Mechanical mapping of the prostate in vivo using Dynamic Instrumented Palpation; towards an in vivo strategy for cancer assessment.

A calibrated palpation sensor has been developed for making instrumented Digital Rectal Examinations (iDREs) with a view to assessing patients for prostate cancer. The instrument measures the dynamic stiffness of the palpable surface of the prostate, and has been trialled on 12 patients in vivo. The patients had been diagnosed with prostate cancer and were scheduled for radical prostatectomy. As far as possible, patients with asymmetric disease were chosen so as to give a variation in gland condition over the palpable surface. The device works by applying an oscillating pressure (force) to a flexible probe whose displacement into the tissue is also measured in order to yield a dynamic stiffness, the static stiffness being incidentally measured at the mean oscillatory force. The device was deployed mounted on the index finger of a urologist and measurements taken at 12-16 positions on each patient using light and firm pressure and palpation frequencies of 1 or 5 Hz. In parallel, conventional DRE assessments were made by a consultant urologist for cancer. After in vivo measurement, the glands were removed and examined histologically with each palpation point being classified as cancerous (C) or not (NC). The work has established the first measurements of static modulus of living prostate tissue to be: 26.8 (13.3) kPa for tissue affected by prostate cancer (C classification), and 24.8 kPa (11.9) for tissue unaffected by cancer (NC classification), values quoted as median (interquartile range). The dynamic properties were characterised by: dynamic modulus, 5.15 kPa (4.86) for the C classification and 4.61 kPa (3.08) for the NC classification and the time lag between force and displacement at 5 Hz palpation frequency, 0.0175 s (0.0078) for the C classification and 0.0186 s (0.0397) for the NC classification, values again quoted as median (interquartile range). With the limited set of features that could be generated, an Artificial Neural Network (ANN) classification yielded a sensitivity of 97%, negative predictive value of 86%, positive predictive value of 67% and accuracy of 70% but with relatively poor specificity (30%). Besides extending the feature set, there are a number of changes in probe design, probing strategy and in mechanics analysis, which are expected to improve the diagnostic capabilities of the method.

Protocol for the TRANSLATE prospective, multicentre, randomised clinical trial of prostate biopsy technique.

OBJECTIVES: Primary objectives: to determine whether local anaesthetic transperineal prostate (LATP) biopsy improves the detection of clinically significant prostate cancer (csPCa), defined as International Society of Urological Pathology (ISUP) Grade Group ≥2 disease (i.e., any Gleason pattern 4 disease), compared to transrectal ultrasound-guided (TRUS) prostate biopsy, in biopsy-naïve men undergoing biopsy based on suspicion of csPCa. SECONDARY OBJECTIVES: to compare (i) infection rates, (ii) health-related quality of life, (iii) patient-reported procedure tolerability, (iv) patient-reported biopsy-related complications (including bleeding, bruising, pain, loss of erectile function), (v) number of subsequent prostate biopsy procedures required, (vi) cost-effectiveness, (vii) other histological parameters, and (viii) burden and rate of detection of clinically insignificant PCa (ISUP Grade Group 1 disease) in men undergoing these two types of prostate biopsy. PATIENTS AND METHODS: The TRANSLATE trial is a UK-wide, multicentre, randomised clinical trial that meets the criteria for level-one evidence in diagnostic test evaluation. TRANSLATE is investigating whether LATP biopsy leads to a higher rate of detection of csPCa compared to TRUS prostate biopsy. Both biopsies are being performed with an average of 12 systematic cores in six sectors (depending on prostate size), plus three to five target cores per multiparametric/bi-parametric magnetic resonance imaging lesion. LATP biopsy is performed using an ultrasound probe-mounted needle-guidance device (either the 'Precision-Point' or BK UA1232 system). TRUS biopsy is performed according to each hospital's standard practice. The study is 90% powered to detect a 10% difference (LATP biopsy hypothesised at 55% detection rate for csPCa vs 45% for TRUS biopsy). A total of 1042 biopsy-naïve men referred with suspected PCa need to be recruited. CONCLUSIONS: This trial will provide robust prospective data to determine the diagnostic ability of LATP biopsy vs TRUS biopsy in the primary diagnostic setting.

Locating and sizing tumor nodules in human prostate using instrumented probing - computational framework and experimental validation.

Detection of tumor nodules is key to early cancer diagnosis. This study investigates the potential of using the mechanical data, acquired from probing the prostate for detecting the existence, and, more importantly, characterizing the size and depth, from the posterior surface, of the prostate cancer (PCa) nodules. A computational approach is developed to quantify the uncertainty of nodule detectability and is based on identifying stiffness anomalies in the profiles of point force measurements across transverse sections of the prostate. The capability of the proposed method was assessed firstly using a 'training' dataset of in silico models including PCa nodules with random size, depth and location, followed by a clinical feasibility study, involving experimental data from 13 ex vivo prostates from patients who had undergone radical prostatatectomy. Promising levels of sensitivity and specificity were obtained for detecting the PCa nodules in a total of 44 prostate sections. This study has shown that the proposed methods could be a useful complementary tool to exisiting diagnostic methods of PCa. The future study will involve implementing the proposed measurement and detection strategies in vivo, with the help of a miniturized medical device.

Identification of tumor nodule in soft tissue: An inverse finite-element framework based on mechanical characterization.

Identification and characterization of nodules in soft tissue, including their size, shape, and location, provide a basis for tumor identification. This study proposes an inverse finite-element (FE) based computational framework, for characterizing the size of examined tissue sample and detecting the presence of embedded tumor nodules using instrumented palpation, without a priori anatomical knowledge. The inverse analysis was applied to a model system, the human prostate, and was based on the reaction forces which can be obtained by trans-rectal mechanical probing and those from an equivalent FE model, which was optimized iteratively, by minimizing an error function between the two cases, toward the target solution. The tumor nodule can be identified through its influence on the stress state of the prostate. The effectiveness of the proposed method was further verified using a realistic prostate model reconstructed from magnetic resonance (MR) images. The results show the proposed framework to be capable of characterizing the key geometrical indices of the prostate and identifying the presence of cancerous nodules. Therefore, it has potential, when combined with instrumented palpation, for primary diagnosis of prostate cancer, and, potentially, solid tumors in other types of soft tissue.

A novel method for rapid and quantitative mechanical assessment of soft tissue for diagnostic purposes: A computational study.

Biological tissues often experience drastic changes in their microstructure due to their pathophysiological conditions. Such microstructural changes could result in variations in mechanical properties, which can be used in diagnosing or monitoring a wide range of diseases, most notably cancer. This paves the avenue for non-invasive diagnosis by instrumented palpation although challenges remain in quantitatively assessing the amount of diseased tissue by means of mechanical characterization. This paper presents a framework for tissue diagnosis using a quantitative and efficient estimation of the fractions of cancerous and non-cancerous tissue without a priori knowledge of tissue microstructure. First, the sample is tested in a creep or stress relaxation experiment, and the behavior is characterized using a single term Prony series. A rule of mixtures, which relates tumor fraction to the apparent mechanical properties, is then obtained by minimizing the difference between strain energy of a heterogeneous system and an equivalent homogeneous one. Finally, the percentage of each tissue constituent is predicted by comparing the observed relaxation time with that calculated from the rule of mixtures. The proposed methodology is assessed using models reconstructed from histological samples and magnetic resonance imaging of prostate. Results show that estimation of cancerous tissue fraction can be obtained with a maximum error of 12% when samples of different sizes, geometries, and tumor fractions are presented. The proposed framework has the potential to be applied to a wide range of diseases such as rectal polyps, cirrhosis, or breast and prostate cancer whose current primary diagnosis remains qualitative.

Quantitative mechanical assessment of the whole prostate gland ex vivo using dynamic instrumented palpation.

An instrumented palpation sensor, designed for measuring the dynamic modulus of tissue in vivo, has been developed and trialled on ex vivo whole prostate glands. The sensor consists of a flexible membrane sensor/actuator with an embedded strain gauge and is actuated using a dynamically varying airflow at frequencies of 1 and 5 Hz. The device was calibrated using an indentation stiffness measurement rig and gelatine samples with a range of static modulus similar to that reported in the literature for prostate tissue. The glands were removed from patients with diagnosed prostate cancer scheduled for radical prostatectomy, and the stiffness was measured within 30 min of surgical removal. Each prostate was later examined histologically in a column immediately below each indentation point and graded into one of the four groups; normal, benign prostatic hyperplasia, cancerous and mixed cancer and benign prostatic hyperplasia. In total, 11 prostates were assessed using multiple point probing, and the complex modulus at 1 and 5 Hz was calculated on a point-by-point basis. The device yielded values of quasi-static modulus of 15 ± 0.5 kPa and dynamic modulus of 20 ± 0.5 kPa for whole prostates, and a sensitivity of up to 80% with slightly lower specificity was achieved on diagnosis of prostate cancer using a combination of mechanical measures. This assessment did not take into account some obvious factors such as edge effects, overlap and clinical significance of the cancer, all of which would improve performance. The device, as currently configured, is immediately deployable in vivo. A number of improvements are also identified which could improve the sensitivity and specificity in future embodiments of the probe.

Histology-based homogenization analysis of soft tissue: application to prostate cancer.

It is well known that the changes in tissue microstructure associated with certain pathophysiological conditions can influence its mechanical properties. Quantitatively relating the tissue microstructure to the macroscopic mechanical properties could lead to significant improvements in clinical diagnosis, especially when the mechanical properties of the tissue are used as diagnostic indices such as in digital rectal examination and elastography. In this study, a novel method of imposing periodic boundary conditions in non-periodic finite-element meshes is presented. This method is used to develop quantitative relationships between tissue microstructure and its apparent mechanical properties for benign and malignant tissue at various length scales. Finally, the inter-patient variation in the tissue properties is also investigated. Results show significant changes in the statistical distribution of the mechanical properties at different length scales. More importantly the loss of the normal differentiation of glandular structure of cancerous tissue has been demonstrated to lead to changes in mechanical properties and anisotropy. The proposed methodology is not limited to a particular tissue or material and the example used could help better understand how changes in the tissue microstructure caused by pathological conditions influence the mechanical properties, ultimately leading to more sensitive and accurate diagnostic technologies.

Primary SWL Is an Efficient and Cost-Effective Treatment for Lower Pole Renal Stones Between 10 and 20 mm in Size: A Large Single Center Study.

INTRODUCTION: To assess the clinical features, outcomes, complications, and cost-effectiveness of shockwave lithotripsy (SWL), flexible ureterorenoscopy (FURS), and percutaneous nephrolithotomy (PCNL) in the treatment of lower pole (LP) stones (10-20 mm) in a large tertiary referral center. PATIENTS AND METHODS: Consecutive patients treated for solitary LP stones (10-20 mm) between 2008 and 2013 were identified from a prospective database. SWL was used as primary treatment in all cases (following a stone multidisciplinary team assessment), with FURS and PCNL reserved for SWL contraindications, failure, or patient choice. "Success" was defined as stone free and/or clinically insignificant stone fragments (≤3 mm) at 1 and 3 months follow-up. Effect of anatomy on SWL success was determined from using CT images and regression analysis. Average cost per treatment modality (including additional second-line treatments) was calculated for each group using the National Health Service England 2014/15 National Tariff Healthcare Resource Group codes. RESULTS: Two hundred twenty-five patients were included (mean age 54.9; median stone size 12 mm). One hundred ninety-eight (88%), 21 (9.3%), and 6 (2.7%) patients underwent SWL, FURS, and PCNL as primary treatments, respectively, for median stone sizes of 12, 12, and 20 mm. Overall success rates were 82.8%, 76.1%, and 66.7%, respectively (p < 0.05). Sixty-three percent of patients undergoing primary SWL were effectively treated after one session. Anatomical analysis determined infundibulopelvic angle and infundibular length to be significantly different in patients effectively treated with SWL (p = 0.04). The average cost per treatment modality was also significantly lower for SWL (£750) than for FURS (£1261) or PCNL (£2658) (p < 0.01). CONCLUSION: SWL is both an efficacious and cost-effective primary treatment for patients with solitary LP stones (10-20 mm). The majority of patients can be effectively treated with primary SWL in a dedicated stone center, with the benefits of a short length of stay, low complication, and auxiliary treatment rates. The referral of such patients to high-volume lithotripsy centers with demonstrable outcomes should be given due consideration.

Striated Muscle in Radical Prostatectomy Specimens: A Marker of Apical Dissection Quality and an Independent Predictor of Urinary Continence after Endoscopic Extraperitoneal Radical Prostatectomy.

INTRODUCTION: The study aimed to determine if the presence and amount of striated muscle on the apical sections of the cruciate sections of laparoscopic radical prostatectomy (LRP) specimens predict early and long-term urinary continence outcomes. PATIENTS AND METHODS: We conducted a retrospective review of our prospectively collected single surgeon LRP database. We identified patients based on their continence outcomes (continent (0 pads) or incontinent at 12 months), with an approximate even spread early continent and incontinent patients). An uropathologist separate from the urology team was blinded to outcome and assessed each patients' apical cruciate sections (H&E stained) for the presence, percentage and maximal diameter of muscle and extraprostatic tissue on these sections. Specifically 2 scoring systems were used: (1) semi-quantitative estimation of percentage of muscle on the apical cruciate sections (low <5% and high >5%) and (2) percentage of total extraprostatic tissue on cruciate section (low <10% and high >10%). Logistic regression and classification and regression tree analyses were performed to identify the predictors of urinary incontinence (UI). RESULTS: In total 80 patients were analyzed, 38 were continent and 42 were incontinent at 12 months follow-up. The percentage of extraprostatic tissue/muscle being an independent predictor of being wet at 12 months (p = 0.002) on multivariate regression along with age (p = 0.04). Using percentage of extraprostatic tissue in cruciate section (high >10%) to predict UI at 12 months, it yielded 71% sensitivity, 82% specificity, 81% PPV, 72% NPV and 76% accuracy. CONCLUSION: The use of simple additional reporting of muscle and extraprostatic tissue on the apical sections of RP specimens can help to better predict the likelihood of continence return.

Consultation audio-recording reduces long-term decision regret after prostate cancer treatment: A non-randomised comparative cohort study.

INTRODUCTION: The life expectancy of prostate patients is long and patients will spend many years carrying the burdens & benefits of the treatment decisions they have made, therefore, it is vital that decisions on treatments are shared between patient and physician. The objective was to determine if consultation audio-recording improves quality of life, reduces regret or improves patient satisfaction in comparison to standard counselling. PATIENTS AND METHODS: In 2012 we initiated consultation audio-recordings, where patients are given a CD of their consultation to keep and replay at home. We conducted a prospective non-randomised study of patient satisfaction, quality of life (QOL) and decision regret at 12 months follow-up using posted validated questionnaires for the audio-recording (AR) patients and a control cohort. Qualitative and thematic analyses were used. RESULTS: Forty of 59 patients in the AR group, and 27 of 45 patients in the control group returned the questionnaires. Patient demographics were similar in both groups with no statistically significant differences between the two groups. Decision regret was lower in the audio-recording group (11/100) vs control group (19/100) (p = 0.04). The risk ratio for not having any long-term decision regret was 5.539 (CI 1.643-18.674), with NNT to prevent regret being 4. Regression analysis showed that receiving audio-recording was strongest predictor for absence of regret even greater than potency and incontinence. CONCLUSION: The study has shown that audio-recording clinic consultation reduces long-term decision regret, increases patient information recall, understanding and confidence in their decision. There is great potential for further expansion of this low-cost intervention.

Patient specific modeling of palpation-based prostate cancer diagnosis: effects of pelvic cavity anatomy and intrabladder pressure.

Computational modeling has become a successful tool for scientific advances including understanding the behavior of biological and biomedical systems as well as improving clinical practice. In most cases, only general models are used without taking into account patient-specific features. However, patient specificity has proven to be crucial in guiding clinical practice because of disastrous consequences that can arise should the model be inaccurate. This paper proposes a framework for the computational modeling applied to the example of the male pelvic cavity for the purpose of prostate cancer diagnostics using palpation. The effects of patient specific structural features on palpation response are studied in three selected patients with very different pathophysiological conditions whose pelvic cavities are reconstructed from MRI scans. In particular, the role of intrabladder pressure in the outcome of digital rectal examination is investigated with the objective of providing guidelines to practitioners to enhance the effectiveness of diagnosis. Furthermore, the presence of the pelvic bone in the model is assessed to determine the pathophysiological conditions in which it has to be modeled. The conclusions and suggestions of this work have potential use not only in clinical practice and also for biomechanical modeling where structural patient-specificity needs to be considered. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.

A Critical Analysis of the Learning Curve and Postlearning Curve Outcomes of Two Experience- and Volume-Matched Surgeons for Laparoscopic and Robot-Assisted Radical Prostatectomy.

BACKGROUND AND PURPOSE: There remains equipoise with regard to whether laparoscopic radical prostatectomy (LRP) or robot-assisted radical prostatectomy (RARP) has any benefit over the other. Despite this, there is a trend for the increasing adoption of RARP at great cost to health services across the world. The aim was to critically analyze the learning curve and outcomes for LRP and RARP for two experience- and volume-matched surgeons who have completed the learning curve for LRP and RARP. PATIENTS AND METHODS: Two experience- and volume-matched LRP and RARP surgeons who have completed the learning curve were compared with respect to their learning curve and outcomes for RARP and LRP. There were 531 RARP and 550 LRPs analyzed from April 2003 until January 2012 at two relatively high-volume United Kingdom centers. Outcome measures included operative time, blood loss, complication rate (Clavien-Dindo grade III), positive surgical margin (PSM) rate, and early continence rate. RESULTS: Learning curves for blood loss, operative times, and complication rate were similar between groups. The overall PSM rate and pT2 PSM rate learning curves were longer for RARP compared with LRP but shorter for early continence. Apical PSM showed no learning curve for RARP; however, a long learning curve for LRP and the rate was lower for RARP than for LRP (P=<0.001). CONCLUSIONS: This study of RARP and LRP identified that both modalities had long learning curves. Despite the long learning curve for RARP, significant benefits in lower PSM rates and better early continence in comparison with LRP exist. There are benefits to patients with RARP over LRP, especially those linked to better apical dissection (apical PSM and early continence).

Contemporary practice and technique-related outcomes for radical prostatectomy in the UK: a report of national outcomes.

OBJECTIVE: To determine current radical prostatectomy (RP) practice in the UK and compare surgical outcomes between techniques. PATIENTS AND METHODS: All RPs performed between 1 January 2011 and 31 December 2011 in the UK with data entered into the British Association of Urological Surgeons (BAUS) database, were identified for analysis. Overall surgical outcomes were assessed and subgroup analyses of these outcomes, based on operative technique [open RP (ORP), laparoscopic RP (LRP) and robot-assisted laparoscopic RP (RALP)], were made. Continuous variables were compared using the Mann-Whitney U-test and categorical variables using the Pearson chi-squared test. Univariate and multivariate binary regression analyses were performed to assess the effect of patient, surgeon and technique-related variables on surgical outcomes. RESULTS: During the study period 2163 RPs were performed by 115 consultants with a median (range) of 11 (1-154) cases/consultant. Most RPs were performed laparoscopically (ORP 25.8%, LRP 54.6%, RALP 19.6%) and those performing minimally invasive techniques are more likely to have a higher annual case volume with <1% ORP, 39% LRP and 62% RALP being performed by consultants with an annual caseload of >50 cases/year. Most patients were classified as having intermediate- or high-risk disease preoperatively (1596 patients, 82.5%) and this increased to 97.2% (1649) on postoperative risk stratification. The overall intraoperative complication rate was 14.2% and was significantly greater for LRP (17.8%) vs ORP (8.2%) and RALP (12.4%), (P < 0.001). In all, 71% of patients had an estimated blood loss (EBL) of <500 mL, although there were significantly more patients undergoing ORP with >500, > 1000 and >2000 mL EBL compared with the other techniques (P < 0.001). The postoperative complication rate was 10.7% overall, with a significantly greater postoperative complication rate in the LRP group (LRP 14.6%, ORP 8.8% and RALP 10.3% respectively, P = 0.007). Positive surgical margin (PSM) rates were 17.5% for pT2 disease and 42.3% for pT3 disease. The PSM rate was significantly lower in the RALP patients compared with the ORP patients for those with pT2 disease (P = 0.025), while there was no difference between ORP and LRP (ORP 21.7%, LRP 18.1% and RALP 13.0%). There was no significant difference in the PSM rate in pT3 disease between surgical techniques. CONCLUSION: Most RPs in the UK are performed using minimally invasive techniques, which offer reduced blood loss and transfusion rates compared with ORP. The operation time, complication rate, PSM rates, and association with higher volume practice support RALP as the minimally invasive technique of choice, which could have implications for regions without access to such services. The disparity in outcomes between this national study and high-volume single centres, most probably reflects the low median national case volume, and combined with the positive effect of high case volume on multivariate analysis of surgical outcomes and PSM rates, strengthens the argument for centralisation of services.

Quantitative diagnostics of soft tissue through viscoelastic characterization using time-based instrumented palpation.

Although palpation has been successfully employed for centuries to assess soft tissue quality, it is a subjective test, and is therefore qualitative and depends on the experience of the practitioner. To reproduce what the medical practitioner feels needs more than a simple quasi-static stiffness measurement. This paper assesses the capacity of dynamic mechanical palpation to measure the changes in viscoelastic properties that soft tissue can exhibit under certain pathological conditions. A diagnostic framework is proposed to measure elastic and viscous behaviors simultaneously using a reduced set of viscoelastic parameters, giving a reliable index for quantitative assessment of tissue quality. The approach is illustrated on prostate models reconstructed from prostate MRI scans. The examples show that the change in viscoelastic time constant between healthy and cancerous tissue is a key index for quantitative diagnostics using point probing. The method is not limited to any particular tissue or material and is therefore useful for tissue where defining a unique time constant is not trivial. The proposed framework of quantitative assessment could become a useful tool in clinical diagnostics for soft tissue.

Tissue quality assessment using a novel direct elasticity assessment device (the E-finger): a cadaveric study of prostatectomy dissection.

INTRODUCTION: Minimally invasive radical prostatectomy (RP) (robotic and laparoscopic), have brought improvements in the outcomes of RP due to improved views and increased degrees of freedom of surgical devices. Robotic and laparoscopic surgeries do not incorporate haptic feedback, which may result in complications secondary to inadequate tissue dissection (causing positive surgical margins, rhabdosphincter damage, etc). We developed a micro-engineered device (6 mm2 sized) [E-finger]) capable of quantitative elasticity assessment, with amplitude ratio, mean ratio and phase lag representing this. The aim was to assess the utility of the device in differentiating peri-prostatic tissue types in order to guide prostate dissection. MATERIAL AND METHODS: Two embalmed and 2 fresh frozen cadavers were used in the study. Baseline elasticity values were assessed in bladder, prostate and rhabdosphincter of pre-dissected embalmed cadavers using the micro-engineered device. A measurement grid was created to span from the bladder, across the prostate and onto the rhabdosphincter of fresh frozen cadavers to enable a systematic quantitative elasticity assessment of the entire area by 2 independent assessors. Tissue was sectioned along each row of elasticity measurement points, and stained with haematoxylin and eosin (H&E). Image analysis was performed with Image Pro Premier to determine the histology at each measurement point. RESULTS: Statistically significant differences in elasticity were identified between bladder, prostate and sphincter in both embalmed and fresh frozen cadavers (p = < 0.001). Intra-class correlation (ICC) reliability tests showed good reliability (average ICC = 0.851). Sensitivity and specificity for tissue identification was 77% and 70% respectively to a resolution of 6 mm2. CONCLUSIONS: This cadaveric study has evaluated the ability of our elasticity assessment device to differentiate bladder, prostate and rhabdosphincter to a resolution of 6 mm2. The results provide useful data for which to continue to examine the use of elasticity assessment devices for tissue quality assessment with the aim of giving haptic feedback to surgeons performing complex surgery.

Midterm oncological outcome and clinicopathological characteristics of anterior prostate cancers treated by endoscopic extraperitoneal radical prostatectomy.

PURPOSE: The purpose of the study is to characterise the clinicopathological characteristics of anterior prostate cancer (APC) compared to posterior prostate cancer (PPC)s and to determine the midterm oncological outcomes of patients with APCs undergoing endoscopic extraperitoneal radical prostatectomy (EERPE). METHODS: A retrospective review was carried out on all EERPEs performed in 2009. Pathology reports (transrectal ultrasound biopsy and surgical specimen), specimen photographs, demographic details and oncological outcome data from a prospectively maintained database were reviewed. Unpaired t test, chi-squared test and Kaplan-Meier curves were used for the analysis. RESULTS: Of 139 patients identified, 53 were APCs (38 %) and 86 were PPCs (62 %). Significantly, greater number of repeat biopsies were required to diagnose APCs (p = 0.02) and they had significantly fewer positive biopsy cores (p = 0.0005). The APC group had a significantly higher PSA density (PSAd) with (<5 and 5-25 %) tumour involvement in positive cores compared to PPCs (p = 0.036 and 0.024, respectively). APCs had higher positive surgical margin (PSM) rates (p = ns), the apical margin more likely positive than PPCs (p = 0.0006). Biochemical recurrence-free survival (BRFS) for APCs at 1, 2 and 3 years was lower than PPCs, although not statistically significant (p = 0.16). CONCLUSION: In our study, APCs proved more difficult to diagnose and stage, had a higher PSM rate and a trend towards a worse bRFS than PPCs. Additionally, the use of PSAd low core involvement biopsies might aide clinicians to investigate this cohort of patients more thoroughly before advising active surveillance.

Five-year oncological outcomes of endoscopic extraperitoneal radical prostatectomy (EERPE) for prostate cancer: results from a medium-volume UK centre.

OBJECTIVE: To determine the 5-year oncological outcomes of endoscopic extraperitoneal radical prostatectomy (EERPE) from a medium-volume centre, thereby providing much needed data on outcomes from the UK. PATIENTS AND METHODS: From January 2006 to January 2012, 575 patients underwent EERPE for localized prostate cancer, performed by a single surgeon who had completed a modular training programme. Follow-up was as per local hospital policy and data were collected in our prospective database. A retrospective review of patient demographics, prostate-specific antigen (PSA) levels, pathological T stages, Gleason scores, surgical margin status and biochemical recurrence (BCR) data was performed. BCR was defined as PSA >0.2 µg/L. RESULTS: The mean (range) patient age was 62 (40.3-76.5) years and the mean (range) follow-up was 30 (12-72) months. The median (interquartile range [IQR]) operating time was 135 (120-170) min and the median (IQR) blood loss was 200 (100-250) mL. Of the 575 patients, 135 (23.5%) had positive surgical margins (PSMs). The PSM rate for pT2 disease was 66/406 patients (16.3%) and for pT3 disease it was 68/168 patients (40.5%). Overall BCR-free survival at 5-years was 81.5%. Multivariate Cox analysis showed that PSMs, Gleason score, D'Amico risk category and pT stage were independent predictors of BCR-free survival. CONCLUSIONS: This assessment of the oncological results of EERPE, which included the surgical learning curve, shows that the adoption of EERPE after mentored fellowship training translates into mid-term oncological outcomes in line with those of retropubic/transperitoneal laparoscopic approaches and with large-volume centres worldwide which have pioneered laparoscopic radical prostatectomy. The study shows that EERPE in a medium-volume second generation laparoscopic centre (that introduced EERPE after adequate training in pioneering centres) produces results with good 5-year oncological outcomes, similar to those of other major series, for patients in the UK.