Citations

7 Background: Improved prognostic biomarkers are needed for localized prostate cancer. We undertook an unbiased large-scale analysis of genes associated with metastatic progression and validated the prognostic ability of the top candidate gene. Methods: Prostate cancer samples from prostatectomy patients were analyzed for gene expression using a clinical-grade, high-density Affymetrix GeneChip platform, encompassing >1 million genomic loci and assessed in a CLIA-certified laboratory. Nomination of prognostic candidate genes was performed on a discovery cohort (n=545) and validated on 3 independent cohorts (n=463). Multivariate analyses were performed for the primary endpoint of metastasis. The top prostate-specific gene was further evaluated in 208 additional tumor samples with a novel RNA in-situ hybridization (ISH) assay and in urine samples from 230 patients using PCR. Results: Of all known genes, the long noncoding RNA SChLAP1 ranked first for elevated expression in patients with metastatic progression by receiver-operator-curve analyses. Validation in three independent cohorts confirmed the prognostic value of SChLAP1. On multivariate modeling, SChLAP1 expression independently predicted metastasis within 10 years (odds ratio (OR) = 2.45, 95% confidence interval (CI) 1.70 – 3.53), death within 10 years (OR = 1.93, 95% CI 1.31 – 2.85), and biochemical recurrence within 5 years (OR = 1.76, 95% CI 1.28 – 2.41) with ORs comparable to Gleason score. Evaluation of SChLAP1 expression by RNA ISH confirmed a significant association with disease recurrence (OR = 1.99, 95% CI 1.06 – 3.73). Evaluation of urine SChLAP1 levels demonstrated increased expression in patients at higher risk for disease progression. Conclusions: We perform the largest high-throughput, unbiased study of prostate cancer prognostic biomarkers to date and discover SChLAP1 as a top gene predictive of metastatic progression. We validate SChLAP1 extensively with a clinical-grade assay. We show feasibility of a RNA ISH assay and a non-invasive urine test for SChLAP1. Our results, spanning 1,446 patients from 6 independent patient cohorts, suggest that SChLAP1 represents a very promising biomarker for aggressive clinical course.

507 Background: Clear cell renal cell carcinoma (ccRCC) is a well-described molecularly heterogeneous tumor. Herein, we assessed the concordance of two of the most commonly mutated genes in ccRCC, PBRM1 (~50%), and BAP1 (~15%), in patient-matched primary and metastatic tumors. Methods: One pathologist (PK) assessed PBRM1 and BAP1 protein expression using immunohistochemistry (IHC) in 99 patients with a primary and at least one metastatic ccRCC tumor available for analysis. All available metastatic tumors were analyzed. Results: A total of 99 patients (48 M0 and 51 M1) had both a primary tumor and at least one metastatic tumor available for analysis. There were a total of 158 metastases with one patient having up to 7 metastases available for analysis. The concordance between primary and patient-matched metastasis was 87% for PBRM1 and 99% for BAP1. We observed a similar concordance between patients with M0 versus M1 disease. Conclusions: While ccRCC is molecularly heterogeneous, PRBM1, and BAP1 are largely concordant between primary and metastatic lesions suggesting that PBRM1 and BAP1 are genetically truncal events in the molecular pathogenesis of ccRCC.

501 Background: Predictive biomarkers of response to targeted therapy are lacking in renal cell carcinoma (RCC). We evaluated a cohort of RCC patients referred for molecular profiling to identify potentially actionable recurrent molecular aberrations. Methods: 166 consecutive renal cases referred to Caris Life Sciences over 2 yrs were evaluated with central pathology review. Cases were subtyped into clear cell (ccRCC), n=100, papillary (PRCC), n=20, sarcomatoid, n=10, translocation, n=6, medullary, n=4 or unclassified, n=26. 63% of cases were metastatic. Testing included a combination of sequencing (Sanger or next generation sequencing [NGS]), protein expression (immunohistochemistry [IHC]), and/or gene amplification (CISH or FISH). Results: ccRCC had a 52% loss of PTEN, while PRCC had a 21% loss (p value=0.02). 100% of ccRCC with sarcomatoid features (4) showed aberrant expression of PD-L1 and were infiltrated with PD-1+ tumor infiltrating lymphocytes; 100% of 10 non-ccRCC sarcomatoids also had aberrant expression of PD-L1. Loss of PBRM1 expression was observed in 60% of ccRCC. Loss of histone 3 lysine 36 trimethylation (H3K36me3), which is associated with SETD2 mutations, was observed in 30% of ccRCC. TOP2A was overexpressed in ccRCC at 30% and in non-ccRCC at 50%. 100% of ccRCC and PRCC overexpressed EGFR; a single unclassified renal cell carcinoma did not overexpress EGFR. 50% of cases had cMET overexpression, amplification, or mutation. HER2 was not amplified or overexpressed in any RCC; a single rare HER2 mutation (R816H) was found in a collecting duct carcinoma. VHL mutations were identified in 50% of ccRCC tumors. We observed lower rates of TP53 (14%), ATM (6%), and PIK3CA(4% ccRCC, 7% PRCC) mutations compared to other cancers. Conclusions: Multiplatform molecular profiling of renal cell carcinoma identifies potential predictive biomarkers in ccRCC. The documented activity of everolimus in ccRCC (RECORD-1 trial) may be attributable to PIK3CA pathway alterations. RCC with sarcomatoid features may respond to PD1/PD-L1 targeted immunotherapies. The impact of molecular profiling in ccRCC to predict responses to currently available targeted therapy has important implications for trial design and patient selection.

494 Background: Renal cell carcinoma (RCC) with rhabdoid differentiation is thought to portend a poor prognosis, similar to RCC with sarcomatoid differentiation. Both rhabdoid and sarcomatoid differentiation are classified as grade 4 RCC based on the most recent International Society of Urological Pathology (ISUP) grading system. We sought to determine the prognostic value of rhabdoid differentiation in comparison to RCC with sarcomatoid differentiation, grade 4 RCC without rhabdoid or sarcomatoid differentiation, and grade 3 RCC. Methods: Using the Mayo Clinic Nephrectomy Registry, we identified 406 patients with ISUP grade 4 RCC and 1,758 patients with grade 3 RCC. A urologic pathologist reviewed all specimens to determine the presence of both rhabdoid and sarcomatoid differentiation. Associations of clinical and pathologic features with death from RCC were evaluated using Cox models. Results: Among the 406 grade 4 RCC tumors, 111 (27%) had rhabdoid differentiation and 189 (47%) had sarcomatoid differentiation, although only 28 (7%) demonstrated both rhabdoid and sarcomatoid differentiation. In multivariable analysis of grade 4 RCC tumors, the presence of rhabdoid differentiation was not associated with death from RCC (HR 0.95, p=0.75); in contrast, sarcomatoid differentiation was significantly associated with death from RCC (HR 1.63, p<0.001). Patients with RCC with rhabdoid differentiation were significantly more likely to die of RCC than patients with grade 3 RCC (HR 2.45, p<0.001) and grade 3 RCC with necrosis (HR 1.62; p<0.001). Conclusions: This study confirms that RCC with rhabdoid differentiation is appropriately classified as grade 4. However, unlike sarcomatoid differentiation, the presence of rhabdoid differentiation in grade 4 RCC is not associated with an increased risk of death from RCC. Therefore, rhabdoid and sarcomatoid differentiation should not be grouped together when assessing risk in a patient with grade 4 RCC.

475 Background: The vascular disrupting agent (VDA) BNC105P shows synergy with everolimus in preclinical models. The DisrupTOR-1 trial included a phase I component exploring this combination and a randomized phase II component comparing everolimus with BNC105P (Arm A) to everolimus monotherapy (Arm B) (Pal et al. ESMO 2014). Methods: Pts with clear cell mRCC and 1-2 prior therapies (including ≥1 VEGF-TKI) were randomized in the phase II study component. In Arm A, patients received a 7 day lead-in dose of everolimus followed by dosing with BNC105P. Patients in Arm A had optional blood collections prior to administration of BNC105P and 3 hours after receiving BNC105P. A fluorescence-based assay was used to characterize a broad panel of analytes at each time point. Biomarkers were assessed in both a static and dynamic fashion. For the former, biomarkers were stratified by median value, and progression-free survival (PFS) was compared in resulting subgroups using the Kaplan-Meier method. For the latter, change in biomarker level before and after BNC105P infusion was stratified by median difference, and PFS was compared in resulting subgroups using the Kaplan-Meier method. Results: 139 pts were randomized with 69 and 67 evaluable pts in Arms A and B, respectively. Dynamic biomarkers were assessed in a total of 44 patients who received everolimus with BNC105P. Increases in matrix metalloproteinase-9 (MMP-9) and stem cell factor (SCF) were associated with improved PFS (p=0.0421 and p=0.0291, respectively). Decreases in sex hormone binding globulin (SHBG) and serum amyloid protein (SAP) were associated with improved PFS (p=0.0184 and p=0.0063). With respect to static biomarkers, elevated baseline ferritin and lower baseline IL-8 were associated with improved PFS (p=0.0291 and p=0.0149, respectively). Conclusions: Several static and dynamic biomarkers in the DisrupTOR-1 trial were associated with PFS. A prospective biomarker-driven study examining everolimus with BNC105P selected by baseline IL-8 and ferritin is in development. Clinical trial information: NCT01034631.

447 Background: Components of the peripheral blood counts (PBC) are associated with poor prognosis in patients diagnosed with non-metastatic clear cell renal cell carcinoma (ccRCC). Related to this, higher tumor expression of programmed death ligand one (PDL1) is also associated with poor ccRCC prognosis. Herein, we utilize a large cohort of patients undergoing nephrectomy for localized ccRCC to evaluate the association of PBC with tumor expression of PDL1. Secondarily, we examine the association of PBC and relapse free survival (RFS) after adjusting for age and PDL1 expression. Methods: Through chart review, we obtained PBC values at time of nephrectomy for patients enrolled in the Mayo Clinic Renal Registry from 1990-2009 who were treated for localized (M0) ccRCC including the following: hemoglobin (HGB), white blood cell (WBC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), absolute eosinophil count (AEC), absolute monocyte count (AMC), and platelets (PLT). We determined tumor PDL1 expression as a continuous variable (% of positive PDL1 tumor cells) using the 5H1 antibody on archived tissues. We analyzed the correlation of PBC values with PDL1 expression as a continuous variable using a linear estimate. To evaluate the association of PBC values with RFS after adjusting for PDL1 expression, we employed multivariate Cox regression models. Results: A total of 706 ccRCC patients had available PDL1 expression and PBC. PDL1 expression was inversely associated with HGB (linear estimate of -0.02, p<0.001) and positively associated with platelets (linear estimate 1.73, p<0.001) whereas there was no association with PDL1 with WBC, ANC, AEC, or AMC. After adjusting for age and PDL1 expression, a higher HGB (HR=0.87, p<0.001), higher ALC (HR 0.68, p=0.003), and higher AEC (HR 0.12, p=0.002) were all associated with improved relapse free survival. Conversely, higher PLT was associated with decreased RFS (HR 1.002, p<0.001). Conclusions: PDL1 expression is associated with decreased HGB and increased PLT at the time of nephrectomy. After adjusting for PDL1 expression and age, higher HGB, ALC, and AEC are associated with improved RFS, while higher platelets are associated with decreased RFS.

422 Background: There is significant variability in the response to VEGF-TT in mRCC with no validated predictive biomarkers. We hypothesized that whole exome analysis might identify markers of response and resistance to VEGF-TT in mRCC. Methods: mRCC patients who received first-line sunitinib or pazopanib and were in two extreme phenotypes of response were identified. Extreme responders (ER) were defined as PR or CR for ≥3 years (n=10) and primary refractory patients (PRP) were defined as PD within the first 3 months of therapy (n=10). WES was performed in pre-treatment specimens and established Broad Institute analytical pipelines were utilized to identify point mutations and copy number alterations across the exome. ER (n=4) and PRP (n=4) who were part of TCGA project for clear-cell RCC were included in this analysis. Nonsense, missense and indel mutations in established or novel RCC genes were investigated. Results: IMDC prognostic scores were not significantly different between the two groups. VHL mutations were observed at similar frequency in ER and PRP, overall 57%. Mutations in PBRM1 were identified in 7 ER (50%) vs. 1 PRP (7%) (p=0.03). In addition, mutations in TP53 were only found in PRP (p=0.09). No other gene had mutations that were associated with either response or primary refractory disease (Table). Conclusions: In this pilot study, PBRM1 mutations were associated with extreme response to VEGF-TT. However, this was exploratory, and multivariable analysis was not performed. Analysis of additional patient samples is ongoing to confirm or refute this association. If true it suggests that epigenetic effects of PBRM1 mutation may contribute to response to VEGF-TT in mRCC. [Table: see text]

420 Background: Cytoreductive nephrectomy (CN) has been associated with significant morbidity, but there is little data identifying patients at increased risk. We evaluated the association of clinicopathologic features with early post-operative complications and prolonged length of stay (pLOS) among CN patients. Methods: We identified 294 patients treated with radical nephrectomy for M1 renal cell carcinoma between 1990 and 2009 at the Mayo Clinic. All complications within 30 days of surgery were reported using standardized methodology according to the Clavien classification. Associations with the presence of any early complication and pLOS (defined as ≥8 days, the top 25th percentile) were evaluated using logistic regression models. Results: Thirty-five (12%) patients experienced at least one early complication and 15 (5%) patients experienced at least one Clavien grade ≥3 early complication. The median LOS was 6 days (IQR 5-7), and 68 (23%) patients had a pLOS. On univariate analysis, liver metastases, symptomatic presentation, intraoperative transfusion, and pathologic nodal stage were significantly associated with both early complications and pLOS (Table). Two multivariate models were constructed. In Model 1 (limited to pre-operative features), only liver metastases (p<0.01) were associated with early complications while liver metastases (p=0.01) and open approach (p=0.02) were associated with pLOS. In Model 2 (all variables included), liver metastases (p=0.01), intraoperative transfusion (p<0.01), and high nuclear grade (p<0.01) were associated with early complications while intraoperative transfusion (p<0.01) and positive nodes (p=0.05) were associated with pLOS. Conclusions: CN was associated with a low incidence of early post-operative complications, particularly Clavien ≥3 complications. Presence of liver metastases and intraoperative transfusion were independently associated with increased risk of both complications and pLOS. [Table: see text]

326 Background: The Survival Prediction After Radical Cystectomy (SPARC) score (Eisenberg et al, J Urol 2013) incorporates clinical and pathologic features to predict cancer specific survival (CSS) for urothelial carcinoma of the bladder. Validation of this model would improve its generalizability. Methods: Using the IRB-approved bladder cancer database at the University of Southern California (USC), we identified patients who underwent radical cystectomy (RC) for urothelial carcinoma of the bladder for curative intent from 1971-2009. Clinical factors (Charlson comorbidity index, ECOG performance status, hydronephrosis, adjuvant chemotherapy, smoking status) and pathologic factors (pathologic T stage, nodal status, multifocality, and lymphovascular invasion) included in the SPARC score were obtained. Patients were excluded if there were missing variables or if they underwent neoadjuvant chemotherapy. Associations between clinicopathologic factors and CSS were evaluated using Cox proportional hazards. Calibration plots were generated comparing actuarial CSS with SPARC predicted CSS by deciles. A c-index was generated to determine accuracy of the prediction. Kaplan Meier curves estimated CSS stratified by SPARC score and were compared with the log rank test. Results: A total of 2,045 patients underwent RC and 1,123 (55%) met inclusion criteria with a median follow-up of 4.7 years (IQR 2.0-8.9 years). Of the 1,123 patients, 332 (30%) died of bladder cancer. All the clinical and pathologic variables used in the SPARC scoring model were associated with CSS except for smoking status and tumor multifocality. Calibration plots demonstrated concordance between the SPARC-predicted and actuarial CSS with a c-index of 0.75. Kaplan Meier curves demonstrated significant differences in CSS based upon SPARC score, p<0.001. Conclusions: The SPARC score represents a valid instrument for predicting bladder CSS after RC. The model can be utilized to better tailor adjuvant therapy and surveillance.

295 Background: Patients (pts) with metastatic urothelial carcinoma (UC) progressing after first-line chemotherapy have limited treatment options. Ramucirumab (Ram), a human VEGFR2-targeted mAb, has demonstrated clinical activity in several solid tumors. Preclinical testing supports a role for Ram-taxane combinations in UC. Study JCDC is an open-label, multicenter, randomized phase 2 study of docetaxel (Doc) alone or combined with Ram or icrucumab (Icr) in locally advanced or metastatic platinum-resistant UC. We report on a planned interim analysis for Doc + Ram vs Doc; Icr results will be reported later. Methods: Eligible pts with advanced UC and ECOG PS 0-1 who relapsed ≤ 1 year from a platinum-regimen were randomized to receive Doc 75 mg/m2IV alone or with Ram 10mg/kg IV on Day 1 of repeating 21-day cycles. A sample size of 46 pts per arm enabled 71% power to demonstrate statistical significance of 4.5 mo (Doc + Ram) vs 3 mo (Doc) at a 1-sided α= 0.1. Treatment continued until disease progression or unacceptable toxicity. The primary endpoint is investigator-assessed PFS with RECIST v1.1, analyzed by K-M methods. A planned interim analysis was performed after 75% of the PFS events. Results: 44 pts received Doc and 46 received Doc + Ram. Study arms were well matched with a mean age of 67 yr (29-84), and a 4:1 male to female ratio. 58.7% (Doc + Ram) vs 61.4% (Doc) had ECOG PS 1. 58.7% (Doc + Ram) vs 52.3% (Doc) had visceral metastases. Doc + Ram reduced the risk of disease progression, stratified HR = 0.388; 95% CI: 0.222, 0.677; log-rank p = 0.0005, improving median PFS (5.1 vs 2.4 mo). The ORR for Doc + Ram was 19.6 vs 4.5% for Doc (p= 0.0502), and the disease control rate was 67.4 vs 43.2%. OS maturity is pending. The most common adverse events in the Doc + Ram arm (all grades) were fatigue (80.4% Doc + Ram v 75.0% Doc), decreased appetite (54.3 v 43.2%), nausea (54.3 v 25.0%), and neuropathy (50.0 v 38.6%). Grade (G) ≥3 febrile neutropenia (19.6 v 11.4%), pneumonia (13 v 9.1%), hypertension (4.3 v 0%) were higher with Doc + Ram. One G3 hematuria was observed in each arm. Conclusions: Results support a statistically significant improvement in PFS for Doc + Ram in second-line UC. Final results are expected in 2015. Clinical trial information: NCT01282463.