Tamboli, Pheroze

Pelvicalyceal invasion (PCI) is a relatively novel pT3a staging parameter for renal cell carcinoma (RCC) nephrectomies. While interobserver reproducibility staging studies of sinus/vascular invasion in RCC exist, a similar evaluation for PCI has not been performed. Moreover, in our experience, there is also diagnostic variability in how pathologists interpret PCI. Herein, we explore interobserver reproducibility among genitourinary (GU) pathologists. Twenty hematoxylin and eosin-stained digitized slides from RCCs (all grossly approaching the renal pelvis) were distributed to 31 GU pathologists to classify each as PCI or not PCI based on their respective clinical practices; slides with concomitant sinus/fat/vascular invasion were excluded. Slides were then evaluated for the following 4 morphologic features: tumor abutting renal pelvis, tumor pushing/indenting into the renal pelvis, polypoid configuration of tumor into the renal pelvis, and tumor eroding through renal pelvic urothelium. Interobserver reproducibility was assessed, and the morphologic features were correlated with PCI. Relationships between pathologists’ interpretations, morphologic features, and PCI were evaluated using hierarchical clustering. Although the diagnosis of PCI was relatively uniform with a majority agreement (>67%) reached in 16/20 slides, overall interobserver reproducibility was only moderate (kappa=0.601). While all 4 morphologic features were sensitive for PCI, polypoid configuration of the tumor into the renal pelvis and the tumor eroding through the renal pelvic urothelium were most specific (90%, 100%, respectively). Although we show general consensus among genitourinary pathologists on PCI assessment, clarifying the diagnostic guidelines with specific criteria should be included in pathologic staging systems.

AimsCompared to lymphovascular invasion (LVI), hilar soft tissue invasion (HSTI) is a relatively novel pT2 staging parameter in testicular germ cell tumours (GCT), associated with metastasis at the time of diagnosis and a risk factor for disease relapse. Given diagnostic variability in how pathologists interpret HSTI, herein we explore interobserver reproducibility among genitourinary (GU) pathologists.MethodsTwenty haematoxylin and eosin‐stained digitized slides from testicular GCTs were distributed to 30 GU pathologists to classify each as HSTI or not HSTI based on their respective clinical practices; slides with concomitant LVI were excluded. Slides were then evaluated for the following morphologic features: tumour invasion beyond prominent hilar vessels, tumour invasion beyond the rete, tumour invasion beyond the level parallel to hilar adipose tissue and tumour within (directly touching) hilar adipose tissue. Interobserver reproducibility was assessed, and the morphological features were correlated with HSTI. Relationships between pathologists' interpretations, morphological features and HSTI were evaluated using hierarchical clustering.ResultsAlthough the diagnosis of HSTI was relatively uniform with a majority agreement (>67%) reached in 17/20 slides, overall interobserver reproducibility was only moderate (kappa = 0.50). Morphological features such as invasion beyond the level parallel to hilar adipose tissue and invasion into fat were more sensitive and specific for HSTI, while features such as invasion beyond hilar vessels and invasion beyond rete were less useful.ConclusionsThese findings suggest that more specific defined diagnostic criteria for testicular GCT HSTI are needed.

4597 Background: NCCRCC are a diverse group of rare diseases with limited data to guide treatment. CABO is highly effective in clear cell RCC, but it is unknown whether it is superior to SUN, the historic standard of care for metastatic NCCRCC. Methods: CABOSUN II (NCT03541902) was a randomized phase II study at 3 centers for patients (pts) with metastatic NCCRCC. Sixty pts were planned to detect CABO as better than SUN with a 1-sided test. Pts were randomized 1:1 to CABO 60mg daily or SUN 50mg daily (4 weeks on, 2 weeks off). SUN dose modification to 2 weeks on, 1 week off was allowed for toxicity. Stratification was by papillary RCC (PRCC) vs. non-PRCC (NPRCC), good/intermediate vs. poor risk disease by IMDC criteria, and prior TKI use. The primary outcome was progression-free survival (PFS) by RECIST v1.1 compared between the 2 arms using the log-rank test. Secondary outcomes were objective response rate (ORR), overall survival (OS), and adverse event (AE) rates (2-sided tests). Results: 32 pts were randomized to CABO (N=15) or SUN (N=17) between 9/2018 and 6/2021. The trial stopped early due to a change in standard therapy for PRCC not based on these pts’ outcomes. Age range was 22-88 years with medians 57 and 61 for CABO and SUN. Pts were primarily white (84%) and male (72%), with good/intermediate risk (88%), and these were balanced between arms. More pts on the CABO arm had bone metastases (62% vs. 24%). NPRCC were chromophobe (N=6; 5 randomized to SUN), unclassified (N=5), and MiT family translocation (N=3; all randomized to CABO). With median follow-up of 33.3 months and 20 PFS events, median PFS for CABO vs. SUN was 8.2 vs. 13.8 months (1-sided p=0.96). There were no statistically significant differences in ORR or OS between the arms. AEs were in line with previous studies. Conclusions: CABO was not superior to SUN for metastatic NCCRCC in this study. Both arms had high rates of stable disease or better. Despite stratification by PRCC or NPRCC, there were major differences in NPRCC subtypes between the arms that may have impacted the results. More pts with chromophobe histology, an often indolent subtype, received SUN while all pts with MiT family translocation, a relatively aggressive subtype, received CABO. Permitted SUN dose modifications may have also influenced outcomes. While the PAPMET study showed CABO to be superior to SUN for PRCC, optimal treatments for rare, NPRCC remain a pressing need. Clinical trial information: NCT03541902 . [Table: see text]

Abstract Purpose: Clear cell renal cell carcinoma (ccRCC) is frequently associated with inactivation of the von Hippel–Lindau tumor suppressor, resulting in activation of HIF-1α and HIF-2α. The current paradigm, established using mechanistic cell-based studies, supports a tumor promoting role for HIF-2α, and a tumor suppressor role for HIF-1α. However, few studies have comprehensively examined the clinical relevance of this paradigm. Furthermore, the hypoxia-associated factor (HAF), which regulates the HIFs, has not been comprehensively evaluated in ccRCC. Experimental Design: To assess the involvement of HAF/HIFs in ccRCC, we analyzed their relationship to tumor grade/stage/outcome using tissue from 380 patients, and validated these associations using tissue from 72 additional patients and a further 57 patients treated with antiangiogenic therapy for associations with response. Further characterization was performed using single-cell mRNA sequencing (scRNA-seq), RNA-in situ hybridization (RNA-ISH), and IHC. Results: HIF-1α was primarily expressed in tumor-associated macrophages (TAMs), whereas HIF-2α and HAF were expressed primarily in tumor cells. TAM-associated HIF-1α was significantly associated with high tumor grade and increased metastasis and was independently associated with decreased overall survival. Furthermore, elevated TAM HIF-1α was significantly associated with resistance to antiangiogenic therapy. In contrast, high HAF or HIF-2α were associated with low grade, decreased metastasis, and increased overall survival. scRNA-seq, RNA-ISH, and Western blotting confirmed the expression of HIF-1α in M2-polarized CD163-expressing TAMs. Conclusions: These findings highlight a potential role of TAM HIF-1α in ccRCC progression and support the reevaluation of HIF-1α as a therapeutic target and marker of disease progression.

386 Background: Angiogenesis plays a role in tumor growth and is partly mediated by factors in both the fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) pathways. Brivanib inhibits both VEGF receptor 2 and FGF receptors (FGFR)-1/2. Methods: Nephrectomy material from 40 patients with metastatic renal cell carcinoma (RCC) receiving sorafenib ± interferon was assessed by immunohistochemical (IHC) staining. The Ariol imaging platform was used to stratify the specimens based on intensity of staining for FGF biomarkers: FGFR-1 and fibroblast growth factor receptor substrate 2 (pFRS2). The relationship between fibroblast growth factor pathway marker levels and progression-free survival (PFS) was analyzed using Kaplan-Meier and Cox proportional hazards regression methods. To assess the efficacy of dual targeting of VEGF and FGF receptor signaling by brivanib, we treated a xenograft RCC mouse model with sunitinib, brivanib, or sunitinib followed by brivanib. Results: Our analysis indicated that more intense FGFR-1 staining was associated with shorter PFS (p = 0.0452), and that pFRS2 staining were not significantly associated with PFS (p = 0.2610). FGF pathway activation was associated with decreased PFS in patients with metastatic RCC treated with sorafenib. Xenograft mice were treated with 20 mg/kg sunitinib and after an initial stabilization phase, resistance developed by day 20. A switch to 30 mg/kg brivanib prolonged the stabilization phase after progression on sunitinib (p = 0.0033). Conclusions: The PFS of patients treated with sorafenib is associated with FGF pathway activation. In a xenograft RCC mouse model, brivanib overcame the tumor escape after initial treatment with sunitinib. Switching from sunitinib to brivanib at the time of tumor escape prolonged the stabilization phase and overcame a sunitinib-induced resistance phenotype. The results suggest that FGF pathway activation mediates both innate and acquired tumor resistance to VEGF receptor inhibition. The efficacy of dual inhibition of FGF and VEGF in the subset of patients with increased FGF activation prior to treatment requires further study.

536 Background: DNA methylation is a heritable covalent modification that is developmentally regulated and is critical in tissue-type definition. Although genotype-phenotype correlations have been described for different subtypes of renal cell carcinoma (RCC), it is unknown if DNA methylation profiles correlate with morphological or ontology based phenotypes. Here we test the hypothesis that DNA methylation signatures can discriminate between putative precursor cells in the nephron. Methods: We performed deep profiling of DNA methylation in diverse histopathological RCC subtypes and validated DNA methylation and transcriptome signatures in The Cancer Genome Atlas Clear Cell and Chromophobe Renal Cell Carcinoma Datasets. Results: Our data provide the first mapping of methylome epi-signature and indicates that RCC subtypes can be grouped into two major epi-clusters: C1 which encompasses clear cell RCC, papillary RCC, mucinous and spindle cell carcinomas and translocation RCC; C2 which comprises oncocytoma and chromophobe RCC. Interestingly, C1 epi-cluster displayed three fold more hypermethylation as compared to C2 epi-cluster. Of note, differentially methylated regions between C1 and C2 epi-clusters occur in gene bodies and intergenic regions, instead of gene promoters. Transcriptome analysis of C1 epi-cluster suggests a functional convergence on Polycomb targets, whereas C2 epi-cluster displays DNA methylation defects. Furthermore, we find that our epigenetic ontogeny signature is associated with worse outcomes of patients with clear-cell RCC. Conclusions: Taken together, our data defines the epi-clusters that can discriminate between distinct RCC subtypes and for the first time, to our knowledge, define the epigenetic basis for proximal versus distal tubule derived kidney tumors.

Objective To identify factors associated with regional recurrence after lymph node dissection ( LND ) for squamous cell carcinoma ( SCC ) to determine which patients might benefit from adjuvant therapy. Patients and Methods Men who underwent LND for penile SCC from 1977 to 2014 were identified from an institutional database. Kaplan–Meier curves estimated recurrence‐free survival ( RFS ) calculated from the date of LND . Cox regression models evaluated the association between RFS and patient and tumour characteristics. Results In all, 182 men who underwent LND for penile SCC were identified. The median patient age was 62 years and the median follow‐up was 4.2 years. After LND 34 men had regional recurrence, of which 24 developed isolated regional recurrences without distant metastasis. The median RFS was 5.7 months, and the 3‐year RFS rate was 70%. On univariate analysis, lymphovascular invasion, clinical and pathological nodal stage, pathological inguinal laterality, pelvic nodal involvement, lymph node density ≥5.2%, ≥3 pathologically involved lymph nodes, and extranodal extension ( ENE ) were associated with worse RFS (all P < 0.05). On multivariate analysis, clinical N3 disease [adjusted hazard ratio ( AHR )] 3.53, 95% confidence interval ( CI ) 1.68–7.45; P = 0.001), ≥3 pathologically involved lymph nodes ( AHR 3.78, 95% CI 2.12–6.65; P < 0.001), and ENE ( AHR 3.32, 95% CI 1.93–5.76; P < 0.001) were associated with worse RFS . The 3‐year RFS for patients with cN 0, cN 1, cN 2, and cN 3 disease was 91.7%, 64.5%, 54.7%, and 38.3%, respectively. For men with ≥3 involved nodes, the 3‐year RFS was 17% vs 82.4% in men with <3 involved nodes. The 3‐year RFS was 29.7% in men with ENE and 85.7% in men without ENE. Conclusion The presence of clinical N3 disease, ≥3 pathologically involved lymph nodes, and ENE was associated with worse RFS . As regional recurrence portends a dismal prognosis with few salvage options, adjuvant therapies should be developed for men with the aforementioned adverse factors.

Abstract Purpose: DNA methylation is a heritable covalent modification that is developmentally regulated and is critical in tissue-type definition. Although genotype–phenotype correlations have been described for different subtypes of renal cell carcinoma (RCC), it is unknown if DNA methylation profiles correlate with morphological or ontology based phenotypes. Here, we test the hypothesis that DNA methylation signatures can discriminate between putative precursor cells in the nephron. Experimental Designs: We performed deep profiling of DNA methylation and transcriptome in diverse histopathological RCC subtypes and validated DNA methylation in an independent dataset as well as in The Cancer Genome Atlas Clear Cell and Chromophobe Renal Cell Carcinoma Datasets. Results: Our data provide the first mapping of methylome epi-signature and indicate that RCC subtypes can be grouped into two major epi-clusters: C1, which encompasses clear-cell RCC, papillary RCC, mucinous and spindle cell carcinomas and translocation RCC; C2, which comprises oncocytoma and chromophobe RCC. Interestingly, C1 epi-cluster displayed 3-fold more hypermethylation as compared with C2 epi-cluster. Of note, differentially methylated regions between C1 and C2 epi-clusters occur in gene bodies and intergenic regions, instead of gene promoters. Transcriptome analysis of C1 epi-cluster suggests a functional convergence on Polycomb targets, whereas C2 epi-cluster displays DNA methylation defects. Furthermore, we find that our epigenetic ontogeny signature is associated with worse outcomes of patients with clear-cell RCC. Conclusions: Our data define the epi-clusters that can discriminate between distinct RCC subtypes and for the first time define the epigenetic basis for proximal versus distal tubule derived kidney tumors. Clin Cancer Res; 22(24); 6236–46. ©2016 AACR.