Michael A. S. Jewett

Renal tumor biopsy (RTB), as distinct from the more common renal biopsy for medical renal disease, is an option for patients with renal masses. It is mainly used for small renal masses (SRM) but it may also be indicated for larger masses and even in the presence of metastatic disease. Its main indication in SRM is to avoid intervention for benign kidney tumors but increasingly enables more personalized treatment for kidney cancer patients.

TPS4596 Background: The anti-PD-1 antibody nivolumab (nivo) improves overall survival (OS) in metastatic treatment refractory RCC and is generally tolerable. In 2017, there is no standard adjuvant therapy proven to increase OS over surgery alone in non-metastatic (M0) disease. Mouse solid tumor models have revealed an OS benefit with a short course of neoadjuvant PD-1 blockade compared to adjuvant therapy. Two ongoing phase 2 studies of perioperative nivo in RCC patients (pts) have shown preliminary feasibility and safety with no surgical delays or complications. The PROSPER RCC trial will examine if the addition of perioperative nivo to radical or partial nephrectomy can improve clinical outcomes in pts with locally advanced RCC. With the goal of increasing cure and recurrence-free survival (RFS) rates in M0 RCC, we propose a three-pronged, multidisciplinary approach of presurgical priming with nivo followed by resection and adjuvant PD-1 blockade. Methods: Tumorbiopsy prior to randomization is mandatory to ensure the correct diagnosis and will permit unparalleled correlative science in this global, randomized, unblinded, phase 3 National Clinical Trials Network study. 766 pts with clinical stage ≥T2 or any node positive M0 RCC of any histology will be enrolled. The study arm will receive nivo 240mg IV for 2 doses prior to surgery followed by nivo adjuvantly for 9 months (q2 wks x 3 mo followed by q4 wks x 6 mo). The control arm will undergo the current standard of care: surgical resection followed by observation. Pts are stratified by clinical T stage, node positivity, and histology. There is 84.2% power to detect a 14.4% absolute increase in the primary endpoint of RFS from the ASSURE historical control of 55.8% to 70.2% at 5 yrs (HR 0.70). The study is also powered to detect a significant OS benefit (HR 0.67). Key safety, feasibility, and quality of life endpoints are incorporated. PROSPER RCC exemplifies team science with a host of planned correlative work to investigate the significance of the baseline immune milieu and changes after neoadjuvant priming and to identify predictive gene expression patterns. Additional collaborations are welcomed.

E16003 Background: Multidisciplinary management improves complex treatment decision making in cancer care, but its impact for bladder cancer (BC) has not been documented. While radical cystectomy (RC) is currently viewed as the standard of care for muscle-invasive bladder cancer (MIBC), radiotherapy-based, bladder-sparing trimodal therapy (TMT) combining transurethral resection of bladder tumor, chemotherapy for radiation sensitization and external beam radiotherapy has emerged as a valid treatment option. In the absence of randomized studies, we compared the oncological outcomes between patients managed by RC or TMT using a propensity-score matched cohort analysis. Methods: Patients seen in our multidisciplinary bladder cancer clinic (MDBCC) from 2008 to 2013 were retrospectively reviewed. Those who received TMT for MIBC were identified and matched (for gender, cT and cN stage, ECOG status, Charlson comorbidity score, treatment date, age, CIS, hydronephrosis) using propensity scores, to patients who underwent RC. Overall survival and disease-specific survival (DSS) were assessed with Cox Proportional hazards modeling and competing risk analysis, respectively. Results: 112 patients with MIBC were included after matching, 56 treated with TMT and 56 by RC. Median age was 68.0 years and 29.5% were cT3/cT4. At a median follow up of 4.51 years, there were 20 (35.7%) deaths (13 from BC) in the RC group and 22 (39.3%) deaths (13 from BC) in the TMT group. 5 year DSS was 73.2% and 76.6%, in the RC and TMT groups, respectively (p = 0.49). Salvage cystectomy was performed in 6/56 TMT patients (10.7%). Conclusions: In the setting of a MDBCC, TMT yielded survival outcomes similar to matched RC patients. Appropriately selected MIBC patients should be offered the opportunity to discuss various treatment options including organ-sparing TMT.

493 Background: Genomic signatures may compliment pathological features in identifying appropriate patients who may benefit from adjuvant therapy in Stage I (SI) TGCT. This study aimed to identify a gene expression pattern to differentiate between relapsed (R) and non-relapsed (NR) SI TGCT. Methods: Patients with SI non-seminoma (NS) and seminoma (S) were identified from an institutional database from 2000 to 2012. All patients were managed with active surveillance. NR-NS and NR-S patients were defined as having no evidence of relapse after 2 and 3 years of surveillance respectively. Following pathology review, RNA extraction and gene expression analysis was performed on archived paraffin embedded tumor and normal testicular tissue using Illumina Whole Genome DASL Human HT-12 V4 BeadChip. Hierarchical clustering analysis, ANOVA and t-tests were used to evaluate candidate genes and expression patterns that could differentiate NR and R samples. Results: 57 patients (12 R-NS, 15 R-S, 15 NR-NS, 15 NR-S) were identified with median relapse time of 5.6 (2.5-18.1) and 19.3 (4.7-65.3) months in NS and S cohorts respectively. 3 additional normal testis samples were included. Poor prognostic factors were more frequent in R versus NR cases (NS: vascular invasion [5/12 vs 0/15]; S: median size [4cm vs 2.8cm]). Unsupervised hierarchical clustering of 22822 probes randomly separated S from NS, indicating no batch effect. One-way ANOVA revealed 4525 significantly varying probes (p < 0.05) however, no statistically significant gene expression profile differentiated the 4 cohorts. A discriminative gene expression profile between R and NR cases was discovered when combining NS and S samples using 10 (p = 0.03) and 30 (p = 0.03) probe signatures with a 10 fold cross-validation. However, this profile was not observed in the S and NS cohorts individually. Conclusions: A discriminating signature for R and NR was identified for SI testis tumors, but not separately for NS and S. Biological relevance of these signatures is to be determined. Further studies are required to corroborate this profile in NS and S. If validated, these expression patterns could help identify patients beyond standard pathological risk algorithms for optimal management.

475 Background: Surveillance is recommended for patients with stage I seminoma post orchidectomy but CT imaging involves ionising radiation, with risk of associated secondary malignancies. We assessed site of disease relapse during surveillance to guide development of a risk adapted imaging protocol. Methods: Data was obtained from a prospectively maintained database of patients with stage I seminoma on surveillance after orchidectomy from 1981-2011. Relapse was determined by clinical and/or radiographic finding with or without pathological confirmation or tumour marker elevation. Results: 753 patients were identified. The median age at orchidectomy was 33.7 years. With a median follow up of 10.5 years, range 1.1-30.1, 115 (15.3%) patients relapsed. Relapse was detected radiologically in 114 (99.1%), with 9 (7.8%) having simultaneously elevated tumour markers. A clinical diagnosis of relapse was made in 1 case (inguinal node – 0.9%). The location and time to relapse are shown in table. Conclusions: In stage I seminoma surveillance, pelvic nodal relapse was restricted to the early period of follow up. Excluding the pelvis during CT imaging after the third year of surveillance may optimise the detection of relapse whilst minimising total radiation exposure. This has now been adopted at our centre since 2011 without any subsequent late pelvic relapses. [Table: see text]