Prevalence of Germline Mutations in Cancer Susceptibility Genes in Patients With Advanced Renal Cell Carcinoma

Importance

Identification of patients with hereditary renal cell carcinoma (RCC) is important for cancer screening and, in patients with advanced disease, for guiding treatment. The prevalence of cancer-related germline mutations in patients with advanced RCC and the phenotypes associated with some rare mutations are unknown.

Objectives

To examine the prevalence of germline mutations in both known RCC predisposition genes and other cancer-associated genes and to identify clinical and pathologic factors associated with germline mutations.

Design, Setting, and Participants

In this cohort study conducted from October 1, 2015, to July 31, 2017, 254 of 267 patients with advanced (American Joint Committee on Cancer stage III or IV) RCC who were seen in medical oncology or urology clinics agreed to germline sequencing and disclosure of results under an institutional protocol of matched tumor-germline DNA sequencing.

Main Outcomes and Measures

Mutation prevalence and spectrum in patients with advanced RCC were determined. Clinical characteristics were assessed by mutation status.

Results

Of the 254 patients (median age [range], 56 [13-79] years; 179 [70.5%] male; 211 [83.1%] non-Hispanic white), germline mutations were identified in 41 (16.1%); 14 (5.5%) had mutations in syndromic RCC-associated genes (7 in FH, 3 in BAP1, and 1 each in VHL, MET, SDHA, and SDHB). The most frequent mutations were CHEK2 (n = 9) and FH (n = 7). Of genes not previously associated with RCC risk, CHEK2 was overrepresented in patients compared with the general population, with an odds ratio of RCC of 3.0 (95% CI, 1.3-5.8; P = .003). Patients with non-clear cell RCC were significantly more likely to have an RCC-associated gene mutation (9 [11.7%] of 74 vs 3 [1.7%] of 177; P = .001), and 8 (10.0%) had a mutation in a gene that could guide therapy. Of patients with mutations in RCC-associated genes, 5 (35.7%) failed to meet current clinical guidelines for genetic testing.

Conclusions and Relevance

Of patients with non-clear cell RCC, more than 20% had a germline mutation, of which half had the potential to direct systemic therapy. Current referral criteria for genetic testing did not identify a substantial portion of patients with mutations, supporting the role of a more inclusive sequencing approach.

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.

Systemic therapy for advanced clear cell renal cell carcinoma (ccRCC) after progression on immune-oncology plus VEGF targeted therapy combinations (IO-VEGF)

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Background: IO-VEGF combinations are the backbone for current and future therapeutic developments in RCC with several IO-VEGF regimens reporting positive results in phase 3 trials. However, limited data exists on outcomes to subsequent therapy in patients progressing on IO-VEGF regimens. Methods: A retrospective analysis was performed on patients with ccRCC at the Memorial Sloan Kettering Cancer Center and Cleveland Clinic Cancer Institute who initiated systemic therapy post IO-VEGF regimens including combinations with VEGFR tyrosine kinase inhibitors (IO-TKI) and combinations with anti-VEGF monoclonal antibodies (IO-mAB). Patients treated on unreported clinical trials were excluded from the outcomes analysis. The primary objective was to evaluate the overall survival (OS) post IO-VEGF. The secondary objectives included objective response rate (ORR) and progression-free survival (PFS) according to RECIST v1.1. Kaplan-Meier methods and the log-rank test were used to evaluate time from start of systemic therapy post IO-VEGF to the event of interest. Results: Fifty-nine patients were treated after discontinuation of IO-VEGF regimens. Prior IO-VEGF regimens included IO-mAB (n = 35, 59%) and IO-TKI (n = 24, 41%). IMDC scores at the start of next line of therapy were favorable in 20%, intermediate in 60% and poor in 20%. Next line of therapy included VEGFR-TKI monotherapy (n = 45, 76%), VEGFR-TKI based combinations (n = 6, 10%), mTOR inhibitors (n = 3, 5%), and unreported clinical trials (n = 5, 9%). VEGFR-TKI containing regimens (n = 51) included cabozantinib (n = 22), axitinib (n = 17), lenvatinib/everolimus (n = 4), pazopanib (n = 4), and others (n = 4). Median OS was 24.5 months (95% CI 12-NE) with a 12 months OS rate of 63%. The ORR was 27% (14/51) and the median PFS was 6.8 months (95% CI 4.8-11). No difference in post IO-VEGF OS was observed when comparing IO- TKI vs IO-mAB (log rank p = 0.7). Conclusions: Post combination IO-VEGF treatment, most patients received VEGFR-TKIs. In this setting, VEGFR-TKIs continue to show clinical activity similar to historic experiences of patients post VEGF monotherapy.

Comprehensive Genomic Analysis of Metastatic Non-Clear-Cell Renal Cell Carcinoma to Identify Therapeutic Targets

PURPOSE

Non-clear-cell renal cell carcinoma (nccRCC) encompasses approximately 20% of renal cell carcinomas and includes subtypes that vary in clinical and molecular biology. Compared with clear cell renal cell carcinoma, nccRCC demonstrates limited sensitivity to conventional vascular endothelial growth factor- and mammalian target of rapamycin-directed agents, indicating a need for better therapies. Characterizing the genomic landscape of metastatic nccRCC variants may help define novel therapeutic strategies.

PATIENTS AND METHODS

We retrospectively analyzed tumor tissue from patients with metastatic nccRCC who consented to genomic analysis of their tumor and germline DNA. A hybridization capture-based assay was used to identify single nucleotide variants and small insertions and deletions across more than 340 cancer-associated genes with germline comparison. Clinical actionability of somatic mutations was assessed using OncoKB levels of evidence. Microsatellite instability (MSI) in the tumor was investigated.

RESULTS

Of 116 patients included in the analysis, 57 (49%) presented with de novo metastatic disease, and 59 (51%) presented with localized disease that later metastasized. Subtype classifications included unclassified (n = 41; 35%), papillary (n = 26; 22%), chromophobe (n = 17; 15%), translocation associated (n = 13; 11%), and other (n = 19; 16%). Of all tumors, 15 (13%) had putative driver somatic alterations amenable to targeted therapies, including alterations in MET, TSC1/2, and an ALK translocation. Of 45 patients who had germline testing, 11 (24%) harbored mutations, seven of which could potentially guide therapy. Of 115 available tumors for analysis, two (1.7%) had high and six (5%) had intermediate MSI status.

CONCLUSION

The mutation profiles of metastatic nccRCC vary by subtype. Comprehensive analysis of somatic mutations, germline mutations, and MSI, interpreted via an annotated precision oncology knowledge base, identified potentially targetable alterations in 22% of patients, which merits additional investigation.

Metastatic Chromophobe Renal Cell Carcinoma: Presence or Absence of Sarcomatoid Differentiation Determines Clinical Course and Treatment Outcomes

BACKGROUND

Sarcomatoid features (SF) in renal cell carcinoma (RCC) denote poor prognosis. Data for metastatic chromophobe RCC (ChRCC) with SF are limited. We studied clinical outcomes and genomic features in this setting.

PATIENTS AND METHODS

We performed a retrospective review of newly diagnosed metastatic ChRCC patients; end points included overall survival (OS), time to treatment failure (TTF), and time to metastatic recurrence (TTR) after nephrectomy for localized disease. A subset of patients underwent next-generation sequencing (NGS). Outcomes were compared using nonparametric tests.

RESULTS

One hundred nine patients with metastatic ChRCC were identified including 29 with SF. Median TTR after nephrectomy was shorter for patients with versus without SF (2.7 months [95% confidence interval (CI), 0.7-6.9] versus 48.8 months [95% CI, 30.8-80.7], log rank P < .001). Median TTF during first-line therapy was shorter for patients with versus without SF (1.8 months [95% CI, 0.9-2.7] vs. 8.0 months [95% CI, 5.1-13.0]; log rank P < .001). No responses were observed in 6 patients treated with nivolumab including 4 with SF. Median OS was inferior for patients with versus without SF (38 months vs.7.5 months; hazard ratio, 4.7 [95% CI, 2.7-8.2]; P < .001). NGS, performed in 22 patients, showed that 64% and 45% harbored tumor protein P53 and phosphatase and tensin homolog alterations, respectively. Microsatellite instability high status was identified in 3 patients.

CONCLUSION

Metastatic ChRCC patients with SF had worse outcomes compared with those without SF. Median TTR < 3 months for this subgroup supports close surveillance after nephrectomy for localized tumors. Lack of benefit with various systemic regimens warrants studying underlying biology and investigating novel agents.

Genomic biomarkers of response to nivolumab/ipilimumab (nivo/ipi) and nivolumab (nivo) monotherapy in 108 patients with advanced renal cell carcinoma

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Background: Both the combination of nivo/ipi and nivo monotherapy have shown efficacy across multiple malignancies including clear cell Renal Cell Carcinoma (ccRCC). Biomarkers such as tumor mutation burden (TMB) are prognostic in other malignancies, however, remain unvalidated in ccRCC. This study investigates genomic biomarkers associated with nivo/ipi and nivo clinical response. Methods: Whole exome sequencing (WES) was performed on pretreatment tumor derived DNA from nivo/ipi and nivo treated patients from MSKCC and publicly available WES datasets (Miao D, Science, 2018, 359: 6377). Somatic mutations, TMB, neoantigen load (NA), and HLA zyogosity were correlated to objective response rate (ORR), progression free survival (PFS), and Overall Survival (OS). Alterations occurring in < 10% of the cohort were considered non-evaluable (NE). Results: 108 patients had tumors studied; 32 patients with nivo/ipi and 76 patients with nivo therapy. No individual factors showed significant correlations to ORR or both PFS and OS. In the combined cohort, homozygosity at HLA-C was associated with shorter OS (HR=2.55 95% CI 1.17-5.57; P=0.02). In the nivo/ipi cohort, TMB (HR=0.36 95% CI 0.16-0.84; P=0.02) and NA (HR=0.43 95% CI 0.19-0.98; P=0.04) were associated with longer PFS. Conclusions: Increased TMB and NA load may predict for improved outcomes, and homozygosity at HLA loci may predict for worse outcomes. The predictors of response to nivo may not be generalizable to nivo/ipi. To rule out artifacts of multiple testing in a small cohort, validation in a larger dataset is necessary. [Table: see text]

Rates of occult brain metastases in patients (pts) with advanced renal cell carcinoma (RCC): A cohort study from patients treated across 22 clinical trials

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Background: National guidelines for RCC management only recommend brain imaging ‘if clinically indicated’; the rate of occult brain metastases is not defined. Early detection of CNS disease has major implications as it typically triggers early intervention with the aim to limit morbidity, including major complications of local progression. In an effort to define the utility of brain screening, we investigated the rate of occult brain metastasis in a large cohort of metastatic RCC pts. Methods: We performed a retrospective review of completed and actively accruing metastatic RCC clinical trials conducted at Memorial Sloan Kettering Cancer Center. Individual charts of pts screening for those studies with mandatory brain imaging at baseline were reviewed to identify subjects harboring occult brain metastases. We collected patient demographics, International Metastatic Database Consortium (IMDC) risk status, sites of metastatic disease, and tumor histology. Patients with neurologic symptoms were excluded. Descriptive statistics were applied to analyze findings across the cohort. Results: A total of 22 clinical trials for metastatic RCC conducted from 2004-2017 required brain imaging at baseline, and a total of 535 pts were screened in this context. A total of 25/535 pts were found to have occult brain metastasis (4.67%), which was multi-focal in 10/25 (40%) and sub-cm in 15/25 (60%). For these 25 pts, the mean age at diagnosis was 56 years (38-77), and IMDC risk score at enrollment was: 1/24 favorable (4%), 21/24 intermediate (88%), and 2/24 poor-risk (8%) patients. 18/25 patients presented with de novo metastatic disease; 13/25 had received prior therapies; and 24/25 patients (96%) had > 2 additional non-CNS sites of metastatic disease at time of screening. 21/23 pts and 2/23 pts were then treated with radiation and surgical resection, respectively. Conclusions: This retrospective cohort study shows a 5% rate of occult CNS disease in asymptomatic patients with advanced RCC. These findings can inform current screening guidelines for full disease assessment in metastatic RCC patients.

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.

Outcomes of metastatic chromophobe renal cell carcinoma (ChRCC) with sarcomatoid features (SF)

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Background: ChRCC makes up 5-10% of RCC subtypes and is generally thought to confer favorable prognosis. Presence of SF on histologic review can occur in any RCC subtype and is considered a hallmark of aggressive disease. We assessed outcomes in a cohort of patients (pts) with metastatic ChRCC and SF (sChRCC). Methods: Baseline clinical features and details on treatment were collected for pts with newly diagnosed metastatic sChRCC evaluated at Memorial Sloan Kettering Cancer Center (MSKCC) between 2002-17. Overall survival (OS) was calculated for all patients and time to treatment failure (TTF) for those who received first-line therapy at MSKCC. Next generation sequencing (NGS) with MSK-IMPACT was performed in a subset of pts. Results: 27 pts with newly diagnosed metastatic sChRCC were identified; other clinical features are summarized below ( table). 2 pts never received first line therapy based on poor performance status. 16 were treated at MSKCC and received a median of 2 lines of systemic therapy. First line agents included sunitinib (n = 6), pazopanib (n = 2), temsirolimus (n = 2), everolimus + bevacizumab (n = 2), sunitinib + gemcitabine (n = 2) and interferon alpha (n = 2) with median TTF of 2.1 months (0.9-14.5). Across the entire cohort (n = 27), median OS was 7.9 months (95% CI 4.2-11.2) with estimated 1 year OS rate of 25%. By comparison, a cohort of 67 pts with metastatic ChRCC lacking SF also treated at MSKCC 2002-17 achieved median OS of 38.1 months, (HR 4.6; 95% CI: 2.6-8.3; p < 0.001). In the 6 sChRCC pts with NGS analysis, TP53 (n = 4), PTEN (n = 2) and CHEK2 (n = 2) were the most frequently altered genes. Conclusions: Outcome for pts with metastatic sChRCC was poor in contrast to pts with ChRCC lacking SF. The lack of benefit observed across various classes of systemic agents warrants study of underlying biology and novel agents. [Table: see text]

Phase II Trial and Correlative Genomic Analysis of Everolimus Plus Bevacizumab in Advanced Non-Clear Cell Renal Cell Carcinoma

Purpose The decreased effectiveness of single-agent targeted therapies in advanced non-clear cell renal cell carcinoma (ncRCC) compared with clear cell renal cell carcinoma (RCC) supports the study of combination regimens. We evaluated the efficacy of everolimus plus bevacizumab in patients with metastatic ncRCC. Patients and Methods In this single-center phase II trial, treatment-naive patients received everolimus 10 mg oral once per day plus bevacizumab 10 mg/kg intravenously every 2 weeks. The primary end point was progression-free survival (PFS) at 6 months. Correlative analyses explored candidate tissue biomarkers through next-generation sequencing. Results Thirty-five patients were enrolled with the following histologic subtypes: chromophobe (n = 5), papillary (n = 5), and medullary (n = 2) RCC and unclassified RCC (uRCC, n = 23). The majority of patients had papillary growth as a major component (n = 14). For 34 evaluable patients, median PFS, overall survival, and objective response rate (ORR) were 11.0 months, 18.5 months, and 29%, respectively. PFS varied by histology ( P < .001), and ORR was higher in patients with significant papillary (seven of 18) or chromophobe (two of five) elements than for others (one of 11). Presence of papillary features were associated with benefit, including uRCC, where it correlated with ORR (43% v 11%), median PFS (12.9 v 1.9 months), and overall survival (28.2 v 9.3 months; P < .001). Several genetic alterations seemed to segregate by histology. In particular, somatic mutations in ARID1A were seen in five of 14 patients with papillary features but not in other RCC variants. All five patients achieved treatment benefit. Conclusion The study suggests efficacy for this combination in patients with ncRCC characterized by papillary features. Distinct mutational profiles among ncRCCs vary according to specific histology.

Tumor Xenografts of Human Clear Cell Renal Cell Carcinoma But Not Corresponding Cell Lines Recapitulate Clinical Response to Sunitinib: Feasibility of Using Biopsy Samples

BACKGROUND

Parallel development of preclinical models that recapitulate treatment response observed in patients is central to the advancement of personalized medicine.

OBJECTIVE

To evaluate the use of biopsy specimens to develop patient-derived xenografts and the use of corresponding cell lines from renal cell carcinoma (RCC) tumors for the assessment of histopathology, genomics, and treatment response.

DESIGN, SETTING, AND PARTICIPANTS

A total of 74 tumor specimens from 66 patients with RCC were implanted into immunocompromised NOD-SCID IL2Rg-/- mice. Four cell lines generated from patients' specimens with clear cell pathology were used for comparative studies.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Preclinical models were established and assessed. Engraftment rates were analyzed using chi-square testing. Analysis of variance (two-way analysis of variance) was conducted to assess tumor growth.

RESULTS AND LIMITATIONS

Overall, 33 RCC mouse xenograft models were generated with an overall engraftment rate of 45% (33 of 74). Tumor biopsies engrafted comparably with surgically resected tumors (58% vs 41%; p=0.3). Xenograft tumors and their original tumors showed high fidelity in regard to histology, mutation status, copy number change, and targeted therapy response. Engraftment rates from metastatic tumors were higher but not more significant than primary tumors (54% vs 34%; p=0.091). Our engraftment rate using metastases or biopsies was comparable with recent reports using resected primary tumors. In stark contrast to corresponding cell lines, all tested xenografts recapitulated patients' clinical response to sunitinib.

CONCLUSIONS

Patient-derived xenograft models can be effectively established from tumor biopsies. Preclinical xenograft models but not matched cell lines reflected clinical responses to sunitinib.

PATIENT SUMMARY

Matched patient-derived clear cell renal cell carcinoma xenografts and cell lines from responsive and refractory patients treated with sunitinib were established and evaluated for pharmacologic response to anti-vascular endothelial growth factor treatment. Both models accurately reflected the genetic characteristics of original tumors, but only xenografts recapitulated drug responses observed in patients. These models could serve as a powerful platform for precision medicine.

Characterizing recurrent and lethal small renal masses in clear cell renal cell carcinoma using recurrent somatic mutations

INTRODUCTION

Small renal masses (SRMs) with evidence of clear cell renal cell carcinoma (ccRCC) are understudied. Current algorithms for the management of SRMs include surgical resection, ablation, and active surveillance. We sought to identify genomic biomarkers that could potentially refine the management of ccRCC in SRMs, especially in patients being evaluated for active surveillance.

METHODS

We identified patients who had SRMs (4cm or less) at time of surgery, had sequencing performed on their primary tumor and had a diagnosis of ccRCC. Patients were selected from 3 publicly available cohorts, The Cancer Genome Atlas (n = 110), University of Tokyo (n = 37), The International Cancer Genome Consortium (n = 31), and from our own institutional prospective database (n = 25). Among this cohort we analyzed mutations present in at least 5% of tumors, assessing for the enrichment of mutations and progression-free survival using the composite endpoint of recurrence or death of disease. Analysis was adjusted for multiple testing. A Cox regression model was used to assess clinical variables with significant mutations.

RESULTS

In total, 203 patients were available for analysis. Median follow-up was 43.1 months among survivors. Mutations in VHL, PBRM1, SETD2, BAP1, KDM5C, and MTOR were present in more than 5% of tumors. Twenty-three patients (11.3%) had recurrence or died of their disease. Mutations in KDM5C were associated with inferior survival from either recurrence or death from disease, adjusted P 0.033.

CONCLUSIONS

We identified mutations in SRMs in ccRCC that are associated with recurrence and lethality. The strongest association was seen in those with KDM5C mutations. Use of these genomic biomarkers may improve stratification of patients with SRMs and for those who may be appropriate for active surveillance. Prospective evaluation of these markers is needed.

Integration of Recurrent Somatic Mutations with Clinical Outcomes: A Pooled Analysis of 1049 Patients with Clear Cell Renal Cell Carcinoma

BACKGROUND

Analyses of associations between clinicopathologic outcomes and recurrent somatic mutations in clear cell renal cell carcinoma (ccRCC) have been limited to individual cohorts.

OBJECTIVE

To define clinicopathologic associations between specific mutations and ccRCC disease characteristics.

DESIGN, SETTING, AND PARTICIPANTS

DNA sequencing data were pooled from three collaborative genomic cohorts (n=754) and our institutional database (n=295). All patients had clinical data and identification of somatic mutations from their primary tumors.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Analysis of gene mutations for associations with maximal tumor size (linear regression) and pathologic stage (logistic regression). Cancer-specific survival (CSS) and recurrence-free survival (RFS) were calculated using competing risks methods. Analyses were adjusted for cohort site, and results were adjusted for multiple testing (q value). Relevant genes were used in multivariable models that included confounding variables and the validated Mayo Clinic Stage, Size, Grade, and Necrosis (SSIGN) score.

RESULTS AND LIMITATIONS

Association with tumor size was found for mutations in BAP1 (q=0.013). No mutations were found to be associated with stage after adjusted analysis. Mutations in BAP1 (q=0.004) and TP53 (q=0.001) were associated with decreased CSS in a multivariable model; only TP53 (q=0.005) remained significant when SSIGN score was included. SETD2 mutations (q=0.047) were associated with decreased RFS in multivariable models, including models with SSIGN score.

CONCLUSIONS

In >1000 patients with ccRCC, pooled analysis and multivariable modeling demonstrated that three mutated genes have statistically significant associations with poor clinical outcomes. This included the more commonly mutated BAP1 and SETD2 and the less frequently mutated TP53. After adjustment for clinical confounders, mutations of TP53 and SETD2 were associated with decreased CSS and RFS, respectively.

PATIENT SUMMARY

Using rigorous statistical methods, this study affirmed that certain mutations in clear cell renal cell carcinoma may portend inferior survival and an increased risk of recurrence.

Genomic Alterations and Outcomes with VEGF-Targeted Therapy in Patients with Clear Cell Renal Cell Carcinoma

Background: Mutations in VHL, PBRM1, SETD2, BAP1, and KDM5C are common in clear cell renal cell carcinoma (ccRCC), and presence of certain mutations has been associated with outcomes in patients with non-metastatic disease. Limited information is available regarding the correlation between genomic alterations and outcomes in patients with metastatic disease, including response to VEGF-targeted therapy.

Objective: To explore correlations between mutational profiles and cancer-specific outcomes, including response to standard VEGF-targeted agents, in patients with metastatic cc RCC.

Methods: A retrospective review of 105 patients with metastatic ccRCC who had received systemic therapy and had targeted next-generation sequencing of tumors was conducted. Genomic alterations were correlated to outcomes, including overall survival and time to treatment failure to VEGF-targeted therapy.

Results: The most frequent mutations were detected in VHL (83%), PBRM1 (51%), SETD2 (35%), BAP1 (24%), KDM5C (16%), and TERT (14%). Time to treatment failure with VEGF-targeted therapy differed significantly by PBRM1 mutation status (p = 0.01, median 12.0 months for MT versus 6.9 months for WT) and BAP1 mutation status (p = 0.01, median 6.4 months for MT versus 11.0 months for WT). Shorter overall survival was associated with TERT mutations (p = 0.03, median 29.6 months for MT versus 52.6 months for WT) or BAP1 mutations (p = 0.02, median 28.7 months for MT versus not reached for WT).

Conclusions: Genomic alterations in ccRCC tumors have prognostic implications in patients with metastatic disease. BAP1 and TERT promoter mutations may be present in higher frequency than previously thought, and based on this data, deserve further study for their association with poor prognosis.

Genomic landscape and evolution of metastatic chromophobe renal cell carcinoma

Chromophobe renal cell carcinoma (chRCC) typically shows ~7 chromosome losses (1, 2, 6, 10, 13, 17, and 21) and ~31 exonic somatic mutations, yet carries ~5%-10% metastatic incidence. Since extensive chromosomal losses can generate proteotoxic stress and compromise cellular proliferation, it is intriguing how chRCC, a tumor with extensive chromosome losses and a low number of somatic mutations, can develop lethal metastases. Genomic features distinguishing metastatic from nonmetastatic chRCC are unknown. An integrated approach, including whole-genome sequencing (WGS), targeted ultradeep cancer gene sequencing, and chromosome analyses (FACETS, OncoScan, and FISH), was performed on 79 chRCC patients including 38 metastatic (M-chRCC) cases. We demonstrate that TP53 mutations (58%), PTEN mutations (24%), and imbalanced chromosome duplication (ICD, duplication of ≥ 3 chromosomes) (25%) were enriched in M-chRCC. Reconstruction of the subclonal composition of paired primary-metastatic chRCC tumors supports the role of TP53, PTEN, and ICD in metastatic evolution. Finally, the presence of these 3 genomic features in primary tumors of both The Cancer Genome Atlas kidney chromophobe (KICH) (n = 64) and M-chRCC (n = 35) cohorts was associated with worse survival. In summary, our study provides genomic insights into the metastatic progression of chRCC and identifies TP53 mutations, PTEN mutations, and ICD as high-risk features.

Integrated biomarker analysis for 412 renal cell cancer (RCC) patients (pts) treated on the phase 3 COMPARZ trial: Correlating common mutation events in PBRM1 and BAP1 with angiogenesis expression signatures and outcomes on tyrosine kinase inhibitor (TKI) therapy

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Background: In RCC biology mutations in PBRM1 and BAP1are largely non-overlapping and collectively affect >50% of pts. How and through which mechanism they influence disease kinetics is poorly understood. Sunitinib and pazopanib inhibit angiogenesis, a key driver in RCC. We analyzed mutation status and gene expression signatures in a large cohort of pts receiving first-line sunitinib or pazopanib on the COMPARZ trial. Methods: RNA and DNA were extracted from archival tissue. PBRM1 and BAP1mutation status was determined via a custom exon-targeted platform. Transcriptome analysis was done using Affymetrix GeneChip HTA 2.0. We computed a 43 gene angiogenesis expression score with previously reported dynamic response to VEGF-directed therapy in xenograft models (Masiero, Cancer Cell 2013). DNA and RNA findings were correlated with clinical outcomes using parametric and non-parametric tests. Results: 412 pts contributed tumor RNA, 377 pts DNA; 362 pts both. PBRM1 and BAP1 were mutated (MT) in 44% and 15% of pts, respectively. Presence of PBRM1mutations correlated with superior PFS (p=0.008) and OS (p=0.004) on log-rank test, and PBRM1 mutation rate was higher in pts with objective response than those with progression (Fisher’s Exact, p=0.012). In contrast, pts with MT BAP1 had inferior OS compared to those whose were wild type (WT) (log-rank, p=0.012). Across all 412 pts angiogenesis score associated favorably with outcome on uni and multivariate analyses (Cox proportional hazard regression, OS p<0.001 and PFS p<0.005); scores were higher in 123 pts with objective response than 81 pts with progression as best response (Mann-Whitney, p=0.009). Angiogenesis scores were higher in PBRM1 MT vs WT patients (Mann-Whitney, p<0.001), but lower in BAP1 MT vs WT patients (p<0.001). Conclusions: PBRM1 and BAP1 mutations appear to have opposite effects in advanced RCC. Loss of PBRM1 enhances the pro-angiogenic microenvironment of RCC with favorable effects on response to TKI; BAP1 loss associates with decreased angiogenic signaling and adverse outcome to TKI. Clinical trial information: NCT00720941.

Persistent Severe Hyperlactatemia and Metabolic Derangement in Lethal SDHB-Mutated Metastatic Kidney Cancer: Clinical Challenges and Examples of Extreme Warburg Effect

To describe the unique clinical features, determine the genomics, and investigate the metabolic derangement of an extremely rare form of a hereditary lethal kidney cancer syndrome.

Patients and Methods

Three patients with lethal kidney cancer (age 19, 20, and 37 years) exhibiting persistent (1 to 3 months) extremely high levels of blood lactate (> 5 mM) despite normal oxygen perfusion, highly avid tumors on [18F]fluorodeoxyglucose positron emission tomography (PET), and pleomorphic histopathologic features were identified and treated in a single institute. Integrated studies including whole-genome sequencing (WGS), targeted sequencing, immunohistochemistry, cell-based assays, and 18F-glutamine PET imaging were performed to investigate this rare kidney cancer syndrome.

Results

All three patients with kidney cancer were initially given various diagnoses as a result of diverse tumor histopathology and atypical clinical presentations. The correct diagnoses of these SDHB-mutated renal cell carcinomas were first made based on cancer genomics. Genomic studies of the blood and tumors of these patients identified three different kinds of germline loss-of-function mutations in the SDHB gene and the common loss of heterozygosity in the remaining SDHB allele thorough somatic chromosome 1p deletion. In one patient, WGS revealed that a germline mutation of SDHB coupled with loss of heterozygosity was the sole genetic event. Cancer evolution analysis of SDHB tumors based on WGS demonstrated that SDHB in kidney epithelium fulfills the Knudson two-hit criteria as a major tumor suppressor gene. SDHB -/- tumor cells displayed increase in glucose uptake and lactate production, alteration in mitochondrial architecture, and defect in oxidative respiration. 18F-Glutamine PET imaging studies demonstrated increased glutamine metabolism.

Conclusion

SDHB-deficient metastatic renal cell carcinoma is a rare, aggressive form of kidney cancer that manifests with clinical evidence of a severe Warburg effect, and genomic studies demonstrated two genetic hits at SDHB genes during kidney tumorigenesis.

Genomic alterations as predictors of survival among patients within a combined cohort with clear cell renal cell carcinoma undergoing cytoreductive nephrectomy

PURPOSE

To establish prognostic genomic biomarkers for patients with metastatic clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

We identified 60 patients who presented with metastatic ccRCC at our institution between 2001 and 2015 and had genomic sequencing on their primary tumor. We pooled these patients with 107 other patients with the same inclusion criteria from three well-known public databases. Five commonly mutated genes were chosen for analysis: VHL, PBRM1, BAP1, SETD2, and KDM5C. Overall survival (OS) was estimated using the Kaplan-Meier method and the log-rank test was used for comparisons between groups.

RESULTS

Median OS in the cohort was 2.5 years. Higher Fuhrman grade was associated with decreased median OS (P<0.001). Mutations in SETD2 (P = 0.027) and KDM5C (P = 0.019) were associated with reduced risk of death (hazard ratio [HR] = 0.58 [95% CI: 0.35-0.94] and HR = 0.43 [95% CI: 0.22-0.85], respectively). BAP1 mutations (P = 0.008) were associated with increased risk of death (HR = 1.81 [95% CI: 1.16-2.83]). There were significantly more female patients with a BAP1 mutation than females in the overall cohort (P = 0.001).

CONCLUSIONS

Mutations in BAP1 negatively affected OS, whereas SETD2 and KDM5C mutations were associated with prolonged OS in our pooled cohort of 167 patients with metastatic ccRCC. Our results expand upon efforts at understanding genomic biomarkers in localized disease. Those efforts set the stage for our novel investigation examining associations of select recurrent somatic mutations in stage IV patients with ccRCC.

Immune cell phenotyping of clear cell renal cell carcinoma

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Background: Clear cell renal cell carcinoma (ccRCC) tumors develop mechanisms that impair function and/or prevent entry of the host infiltrating immune cells (immune exclusion) within the tumor microenvironment. The goal of immunotherapy is to overcome this immune resistance. We aim to characterize the T−cell populations in a cohort of largely untreated high risk patients with ccRCC. Methods: We prospectively collected ccRCC tumor and adjacent normal kidney (NK) from patients undergoing surgical resection at our institution from 6/2015-8/2016. Immune cell phenotyping was performed by immune cell staining of single cell suspensions. Analysis of immune cell populations were determined by CD45+ staining and corresponding proportions of different T−cell populations (CD3+, CD4+, CD4+Treg, and CD8+ T cells). Staining for CD4+Treg was not available for two patients. Student t−test was utilized to compare the immune populations between tumor and adjacent NK tissue. Analysis was also conducted by stratifying patients who presented with localized versus metastatic disease. Results: A total of 31 tumor and adjacent NK were analyzed. Median tumor pathological size was 8.5cm (2.9cm−18cm), 27(87%) had pT3a−pT3b and 13(42%) presented with metastatic disease. Overall 84% of tumors had higher immune infiltrate with an average ratio of four-fold increase compared to adjacent NK as determined by CD45+ cells. Intriguingly, the other 16% presented with metastatic (4) or rapidly metastatic disease (1). Orthogonal validation with inferred immune populations using RNAseq data from the The Cancer Genome Atlas (TCGA) demonstrated similar aggressive behavior in tumors with lower immune infiltrate compared to NK. Comparison of immune cell populations of tumor and NK tissue is shown in table 1. No specific T-cell subtype was associated with specific clinical outcomes in this cohort. Conclusions: Our data shows a general trend of immune infiltration in ccRCC when compared to adjacent NK with a diversity of T-cell subsets and possible evidence of immune exclusion. Further genomic characterization of these tumors is currently underway. [Table: see text]

Genomic Biomarkers of a Randomized Trial Comparing First-line Everolimus and Sunitinib in Patients with Metastatic Renal Cell Carcinoma

BACKGROUND

Metastatic renal cell carcinoma (RCC) patients are commonly treated with vascular endothelial growth factor (VEGF) inhibitors or mammalian target of rapamycin inhibitors. Correlations between somatic mutations and first-line targeted therapy outcomes have not been reported on a randomized trial.

OBJECTIVE

To evaluate the relationship between tumor mutations and treatment outcomes in RECORD-3, a randomized trial comparing first-line everolimus (mTOR inhibitor) followed by sunitinib (VEGF inhibitor) at progression with the opposite sequence in 471 metastatic RCC patients.

DESIGN, SETTING, AND PARTICIPANTS

Targeted sequencing of 341 cancer genes at ∼540× coverage was performed on available tumor samples from 258 patients; 220 with clear cell histology (ccRCC).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Associations between somatic mutations and median first-line progression free survival (PFS1L) and overall survival were determined in metastatic ccRCC using Cox proportional hazards models and log-rank tests.

RESULTS AND LIMITATIONS

Prevalent mutations (≥ 10%) were VHL (75%), PBRM1 (46%), SETD2 (30%), BAP1 (19%), KDM5C (15%), and PTEN (12%). With first-line everolimus, PBRM1 and BAP1 mutations were associated with longer (median [95% confidence interval {CI}] 12.8 [8.1, 18.4] vs 5.5 [3.1, 8.4] mo) and shorter (median [95% CI] 4.9 [2.9, 8.1] vs 10.5 [7.3, 12.9] mo) PFS1L, respectively. With first-line sunitinib, KDM5C mutations were associated with longer PFS1L (median [95% CI] of 20.6 [12.4, 27.3] vs 8.3 [7.8, 11.0] mo). Molecular subgroups of metastatic ccRCC based on PBRM1, BAP1, and KDM5C mutations could have predictive values for patients treated with VEGF or mTOR inhibitors. Most tumor DNA was obtained from primary nephrectomy samples (94%), which could impact correlation statistics.

CONCLUSIONS

PBRM1, BAP1, and KDM5C mutations impact outcomes of targeted therapies in metastatic ccRCC patients.

PATIENT SUMMARY

Large-scale genomic kidney cancer studies reported novel mutations and heterogeneous features among individual tumors, which could contribute to varied clinical outcomes. We demonstrated correlations between somatic mutations and treatment outcomes in clear cell renal cell carcinoma, supporting the value of genomic classification in prospective studies.

Understanding the genomic underpinnings of metastatic chromophobe renal cell carcinoma

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Background: Chromophobe renal cell carcinoma (chRCC) is the third most common histologic subtype of kidney cancer. While most of these tumors have an indolent behavior, 7% of patients with chRCC develop metastases, with no currently available standard of care. The Cancer Genome Atlas characterized chRCC, highlighting pathognomonic single copy chromosomal losses of 1, 2, 6, 10, 13 and 17, as well as a minimal mutation burden distinguishing it from all other cancer types. However, only 15% of the analyzed patients had advanced disease. We analyzed metastatic chRCC to further characterize these tumors and elucidate mechanisms leading to aggressive disease using a variety of next generation and whole genome sequencing. Methods: Our cohort of metastatic chRCC consisted of 40 patients with available clinical and pathologic data. Whole genome sequencing (WGS) was performed on 6 patients (4 primary tumors and 2 metastases), 42 additional samples from 33 patients were analyzed using targeted next-generation sequencing (MSK-IMPACT). Notably, we were able to collect and analyze matched primary and metastatic tumors from 7 patients. As control cohort 27 non-metastatic chRCC tumors were sequenced with MSK-IMPACT. Copy number patterns were computed with OncoSNP seq and FACETS. Results: The most commonly mutated genes in the aggressive chRCC tumors were TP53 and PTEN (WGS: TP53 67 %, PTEN 33%; MSK-IMPACT: TP53 61%, PTEN 27%). No other genes were mutated frequently. Primary tumor samples of chRCC did show the typical pattern of chromosomal losses in 1, 2, 6, 10, 13 and 17. Interestingly, these canonical losses could not be detected in the metastases even when accounting for tumor purity. Conclusions: TP53 and PTEN mutations are highly enriched in both primary and metastatic tumors of aggressive chRCC compared to the non-aggressive tumors and likely play a critical role in disease progression. More intriguingly, the observation of differential copy numbers in matched primary and metastatic tumors suggest whole genome or whole chromosome events in these samples. We are currently employing different bioinformatic and cytogenetic platforms to validate our novel hypothesis of chromosomal events as driver for metastatic development in chRCC.

Analysis of mtDNA, miR-155 and BACH1 expression in hearts from donors with and without Down syndrome

Cancer patients with Down syndrome (DS) are at increased risk for anthracycline-related cardiotoxicity. Mitochondrial DNA (mtDNA) alterations in hearts with-DS may contribute to anthracycline-related cardiotoxicity. Cardiac mtDNA and the mtDNA(4977) deletion were quantitated in samples with- (n = 11) and without-DS (n = 31). Samples with-DS showed 30% lower mtDNA (DS(MT-ND1/18Sratio): 1.48 ± 0.72 versus non-DS(MT-ND1/18Sratio): 2.10 ± 1.59; p = 0.647) and 30% higher frequency of the mtDNA(4977) deletion (DS(% frequency mtDNA(4977)) deletion: 0.0086 ± 0.0166 versus non-DS(% frequency mtDNA(4977)) deletion: 0.0066 ± 0.0124, p = 0.514) than samples without-DS. The BACH1 and microRNA-155 (miR-155) genes are located in chromosome 21, and their products have demonstrated roles during oxidative stress. BACH1 and miR-155 expression did not differ in hearts with- and without-DS. An association between BACH1 and miR-155 expression was detected in hearts without-DS, suggesting alterations between BACH1-miR-155 interactions in the DS settings.