Abstract B010: Germline susceptibility to renal cell carcinoma and implications for genetic screening

BACKGROUND To investigate recurrence rates in patients with T1 renal cell carcinoma (RCC) undergone partial nephrectomy (PN), radiofrequency ablation (RFA) or cryoablation (Cryo). METHODS We retrospectively evaluated data from 665 (81.4%), 68 (8.3%) and 83 (10.3%) patients who underwent PN, RFA and Cryo, respectively. Kaplan-Meier curves depict recurrence-free survival (RFS) rates in the overall population and after stratifying according to tumor's histology (namely, clear cell RCC and non-clear RCC) and size (namely < 2 cm and 2-4 cm). Multivariable Cox regression model was used to identify predictors of recurrence. Cumulative-incidence plots evaluated disease recurrence and other causes of mortality (OCM). RESULTS Patients referred to PN experienced higher RFS rate compared to those treated with RFA and Cryo at 60-month in the overall population (96.4% vs. 79.4 % vs. 87.8%), in patients with clear cell RCC (93.3% vs 75% vs. 80.4%) and in those with tumor of 2-4 cm (97.3% vs 78% and 84.4%; all p≤0.01). In patients with non-clear cell RCC and with tumor <2cm, PN showed higher RFS rate at 60-month as compared to RFA (97.9% vs 84.4% and 95.1% vs 78.1%, respectively; all p≤0.02). At multi-variate analysis, ablative techniques (RFA [HR=4.03] and Cryo [HR=3.86]) were independent predictors of recurrence (all p<0.03). At competing risks analysis, recurrence rate and OCM were 7.3% and 1.3% vs 25% and 7.2% vs 19.9% and 19.9% for PN, RFA and Cryo, respectively. CONCLUSIONS PN and Cryo showed similar RFS rates in patients with non-clear cell RCC and with renal mass < 2cm.

The prognostic significance of PD-L1 in renal cell carcinoma (RCC) had been investigated in previous studies; however, the results remain controversial. The primary aim of this meta-analysis was to investigate the prognostic and clinicopathological significance of the PD-L1 expression in patients with RCC. Relevant literature was identified form PubMed, Embase, Web of Science and Cochrane library, which compared the prognostic significance between PD-L1 expression and RCC. Hazard ratios (HRs) for survival outcomes and odds ratios (ORs) for clinical parameters associated with PD-L1 were extracted from eligible studies. Heterogeneity was assessed using the I2 value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg's funnel plots and Egger's regression test. A total of 1863 patients from ten eligible studies were analyzed. The results showed that PD-L1 expression is associated with poor overall survival in clear cell RCC (ccRCC) (HR=2.76, 95%CI: 2.25-3.38, I2=14.4%, P<0.001) and non-clear cell RCC (non-ccRCC) (HR=2.77, 95%CI: 1.62-4.72, I2=28.8%, P<0.001). In addition, PD-L1 expression was found to be significantly associated with primary tumor stage (OR=1.76, 95%CI: 1.39-2.23; I2=56.3%), regional lymph node involvement (OR=2.10, 95%CI: 1.48-2.98; I2=14.9%), distant metastases (OR=2.69, 95%CI: 2.05-3.54; I2=0.0%), nuclear grade (OR=1.72, 95%CI: 1.32-2.23; I2=79.4%) and histologic tumor necrosis (OR=2.25, 95%CI: 1.59-3.18; I2=66.1%) in patients with RCC. The outcome stability was confirmed by sensitivity analysis. Both the Begg's funnel plot test (P=0.276) and the Egger's (P=0.388) verified that there was no publication bias within the included studies. This study suggests that PD-L1 expression is correlated with poor prognosis and advanced clinicopathological features in RCC patients.

Background: Racial/ethnic minority groups, including Hispanic Americans (HAs) and Native Americans (NAs), have a heavier burden of kidney cancer with a higher incidence and mortality than European Americans (EAs). However, HAs and NAs are under-represented in clinical and molecular genomic studies of renal cell carcinoma (RCC), the most common type of kidney cancer, and clinical and molecular characteristics of RCC among them are also unknown. We investigated variations in clinical and molecular characteristics of RCC patients. Methods: A total of 284 patients, including 90 HAs (31.6%) and 22 NAs (7.7%), who were diagnosed with RCC and without prior diagnosis of cancer were included to understand the patients' clinical characteristics. A subset of 51 samples were selected to screen for somatic mutations on the VHL gene, and 33 samples were selected for whole-transcriptome sequencing analysis. Results: Compared to EAs, HA and NA patients were diagnosed with RCC at younger ages (P&amp;lt;0.001). HA had about 5 years younger average age at diagnosis than EAs (55.2 vs. 60.6) and an over 2-fold increased odds of diagnosis before age 60 years (OR 2.50, 95% C.I.: 1.36-4.60). Mean age of diagnosis among NAs was 48.9, and NAs had more than 4-fold higher odds of diagnosis at a younger age (OR 4.12, 95% C.I.: 1.31-12.95). NA patients had higher body mass index than EA patients with 77.3% of NA obese patients. Diabetes was more common in HA (45.6%) and NA (50.0%) patients compared to EA (19.6%) patients. An RCC histologic subtype, clear cell RCC (ccRCC), was more common in HAs and NAs than EAs. Over 90% of HA patients had ccRCC, while only 77.6% of EA patients had ccRCC. HAs had increased odds of diagnosis with ccRCC compared to EAs (OR 2.39, 95% C.I.: 1.01-5.67). Among HAs, older patients were more likely to have advanced-stage RCC diagnosis (OR 7.06, 95% C.I.: 1.46-34.11). HAs who used Spanish as their primary language were more likely to have radical nephrectomy rather than partial nephrectomy (OR 5.13, 95% C.I.: 1.23-21.33). We detected pathogenic somatic mutations on the VHL gene, which is known to cause von Hippel-Lindau syndrome, in 4 patients, and these patients were younger than the patients without these mutations (45.5 vs. 57.1). We were able to assign 32 out of 33 patients into molecular subtypes (ccA and ccB). Molecular subtype could not be assigned to one HA patient with high-grade and advanced-stage ccRCC. Molecular subtype, ccA, was more common in HAs than EAs (64.3% vs. 41.2%), but this difference was not statistically significant. One gene, HABP2, showed evidence of differential expression between HA and EA tumors (PADJ&amp;lt;0.05) and was downregulated in HA tumors with log2 fold change &amp;lt;-2.0. Conclusion: HA and NA RCC patients had different clinical and molecular characteristics from EA patients. Impact: As we move toward a precision medicine approach for RCC care, it is necessary to better understand the clinical and molecular characteristics of these underserved HA and NA populations with high kidney cancer burden. Citation Format: Ken Batai, Alfredo Harb de la Rosa, Francine Gachupin, Elliot Imlaer, Erika R. Bracamonte, Bruce Seligmann, Benjamin R. Lee. Clinical and molecular profile of renal cell carcinoma in Hispanic Americans, Native Americans, and European Americans [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C059.

von Hippel-Lindau Exonic Methylation Analysis Using MALDI-TOF Mass Spectrometry

BACKGROUND: Metastatic and unresectable non-clear cell renal cell carcinoma comprises more than a quarter of kidney cancers but does not have standardized treatment. Non-clear renal carcinoma consists of a variety of diverse histologic subtypes, including papillary, chromophobe, collecting duct, translocation, and medullary histologies, many of which carry a poor prognosis. Many prospective clinical trials exclude these kidney cancers, and for most clinical trials of non-clear cell renal cell carcinoma, only a small number of patients are enrolled. OBJECTIVE: To perform a systematic review of recently published and currently enrolling prospective clinical trials for advanced non-clear cell renal cell carcinoma. METHODS: A systematic search of Pubmed and MEDLINE (Ovid) was conducted as per PRISMA guidelines to identify recent prospective clinical trials in non-clear cell renal cell carcinoma. To ensure a thorough search, terms not only included non-clear cell renal carcinoma but also molecular subtypes. A review of currently enrolling clinical trials was conducted on Clinicaltrials.gov and the EU Clinical Trials Register as well. RESULTS: A total of 33 prospective clinical trials with published results and 10 currently enrolling clinicals trials were identified. About half (48.5%) of these studies were reported in 2020 or 2021, and 36.4% were in the first-line setting. Treatments investigated in these trials included mTOR inhibitors, VEGF- and MET-targeted tyrosine kinase inhibitors, immune checkpoint inhibitors, and combinatorial strategies. Outcomes from these data revealed a wide range of response rate and progression free survival, favoring TKIs and immune checkpoint inhibitors -based combination regimens. CONCLUSIONS: Novel targeted therapies and immunotherapies have changed the landscape of treatment for advanced non-clear cell renal cell carcinoma. Combination regimens may provide even further clinical benefit and warrant further investigation in larger, randomized prospective clinical trials.

IntroductionBiomarkers for early detection of renal cell carcinoma (RCC) may help diagnose minimal residual disease in patients at risk for RCC, can guide anti-angiogenic therapy, or may help identify candidates for adjuvant treatment. In this study, we investigated whether blood levels of carbonic anhydrase 9 (CA9) correlate with RCC tumor burden and therefore disease activity.MethodsCA9 is a von Hippel–Lindau–hypoxia inducible factor target upregulated in clear cell RCC. We used an anti-CA9 antibody (M75)-based enzyme-linked immunosorbent assay test to measure CA9 levels in blood obtained before and after nephrectomy for clinically localized disease in patients with: (1) clear cell RCC, (2) papillary and chromophobe RCC or oncocytoma, or (3) benign kidney lesions, and we compared these samples to blood drawn from normal control individuals.ResultsWe observed a significant (p &lt; 0.006) decrease in the blood levels of CA9, after nephrectomy for localized disease, in the majority of patients with clear cell RCC (57%). In contrast, patients with nonclear cell RCC, benign disease, or those having undergone debulking nephrectomy for metastatic disease did not have a decrease in CA9 blood levels after nephrectomy. Preliminary longitudinal follow up measurements of CA9 levels in a small group of patients indicated that rising CA9 levels may correlate with disease progression.ConclusionsPlasma CA9 levels correlate with disease activity in a subset of clear cell RCC patients and should be considered in future multiplex RCC biomarker development algorithms.

Anti-programmed Cell Death Protein 1 (PD-1) Antibody Nivolumab Leads to a Dramatic and Rapid Response in Papillary Renal Cell Carcinoma with Sarcomatoid and Rhabdoid Features

680 Background: With the induction of targeted agents and immune checkpoint inhibitors, treatment strategies for systemic treatment of metastatic renal cell carcinoma (mRCC) have been changed with improved survival. However, those agents were approved based on phase 3 study results designed for clear cell mRCC. For patients with non-clear cell mRCC, those drugs designed for clear cell mRCC have also been used because no validated systemic therapy exists. This retrospective study aimed to identify patients with non-clear cell mRCC who benefit from systemic therapy. Methods: A total of 255 patients with mRCC were reviewed (Institutional review board approval No 2013-0425). Among them, 41 patients who pathologically diagnosed as non-clear cell mRCC and received systemic therapy were retrospectively analyzed. Clinical and pathological data were retrieved and analyzed retrospectively. The prognostic effect of each variable on progression free survival (PFS) and overall survival (OS) were investigated. OS for patients with non-clear cell mRCC was further investigated with univariate and multivariate Cox’s proportional hazards regression models. Results: After a median follow-up of 33.9 months after first line treatment initiation, the median PFS was 3.3 and 19.7 months for non-clear cell and clear cell RCC, respectively (p&lt;0.0001). The median OS was 20.9 and 50.1 months for non-clear cell and clear cell RCC, respectively (p&lt;0.0001). For patients with non-clear cell RCC, univariate analyses revealed duration of first line treatment, baseline C-reactive protein, and International Metastatic RCC Database Consortium (IMDC) risk group (favorable vs intermediate/poor) were significantly correlated with OS, respectively. Multivariate analysis revealed that the duration of first line treatment (HR: 0.997, p=0.027) and the baseline C-reactive protein (HR:1.128, p=0.004) were independent predictors for longer OS in non-clear cell mRCC patients. Conclusions: Systemic therapy for non-clear cell mRCC patients resulted in relatively shorter PFS and OS. A shorter duration of first line treatment and elevated baseline C-reactive protein are correlated with longer OS.

Renal cell carcinoma (RCC) is a heterogeneous disease that represents the most common type of kidney cancer. The classification of RCC is primarily based on distinct morphological and molecular characteristics, with two broad categories: clear cell RCC (ccRCC) and non-clear cell RCC (nccRCC). Clear cell RCC is the predominant subtype, representing about 70-80% of all RCC cases, while non-clear cell subtypes collectively make up the remaining 20-30%. Non-clear cell RCC encompasses many histopathological variants, each with unique biological and clinical characteristics. Additionally, any RCC subtype can undergo sarcomatoid dedifferentiation, which is associated with poor prognosis and rapid disease progression. Recent advances in molecular profiling have also led to the identification of molecularly defined variants, further highlighting the complexity of this disease. While immunotherapy has shown efficacy in some RCC variants and subpopulations, significant gaps remain in the treatment of rare subtypes. This review explores the outcomes of immunotherapy across RCC subtypes, including rare variants, and highlights opportunities for improving care through novel therapies, biomarker-driven approaches, and inclusive clinical trial designs.

Clear cell renal cell carcinoma (CCRCC) is the most common pathological type of renal cell carcinoma and the main cause of renal carcinoma mortality. NDRG2, a new member of the N-Myc downstream-regulated gene (NDRG) family, is a focus for study at present. Up to now, its expression and function in carcinoma remain unclear. The aim of this study was to investigate its expression in CCRCC tissues and several renal carcinoma cell lines. The expression of NDRG2 was evaluated in renal cell carcinoma cell lines, tumor and adjacent non-tumor tissues from same clear cell renal cell carcinoma patients, by using immunohistochemistry, immunofluorescence, RT-PCR and Western blot. By immunohistochemistry and immunofluorescence we found that NDRG2 was predominantly located in the cytoplasm and membrane of renal carcinoma cancer cells, and the positive rate of NDRG2 in renal carcinoma specimens was 30.3% (40/132), which is significantly lower than 91.67% (121/132) in normal renal tissues (p<0.01). The average staining score in normal renal tissues was significantly higher than renal carcinoma (6.12+/-1.84 versus 2.65+/-1.23, p<0.01). Moreover, NDRG2 mRNA and protein were down-regulated in 6 fresh CCRCC tissues compared with their adjacent noncancerous tissues and normal tissues. Its expression was also lower in the human CCRCC-derived cell lines A-498 and 786-O than in the human proximal tubular cell lines HK-2 and HKC. These results indicated that NDRG2 might play an important role in the carcinogenesis and development of CCRCC and may function as a tumor suppressor in CCRCC.

e16052 Background: Renal cell carcinoma (RCC) confers a lifetime risk of 1.6% of developing cancers. Early, localized cancers have high cure rates after surgical treatment, but locally advanced/distant metastatic disease remains a devastating disease. The use of TKIs has been considered a mainstay of treatment for clear cell pathology, but other histologic subtypes such as papillary, chromophobe, and mixed subtypes, which is considered non-clear cell RCC, also make up a heterogeneous pattern and course of disease. This retrospective study characterizes renal cell carcinomas and their treatments. Methods: A retrospective chart review of the last 15 years was performed using data from a single-institution center at the George Washington University Cancer Center Tumor Registry Data. Statistical analysis was performed using the Fisher’s test, Chi-squared test, T-test, and Kaplan-Meier survival curves. Results: 1043 patients with RCC were identified. Preliminary data analysis was performed on 92 of these patients. 48 had pure clear cell renal cell carcinoma (CCRCC) and 44 had non-clear cell carcinoma (NCC). Mean age of diagnosis was similar for both groups (58.25 years for CCRCC vs 62.14 years for NCC, p = 0.0977). However, hemoglobin levels at diagnosis were statistically significantly lower for CCRCC (p = 0.0261), as were calcium levels (p = 0.0187). All patients underwent surgical or local treatment. Only 2 patients received chemotherapy and 5 patients received molecularly targeted therapy. While not statistically significant, patients with CCRCC had surgery sooner after diagnosis than NCC (71 days vs 92 days), had longer time to metastatic disease (1033 days vs 820 days), and improved overall survival (1955 days vs 1446 days). Conclusions: NCC was a less favorable pathology than CCRCC with apparent later institution of surgical intervention as well as shorter time to metastatic disease and worse overall survival. Identifying patients with more aggressive disease earlier allows for the potential role for more aggressive therapies that may result in improved outcomes.

Purpose: The aim of this study was to evaluate the clinical relevance of the presence of disseminated tumor cells in peripheral blood [so called circulating tumor cells (CTCs)] for renal cell carcinoma (RCC) patients after a median follow-up time of 81 months. Methods: 233 peripheral blood samples from 154 RCC patients were investigated for the presence of disseminated tumor cells (DTCs) by autoMACS technique and immunocytochemical (ICC) staining of cytokeratin. The frequency of CTCs was analyzed statistically for correlation with relevant clinical data. Results: Two kinds of tumor cells were detected: Those with expression of cytokeratin 8/18 (CK+), but also cells without a detectable CK+ expression, which we called large blue stained cells (Bl+) with a tumor-like morphology. We hypotesized, that the latter cells could be “sleeping” tumor cells. After following the CD45 autoMACS depletion protocol, we identified CTCs in 96 out of 233 peripheral blood samples (41%), which originated from 81 out of 154 (53%) RCC patients. An update to follow up the RCC patients was conducted in 2012. Besides a significant correlation between the detection of CTCs before and after primary tumor resection a significant association with prognosis was found (p &amp;lt; 0.002; Chi-squared test). RCC patients with CK+ CTCs in their peripheral blood had a 5 times risk of tumor-related death compared to patients without these cells. In a Kaplan-Meier-Analysis these results were confirmed (p &amp;lt; 0.001). Patients with large blue stained cells (Bl+) also had a shorter survival time. Conclusion: In summary, for RCC patients, the presence of CTCs was associated with a poor overall survival and significantly correlated with an increased risk of tumor-related death. It is important to evaluate CK+ tumor cells to determine the role of CTCs in tumor behavior and disease progression. Detection of CK+ CTCs in peripheral blood is a significant and independent prognostic factor for renal cell carcinoma patients. Citation Format: Steffen Goebel, Karen Bluemke, Udo Bilkenroth, Axel Meye, Susanne Fuessel, Christine Lautenschlaeger, Andres Melchior, Hans Heynemann, Paolo Fornara, Helge Taubert. Detection of circulating tumor cells in peripheral blood of renal cell carcinoma patients is correlated with survival. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 368. doi:10.1158/1538-7445.AM2013-368

Introduction: tyrosine kinases receptors (RTKs) play an important role in the pathogenesis of renal cell carcinoma (RCC). RTKs were studied on tumor and endothelial cells, but the presence of these receptors on lymphocytes was not confirmed. The objective of this study was to investigate the expression of tyrosine kinases receptors on lymphocyte subpopulations in healthy volunteers and RCC patients before and after removal of the primary tumor.Materials and methods: the study included 19 patients with pT1‑T3N0 / N+M0 / M+ RCC, subjected to nephrectomy, and 10 healthy volunteers. Blood samples were collected once from healthy donors and twice from RCC patients, immediately before and 180 days after surgery. Isolation of lymphocytes and flow cytometry were carried out using standard methods. A comparative analysis of RTKs expression levels in peripheral lymphocytes from healthy volunteers and RCC patients, as well as in RCC patients before and after the operation, was carried out. A search was performed for correlations between the initial RTKs expression on lymphocytes from RCC patients and characteristics of the tumor development, as well as the disease prognosis.Results: VEGFR-1, -2, -3, FGFR2, PDGFRα, β RTKs are expressed on CD45+ peripheral blood mononuclear cells, as well as subpopulations of CD3+ and CD8+ lymphocytes in healthy volunteers and untreated patients with RCC. No differences in the expression levels of all studied RTKs between subpopulations of lymphocytes were found in RCC patients (p &gt; 0.05 for all). The level of RTKs expression on CD45+ peripheral cells in RCC patients before treatment is significantly lower than in healthy volunteers (p &lt; 0.05 for all). The degree of a decrease in RTKs expression correlated with the pT status and the presence of tumor-associated venous thrombosis. A significant increase in the expression levels of VEGFR1 (on CB45+) and VEGFR2 (on CD8+, CD3+) (p &lt; 0.05 for all) was noted 180 days after the removal of the primary tumor in patients with RCC. No other significant changes in RTKs production were identified. We were not able to determine the effect of RTKs expression on the RCC outcome.Conclusions: lymphocytes express RTKs, their expression is more pronounced in healthy people than in patients with RCC. After surgical treatment, the RTKs expression becomes restored.

Background Cytokine therapies show promise in treating renal cell carcinoma (RCC). Transforming growth factor beta 1 (TGF-β1) is a cytokine whose downstream Smad2/3 signaling activity is inhibited by the protein phosphatase Mg2+/Mn2+-dependent 1 A (PPM1A). Here, we hypothesized that PPM1A may be involved in suppressing RCC cell aggressiveness through its negative regulation of Smad2/3. Methods We quantified PPM1A expression from RCC tumors and matching healthy tissue and performed a Kaplan-Meier survival analysis. In silico analysis on PPM1A was performed using Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma and Clinical Proteomic Tumor Analysis Consortium RCC cohort data. We tested four RCC cell lines and selected the ACNH and A498 cells lines as expressing the greatest PPM1A levels. We assayed the effects of RNAi-mediated PPM1A silencing on invasiveness, proliferation, colony formation, and Smad2/3 phosphorylation in untreated and TGF-β1-stimulated ACNH and A498 cells. A nude mouse A498 xenograft tumor model was constructed to validate PPM1A’s effects in vivo. Results PPM1A levels are reduced in RCC tumors and are negatively correlated with RCC grade and stage. Below-median PPM1A expression is associated with reduced overall survival in RCC patients. PPM1A silencing promoted cellular invasiveness, proliferation, colony formation, and Smad2/3 phosphorylation under TGF-β1-stimulated conditions but not under untreated conditions. These effects of PPM1A were shown to be dependent on Smad2/3. Intratumor PPM1A overexpression inhibited A498 xenograft tumor growth. Conclusions This study establishes a direct link between PPM1A’s suppression of Smad2/3 signaling and RCC cell aggressiveness. PPM1A could potentially serve as a biomarker for RCC cell aggressiveness.

Background: This study aims to tackle the impact of histological subtype on the presentation and treatment trends of renal cell carcinoma (RCC).Methods: RCC cases, diagnosed from 2001 to 2013, were assembled from the Surveillance, Epidemiology and End Results (SEER) database. The incidence of different RCC histological subtypes (clear cell, papillary, chromophobe and collecting duct) was assessed and Join-Point analysis was conducted. Relevant clinicopathological characteristics were assessed and correlated with subtypes through chi-square testing. Survival analysis was then evaluated using Kaplan–Meier analysis and multivariate analyses for factors affecting overall and cancer-specific survivals were assessed.Results: A total of 89,968 RCC patients were evaluated. The incidence of different RCC subtypes has increased during the study period. Chromophobe subtype seems to have the best overall and cancer-specific survivals, whilst collecting duct subtype has the worst outcomes (p < .0001 for all endpoints). Multivariate analysis for factors affecting overall survival among non-metastatic RCC patients showed that the following factors are associated with worse overall survival (collecting duct carcinoma histology, older age, T4 disease, N2 disease, no receipt of local treatment, black race, male gender and unmarried status) (p < .0001 for all parameters).Conclusion: This analysis suggests that the prognosis of RCC varies widely according to the histological subtype. Biology-oriented preclinical and clinical assessments of novel therapeutics are needed particularly for non-clear cell RCC.