maximum tumor length 50% on any core, and tumor volume 5% of biopsy volume. Regularly scheduled follow-up visits including PSA, PCA3, physical examination, and biopsies were performed. RESULTS: A total of 138 patients were considered for enroll- ment over two years. Two men subsequently decided to be treated without enrolling, 19 were deemed ineligible on confirmation biopsies, and 4 demonstrated disease progression. Total serum mean PSA ranged from [3.72-4.68] with SD [2.25-2.64], free PSA 0.77 with SD 0.57. Median enrollment PCA3 was [47.56] with SD of 58.75. Longitu- dinal trend revealed a significant change of both PSA and PCA3 from baseline. At 12 and 15 months PSA showed a significant increase (0.71 and 0.48 respectively) compared to enrollment level (Bonferroni ad- justed p=0.002). Similarly PCA3 increased significantly at 6 and 12 months compared to enrollment level by 8.17 and 12.81 points respec- tively. (Bonferroni adjusted p=0.075). On univariate analysis, neither PSA levels nor PCA3 scores varied by number of positive cores 1 vs. 2 vs. 3 (p0.05). CONCLUSIONS: Based on our longitudinal follow-up in men with stable disease on AS, both PSA and PCA3 show significant increases with time. In light of stable disease proven on surveillance biopsies, these increases in biochemical markers may not be clinically significant for men with low risk disease on AS. Source of Funding: None 1633 TARGETING THE NEURAL MICROENVIRONMENT IN PROSTATE CANCER: A NEOADJUVANT BOTOX CLINICAL TRIAL Gustavo Ayala*, Diego Florentin, Jason K. Au, Yi Ding, Dandan He, Chad J. Creighton, Anna Frolov, Olga Dakhova, Yiqun Zhang, Christopher Smith, Dov Kadmon, Brian Miles, Michael Ittmann, David Rowley, Houston, TX INTRODUCTION AND OBJECTIVES: Nerve-cancer interac- tion provides a survival advantage for prostate cancer through perineu- ral invasion, neurogenesis, and regulation of epithelial homeostasis. Physical and chemical (Botox) denervation affect tumor growth in vivo, using similar mechanisms. As clinical translation and proof-of-concept study, we next evaluated tissues from three patients enrolled in a Phase I clinical trial to assess the effects of Botox injections on specific endpoints of prostate tumor biology. METHODS: Patients with bilateral Gleason 6-7 tumors received unilateral Botox injections (100 U in a 2.0-ml volume) into one lobe and a vehicle control injection into the contralateral lobe. Radical prostatec- tomy was performed 4 weeks later and biological endpoints studied in the pathologic specimen. RESULTS: Examination of tissues revealed a general atrophic effect in prostate cancer cells obtained from Botox-injected lobes. Vehicle control lobes exhibited a typical Gleason 6-7 histopathology. We also identified extensive degenerative features, as evidenced by reduced cytoplasm and pyknotic nuclei, compared to features in saline- injected cancer tissues. TUNEL studies revealed a significant increase in the apoptotic ratio in the botox side than saline injected tumor. No significant changes were observed in the proliferation index, measured by Ki67. Microvessel density was increased in the tumor of 1 patients, no changes were observed in 2 patients. Nerve density was significantly decreased in the tumor of 1 patient and a trend toward decrease in another. These data suggest that Botox has an atrophic effect on the nerves, without affecting the tumor vasculature in human prostate cancer. The gene profile of the Botox treated tumors had extensive similarities with those of prostate cancer arising in patients with spinal cord injury, confirm- ing that the effect is due mainly to denervation. CONCLUSIONS: Together, previous experimental tumor study, preliminary Phase I Clinical trial study, and gene expression analysis of prostate tumors from patients with spinal cord injuries suggest that the nerve-cancer cell interaction is a key and critical element in prostate cancer cell survival and tumorigenicity. Targeting the neural microen- vironment is becoming a necessity. Botox, as a chemical denervation agent, has effects on human prostate cancer. The Botox strategy could be easily translated to an active surveillance cohort. Source of Funding: This work was supported by National Institutes of Health grant TMEN U54CA126568-01 and a Prostate Cancer Foundation Creativity Award. We acknowledge the joint participation of the Diana Helis Henry Medical Research Foundation. 1634 PROSTATE CANCER DETECTION USING REAL-TIME TISSUE ELASTOGRAPHY IN PATIENTS WITH LOWER PSA LEVELS Masahiro Sumura*, Haruki Anjiki, Chiaki Kobara, Keita Inoue, Naoko Arichi, Yozo Mitsui, Takeo Hiraoka, Satoshi Honda, Hiroaki Yasumoto, Hiroaki Shiina, Takeshi Yoshizako, Hajime Kitagaki, Mikio Igawa, Izumo, Shimane, Japan INTRODUCTION AND OBJECTIVES: Although PSA is the gold standard examination for prostate cancer screening, could the disease also occurs in patients with lower PSA levels.No imaging modality is able to visualize prostate cancer foci precisely for use in focal therapy. Real-time tissue elastography (RTE) is a recently devel- oped novel approach for revealing prostate cancer based on tissue elasticity. We investigated whether objective analysis of prostate tissue elasticity using real-time tissue elastography (RTE) is more useful to detect localized prostate cancer (PC) than a conventional approach with a PC-detection screening program. METHODS: Of 306 patients who underwent a needle biopsy of the prostrate at our institute, 57 with PSA 4 ng/ml (474 samples) were enrolled in this study. Median age was 72 years old (range 38-87 years) and median PSA level was 3.953 ng/ml (range 0.7-3.9 ng/ml). All patients underwent TRUS, power Doppler ultrasonogra- phy (PDUS), RTE, and MRI examinations prior to the biopsy, and none had a known history of prostate carcinoma. An EUB-7500 ultrasound system (Hitachi Medical/Chiba, Japan) equipped with 4- and 8-MHz end-fire transducers was utilized for prostate ultrasonog- raphy examinations, while a 1.5T MR device (Signa, GE Medical Systems, Milwaukee, WI) and phased array type external surface coil were used for prostate MRI. A single urologist evaluated the utility of RTE, gray-scale, PDUS, RTE, and MRI (T2WI, DCE-MRI, DWI) findings obtained prior to the biopsy by comparing among those modalities and the biopsy findings. RESULTS: Prostate cancer was detected in 19 of 57 patients (33.3%) and 49 of 474 samples (10.3%). Clinical stage was T1c in 5, T2a in 8, T2b in 3, T2c in 1, and T3a in 2 cases. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of RTE were 68.3%, 98.4%, 80.0%, 97.0%, and 95.7%, respectively, while those were 61%, 98.6%, 80.6%, 96.3%, and 95.3%, respectively, for DCE-MRI, and 61.0%, 98.1%, 75.8%, 96.3%, and 94.8%, respectively, for DWI. All results related to the diagnostic probability of PC detection were higher for RTE than for PDUS or TRUS, and RTE was not inferior to T2WI, DCE-MRI, and DWI. CONCLUSIONS: Even in patients with lower PSA levels, RTE was able to detect prostate cancer and found to be not inferior to MRI, currently considered to be the best modality to reveal prostate cancer. Source of Funding: None 1635 AN UPDATE OF PROGRESSION FREE SURVIVAL (PFS) OF LOCALLY ADVANCED PROSTATE CANCER AMONG AFRICAN AMERICAN AND EUROPEAN AMERICAN MEN WHO HAVE UNDERGONE RADICAL PROSTATECTOMY (RP) Isaac Powell*, Lance Heilbrun, Daryn Smith, Susan Bolton, Samuel Kieley, Cathryn Bock, Detroit, MI INTRODUCTION AND OBJECTIVES: Introduction: In the past we have reported that prostate cancer (PCa) biochemical recurrence e660 THE JOURNAL OF UROLOGY Vol. 187, No. 4S, Supplement, Tuesday, May 22, 2012