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The statin family of cholesterol-lowering drugs has been shown to induce tumor-specific apoptosis by inhibiting the rate-limiting enzyme of the mevalonate (MVA) pathway, HMG-CoA reductase (HMGCR). Accumulating evidence suggests that statin use may delay prostate cancer (PCa) progression in a subset of patients; however, the determinants of statin drug sensitivity in PCa remain unclear. Our goal was to identify molecular features of statin-sensitive PCa and opportunities to potentiate statin-induced PCa cell death. Deregulation of HMGCR expression in PCa was evaluated by immunohistochemistry. The response of PCa cell lines to fluvastatin-mediated HMGCR inhibition was assessed using cell viability and apoptosis assays. Activation of the sterol-regulated feedback loop of the MVA pathway, which was hypothesized to modulate statin sensitivity in PCa, was also evaluated. Inhibition of this statin-induced feedback loop was performed using RNA interference or small molecule inhibitors. The achievable levels of fluvastatin in mouse prostate tissue were measured using liquid chromatography–mass spectrometry. High HMGCR expression in PCa was associated with poor prognosis; however, not all PCa cell lines underwent apoptosis in response to treatment with physiologically-achievable concentrations of fluvastatin. Rather, most cell lines initiated a feedback response mediated by sterol regulatory element-binding protein 2 (SREBP2), which led to the further upregulation of HMGCR and other lipid metabolism genes. Overcoming this feedback mechanism by knocking down or inhibiting SREBP2 potentiated fluvastatin-induced PCa cell death. Notably, we demonstrated that this feedback loop is pharmacologically-actionable, as the drug dipyridamole can be used to block fluvastatin-induced SREBP activation and augment apoptosis in statin-insensitive PCa cells. Our study implicates statin-induced SREBP2 activation as a PCa vulnerability that can be exploited for therapeutic purposes using clinically-approved agents. • High HMGCR protein expression in prostate cancer is associated with poor prognosis. • Statin-mediated HMGCR inhibition induces apoptosis in a subset of prostate cancer cells. • Statin-induced SREBP2 activation modulates statin sensitivity in prostate cancer. • Inhibiting SREBP2 sensitizes prostate cancer cells to statin-induced apoptosis. • Combined statin and dipyridamole therapy significantly delays prostate tumor growth. [ABSTRACT FROM AUTHOR]

Aims: Intraductal and cribriform carcinoma of the prostate are increasingly recognised as independent prognosticators of poor outcome, both in prostate biopsies and surgical specimens. We studied the concordance of biopsy and prostatectomy diagnosis for these two subpathologies in relationship with pathological stage. Methods and results: Mandatory synoptic reporting of intraductal and cribriform carcinoma in prostate biopsies and prostatectomy specimens was adopted by two academic institutions in November 2015. Synoptic reports of 245 biopsy and corresponding prostatectomy specimens were interrogated to determine the prevalence of intraductal and cribriform carcinoma. Sensitivity and specificity were determined, with prostatectomy diagnosis as the gold standard. Associations with pathological stage as primary outcome parameter were determined using univariable and multivariable logistic regression analysis. Prevalence of the combination of intraductal and cribriform carcinoma was 26.9% in biopsies and 51.8% in prostatectomy specimens. Sensitivity and specificity at biopsy were 47.2% and 94.9%, respectively. Intraductal and cribriform carcinoma at biopsy were associated with advanced pathological stage independent of grade (P = 0.013). Among patients with grade group 2 prostate cancer at biopsy, the more advanced pathological stage distribution was similar for those with a false negative and a true positive biopsy diagnosis of intraductal and cribriform carcinoma (P = 0.29). Conclusion: In spite of low sensitivity, intraductal and cribriform carcinoma at biopsy was associated strongly with advanced stage at radical prostatectomy. As a false negative biopsy diagnosis was equally associated with advanced pathological stage, efforts should be undertaken to improve the sensitivity of biopsy diagnosis for intraductal and cribriform carcinoma. [ABSTRACT FROM AUTHOR]

Purpose Longitudinal cohort studies and guidelines demonstrate that prostate specific antigen 1 ng/ml or greater in younger patients confers an increased risk of delayed prostate cancer death. At our institution we have used an aggressive biopsy strategy in younger patients with prostate specific antigen 1 ng/ml or greater. Our objective was to determine the proportion of detected cancer and specifically clinically significant cancer by this strategy. Materials and Methods The prostate biopsy database at Princess Margaret Cancer Centre was queried for patients younger than 50 years who underwent a first prostate biopsy between 2000 and 2016. We included only patients who underwent prostate biopsy due to prostate specific antigen 1 ng/ml or greater and those with a suspicious digital rectal examination, a positive family history or a suspicious lesion on transrectal ultrasound. All clinical and pathological parameters were analyzed. Patients were stratified according to specific prostate specific antigen values. Multivariable logistic regression was performed to ascertain predictors of any prostate cancer diagnosis and of clinically significant prostate cancer. Results Of the 199 patients who met study inclusion criteria 37 (19%) were diagnosed with prostate cancer and 8 (22%) had a Gleason score of 7 or greater. Of those diagnosed with prostate cancer 25 (68%) had prostate specific antigen 1.5 ng/ml or greater and all men with a Gleason score of 7 or greater had prostate specific antigen 1.5 ng/ml or greater. Notably 19 patients (51%) had prostate cancer exceeding the Epstein criteria for active surveillance. Factors predicting prostate cancer included a positive family history, rising prostate specific antigen and lower prostate volume. Conclusions Our results justify adopting an aggressive prostate biopsy strategy in men younger than 50 years with prostate specific antigen 1.5 ng/ml or greater while patients with prostate specific antigen less than 1.5 ng/ml are unlikely to have significant cancer. Special attention should be given to patients with a smaller prostate and a positive family history. [ABSTRACT FROM AUTHOR]

Background: The mammalian target of rapamycin (TOR) is a serine/threonine protein kinase which associates with regulatory-associated protein of TOR (RAPTOR), forming the mTORC1 complex, which is necessary for activation of the TOR pathway. 14-3-3s belongs to a family of proteins known to regulate the mTOReRAPTOR interaction and signalling of this cascade. The TOR pathway is a key regulator of protein synthesis and growth and is up-regulated in many cancers. The correlation of TOR, RAPTOR and 14-3-3s in high grade prostatic intraepithelial neoplasia (HGPIN) and prostate cancer has not previously been investigated. Aims: To examine the immunohistochemical expression of phosphorylated TOR (p-TOR), RAPTOR and 14-3- 3s in HGPIN and prostatic adenocarcinoma (PCa) using tissue microarrays. Methods and results: There were contrasting immunohistochemical patterns of expression for TOR and 14-3-3s in HGPIN and PCa. CochraneArmitage analysis demonstrated decreasing p-TOR and increasing 14-3-3s expression, progressing from PIN through GL6 and GL7 to high grade PCa. In cores with coexistent staining for 14-3-3s and p-TOR, the expression of each marker was restricted to different geographical areas of an individual core. Conclusion: The inverse correlation of p-TOR and 14-3- 3s expression supports the role of 14-3-3s as an inhibitor of p-TOR activity in the prostate. The extent of 14 3-3s and TOR expression in an individual patient with prostate cancer would determine how effective the use of TOR inhibitors would be as potential therapeutic agents. [ABSTRACT FROM AUTHOR]

Purpose: Serum prostate specific antigen screening has increased the number of prostate biopsies performed increasing the number of patients with high grade prostatic intraepithelial neoplasia. The criteria for re-biopsy are not standardized but may be refined by the identification of novel biomarkers demonstrating prognostic significance. Alpha-methylacyl-CoA racemase is a robust marker of prostate cancer and is expressed in a subset of high grade prostatic intraepithelial neoplasia. This study evaluates the prognostic significance of α-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia glands in prostate biopsies. Materials and Methods: Immunohistochemical staining with α-methylacyl-coA racemase and p63 was examined in a selected group of 62 patients with a diagnosis of high grade prostatic intraepithelial neoplasia on initial prostate biopsy, of which on repeat biopsy 32 had no carcinoma and 30 had prostate cancer. There was no significant difference in age, number of cores sampled or prostate specific antigen history between the 2 outcome groups (ANOVA p >0.9). High grade prostatic intraepithelial neoplasia glands in each case were evaluated for α-methylacyl-coA racemase and p63. Results: Reactivity for α-methylacyl-coA racemase was found in 27 of the 62 cases examined. Fisher’s exact analysis revealed that patients with at least 1 α-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia gland were 5.2 times more likely to have a subsequent diagnosis of prostate cancer on repeat biopsy than those without any α-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia glands (p = 0.0044). No correlation was found between α-methylacyl-coA racemase positivity and any other clinical variable. Conclusions: This is the first study to our knowledge to illustrate that α-methylacyl-coA racemase reactivity in high grade prostatic intraepithelial neoplasia may be useful to refine re-biopsy criteria and assist in clinical management decisions. [Copyright &y& Elsevier]

Background: Current ancillary markers for diagnosis in prostate biopsies include p63 and α-methylacyl-CoA racemase (AMACR). Annexin II (ANXII), a calcium and phospholipid binding protein, is lost in prostate cancer. Aims: To investigate ANXII expression in order to assess its utility as a novel diagnostic marker in comparison to p63 and AMACR. Methods: Using immunohistochemistry on six tissue microarrays, ANXII, p63, and AMACR expression was analysed from 210 radical prostatectomy cases. Staining was evaluated in benign and atrophic glands, high- grade prostatic intraepithelial neoplasia (HGPIN), and prostatic adenocarcinoma. Separate scores were given for ANXII, AMACR and p63 expression. Results: Diffuse cytoplasmic expression of ANXII correlated with p63 reactivity in basal cells. Benign glands were positive for ANXII in 286/292 cores (98%) and negative for AMACR in all 292 cores. HGPIN showed heterogeneous expression of AMACR and ANXII. A significantly larger proportion of HGPIN glands were correctly identified as ANXII negative than as positive for AMACR. ANXII loss in prostate cancer was found in 282/320 cores (88%) and correlated with positive AMACR expression (272/320 cores, 85%), which was not statistically significant. There was no statistically significant correlation between ANXII scores and the clinical parameters examined. Conclusions: Immunohistochemical staining for ANXII is a consistent and reliable marker of prostatic neoplasia. The findings of this study suggest the potential utility of ANXII as a diagnostic aid in prostate cancer histopathology. [ABSTRACT FROM AUTHOR]

Purpose: In light of a recent tendency toward systematic nontargeted biopsy we reassessed whether identification and biopsy of ultrasonographically suspicious lesions contribute to the detection of prostate cancer. Materials and Methods: We reviewed prospectively gathered data on 7,426 transrectal ultrasound directed prostatic biopsies performed at our institution between June 16, 2000 and September 1, 2005. Patients underwent systematic biopsy (6 to 10 cores on initial biopsy and 13 to 15 on rebiopsy) with additional sampling of visible suspicious lesions. The RR for finding cancer in transrectal ultrasound positive and negative patients was calculated for likely independent prognostic variables. Results: A total of 3,828 biopsies (51.5%) were transrectal ultrasound negative and 3,598 (48.5%) were transrectal ultrasound positive. Prostate cancer was detected in 3,258 biopsies (43.9%). For each independent variable the RR for prostate cancer was higher if a sonographic lesion was present. A lesion increased the likelihood of cancer detection (57.8% vs 30.8%, RR 1.8). Biopsies from lesions identified by transrectal ultrasound had a greater median percent of the core involved with cancer (50% vs 10%, p <0.001) and they were more likely to have Gleason score 7 or greater (69.3% vs 28.3%, p <0.001). Conclusions: Biopsies taken when a prostatic lesion is identified by transrectal ultrasound are almost twice as likely to show cancer than when no lesion is visible. These cancers are of higher grade and volume and, therefore, they are more clinically significant. The search for and targeted biopsy of suspicious lesions seen on transrectal ultrasound remains important for prostate cancer diagnosis. [Copyright &y& Elsevier]

Purpose: Differentiation between Gleason score 6 and 7 in prostate biopsy is important for treatment decision making. Nevertheless, under grading errors compared with the actual pathological grade at radical prostatectomy are common. We compared the characteristics and outcomes of tumors that were scored 6 on prostate biopsy but were 7 on subsequent radical prostatectomy pathological evaluation to those in tumors with a consistent rating of Gleason score 6 or 7 at biopsy and surgery. Materials and Methods: We performed a retrospective database analysis from our referral center (1989 to 2004). We compared pre-prostatectomy characteristics, radical prostatectomy pathological features and the post-radical prostatectomy prostate specific antigen failure rate, defined as any 2 consecutive detectable prostate specific antigen measurements, in 3 subgroups of patients, including 156 with matched Gleason score 6 in the prostate biopsy and radical prostatectomy, 205 with upgraded Gleason score 6/7, that is prostate biopsy Gleason score 6 and radical prostatectomy Gleason score 7, and 412 with matched Gleason score 7 in the prostate biopsy and radical prostatectomy. Results: Radical prostatectomy Gleason score matched the prostate biopsy score in 38.2% of biopsy Gleason score 6 and 81.4% of biopsy Gleason score 7 cases. Higher prostate specific antigen was associated and an increased percent of cancer in the prostate biopsy was predictive of discordance between the prostate biopsy and radical prostatectomy Gleason scores (p <0.001). Margin (p = 0.0075) or seminal vesicle involvement (p = 0.0002), cancer volume (p <0.001) and the prostate specific antigen failures rate (p = 0.014) were significantly higher in under graded Gleason score 7 cancer compared to those in matched Gleason score 6 cases. However, they were comparable to those with a matched Gleason score 7 tumor grade (p = 0.66). Conclusions: Almost half of tumors graded Gleason score 6 at biopsy are Gleason score 7 at surgery. Upgraded Gleason score 6 to 7 tumors have outcomes similar to those of genuine Gleason score 7 cancer. For prostate biopsy Gleason score 6 tumors clinicians should consider the overall likelihood of tumor upgrading as well as specific patient characteristics, such as prostate specific antigen and the percent of tumor in the prostate biopsy, when contemplating treatments that are optimized for low grade tumors, including watchful waiting or brachytherapy. [Copyright &y& Elsevier]

Purpose: The clinical usefulness of PSA for prostate cancer screening is unclear, although the test remains in common use. New methods to interpret PSA are needed. Materials and Methods: We examined a cohort of 2,637 men who underwent prostate biopsies for abnormal DRE or PSA between 1999 and 2004. Using risk factors for prostate cancer, including patient age, ethnicity, family history of prostate cancer, previous negative biopsy, voiding symptoms and prostate volume, we developed risk groups for prostate cancer using recursive partitioning modeling independent of PSA or DRE. We then compared prostate cancer probabilities by PSA ranges by risk group. Results: Of the 2,637 men 1,282 (48.6%) had prostate cancer. Age, ethnicity, family history, previous negative biopsy and prostate volume were predictive for cancer. We constructed 6 risk groups by combining these factors and created tables to assign patients to these groups. Independent of PSA and DRE the probability of cancer ranged from 15% in patients in group 1 to 78% in patients in group 6 (p <0.0001). By adding PSA and DRE to each risk group prostate cancer probabilities were refined from 0% to 100%. Patients in the higher risk groups also had higher grade cancer (p <0.0001). Conclusions: We generated 6 risk groups based on simple risk factors for prostate cancer. When used in the right context and patient, PSA is highly accurate for predicting prostate cancer and permitting rational decision making in patients with abnormal PSA. [Copyright &y& Elsevier]

To determine the practice pattern of repeat prostate biopsies to detect prostate cancer, as there is growing evidence to support the recommendation that a repeat prostate biopsy should be taken after an initially negative prostate biopsy, the rate of cancer detection then being≈ 30%.We examined the practice patterns of taking a repeat prostate biopsy after an initial negative biopsy and the predictors for cancer at repeat biopsy among 1536 patients who had an initial prostate biopsy because of an elevated prostate-specific antigen (PSA) level (>4.0 ng/mL) or abnormal digital rectal examination.Of the 1536 men, 712 (46.4%) had cancer detected on the first biopsy; of the remaining 824 with no cancer detected, 268 (32.5%) had a repeat biopsy within a year, and 68 of these (25.4%) had cancer detected. Of the cancers detected at repeat biopsy, 31% were high-grade. Men with abnormal histology (prostatic intraepithelial neoplasia or atypia) had an odds ratio of 3.2 (P < 0.001) for having a repeat biopsy. For men with normal initial prostate histology, those with an initial PSA of 10.0–20.0 and>20.0 ng/mL had an odds ratio of 3.6 and 4.5 (bothP < 0.001), respectively, for a repeat prostate biopsy, compared with patients with a PSA of<10.0 ng/mL. However, the PSA level was not predictive of prostate cancer at repeat biopsy, but age and prostate volume were.A third of patients had a repeat biopsy after a negative biopsy. The most important factors influencing whether a patient was to have a repeat biopsy were initial biopsy histology and PSA level. However, the latter was not an important factor for predicting prostate cancer at repeat biopsy. [ABSTRACT FROM AUTHOR]

Mechanisms underlying prostate cancer (CaP) initiation and progression are poorly understood. A chromosomal instability mechanism leading to the generation of numerical and structural chromosomal changes has been implicated in the preneoplastic and neoplastic stages of CaP. Telomere dysfunction is one potential mechanism associated with the onset of such instability. To determine whether there was alteration in telomere length and chromosome number, 15 paraffin-embedded prostatectomy specimens were investigated using quantitative peptide nucleic acid (PNA) FISH analysis of representative foci of carcinoma, putative precancerous lesions (high-grade prostatic intraepithelial neoplasia, HPIN) and nondysplastic prostate epithelium. A significant decrease in telomere length was shown in both HPIN and CaP in comparison with normal epithelium. In addition, elevated rates of aneusomy suggested that increased levels of chromosomal aberrations were associated with decreased telomere length. Moreover, multiple foci of HPIN were shown to have a heterogeneous overall reduction of telomere length. This reduction was more evident in the histologic regions of the prostate containing CaP. Such observations lend support to the hypothesis that telomere erosion may be a consistent feature of CaP oncogenesis and may also be associated with the generation of chromosomal instability that characterizes this malignancy.Oncogene (2003) 22, 1978-1987. doi:10.1038/sj.onc.1206227 [ABSTRACT FROM AUTHOR]

Purpose: To compare the performance of T2-weighted (T2w) imaging and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate gland in the localization of recurrent prostate cancer in patients with biochemical failure after external beam radiotherapy (EBRT). Methods and Materials: T2-weighted imaging and DCE MRI were performed in 33 patients with suspected relapse after EBRT. Dynamic contrast-enhanced MRI was performed with a temporal resolution of 95 s. Voxels enhancing at 46 s after injection to a greater degree than the mean signal intensity of the prostate at 618 s were considered malignant. Results from MRI were correlated with biopsies from six regions in the peripheral zone (PZ) (base, mid, and apex). The percentage of biopsy core positive for malignancy from each region was correlated with the maximum diameter of the tumor on DCE MRI with a linear regression model. Results: On a sextant basis, DCE MRI had significantly better sensitivity (72% [21of 29] vs. 38% [11 of 29]), positive predictive value (46% [21 of 46] vs. 24% [11 of 45]) and negative predictive value (95% [144 of 152] vs. 88% [135 of 153] than T2w imaging. Specificities were high for both DCE MRI and T2w imaging (85% [144 of 169] vs. 80% [135 of 169]). There was a linear relationship between tumor diameters on DCE MRI and the percentage of cancer tissue in the corresponding biopsy core (r = 0.9, p < 0.001), with a slope of 1.2. Conclusions: Dynamic contrast-enhanced MRI performs better than T2w imaging in the detection and localization of prostate cancer in the peripheral zone after EBRT. This may be helpful in the planning of salvage therapy. [Copyright &y& Elsevier]

The way in which cytogenetic aberrations develop in prostate cancer (CaP) is poorly understood. Spectral karyotype (SKY) analysis of CaP cell lines has shown that they have unstable karyotypes and also have features associated with chromosomal instability (CIN). To accurately determine the incidence of de novo structural and numerical aberrations in vitro in CaP, we performed SKY analysis of three independent clones derived from one representative cell line, DU145. The frequent generation of new chromosomal rearrangements and a wide variation in the number of structural aberrations within two to five passages suggested that this cell line exhibited some of the features associated with a CIN phenotype. To study numerical cell-to-cell variation, chromosome 8 aneusomy was assessed in the LNCaP, DU145, and PC-3 cell lines and a patient cohort of 15 CaP primary tumors by interphase fluorescence in situ hybridization (FISH). This analysis showed that a high frequency of numerical alteration affecting chromosome 8 was present in both in vitro and in CaP tissues. In comparison to normal controls, the patient cohort had a statistically significant (P<.05), greater frequency of cells with one and three centromere 8 copies. These data suggest that a CIN-like process may be contributing towards the generation of de novo numerical and structural chromosome abnormalities in CaP. Neoplasia (2001) 3, 62–69. [ABSTRACT FROM AUTHOR]

Purpose: Neoadjuvant radiation therapy (RT) improves disease control in various cancers and has become an established oncologic treatment strategy. During 2001 to 2004, we conducted a phase 1 pilot study assessing the role of short-course preoperative RT (PreORT) for men with unfavorable intermediate- and high-risk localized prostate cancer. Herein, we present long-term follow-up toxicity and oncologic outcomes.Methods and Materials: Eligible patients had histologically proven prostate cancer, cT1-T2N0M0 disease, prostate-specific antigen >15 to 35 ng/mL regardless of Gleason score, or prostate-specific antigen 10 to 15 ng/mL with Gleason score ≥7. Patients received 25 Gy in 5 consecutive daily fractions (5 Gy per fraction) to the prostate only, followed by radical prostatectomy within 14 days after RT completion. Primary outcomes were intraoperative morbidity and late genitourinary (GU) and gastrointestinal toxicities.Results: In total, 15 patients were enrolled; 14 patients completed PreORT followed by radical prostatectomy, which also included bilateral lymph node dissections in 13 cases. Median follow-up was 12.2 years (range, 6.7-16.3). Late GU toxicity was common, with 2 patients (13.3%) experiencing G2 toxicity and 6 patients (40%) G3 toxicity. There were no patients with G4 to G5 late GU toxicity. Late gastrointestinal toxicity was infrequent, with only 1 patient (6.7%) experiencing transient G2 proctitis. At last follow-up, 8 (53.3%) and 6 (40%) patients experienced biochemical and metastatic disease recurrence, respectively.Conclusions: The use of PreORT in men with high-risk prostate cancer is associated with unexpected high rates of late GU toxicity. Future studies examining the role of RT preradical prostatectomy must cautiously select RT technique and dose schedule. Importantly, long-term follow-up data are essential to fully determine the therapeutic index of PreORT in the management of localized disease. [ABSTRACT FROM AUTHOR]

: PurposeTo describe the oxygenation of clinically localized prostate cancer.: Methods and materialsIntraprostatic oxygen tension was measured using the Eppendorf electrode in 55 unanesthetized men with localized prostate cancer before radiotherapy. Measurements were made along two tracks through regions of suspected tumor in the prostate, and core needle biopsies were then obtained from the same regions.: ResultsThe median pO2 ranged from 0.2 to 57.3 mm Hg, and the grand median pO2 was 4.5 mm Hg. The percentage of oxygen readings <5 mm Hg (HP5) ranged from 0% to 100% (median 60%). The track 1 oxygen readings were greater than those from track 2. Statistically significant heterogeneity was found in the individual oxygen readings: the between- and within-tumor components accounted for 32% and 68% of the total variability, respectively. However, the between-tumor variability in HP5 significantly exceeded the within-tumor variability (61% vs. 39%). No association was found between oxygen values and clinical factors, including age, T stage, Gleason score, prostate-specific antigen level, hemoglobin concentration, or prior hormonal treatment. No difference was noted in the oxygenation between regions of tumor and normal prostate tissue, as determined from the core biopsies.: ConclusionLocalized prostate cancer is characterized by marked hypoxia and significant heterogeneity in oxygenation, similar to other human tumors. The normal prostate may contain regions of low oxygen concentration. HP5, as determined in this study, should adequately discriminate among patients with prostate cancer and allow the independent prognostic significance of oxygenation to be evaluated once the study matures. [Copyright &y& Elsevier]