Eur Urol Suppl 2011;10(9):617 were divided into 2 groups (≤33% and > 33%) and these groups were compared in terms of perineural invasion. Results: The mean age was 70.29±7.98 years in patients with perineural invasion and 69.95±8.68 in patients without perineural invasion (p=0.095). The mean PSA level was 15.95±14.68 mg/dl in patients with perineural invasion and 38.72 ± 214 in patients without perineural invasion (p=0.473). There was no statistically singnificant difference in terms of age, total PSA, prostate volume, PSA density and rectal examination. However gleason score and positive core percentage were significantly higher in the patient with perineural invasion (respectively p<0.001 and p<0.001). Perineural invasion was significantly high in gleason score >6 and positive core percentage > 33% groups (respectively p<0.001 and p<0.001). Conclusions: Gleason score and positive cor percentage are indicators of poor prognosis in patients with prostate cancer. In this study, we observed a strong correlation between the gleason score and positif core percentage with perineural invasion. We believe that perineural invasion is an important prognostic factor to determine treatment options in patients with prostate cancer. C19 IMMUNOHISTOCHEMICAL EXPRESSION OF CAVEOLIN-1 ON BIOPSY CORES IN DETECTION OF SIGNIFICANT PROSTATE CANCER IN LOW RISK PATIENTS Tomaskovic I. 1 , Tomic M. 1 , Ulamec M. 2 , Kruslin B. 2 , Grubisic I. 1 , Justinic D. 1 , Ruzic B. 1 , Spajic B. 1 , Reljic A. 1 , Trnski D. 1 1 University Hospital „Sestre Milosrdnice“, Dept. of Urology, Zagreb, Croatia, 2 University Hospital „Sestre Milosrdnice“, Dept. of Pathology, Zagreb, Croatia Introduction & Objectives: In this retrospective non-randomized study we examined utility of imunohistochemical expression o caveolin-1 protein on preoperative biopsy cores in detection of significant prostate cancer in low risk patients. The existing preoperative criteria for differentiation between significant and insignificant prostate cancer in low risk patients appear to be inadequate. Material & Methods: 873 patients who underwent radical prostatectomy from 01.01.1998. till 31.12.2007. in our institution were included in the study. 105 patients fulfilled the most stringent preoperative criteria for insignificant protate cancer (PSA ≤ 10 ng/ml, Gleason sum ≤6, ≤33% positive biopsy cores, ≤50% of tumor in a core). Archival paraffin wax embedded prostatic biopsy cores were immunostained for caveolin-1 protein. Preoperative clinicopathological parameters and IHC expression caveolin-1 on tumor tissue in biopsy cores were correlated with tumor significance on postprostatectomy surgical specimens. Insignificant tumor was considered if <5% of final specimen contained tumor and Gleason sum was ≤6. Results: Postoperatively, 49 (46,7%) patients had insignificant and 56 (53.3%) had significant prostate cancer. Mann-Whitney non parametric test showed statisically significant difference in epithelial (p <0,001) and stromal (p =0,001) IHC expression of caveolin-1 between two groups of patients (insignificant vs. significant). Fisher´s exact test showed statisically significant difference between the groups in prostate volume (p=0.030), PSA (p=0,014), PSAD (p=0,014), cancer volume (p<0,001). No difference was found in age (p=0.255), number of biopsy cores (p=0,934) and tumor percentage in the core (p=0.086) between two groups. Conclusions: Epithelial expression of caveolin-1 appeared to be a risk factor for significant prostate cancer in low risk patients. Its´ expression on preoperative biopsy cores might be used as an additional criterion to existing ones in identification of significant prostate cancer in the group of low risk patients. This may influence the selection of therapeutic approach to low risk prostate cancer patients. C20 PROSTATIC LESIONS WITH INVERTED PATTERN Dema A. 1 , Taban S. 2 , Borda A. 3 1 Victor Babes University of Medicine and Pharmacy, Dept. of Pathology, Timisoara, Romania, 2 Clinical Emergency County Hospital, Dept. of Pathology, Timisoara, Romania, 3 University of Medicine and Pharmacy, Dept. of Pathology, Targu Mures, Romania Introduction & Objectives: The inverted pattern, with the polarization change of the secretor cells nuclei, is a very rare finding in prostate lesions, being especially associated with high-grade prostate intraepithelial neoplasia (HG-PIN) foci. This paper presents the morphological aspects, along some immunohistochemisty (IHC) aspects, of the prostate lesions with inverted pattern (hobnail). Material & Methods: We have examined 2,000 consecutive prostatic specimens and we have selected all the prostate lesions with inverted pattern. Additional sections of paraffin blocks for these lesions were immunohistochemically marked with anti-basal cells antibodies (p63 and HMWCK), and with anti-alpha-methylacyl- CoA-racemase (AMACR), EnVision System, DAB. Results: We have observed 5 cases of prostatic specimens, in which the nuclei of the principal cells were, at least focally, oriented to the glandular lumen. The 5 cases were of patients aged between 65 and 78 years. One case was interpreted, based on cytological atypia and on the association with the classical patterns inside the same gland, as inverted HG-PIN associated with poorly differentiated carcinoma, on a transurethral resection (TUR) specimen. In the other 4 cases the architectural modification was detected on TUR fragments (3 cases), in association prostate carcinomas, but not in normal prostatic tissue or other normal tissues. The aim of our study was to explore the diagnostic value of detecting aberrant promoter hypermethylation of GSTP1 gene in serum samples from patients with the diagnostic of prostate adenocarcinoma, as a noninvasive epigenetic biomarker for early molecular detection of PCa. Material & Methods: For our study we collected serum samples from 34 patients with the histologically confirmed cases of prostate adenocarcinoma, Gleason score in a range of 3 to 9, and serum PSA was in a range of 4 ng/ml to 28 ng/ml, and 54 cases with BPH. Patients with BPH were used as control subjects. Genomic DNA was extracted from serum samples using Zymo Research Serum DNA kit™. To evaluate the methylation status of the GSTP1 gene we used the methylation- specific PCR (MSP) method. Results: By MSP method the GSTP1 promoter hypermethylation was detected in 32 from 34 PCa samples (94.12%), whereas none of the BPH samples showed aberrant methylation. Conclusions: GSTP1 promoter hypermethylation distinguishes between PCa and BPH, and thus it could be used as an epigenetic biomarker for PCa screening and early molecular detection of this disease. C17 PROSTATE TARGETED BIOPSY USING CADENCE- CONTRAST PULSE SEQUENCING TECHNOLOGY Jinga V. 1 , Budau M. 2 , Braticevici B. 1 , Radavoi G.D. 1 , Calin C. 1 , Badescu D. 1 , Diaconescu D. 1 , Onu M. 2 1 “Th. Burghele Hospital”, Dept. of Urology, Bucharest, Romania, 2 “Th. Burghele Hospital”, Dept. of Radiology, Bucharest, Romania Introduction & Objectives: Transrectal ultrasound-guided needle biopsy of the prostate may not reveal an important amount of clinically relevant cancers. Cancer tissue shows an increased in microvessel density and abnormal pattern of vascularity. Ultrasound contrast agents allow for a more complete delineation of the neovascular anatomy by enhancing the signal strength from small vessels. Cadence contrast pulse sequencing technology (CPS) is using a low mechanical index which protects the microbubbles and increase the parenchimal enhancement provided by ultrasonographic contrast agent. The aim of this study is to compare the prostate cancer detection rate of CPS-targeted biopsies with conventional ultrasound guided systematic biopsies. Material & Methods: A prospective study was performed on 54 men, mean age 62,5 (range 48-75), referred for prostate biopsy due to an increased PSA or abnormal DRE. During the administration of the ultrasound contrast agent (SonoVue, Bracco - 2.4 ml i.v. bolus injection, with a maximum dose of 4.8 mL), a prostate scanning was performed, from base to the apex, to assess suspicious enhancing areas of the peripheral zone. We have seen a rapid and increased contrast enhancement in only 33 patients (61,11%) and these patients were subjected to CPS-guided targeted biopsies (5 or less cores). Subsequently a 10 core systematic biopsy was taken in all 54 men. Results: CPS-targeted biopsy revealed cancer in 20 of 33 patients (60,60%) and overal detection rate using targeted biopsies was 37,03% (20/54). Systematic biopsy detected cancer in 17 of the 54 patients (31,48%). Sensitivity in PCa detection was 86,9% for CPS-targeted biopsy (20/23) and 73,91% (17/23) for systematic biopsy. Cancer was detected by targeted biopsy alone in 6 patients and by systematic biopsy alone in 3 patients. CPS-targeted cores were positive in 44 of 114 cores (38,59%) and in 42 of 540 (7,77%) systematic biopsy cores. Conclusions: 1. CPS-targeted biopsy are superior to systematic prostate biopsy in CaP detection. The targeted approach detect more cancers with a lower number of biopsy cores. 2. An increase in cancer detection was achieved by combining targeted and systematic techniques3. CPS-technique allow for the detection of patients with a very high likelihood of having prostate cancer C18 RELATIONSHIP BETWEEN THE POSITIVE CORE PERCENTAGE AND GLEASON SCORE WITH PERINEURAL INVASION IN PATIENT WITH PROSTATE CANCER ON PROSTATE BIOPSY Gorgel S.N. 1 , Ozdamar Y.K. 2 , Kara C. 1 , Ozer K. 1 1 Izmir Ataturk Training and Research Hospital, Dept. of 1st Urology Clinic, Izmir, Turkey, 2 Manisa Merkez Efendi State Hospital, Dept. of Urology, Manisa, Turkey Introduction & Objectives: We investigated relationship between the positive core percentage and gleason score with perineural invasion (PNI) in patients who underwent transrectal ultrasonography (TRUSG) guided prostate biopsy because of high prostate specific antigen (PSA) values and abnormal digital rectal examination. Material & Methods: A total of 1135 patients underwent 10-quadrant TRUSG guide prostate biopsy because of high PSA values and abnormal digital rectal examination in our clinic between 2004-2011. Prostate adenocarcinoma was detected in 274 patients (24.14%). Perineural invasion was demonstrated in 46 (16.78%) of prostate carcinoma cases. Cases with and without PNI were compared in terms of age, total PSA, prostate volume, PSA density, gleason score, positive core percentage and rectal examination. Patients were divided into 2 groups of total gleason score ≤6 and total gleason score >6, also positive core percentages