Ferrigni, Erin

287 Background: Our preliminary immunohistochemical studies of bladder cancer patients have shown that the inflammatory/immune responses associated with bladder cancer appear to be Th2-polarized as judged by the preponderance of tumor infiltrating GATA-3+ (Th2) vs. T-bet+ (Th1) T cells, as well as by evidence of tumor-associated eosinophil infiltration and activation. The standard-of-care treatment for Tis bladder cancer is intravesical administration of BCG, a Th1-polarizing immunomodulator. The aim of the present study was to assess the Th2/Th1 ratio correlation with response to BCG therapy in patients with Tis bladder cancer. Methods: Two groups of patients were studied. Group A included 20 patients that responded to BCG, and Group B included 20 patients that did not respond to therapy. Response to BCG was determined as presence/absence of disease at 6 months post-BCG therapy. The initial diagnostic biopsies of these patients were subjected to immunohistochemical analysis using commercially available antibodies specific for Th2 (GATA-3+) and Th1 (T-bet+) lymphocytes, and our unique monoclonal antibody specific for eosinophil peroxidase (EPX-mAb). Ten random high powered (400X) fields at the maximum focus of mononuclear infiltration were examined and the number of GATA 3+ and T-bet+ tumor infiltrating T cells were counted to define the G/T ratio for each patient sample. Eosinophils and their degranulation activity were counted in the same fields. Results: Patients with response to BCG therapy had a G/T ratio of ≥ 3 and patients with non-response to BCG therapy had a G/T ratio of ≤ 1.5. Correlation of these scores with subsequent patient outcomes following BCG immune therapy demonstrated that patient responsiveness (i.e., tumor elimination at 6 months) trended with the higher G/T ratio patients. In addition, initial biopsies of BCG responsive patients display a higher number of eosinophils and degranulation relative to BCG non-responsive patients. Conclusions: Evaluations of initial biopsies revealed a strong correlation between Th1 and Th2 immune response with BCG therapy outcomes. The development of specific and novel tools to identify/measure Th2 immune responses in Tis bladder cancer provides a unique opportunity to predict outcomes at the time of diagnosis.

214 Background: In our preliminary in vitro studies, we have demonstrated evidence of enhanced apoptosis and inhibition of cellular proliferation in both hormone sensitive and castrate resistant prostate cancer (PCa) cell lines using a combination of an antiandrogen (Bicalutamide) and a selective estrogen receptor modulator (Raloxifene). The aim of this study was to study the effect of the administration of these two drugs in in vivo models of castrate resistant PCa. Methods: In vivo model consisted on NCr Nude: Mice bearing s.c. human prostate (PC3 cell line) xenografts. Based on the treatment received, mice were divided into 5 groups as follows: Group 1: No drugs (control); Group 2: Bicalutamide 50mg; Group 3: Raloxifene 60 mg; Group 4: Combined administration of Bicalutamide 50 mg and Raloxifene 60 mg; Group 5 Combined administration of Bicalutamide 150 mg and Raloxifene 120 mg. A total of 10 mice where included in each group. All drugs dosages were converted to their equivalent in the mice. Drugs were administered by gavage technique to the mice once per day for a total of 14 days. Results: As expected, Bicalutamide administered alone causes minimal inhibition without reaching statistical significance (Group 2: 0.34 g Vs Group 1: 0.40 g; p=0.073). Although Raloxifene causes some marked growth inhibition, its effect is not statistically significant (Group 3: 0.31 Vs Group 1: 0.40 g; p=0.062). Bicalutamide and Raloxifene, when administered in combination, induced prominent growth inhibition in PC3 tumors when compared to the control group (Group 4: 0.26 g Vs Group 1: 0.40 g; p=0.038). Growth inhibition is significantly more evident when the drugs dosages are increased (Group 5: 0.17 g Vs Group 1: 0.40 g; p=0.024). Conclusions: The simultaneous administration of Bicalutamide and Raloxifene appears to have a synergistic effect on tumor growth inhibition in PC3 xenografts. The pathway(s) responsible for this observation may be independent of the androgen receptor as PC3 cells are AR negative and still affected by the combination over the drugs administered alone. Research is warranted to identify these potential pathways.

Purpose: To determine whether on-clamp partial nephrectomy (ON-PN) has any significant impact on long-term renal function in a two kidney model. Patients and Methods: From November 1999 to July 2013, 607 patients underwent PN at our institution. After excluding patients with solitary kidneys, multiple renal masses, and follow-up less than 90 days, 331 remained. Patient demographics were assessed, as was renal function based on pre- and postoperative mercaptoacetyltriglycine (MAG-3) renal scans and change in estimated glomerular filtration rate (eGFR) using the preoperative and most recent recorded creatinine levels. Results: There were a total of 236 patients who underwent ON-PN and 95 who underwent off-clamp PN (OFF-PN) during the study period. The longest follow-up was 12.6 years with mean follow-up of 3 years. Mean ischemia time of patients undergoing ON-PN was 25 minutes (range 8–63 min). No differences were noted between the ON-PN and OFF-PN cohorts with respect to estimated change in eGFR (ON-PN: −6.07 mL/min/1.73 m 2 vs OFF-PN: −6.00 mL/min/1.73 m 2 , P =0.69). No differences were noted in the % change in the MAG-3 renal scans (ON-PN: −0.77% vs OFF-PN: −1.1%, P =0.94). A post hoc sensitivity analysis of the same two variables stratified by age revealed no differences in change in estimated GFR or % change in differential function on renal scan. Conclusions: In the two kidney model, ischemia does not appear to affect long-term renal function outcomes after PN. These data provide evidence that ON-PN is perfectly acceptable in the appropriately selected patient with two kidneys.