Ohseong Kwon

Salvage radiotherapy after radical prostatectomy: prediction of biochemical outcomes.

Introduction A significant proportion of patients undergoing salvage radiotherapy (RT) for biochemical recurrence (BCR) following radical prostatectomy (RP) may again experience BCR after salvage RT. Thus, we evaluated the clinical significances of different parameters on the biochemical outcome of RT in salvage setting. Methods We reviewed the records of 212 patients who underwent salvage RT between November 2003 and December 2012 for BCR following primary RP. BCR-free survivals after salvage RT were estimated using the Kaplan–Meier method. Cox proportional hazard regression models were used to evaluate the impacts of clinicopathologic parameters on BCR following salvage RT. Results The overall median follow-up duration was 63.5 months. The BCR-free survival rate after salvage RT was 58.2% at 5 years. Multivariate analysis showed that a pre-RT prostate-specific antigen (PSA) level of ≤0.5 ng/mL, a pre-RT PSA doubling time (PSADT) of >4.5 months, concomitant androgen deprivation therapy (ADT) with salvage RT, and a positive surgical margin were independent predictors of favorable biochemical outcomes after salvage RT (hazard ratios [HR] = 3.012, 1.132, 2.000, and 1.805, respectively, p = less than 0.001, 0.013, 0.005, and 0.036, respectively). In the early (pre-RT PSA ≤0.5 ng/mL) salvage RT setting, concomitant ADT administration was also shown to be significantly associated with higher risk of BCR-free survival following salvage RT (HR = 2.611, p = 0.038). Conclusion Lower pre-RT PSA value, longer PSADT before salvage RT, concomitant ADT administration, and a positive surgical margin were significant predictors of favorable biochemical outcomes following salvage RT performed for BCR after primary RP.

Can contemporary patients with biopsy Gleason score 3+4 be eligible for active surveillance?

Introduction We analyzed whether expansion of existing active surveillance (AS) protocols to include men with biopsy Gleason score (GS) 3+4 prostate cancer (PCa) would significantly alter pathologic and biochemical outcomes of potential candidates of AS. Methods Among patients who underwent radical prostatectomy at our center between 2006 and 2013, we identified 577 patients (group A) who preoperatively fulfilled at least one of 6 different AS criteria. Also, we identified 217 patients (group B) with biopsy GS 3+4 but fulfilled non-GS criteria from at least one of 6 AS criteria. Designating group C as expanded group incorporating all patients in group A and B, we compared risk of unfavorable disease (pathologic GS ≥4+3 and/or pathologic T stage ≥pT3a) and biochemical recurrence (BCR)-free survival between groups. Results Rates of unfavorable disease were not significantly different between patients of group A and C who met AS criteria from 5 institutions (all p>0.05), not including University of Toronto (p<0.001). Also BCR-free survivals were not significantly different between patients in group A and C meeting each of 6 AS criteria (all p>0.05). Among group B, PSAD>0.15 ng/mL/cm3 (p = 0.011) and tumor length of biopsy GS 3+4 core>4 mm (p = 0.007) were significant predictors of unfavorable disease. When these two criteria were newly applied in defining group B, rates of unfavorable disease in group A and B was 15.6% and 14.7%, respectively (p = 0.886). Conclusion Overall rate of pathologically aggressive PCa harbored by potential candidates for AS may not be increased significantly with expansion of criteria to biopsy GS 3+4 under most contemporary AS protocols. PSAD and tumor length of biopsy GS 3+4 core may be useful predictors of more aggressive disease among potential candidates for AS with biopsy GS 3+4.

MP72-04 CAN PARTIAL NEPHRECTOMY PROVIDE EQUAL ONCOLOGICAL EFFICIENCY AND SAFETY COMPARED WITH RADICAL NEPHRECTOMY IN PATIENTS WITH RENAL CELL CARCINOMA (= 4 CM)? A PROPENSITY SCORE MATCHED STUDY

Zachary Hamilton*, San Diego, CA; Alessandro Larcher, Milan, Italy; Brian Lane, Grand Rapids, MI; Umberto Capitanio, Milan, Italy; Sumi Dey, Grand Rapids, MI; Aaron Bloch, Charles Field, San Diego, CA; Samer Kirmiz, Grand Rapids, MI; Daniel Han, San Diego, CA; Adam Bezinque, Grand Rapids, MI; Alp Tuna Beksac, San Diego, CA; Cristina Carenzi, Milan, Italy; Fang Wan, James Proudfoot, San Diego, CA; Francesco Montorsi, Milan, Italy; Ithaar Derweesh, San Diego, CA

PD61-07 ACCURACY OF PREOPERATIVE MULTIPARAMETRIC MAGNETIC RESONANCE IMAGING FOR PREDICTION OF UNFAVORABLE PATHOLOGY IN PATIENTS WITH LOCALIZED PROSTATE CANCER UNDERGOING RADICAL PROSTATECTOMY

Introduction We investigated the accuracy of multiparametric MRI (mpMRI) for preoperative staging and its influence on the determination of neurovascular bundle sparing and disease prognosis in patients with localized prostate cancer.

MP27-07 CAN WE PREDICT THE LEARNING CURVE FOR HOLMIUM LASER ENUCLEATION OF THE PROSTATE (HOLEP) BY USING SIMULTANEOUS PARAMETER OF ENUCLEATION-MORCELLATION?

INTRODUCTION AND OBJECTIVES: Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive laser therapy for benign prostatic hyperplasia. However, a steep operative learning curve may be the main drawback to use of HoLEP. The enucleation ratio or efficacy were known as one of the parameters for estimating the learning curve. But this parameter is only focused on time of enucleation not considering morcellation, even though operators spend time of enucleation and morcellation simultaneously during HoLEP surgery. The aim of this study was to evaluate a various method to assess the learning curve of HoLEP of a single surgeon. METHODS: Ninety-two consecutive cases performed by the single surgeon were enrolled. Intraoperative measures, including enucleation time, enucleation ratio (enucleated weight/transitional zone volume), enucleation efficacy (enucleated weight / enucleation time), consumed energy, morcellation time, morcellation efficacy (enucleated weight / morcellation time) and enucleationmorcellation efficacy (enucleated weight/enucleation and morcellation time) were analyzed. Perioperative morbidity, length of hospital stay and length of urinary drainage were also investigated. In addition, functional outcomes such as Qmax, post-void residual volume, IPSS and QoL scores at 3 and 6months were also investigated. RESULTS: The mean age of the patients was 72.9 years (49-86) with a mean prostate volume of 59.2 cc (34-180) on transrectal ultrasonography. Within all procedures, mean total operative time was 86.5 minutes (45-260 minutes) with a mean enucleated weight of 42.2 g (25-120 g). Mean enucleation time, consumed energy, morcellation time and enucleation ratio were 48.9 12.1 min, 67.5 22.8 kJ, 22.4 14.5 min and 0.64 0.32 g/mL, respectively. In terms of efficiency, enucleation efficacy, morcellation efficacy and enucleation-morcellation efficacy were 0.42 0.37 g/min, 4.24 1.26 g/min and 0.24 0.11 g/min, respectively. Perioperative complications were observed in 12 of 92 (13.0%). Of these, 10 were urinary tract infection and 2 was urethral stricture. Considering the learning curve, the plateau of enucleation efficacy was reached after 38 cases. However, considering enucleation and morcellation time simultaneously, enucleationmorcellation efficacy has an increasing trend even after 38 cases and has remained roughly constant after 55 cases. Based on these criteria, we divided cases into two groups. Enucleation efficiency was significantly higher after 38 cases. Morcellation efficiency was also higher in the second group, however, the difference was not significant. Enucleation-morcellation efficiency was significantly higher after 55 cases. Perioperative morbidities, hospital length of stay, urinary drainage length and functional outcomes at 3 and 6months were not significantly different between the groups based on these criteria. CONCLUSIONS: Although the learning curve did not interfere with functional results, our results demonstrated that even after 38 cases, surgical skill advances are still needed. Of these factors, morcellation time is as important as enucleation time in the whole surgical procedure. Enucleation-morcellation efficacy might be considered a better parameter for estimating the operative learning curve of HoLEP rather than enucleation efficacy alone.

MP86-08 EFFECT OF COMBINATION THERAPY WITH NERVE GROWTH FACTOR AND BASIC FIBROBLAST GROWTH FACTOR IN A RAT MODEL OF CAVERNOUS NERVE INJURY

INTRODUCTION AND OBJECTIVES: We investigated combined therapeutic efficacy of human adipose-derived stem cells (h-ADSCs) application on injured cavernous nerve and low-energy shockwave therapy (SWT) on the corpus cavernosum in a rat model of post-prostatectomy erectile dysfunction. METHODS: Rats were randomly divided into five groups: Control, BCNI (bilateral cavernous nerve injury), ADSC (BCNI group with h-ADSCs on the cavernous nerve), SWT (BCNI group with lowenergy SWT on the corpus cavernosum), and ADSC/SWT (BCNI group with a combination of h-ADSCs and low-energy SWT). After four weeks, erectile function was assessed using intracavernosal pressure (ICP). The cavernous nerves and penile tissue were evaluated through immunostaining, western blotting and a cyclic guanosine monophosphate (cGMP) assay. RESULTS: ADSC/SWT significantly improved ICP compared to the other experimental group. ADSC had significantly increased ß-III tubulin expression of cavernous nerve, and SWT had markedly enhanced vascular endothelial growth factor (VEGF) expression in corpus cavernosum. The ADSC/SWT group had a significantly increased in alpha smooth muscle content (P <.05), neural nitric oxide synthase (nNOS) of the dorsal penile nerve (P <.05), endothelial nitric oxide synthase (eNOS) protein expression (P <.05), and cGMP level (P <.05) compared to ADSC or SWT alone group. In addition, ADSC/SWT reduces the apoptotic index in corpus cavernosum. CONCLUSIONS: In this study, h-ADSCs showed effect on recovery of injured cavernous nerve and low-energy SWT improved angiogenesis in the corpus cavernosum. The h-ADSCs combined with low energy SWT showed beneficial effect on the recovery of erectile function in a rat model of post-prostatectomy erectile dysfunction.