Shuch, Brian

TPS684 Background: The anti-PD-1 antibody nivo improves overall survival in metastatic RCC and is well tolerated. There is no standard adjuvant systemic therapy that increases overall survival (OS) over surgery alone for non-metastatic RCC. Priming the immune system prior to surgery with anti-PD-1 has shown an OS benefit compared to a pure adjuvant approach in mouse solid tumor models. The PROSPER RCC trial aims to improve clinical outcomes by priming the immune system prior to nephrectomy with neoadjuvant nivo and continued engagement with adjuvant blockade in patients with high risk M0 RCC compared to surgery alone. Methods: This global, unblinded, phase 3 National Clinical Trials Network study is currently accruing patients with clinical stage ≥T2 or node positive M0 RCC of any histology. Tumor biopsy prior to randomization is mandatory to ensure RCC and permits in depth correlative science. The investigational arm will receive two doses of nivo 240mg prior to surgery followed by adjuvant nivo for 9 months (q2 wks x 3 mo followed by 480mg q4 wks x 6 mo). The control arm will undergo standard nephrectomy followed by observation. Randomized patients are stratified by clinical T stage, node positivity, and histology. To enhance accrual and patient quality of life, key upcoming amendments are being instituted. These include biopsy only in the nivo arm, allowance of oligometastatic disease and bilateral renal masses that can be fully resected/ablated, and change of nivo dosing to q4 wks (1 neoadj; 9 adj). With accrual of 766 patients, there is 84.2% power to detect a 14.4% absolute benefit in recurrence-free survival (RFS) at 5 years assuming the ASSURE historical control of ~56% to 70% (HR = 0.70). The study is also powered to evaluate a significant increase in overall survival (HR 0.67). Safety, feasibility, and quality of life endpoints critical to adjuvant therapy considerations are incorporated. PROSPER RCC embeds a wealth of translational work aimed at investigating the impact of the baseline immune milieu, the changes induced by neoadjuvant anti-PD-1 priming, and how both correlate with clinical outcomes. Clinical trial information: NCT03055013.

560 Background: Level I evidence exists demonstrating the efficacy of the mTOR inhibitor everolimus (EVE) in decreasing tumor volume of syndromic angiomyolipomas (AMLs) among patients with Tuberous Sclerosis. No prospective data are available regarding the effect of mTOR inhibition on growth kinetics in patients with sporadic AMLs. Methods: We conducted a multi-institutional, prospective, phase 2 trial with an optimal two-stage Simon design in patients presenting with > 3cm sporadic AMLs who were candidates for surgical or percutaneous intervention. Response was defined as ≥25% volumetric reduction of the AML. Planned enrollment was 43 patients to test the null hypothesis at a 5% level of significance with 80% power. Baseline, 4- and 6-month volumetric analysis was performed by dynamic contrast-enhanced MRI (DCE-MRI). Patients received EVE 10mg for four 28-day cycles, at which point EVE was discontinued in those with < 25% volumetric reduction. Those with ≥ 25% volumetric reduction received two additional cycles of EVE. Dose reductions and interruptions were allowed to 5 mg QOD. Conservative stopping rules were established for toxicity, given the benign nature of AMLs. Results: The early stopping rules for both efficacy and toxicity were invoked. We enrolled 20 patients (median age = 68) from 5 centers with 21 sporadic AMLs. 11/20 (55%) patients completed 4 cycles of EVE, while 7/20 (35%) completed 6 cycles. Median days on treatment was 88 (2 cycles). 4/20 (20%) patients were withdrawn due to toxicity, while 8/20 (40%) withdrew due to personal preference. Dose reductions were required in 6/20 (30%) patients, and 5/20 (25%) patients had grade 3 toxicities which resolved upon discontinuation or dose reduction of EVE. At 4-month MRI, 10/16 (62.5%) patients had a ≥25% reduction in volume (mean = 54.1% decrease). At 6-month MRI, 8/12 (66.6%) patients had a ≥25% reduction in volume (mean = 51.5% decrease). Conclusions: EVE was effective in reducing tumor volume in patients with sporadic AMLs but was associated with a high rate of treatment termination due to patient preference or prespecified AEs. Neoadjuvant EVE may be useful in potentiating surgical resection of large or anatomically complex AMLs. Clinical trial information: NCT02539459.

167 Background: Physicians have a variety of resources available about the treatment of localized prostate cancer. Yet, it is largely unknown what resources and evidence radiation oncologists and urologists commonly use to inform patients and possibly alter clinical practice. In this national survey study, we assessed the types of resources prostate cancer specialists’ use and the level of evidence needed to change treatment recommendations in localized prostate cancer. Methods: From a random sample, 1,422 physicians were sent a mail survey assessing what type of information was used to guide prostate cancer treatment. The survey also queried what level of evidence could alter recommendations. Multivariable logistic regression models were used to identify for differences in physician characteristics for each outcome. Results: Survey response rates were similar for radiation oncologists and urologists (44% vs. 46%; p=0.46). Specialty-specific journals represented the most commonly used resource to inform the clinical practice for radiation oncologists (65%) and urologists (70%). Relative to radiation oncologists, urologists were less likely to utilize medical journals (25% vs. 38.7%, OR: 0.50; p=0.01), cancer journals (21.7% vs. 50.8%, OR: 0.50; p<0.001), but more likely to rely on clinical guidelines (46.3% vs. 37.7%,OR: 1.6; p=0.006). Radiation oncologists and urologists both viewed RCT’s as the most likely source of evidence needed to change treatment recommendations (85% vs. 77%). Conclusions: Both specialties most commonly rely on their specialty-specific journals to inform their clinical practice and view RCT’s as the level of evidence needed to change treatment recommendations for localized prostate cancer. Radiation oncologists embraced greater diversity in literature, while urologists were more likely to use clinical guidelines. Utilizing this information may overcome barriers to the dissemination and adoption of new treatment paradigms for localized prostate cancer.

BACKGROUNDPartial nephrectomy (PN) and radical nephrectomy (RN) are standard treatments for a small renal mass. Retrospective studies suggest an overall survival (OS) advantage, however a randomized phase 3 trial suggests otherwise. The effects of both surgical modalities on OS were evaluated compared with controls.METHODSA matched cohort study was performed using the Surveillance, Epidemiology, and End Results (SEER)‐Medicare dataset. Individuals treated with PN or RN for localized renal cell carcinoma (RCC) measuring ≤4 cm were compared with 2 control groups (non–muscle‐invasive bladder cancer (BCC) and noncancer controls (NCC). Using a greedy algorithm, RCC groups were matched with controls by demographics and comorbidities. OS for surgical groups and controls were compared. The cause of death was evaluated for cancer groups when differences in OS were noted.RESULTSPatients undergoing PN and RN were matched with controls. All cancer groups had >95% 10‐year cancer‐specific survival (CSS). Median OS was similar between RN (9.05 years) and BCC (8.67 years; P = .067) and NCC (8.77 years; P = .49). Median OS was improved for PN (10.45 years) compared with BCC (8.75 years; P<.001) and NCC controls (8.76 years; P<.001). A multivariate Cox hazards model demonstrated that PN improved OS compared with NCC (hazard ratio, 1.257; P<.001) and BCC (hazard ratio, 1.364; P<.001).CONCLUSIONSRN patients had similar OS compared with controls, suggesting that this treatment modality does not compromise survival. Patients undergoing PN had improved OS compared with controls, suggesting possible selection bias. The apparent survival advantage conferred by PN in SEER‐Medicare case series is likely the result of selection bias involving unmeasured confounders. Cancer 2013;119:2981—2989. © 2013 American Cancer Society.