the MSKCC risk model to create a genomically annotated version. The validation cohort was used to independently test the prognostic value of the annotated model compared with the original MSKCC risk model.

FINDINGS

357 (32%) of 1110 patients assigned to protocol treatment in the COMPARZ study between August, 2008, and September, 2011, were evaluable for mutation status and clinical outcomes in the training cohort. The independent validation cohort included 258 (55%) of 471 evaluable patients, enrolled between October, 2009, and June, 2011, on the RECORD-3 study. In the training cohort, the presence of any mutation in BAP1 or TP53, or both, and absence of any mutation in PBRM1 were prognostic in terms of overall survival (TP53^wt/BAP1^mut, TP53^mut/BAP1^wt o TP53^mut/BAP1^mut vs TP53^wt/BAP1^wt hazard ratio [HR] 1·57, 95% CI 1·21-2·04; p=0·0008; PBRM1^wt vs PBRM^mut, HR 1·58, 1·16-2·14; p=0·0035). The mutation status for these three prognostic genes were added to the original MSKCC risk model to create a genomically annotated version. Distribution of participants in the training cohort into the three risk groups of the original MSKCC model changed from 87 (24%) of 357 patients deemed at favourable risk, 217 (61%) at intermediate risk, and 53 (15%) at poor risk, to distribution across four risk groups in the genomically annotated risk model, with 36 (10%) of 357 deemed at favourable risk, 77 (22%) at good risk, 108 (30%) at intermediate risk, and 136 (38%) at poor risk. Addition of genomic information improved model performance for predicting overall survival (C-index: original model, 0·595 [95% CI 0·557-0·634] vs new model, 0·637 [0·595-0·679]) and progression-free survival (0·567 [95% CI 0·529-0·604] vs 0·602 [0·560-0·643]) with adequate discrimination of the proportion of patients who achieved an objective response (Cochran-Armitage one-sided p=0·0014). Analyses in the validation cohort confirmed the superiority of the genomically annotated risk model over the original version.

INTERPRETATION

The mutation status of BAP1, PBRM1, and TP53 has independent prognostic value in patients with advanced or metastatic renal-cell carcinoma treated with first-line tyrosine kinase inhibitors. Improved stratification of patients across risk groups by use of a genomically annotated model including the mutational status of these three genes warrants further investigation in prospective trials and could be of use as a model to stratify patients with metastatic renal-cell carcinoma in clinical trials.

FUNDING

Novartis Pharmaceuticals Corporation, MSKCC Support Grant/Core Grant, and the J Randall & Kathleen L MacDonald Research Fund.

Chromosome 3p Loss-Orchestrated VHL, HIF, and Epigenetic Deregulation in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype, and metastatic ccRCC is associated with 5-year survival rates of 10% to 20%. Genetically, ccRCC originates from sequential losses of multiple tumor suppressor genes. Remarkably, chromosome 3p loss occurs in more than 90% of sporadic ccRCCs. This results in concurrent one-copy loss of four tumor suppressor genes that are also mutated individually at high frequency in ccRCC (ie, VHL, 80%; PBRM1, 29% to 46%; BAP1, 6% to 19%; and SETD2, 8% to 30%). Pathogenically, 3p loss probably represents the first genetic event that occurs in sporadic ccRCC and the second genetic event in VHL-mutated hereditary ccRCC. VHL constitutes the substrate recognition module of the VCB-Cul2 E3 ligase that degrades HIF1/2α, whereas PBRM1, BAP1, and SETD2 are epigenetic modulators that regulate gene transcription. Because 3p loss and VHL inactivation are nearly universal truncal events in ccRCC, the resulting HIF1/2 signaling overdrive and accompanied tumor hypervascularization probably underlie the therapeutic benefits observed with vascular endothelial growth factor receptor inhibitors, including sorafenib, sunitinib, pazopanib, axitinib, bevacizumab, cabozantinib, and lenvatinib. Furthermore, recent marked advances in ccRCC genomics, transcriptomics, proteomics, metabolomics, molecular mechanisms, mouse models, prognostic and predictive biomarkers, and clinical trials have rendered invaluable translational insights concerning precision kidney cancer therapeutics. With an armamentarium encompassing 13 drugs that exploit seven unique therapeutic mechanisms (ie, cytokines, vascular endothelial growth factor receptor, mTORC1, cMET/AXL, fibroblast growth factor receptor, programmed cell death-1 and programmed death-ligand 1, and cytotoxic T-cell lymphocyte associated-4) to treat metastatic renal cell carcinoma, one of the imminent clinical questions concerning care of patients with metastatic ccRCC is how a personalized treatment strategy, through rationally combining and sequencing different therapeutic modalities, can be formulated to offer the best clinical outcome for individual patients. Here, we attempt to integrate recent discoveries of immediate translational impacts and discuss future translational challenges and opportunities.

PTEN Expression, Not Mutation Status in TSC1, TSC2, or mTOR, Correlates with the Outcome on Everolimus in Patients with Renal Cell Carcinoma Treated on the Randomized RECORD-3 Trial

PURPOSE

Genomic alterations in key components of PI3K/mTOR pathway have been proposed as candidate predictive markers for rapalog therapy in renal cell carcinoma (RCC). We tested this hypothesis in patients from a randomized phase II trial of everolimus versus sunitinib.

PATIENTS AND METHODS

Archival specimens collected at baseline were analyzed with targeted next-generation sequencing (NGS). Focus of interest were alterations in key PI3K pathway components. PTEN expression was assessed by IHC. Association between molecular findings and treatment outcomes was investigated; same associations were tested for 2 everolimus-treated trial cohorts in gastric and hepatocellular carcinoma (HCC).

RESULTS

Among 184 everolimus-treated patients with RCC with NGS data, mutation rates in genes of interest were 6% (TSC1), 4.4% (TSC2), and 8.2% (mTOR); 44% harbored alterations in ≥1 PI3K pathway component. For subjects with presence versus absence of mutations in TSC1, TSC2, or mTOR progression-free survival (PFS) neither differed on univariate analysis (HR, 1.0; P = 0.895) nor on multivariate testing stratified by MSKCC risk group and other established prognostic factors (HR, 1.1; P = 0.806). Everolimus-treated patients with retained (n = 50) versus lost (n = 50) PTEN IHC expression had median PFS of 5.3 months versus 10.5 months (HR, 2.5; P < 0.001). Such differences were not seen with sunitinib (10.9 months vs. 10.3 months; HR, 0.8; P = 0.475). Molecular findings did not correlate with outcomes in gastric and HCC cohorts.

CONCLUSIONS

Association between mutation status for TSC1/TSC2/mTOR and therapeutic outcome on everolimus was not confirmed. Clinically meaningful differences in PFS were seen based on PTEN expression by IHC, lost in >50% of patients.

Plasma Glycosaminoglycans as Diagnostic and Prognostic Biomarkers in Surgically Treated Renal Cell Carcinoma

BACKGROUND

Plasma glycosaminoglycan (GAG) measurements, when aggregated into diagnostic scores, accurately distinguish metastatic clear-cell renal cell carcinoma (RCC) from healthy samples and correlate with prognosis. However, it is unknown if GAG scores can detect RCC in earlier stages or if they correlate with prognosis after surgery.

OBJECTIVE

To explore the sensitivity and specificity of plasma GAGs for detection of early-stage RCC and prediction of recurrence and death after RCC surgery.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective case-control study consisting of a consecutive series of 175 RCC patients surgically treated between May 2011 and February 2014 and 19 healthy controls.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Plasma GAGs in preoperative and postoperative RCC and healthy samples were measured using capillary electrophoresis with laser-induced fluorescence in a single blinded laboratory. A discovery set was first analyzed to update the historical GAG score. The sensitivity of the new GAG score for RCC detection versus healthy subjects was validated using the remaining samples. The correlation of the new GAG score to histopathologic variables, overall survival, and recurrence-free survival was evaluated using nonparametric and log-rank tests and multivariable Cox regression analyses.

RESULTS AND LIMITATIONS

The RCC cohort included 94 stage I, 58 stage II-III, and 22 stage IV cases. In the first discovery set (n=67), the new GAG score distinguished RCC from healthy samples with an area under the receiver operating characteristic curve (AUC) of 0.999. In the validation set (n=108), the GAG score achieved an AUC of 0.991, with 93.5% sensitivity. GAG scores were elevated in RCC compared to healthy samples, irrespective of and uncorrelated to stage, grade, histology, age, or gender. The total chondroitin sulfate concentration was an independent prognostic factor for both overall and recurrence-free survival (hazard ratios 1.51 and 1.25) with high concordance when combined with variables available at pathologic diagnosis (C-index 0.926 and 0.849) or preoperatively (C-index 0.846 and 0.736). Limitations of the study include its retrospective nature and moderate variability in GAG laboratory measurements.

CONCLUSIONS

Plasma GAGs are highly sensitive diagnostic and prognostic biomarkers in surgically treated RCC independent of stage, grade, or histology. Prospective validation studies on GAG scores for early detection, prediction, and surveillance for RCC recurrence are thus warranted.

PATIENT SUMMARY

In this study, we examined if a new molecular blood test can detect renal cell carcinoma in the early stages and predict if the cancer might relapse after surgery. The trial is registered on ClinicalTrial.gov as NCT03471897.