A prospective multicentre phase III validation study of AZGP1 as a biomarker in localized prostate cancer.

BACKGROUND: Prostate cancers (PCs) with similar characteristics at the time of diagnosis can have very different disease outcomes. Conventional biomarkers of PC still lack precision in identifying individuals at high risk of PC recurrence. While many candidate biomarkers are proposed in the literature, few are in clinical practice as they lack rigorous validation. This study prospectively enrolled an independent phase III cohort to evaluate the clinical utility of zinc-alpha 2-glycoprotein (AZGP1) as a prognostic biomarker in localized PC. PATIENTS AND METHODS: In our multicentre, prospective phase III study, AZGP1 status in 347 radical prostatectomy specimens was assayed by immunohistochemistry in a NATA-accredited laboratory. The AZGP1 score was assessed in a multivariable model incorporating established prognostic factors. We also report extended outcomes from our previous phase II study. The primary endpoint was biochemical relapse-free survival (BRFS). Secondary endpoints were metastasis-free survival (MFS) and PC-specific survival (PCSS). RESULTS: In the phase II cohort, with a median follow-up of 15.8 years, low/absent AZGP1 expression was an independent predictor of poor BRFS (HR, 1.4; 95% CI, 1.1-1.9; P = 0.03), MFS (HR, 2.8; 95% CI, 1.2-6.6; P = 0.02) and PCSS (HR, 3.8; 95% CI, 1.5-9.5; P = 0.005). These results were validated in our prospective phase III cohort. Low/absent AZGP1 expression independently predicted for BRFS (HR, 1.9; 95% CI, 1.1-3.3; P = 0.02), with shorter MFS (HR, 2.0; 95% CI, 1.1-3.4; P = 0.02). AZGP1 improved the discriminatory value when incorporated into existing prognostic risk models. CONCLUSION: Our study provides prospective phase III validation that absent/low AZGP1 expression provides independent prognostic value in PC. This study provides robust evidence for the incorporation of this biomarker into clinical practice.

The Diagnostic Performance of Multiparametric Magnetic Resonance Imaging to Detect Significant Prostate Cancer.

PURPOSE: We assess the accuracy of multiparametric magnetic resonance imaging for significant prostate cancer detection before diagnostic biopsy in men with an abnormal prostate specific antigen/digital rectal examination. MATERIALS AND METHODS: A total of 388 men underwent multiparametric magnetic resonance imaging, including T2-weighted, diffusion weighted and dynamic contrast enhanced imaging before biopsy. Two radiologists used PI-RADS to allocate a score of 1 to 5 for suspicion of significant prostate cancer (Gleason 7 with more than 5% grade 4). PI-RADS 3 to 5 was considered positive. Transperineal template guided mapping biopsy of 18 regions (median 30 cores) was performed with additional manually directed cores from magnetic resonance imaging positive regions. The anatomical location, size and grade of individual cancer areas in the biopsy regions (18) as the primary outcome and in prostatectomy specimens (117) as the secondary outcome were correlated to the magnetic resonance imaging positive regions. RESULTS: Of the 388 men who were enrolled in the study 344 were analyzed. Multiparametric magnetic resonance imaging was positive in 77.0% of patients, 62.5% had prostate cancer and 41.6% had significant prostate cancer. The detection of significant prostate cancer by multiparametric magnetic resonance imaging had a sensitivity of 96%, specificity of 36%, negative predictive value of 92% and positive predictive value of 52%. Adding PI-RADS to the multivariate model, including prostate specific antigen, digital rectal examination, prostate volume and age, improved the AUC from 0.776 to 0.879 (p <0.001). Anatomical concordance analysis showed a low mismatch between the magnetic resonance imaging positive regions and biopsy positive regions (4 [2.9%]), and the significant prostate cancer area in the radical prostatectomy specimen (3 [3.3%]). CONCLUSIONS: In men with an abnormal prostate specific antigen/digital rectal examination, multiparametric magnetic resonance imaging detected significant prostate cancer with an excellent negative predictive value and moderate positive predictive value. The use of multiparametric magnetic resonance imaging to diagnose significant prostate cancer may result in a substantial number of unnecessary biopsies while missing a minimum of significant prostate cancers.

Focal irreversible electroporation for prostate cancer: functional outcomes and short-term oncological control.

BACKGROUND: Current data on the use of irreversible electroporation (IRE) in the treatment of prostate cancer (PCa) is limited. We aim to evaluate the safety, short-term functional and oncological outcomes of focal IRE in low-intermediate risk PCa. METHODS: Between February 2013 and May 2014, 32 consecutive men underwent IRE at a single centre. Patients with low-intermediate risk PCa who had not received previous PCa treatment were included for analysis. The tumour was ablated using 3-6 electrodes, ensuring a minimum 5-mm safety margin around the visible magnetic resonance imaging (MRI) lesion. Follow-up included recording Clavien complications, Expanded Prostate Cancer Index Composite (EPIC) questionnaires (baseline, 1.5, 3, 6 months), 6-month multi-parametric MRI (mp-MRI) and 7-month biopsy. Findings on mp-MRI and biopsy were sub-divided into infield, adjacent or outfield of the treatment zone. RESULTS: Twenty-five men were included for final analysis. Safety follow-up revealed one Clavien Grade 3 complication and five Grade 1 complications. Functional follow-up confirmed no significant change in American Urological Association urinary symptom score, sexual or bowel function. Infield, there were no suspicious findings on mp-MRI (n=24) or biopsy (n=21) in all patients. Adjacent to the treatment zone, five (21%) had suspicious findings on mp-MRI with four (19%) proving to be significant on biopsy. Outfield, there were two (8%) with suspicious findings on mp-MRI and one (5%) significant finding on biopsy. For the five patients with significant findings on follow-up biopsy, one is awaiting repeat IRE, one had radical prostatectomy and three remained on active surveillance. CONCLUSIONS: In selected patients with low-intermediate risk PCa, focal IRE appears to be safe with minimal morbidity. There were no infield recurrences and 76% of patients were histologically free of significant cancer at 8 months. Almost all recurrences were adjacent to the treatment zone, and this was addressed by widening the treatment margins.

Initial assessment of safety and clinical feasibility of irreversible electroporation in the focal treatment of prostate cancer.

BACKGROUND: To evaluate the safety and clinical feasibility of focal irreversible electroporation (IRE) of the prostate. METHODS: We assessed the toxicity profile and functional outcomes of consecutive patients undergoing focal IRE for localised prostate cancer in two centres. Eligibility was assessed by multi-parametric magnetic resonance imaging (mpMRI) and targeted and/or template biopsy. IRE was delivered under transrectal ultrasound guidance with two to six electrodes positioned transperineally within the cancer lesion. Complications were recorded and scored accordingly to the NCI Common Terminology Criteria for Adverse Events; the functional outcome was physician reported in all patients with at least 6 months follow-up. A contrast-enhanced MRI 1 week after the procedure was carried out to assess treatment effect with a further mpMRI at 6 months to rule out evidence of residual visible cancer. RESULTS: Overall, 34 patients with a mean age of 65 years (s.d. = ± 6) and a median PSA of 6.1 ng ml(-1) (interquartile range (IQR) = 4.3-7.7) were included. Nine (26%), 24 (71%) and 1 (3%) men had low, intermediate and high risk disease, respectively (D'Amico criteria). After a median follow-up of 6 months (range 1-24), 12 grade 1 and 10 grade 2 complications occurred. No patient had grade >/= 3 complication. From a functional point of view, 100% (24/24) patients were continent and potency was preserved in 95% (19/20) men potent before treatment. The volume of ablation was a median 12 ml (IQR = 5.6-14.5 ml) with the median PSA after 6 months of 3.4 ng ml(-1) (IQR = 1.9-4.8 ng ml(-1)). MpMRI showed suspicious residual disease in six patients, of whom four (17%) underwent another form of local treatment. CONCLUSIONS: Focal IRE has a low toxicity profile with encouraging genito-urinary functional outcomes. Further prospective development studies are needed to confirm the functional outcomes and to explore the oncological potential.

Circulating microRNAs predict biochemical recurrence in prostate cancer patients.

BACKGROUND: Circulating microRNAs (miRNAs) are emerging as promising biomarkers for prostate cancer. Here, we investigated the potential of these molecules to assist in prognosis and treatment decision-making. METHODS: MicroRNAs in the serum of patients who had experienced rapid biochemical recurrence (BCR) (n=8) or no recurrence (n=8) following radical prostatectomy (RP) were profiled using high-throughput qRT-PCR. Recurrence-associated miRNAs were subsequently quantitated by qRT-PCR in a validation cohort comprised of 70 patients with Gleason 7 cancers treated by RP, 31 of whom had undergone disease progression following surgery. The expression of recurrence-associated miRNAs was also examined in tumour tissue cohorts. RESULTS: Three miRNAs - miR-141, miR-146b-3p and miR-194 - were elevated in patients who subsequently experienced BCR in the screening study. MiR-146b-3p and miR-194 were also associated with disease progression in the validation cohort, as determined by log-rank tests and Cox proportional hazards regression. Multivariate analysis revealed that miR-146b-3p possessed prognostic information beyond standard clinicopathological parameters. Analysis of tissue cohorts revealed that miR-194 was robustly expressed in the prostate, elevated in metastases, and its expression in primary tumours was associated with a poor prognosis. CONCLUSION: Our study suggests that circulating miRNAs, measured at the time of RP, could be combined with current prognostic tools to predict future disease progression in men with intermediate risk prostate cancers.

A novel method of bladder neck imbrication to improve early urinary continence following robotic-assisted radical prostatectomy.

Early return of continence forms an important component of quality of life for patients after robotic-assisted radical prostatectomy (RALP). Here we describe the steps of bladder neck imbrication and vesico-urethral anastomosis improving early continence after RALP. Between April 2008 and July 2009, 202 consecutive patients underwent RALP for clinically localised prostate cancer in a tertiary referral centre by a single surgeon. One hundred and thirty-two (65 %) of these patients agreed to participate in the study. Prior to November 2008, 51 patients underwent standard RALP as described by Patel et al. From November 2008, 81 patients underwent a novel method of bladder neck imbrication. The robotic urethro-vesical anastomosis commences on the posterior wall of the urethra and proceeds anteriorly. In our technique the anastomosis is halted with the suture arms fixed to the anterior abdominal wall. A new suture is used to perform a two-layer repair, anchoring proximally then continuing anteriorly to the level of the urethral stump, where it returns upon itself. The aim is to narrow the urethra to 16 Fr and tighten the second layer to create an imbrication effect. Posterior reconstruction was performed in all patients. Outcome measures were recorded prospectively using the Expanded Prostate Cancer Index Composite tool. Our technique shows significant improvement at all stages of follow-up in urinary summary and incontinence scores. Absolute continence rates increased from 8.2 to 20.5 %, 26.7 to 44.3 %, and 47.7 to 62.3 % at 1.5, 3 and 6 months, respectively. These results support the use of our technique in patients undergoing RALP.

Treatment of localized prostate cancer using a combination of high dose rate Iridium-192 brachytherapy and external beam irradiation: initial Australian experience.

Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate- and high-risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate-specific antigen progression-free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.

Prognostic significance of pathologic features in localized prostate cancer treated with radical prostatectomy: implications for staging systems and predictive models.

PURPOSE: Although predicting outcome for men with clinically localized prostate cancer (PC) has improved, the staging system and nomograms used to do this are based on results from the North American health system. To be internationally applicable, these models require testing in cohorts from a variety of different health systems based on the predominant PC case identification methods used. PATIENTS AND METHODS: We studied 732 men with localized PC treated with radical prostatectomy and no preoperative therapy between 1986 and 1999 at one Australian institution to determine the effect of clinicopathologic features on disease-free survival. RESULTS: Preoperative serum prostate-specific antigen (PSA) concentration, Gleason score, pathologic stage, and year of surgery were independent predictors of outcome. Although margin status demonstrated only a trend toward significance in multivariate modeling overall, it proved to be independent in subgroups based on later year of surgery (1986 to 1994 v 1995 to 1998), preoperative PSA of less than 10 ng/mL, and Gleason score > or = 7. Adjuvant radiation therapy improved disease-free survival rates in patients with multiple surgical margin involvement. CONCLUSION: This work confirms the prognostic significance of pathologic stage, Gleason score, and preoperative serum PSA. In the context of a contemporaneous screening effect in Australia, these findings may have implications for methods that predict outcome following surgery as screening becomes more prevalent in a population. The independent prognostic effect of margin status may alter with an increase in the proportion of screening-identified PCs. Staging systems and nomograms that predict outcome following surgery require validation in cohorts with different health practices before being universally applied.

Frequent loss of estrogen receptor-beta expression in prostate cancer.

The role of estrogen and its receptors in the etiology and progression of prostate cancer (PC) is poorly understood. In normal and malignant human prostate, estrogen receptor-alpha is expressed only in the stroma, whereas estrogen receptor-beta (ERbeta) is present in both normal stroma and epithelium. Because loss of ERbeta expression is associated with prostate hyperplasia in ERbeta-null mice, this study determined patterns of ERbeta expression in normal, hyperplastic, and malignant human prostate and associations with clinical outcome. Five normal prostates from organ donors and 159 radical prostatectomy specimens from patients with clinically localized PC were assessed for ERbeta expression using immunohistochemistry. ERbeta-positivity was defined as > or =5% of cells demonstrating nuclear immunoreactivity. All of the five normal prostates showed strong ERbeta-nuclear staining in >95% of the epithelium and 35% of the stromal cells. The number of ERbeta-positive cases declined to 24.2% (38/157) in hyperplasia adjacent to carcinoma and 11.3% (18/159) in PCs. ERbeta-positivity was related to decreased relapse-free survival (log-rank P = 0.04). Thus, loss of ERbeta expression is associated with progression from normal prostate epithelium to PC, whereas those cancers that retained ERbeta expression were associated with a higher rate of recurrence. These data identify the need to further investigate the potential role of ERbeta in the regulation of prostate epithelial cell proliferation and the functional consequences of decreased ERbeta expression in the evolution of PC.

Overexpression of the cell cycle inhibitor p16INK4A in high-grade prostatic intraepithelial neoplasia predicts early relapse in prostate cancer patients.

Prostate cancer (PC) is the most commonly diagnosed male cancer in industrialized societies. No molecular markers of PC progression or outcome with proven clinical utility have been described. Because the loss of normal cell cycle control is an early event in the evolution of cancer, we sought to determine whether changes in expression of the cyclin-dependent kinase inhibitor, p16INK4A, predicted outcome in this disease. We screened a cohort of 206 patients with clinically localized PC treated with radical prostatectomy for overexpression of the INK4A gene, the product of which inactivates the G1-phase cyclin dependent kinases, Cdk4 and Cdk6. p16INK4A protein expression was evaluated by immunohistochemistry in areas of high-grade intraepithelial neoplasia (HGPIN), a precursor to invasive disease, and of cancer in the same specimen. Data were evaluated for disease relapse using the Kaplan-Meier method and in a Cox proportional hazards model by assessing p16INK4A status in areas of HGPIN and cancer with other variables of known clinical relevance. Overexpression of p16INK4A in HGPIN and cancer was correlated with, but independent of, pathological stage and was associated with early relapse in PC patients treated with radical prostatectomy (log-rank test, P < 0.001). In a multivariate model adjusted for Gleason grade, pretreatment prostate-specific antigen levels, pathological stage, and margin status, overexpression of p16INK4A in HGPIN was an independent predictor of disease relapse and increased the risk of recurrence 2.24-fold (95% confidence interval, 1.28-3.93). These data provide the first evidence for a prognostic marker in HGPIN. The clinical utility of p16INK4A status in stratifying patients for aggressive treatment very early in the disease process, potentially several years prior to the onset of invasive disease, requires further investigation.

Altered expression of androgen receptor in the malignant epithelium and adjacent stroma is associated with early relapse in prostate cancer.

The molecular basis of androgen-independent prostate cancer is unknown; however, functional androgen receptor (AR) signaling is maintained after the acquisition of hormone-refractory disease. Because normal and malignant prostate epithelial cell proliferation is regulated by androgen stimulation via both the AR-positive stroma and epithelium, we sought to evaluate patterns of AR expression in these cells and to determine any relationships with prostate cancer progression. AR expression in the malignant epithelium and associated periepithelial and nonperiepithelial stroma was measured in a cohort of 96 patients with clinically localized prostate cancer treated with radical prostatectomy. Data were evaluated for disease relapse using the Kaplan-Meier method and in a Cox proportional hazards model with other variables of known clinical relevance, including Gleason score, pathological stage, clinical stage, and pretreatment prostate-specific antigen concentration. Concurrent overexpression of AR (> or = 70% positive nuclei) in the malignant epithelium and loss of AR immunoreactivity in the adjacent periepithelial stroma (< or = 30%) was associated with higher clinical stage (P = 0.01), higher pretreatment prostate-specific antigen level (P = 0.03), and earlier relapse after radical prostatectomy (log-rank P = 0.009). These data identify a pattern of AR expression in malignant epithelium and adjacent stroma that is associated with a poor clinical outcome in prostate cancer. Equally important, they identify the need to further investigate the mechanistic basis of loss of AR expression in the malignant stroma and its potential role in deregulation of prostate epithelial cell proliferation.

Prognostic significance of p53 nuclear accumulation in localized prostate cancer treated with radical prostatectomy.

The role of p53 in the pathogenesis of, and as a predictive biomarker for, localized prostate cancer (PCa) is contested. Recent work has suggested that patterns of p53 nuclear accumulation determined by immunohistochemistry are prognostic, whereas studies using other methods question the role of p53 mutations in predicting outcome. We studied 263 men with localized PCa treated with radical prostatectomy to determine whether p53 nuclear accumulation predicts relapse and disease-specific mortality. We combined two p53 immunohistochemistry scoring systems: (a) percentage of p53-positive tumor nuclei in all major foci of cancer within the prostate; and (b) clustering, where the presence of 12 or more p53-positive cells within a x 200 power field was deemed "cluster positive." Analysis was undertaken using chi2, Kruskal-Wallis, and Mann-Whitney tests for clinicopathological variables and the Kaplan-Meier method, log-rank test, and univariate and multivariate Cox regression modeling for evaluation of contribution to relapse and disease-specific survival. At mean follow-up of 55.1 months (range, 4.9-123.0 months), 39% (102 of 263) of patients had relapsed and 2.3% (6 of 253) had died of PCa. Pretreatment serum prostate-specific antigen concentration, pathological tumor stage, lymph node involvement, Gleason score, and p53 nuclear accumulation, as determined by either percentage score or cluster status, were independent predictors of relapse in multivariate analysis. Clustering of p53-positive cells distinguished between favorable and poor prognosis patients within the lowest p53-positive stratum (>0 to <2%) and was the most discriminatory threshold for predicting relapse in the entire cohort. p53 status predicted outcome in patients with a Gleason score of 5 and above but not those with a score of 4 and below. In patients treated with neoadjuvant hormonal therapy, p53 cluster positivity carried a 90% (19 of 21) risk of relapse by 36 months. All six patients who died from PCa in the period of the study exhibited p53 nuclear accumulation in 20% or more tumor nuclei. This study demonstrates strong relationships between p53 nuclear accumulation and relapse and disease-specific mortality in a large series of localized PCas. Furthermore, the presence of clusters of p53-positive nuclei delineates a group of patients with poor prognosis not identified by traditional scoring methods and supports the hypothesis that p53 dysfunction within PCa may exist in foci of tumor cells that are clonally expanded in metastases.

Elevated levels of peritumoral chondroitin sulfate are predictive of poor prognosis in patients treated by radical prostatectomy for early-stage prostate cancer.

The disease course of localized prostate cancer is highly variable, and patients potentially curable by aggressive management are not readily identified by current clinical practice. Chondroitin sulfate (CS) glycosaminoglycan is a candidate biomarker as elevated levels of CS in peritumoral stroma of prostate cancer have been associated with prostate-specific antigen (PSA) failure. Immunoreactive CS was measured using image analysis of archived radical prostatectomy tissues, obtained from 157 men with a median of 47 months (range, 16-111 months) clinical follow-up. CS level, Gleason score, and preoperative serum PSA levels were independent predictors of PSA failure by Cox's multivariate analysis. Patients with low CS levels had significantly fewer PSA failures after radical prostatectomy than patients with high levels of CS (Kaplan-Meier plot; 32% PSA failures at 5 years for CS mean integrated absorbance cut point < 7.0 versus 50% for CS > or = 7.0, P = 0.0001). In the subgroup of patients with preoperative serum PSA levels < 10 ng/ml, CS was particularly useful in discriminating retrospectively those patients most suited for surgery (Kaplan-Meier plot; 14% PSA failures at 5 years for CS mean integrated absorbance cut point < 7.0 versus 47% for CS > or = 7.0, P = 0.0001). We conclude that measurements of CS level can assist in predicting patient outcome after surgery. Additionally, our data suggest that the combination of CS and PSA measurements may improve outcome prediction for patients with intermediate Gleason scores.

Proper patient selection for Contigen Bard Collagen implant.

Stress incontinence affects primarily women, and a common cause is intrinsic sphincter deficiency (ISD). Traditionally, patients with ISD are treated surgically with implantation of an artificial sphincter or with a pubovaginal sling procedure. Although these procedures are effective, an alternate nonsurgical treatment option is Contigen Bard Collagen Implant. Ensuring optimal results with Contigen Implant requires proper diagnosis and patient selection. Contigen Implant is indicated for the treatment of urinary incontinence from ISD. Candidates are usually females with at least one previous failed suspension and with an open bladder neck at rest. Patients with a hypermobile urethra, high leak point pressures, or significant detrusor problems are poor candidates for Contigen. Those who are considered for Contigen should undergo a diagnostic evaluation to confirm the presence of incontinence, identify contributing factors, and identify the need for further diagnostic evaluation. The basic evaluation can be performed by any physician. It consists of a thorough history, physical examination, and urinalysis. It may also include a patient diary of voiding activity and a pad test to quantify the degree of incontinence. Those patients in whom incontinence is confirmed with a basic evaluation should undergo urodynamic evaluation by an experienced urologist. The object is to identify the specific cause of incontinence, detect functional, neurological, or anatomic lesions, and help select the most appropriate therapy. The urodynamic evaluation consists of cystometry, uroflowmetry, cystogram with voiding cystourethrogram, determination of leak point pressure and post-void residual, and videourodynamic studies if indicated. Optimal outcomes with Contigen Implant will be realized through proper patient selection, and this requires a thorough patient evaluation.