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Background: Propionibacterium acnes has recently been implicated as a cause of chronic prostatitis and this commensal bacterium may be linked to prostate carcinogenesis. The occurrence of intracellular P. acnes infection in prostate glands and the higher frequency of P. acnes-positive glands in radical prostatectomy specimens from patients with prostate cancer (PCa) than in those from patients without PCa led us to examine whether the P. acnes-positive gland frequency can be used to assess the risk for PCa in patients whose first prostate biopsy, performed due to an increased prostate-specific antigen (PSA) titer, was negative., Methods: We retrospectively collected the first and last prostate biopsy samples from 44 patients that were diagnosed PCa within 4 years after the first negative biopsy and from 36 control patients with no PCa found in repeated biopsy for at least 3 years after the first biopsy. We evaluated P. acnes-positive gland frequency and P. acnes-positive macrophage number using enzyme-immunohistochemistry with a P. acnes-specific monoclonal antibody (PAL antibody)., Results: The frequency of P. acnes-positive glands was higher in PCa samples than in control samples in both first biopsy samples and in combined first and last biopsy samples (P < 0.001). A frequency greater than the threshold (18.5 and 17.7, respectively) obtained by each receiver operating characteristic curve was an independent risk factor for PCa (P = 0.003 and 0.001, respectively) with odds ratios (14.8 and 13.9, respectively) higher than those of serum PSA titers of patients just before each biopsy (4.6 and 2.3, respectively). The number of P. acnes-positive macrophages did not differ significantly between PCa and control samples., Conclusions: These results suggested that the frequency of P. acnes-positive glands in the first negative prostate biopsy performed due to increased PSA titers can be supportive information for urologists in planning repeated biopsy or follow-up strategies., Competing Interests: The authors have declared that no competing interests exist.

Objectives: To identify prostatic quadrants that could be preserved without intervention, using diffusion-weighted magnetic resonance imaging (DWI) and extended core biopsy, as a step toward implementation of quadrant-based focal ablation with potential preservation of erectile and ejaculatory functions, based on comparisons with unilateral hemi-gland ablation., Patients and Methods: We conducted a prebiopsy DWI study including 648 quadrants in 162 men who underwent 14-core biopsy including anterior sampling and radical prostatectomy (RP) for localised cancer. Imaging and pathology were analysed on a quadrant basis. Each quadrant was assessed through four-core sampling. Predictive performance of DWI and biopsy for quadrant status was analysed., Results: On RP specimens, 170 anterior (52.5%) and 172 posterior quadrants (53.1%) harboured significant cancer. Negative predictive values of DWI, biopsy, and their combination for significant cancer were 79.7%, 70.6%, and 91.1%, respectively, in anterior quadrants, and 78.5%, 81.3%, and 91.7%, respectively, in posterior quadrants. DWI incrementally improved the negative predictive values of biopsy in anterior (P < 0.001) and posterior quadrants (P = 0.025), without untoward impacts on positive predictive values. Negative findings on both DWI and biopsy were identified in posterior quadrants of 109 sides (33.6%), but in entire hemi-glands of 54 sides (16.7%)., Conclusions: The combination of DWI and 14-core biopsy including anterior sampling efficiently identifies quadrants without significant cancer in men with localised prostate cancer; the remaining quadrants, therefore, could be potential candidate areas for focal ablation. Focal therapy designed based on quadrant-based assessment could be superior to unilateral hemi-gland ablation for preservation of posterior quadrants and retaining of sexual function in more sides., (© 2014 The Authors BJU International © 2014 BJU International Published by John Wiley & Sons Ltd.)

Background: Recent reports on Propionibacterium acnes (P. acnes) suggest that this bacterium is prevalent in the prostate, is associated with acute and chronic prostatic inflammation, and might have a role in prostate carcinogenesis., Methods: To evaluate the pathogenic role of this indigenous bacterium, we screened for the bacterium in radical prostatectomy specimens using enzyme immunohistochemistry with a novel P. acnes-specific monoclonal antibody (PAL antibody), together with an anti-nuclear factor-kappa B (NF-κB) antibody. We examined formalin-fixed and paraffin-embedded tissue sections of radical prostatectomy specimens from 28 patients with prostate cancer and 18 age-matched control patients with bladder cancer, but without prostate cancer., Results: Immunohistochemistry with the PAL antibody revealed small round bodies within some non-cancerous glandular epithelium and stromal macrophages in most prostate samples. Prostate cancer samples had higher frequencies of either cytoplasmic P. acnes or nuclear NF-κB expression of glandular epithelium and higher numbers of stromal macrophages with P. acnes than control samples. These parameters were also higher in the peripheral zone than in the transitional zone of the prostate, especially in prostate cancer samples. Nuclear NF-κB expression was more frequent in glands with P. acnes than in glands without P. acnes. The number of stromal macrophages with the bacterium correlated with the grade of chronic inflammation in both the PZ and TZ areas and with the grade of acute inflammation in the TZ area., Conclusions: Immunohistochemical analysis with a novel monoclonal antibody for detecting P. acnes in the prostate suggested that intraepithelial P. acnes infection in non-cancerous prostate glands and inflammation caused by the bacterium may contribute to the development of prostate cancer.

Background: Significant cancer in contralateral sides of the prostate that was missed on prostate biopsy (PBx) is a concern in hemiablative focal therapy (FT) of prostate cancer (PCa). However, extended PBx, a common diagnostic procedure, has a limited predictive ability for lobes without significant cancer., Objective: To identify prostate lobes without significant cancer using extended PBx combined with diffusion-weighted imaging (DWI), which has the potential to provide pathophysiologic information on pretreatment assessment., Design, Setting, and Participants: We conducted a prebiopsy DWI study between 2007 and 2012 that included 270 prostate lobes in 135 patients who underwent radical prostatectomy (RP) for clinically localized PCa., Intervention: Participants underwent DWI and 14-core PBx; those with PBx-proven PCa and who were treated with RP were analyzed., Outcome Measurements and Statistical Analysis: Imaging and pathology were assessed in each side. Based on RP pathology, lobes were classified into lobes with no cancer (LNC), lobes with indolent cancer (LIC), and lobes with significant cancer (LSC). Predictive performance of DWI, PBx, and their combination in identifying lobes without significant cancer was examined., Results and Limitations: LNC, LIC, and LSC were identified in 23 (8.5%), 64 (23.7%), and 183 sides (67.8%), respectively. The negative predictive values (NPV) of DWI, PBx, and their combination were 22.1%, 27.8%, and 43.5%, respectively, for lobes with any cancer (ie, either LIC or LSC), and 68.4%, 72.2%, and 95.7%, respectively, for LSC. The NPV of PBx for LSC was improved by the addition of DWI findings (p=0.001), with no adverse influence on the positive predictive value. Limitations included a possible selection bias under which the decision to perform PBx might be affected by DWI findings., Conclusions: The combination of DWI and extended PBx efficiently predicts lobes without significant cancer. This procedure is applicable to patient selection for hemiablative FT., (Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Study Type - Prognosis (inception cohort) Level of Evidence 2 What's known on the subject? and What does the study add? The criteria used for selecting patients with prostate cancer for active surveillance (AS) are still not satisfactory due to the difficulty in predicting the significance of the prostate cancer. Urologists could predict insignificant prostate cancer by incorporating cumulative cancer length and biopsy Gleason score, derived from extended biopsy. The present study has added new criteria for predicting insignificant prostate cancer, which would lead to a better selection of candidates for AS. OBJECTIVE To develop extended biopsy based criteria for predicting insignificant cancer (IC) using extended biopsy findings., PATIENTS AND METHODS From 2000 to 2009, 1575 patients with prostate cancer were primarily treated by radical prostatectomy in two referral hospitals., Of these, the study cohort comprised 499 patients with extended biopsy confirmed, clinically organ-confined (cT1-2N0M0) prostate cancer with PSA levels of <20 ng/mL., Cancer information obtained through extended biopsy included cumulative cancer length (CCL) divided by the number of biopsy cores (CCL/core)., RESULTS Pathological examination revealed 39 ICs (7.8%). All these ICs fell in a category of prostate cancer with clinical stage ≤T2a and 2005 International Society of Urological Pathology Consensus Conference (ISUP) modified biopsy Gleason score ≤7., Accordingly, we analysed predictors of IC in a subset cohort of 370 patients in this category. A multivariate logistic regression analysis revealed that 2005 ISUP modified biopsy Gleason score and CCL/core were independently significant predictors of IC., We determined a threshold value of CCL/core of 0.20 mm for predicting IC using receiver operating characteristic analysis., Based on these findings, we developed simple extended biopsy based criteria for predicting IC as follows: (i) PSA level of <20 ng/mL; (ii) Clinical stage ≤T2a; (iii) 2005 ISUP modified biopsy Gleason score ≤6; (iv) CCL/core of <0.20 mm., The specificity of the criteria was 91%, which was significantly higher than the value from a subset of criteria without item iv ( P < 0.001)., CONCLUSION We have developed extended biopsy based criteria for predicting IC incorporating the 2005 ISUP modified biopsy Gleason score and CCL/core. [ABSTRACT FROM AUTHOR]