Comparative analysis of 1152 African-American and European-American men with prostate cancer identifies distinct genomic and immunological differences.

Racial disparities in prostate cancer have not been well characterized on a genomic level. Here we show the results of a multi-institutional retrospective analysis of 1,152 patients (596 African-American men (AAM) and 556 European-American men (EAM)) who underwent radical prostatectomy. Comparative analyses between the race groups were conducted at the clinical, genomic, pathway, molecular subtype, and prognostic levels. The EAM group had increased ERG (P < 0.001) and ETS (P = 0.02) expression, decreased SPINK1 expression (P < 0.001), and basal-like (P < 0.001) molecular subtypes. After adjusting for confounders, the AAM group was associated with higher expression of CRYBB2, GSTM3, and inflammation genes (IL33, IFNG, CCL4, CD3, ICOSLG), and lower expression of mismatch repair genes (MSH2, MSH6) (p < 0.001 for all). At the pathway level, the AAM group had higher expression of genes sets related to the immune response, apoptosis, hypoxia, and reactive oxygen species. EAM group was associated with higher levels of fatty acid metabolism, DNA repair, and WNT/beta-catenin signaling. Based on cell lines data, AAM were predicted to have higher potential response to DNA damage. In conclusion, biological characteristics of prostate tumor were substantially different in AAM when compared to EAM.

Does Gender Matter in Academic Surgery? Author and Mentor Gender Impact Publication Citations in Surgical Research.

OBJECTIVE: To examine female author representation within publications in the field of urology from the United States from 2000-2019. METHODS: All 25,787 articles with a U.S. correspondence address published in the two largest U.S. headquartered general urology journals, Urology and Journal of Urology, were analyzed from 2000-2019. Gender was assigned to each first and last author based on the author's first name. First names were matched to a database of U.S. Social Security Administration data to determine gender. RESULTS: Overall female authorship, female senior authorship, and female first authorship exhibited a significant upward trend from 2000 to 2019 (P <0.001, P <0.001, P = 0.002). As the number of female last authors increased, female last authors were significantly more likely to publish with female first authors, and significantly less likely publish with male first authors (P <0.001, P <0.001). Furthermore, we found a significant difference for female authors being less likely to get cited than male authors (p = 0.02), despite the greater proportion of females that authored research articles with higher citation counts compared to males (P <0.05). CONCLUSION: Despite the significant progress in female representation within urological publications, female-authored publications continue to constitute a smaller proportion of the urological literature and are less likely to be cited. Our study provides the first evidence on the current status of female underrepresentation within academic urology and literature productivity at this watershed moment. As the number of female urologists evolves, these findings will be of significant impact in the advancement of female investigators in urology.

Racial disparity in prostate cancer in the African American population with actionable ideas and novel immunotherapies.

BACKGROUND: African Americans (AAs) in the United States are known to have a higher incidence and mortality for Prostate Cancer (PCa). The drivers of this epidemiological disparity are multifactorial, including socioeconomic factors leading to lifestyle and dietary issues, healthcare access problems, and potentially tumor biology. RECENT FINDINGS: Although recent evidence suggests once access is equal, AA men have equal outcomes to Caucasian American (CA) men, differences in PCa incidence remain, and there is much to do to reverse disparities in mortality across the USA. A deeper understanding of these issues, both at the clinical and molecular level, can facilitate improved outcomes in the AA population. This review first discusses PCa oncogenesis in the context of its diverse hallmarks before benchmarking key molecular and genomic differences for PCa in AA men that have emerged in the recent literature. Studies have emphasized the importance of tumor microenvironment that contributes to both the unequal cancer burden and differences in clinical outcome between the races. Management of comorbidities like obesity, hypertension, and diabetes will provide an essential means of reducing prostate cancer incidence in AA men. Although requiring further AA specific research, several new treatment strategies such as immune checkpoint inhibitors used in combination PARP inhibitors and other emerging vaccines, including Sipuleucel-T, have demonstrated some proven efficacy. CONCLUSION: Genomic profiling to integrate clinical and genomic data for diagnosis, prognosis, and treatment will allow physicians to plan a "Precision Medicine" approach to AA men. There is a pressing need for further research for risk stratification, which may allow early identification of AA men with higher risk disease based on their unique clinical, genomic, and immunological profiles, which can then be mapped to appropriate clinical trials. Treatment options are outlined, with a concise description of recent work in AA specific populations, detailing several targeted therapies, including immunotherapy. Also, a summary of current clinical trials involving AA men is presented, and it is important that policies are adopted to ensure that AA men are actively recruited. Although it is encouraging that many of these explore the lifestyle and educational initiatives and therapeutic interventions, there is much still work to be done to reduce incidence and mortality in AA men and equalize current racial disparities.

Management of patients who opt for radical prostatectomy during the coronavirus disease 2019 (COVID-19) pandemic: an international accelerated consensus statement.

OBJECTIVE: Coronavirus disease-19 (COVID-19) pandemic caused delays in definitive treatment of patients with prostate cancer. Beyond the immediate delay a backlog for future patients is expected. The objective of this work is to develop guidance on criteria for prioritisation of surgery and reconfiguring management pathways for patients with non-metastatic prostate cancer who opt for surgical treatment. A second aim was to identify the infection prevention and control (IPC) measures to achieve a low likelihood of coronavirus disease 2019 (COVID-19) hazard if radical prostatectomy (RP) was to be carried out during the outbreak and whilst the disease is endemic. METHODS: We conducted an accelerated consensus process and systematic review of the evidence on COVID-19 and reviewed international guidance on prostate cancer. These were presented to an international prostate cancer expert panel (n = 34) through an online meeting. The consensus process underwent three rounds of survey in total. Additions to the second- and third-round surveys were formulated based on the answers and comments from the previous rounds. The Consensus opinion was defined as ≥80% agreement and this was used to reconfigure the prostate cancer pathways. RESULTS: Evidence on the delayed management of patients with prostate cancer is scarce. There was 100% agreement that prostate cancer pathways should be reconfigured and measures developed to prevent nosocomial COVID-19 for patients treated surgically. Consensus was reached on prioritisation criteria of patients for surgery and management pathways for those who have delayed treatment. IPC measures to achieve a low likelihood of nosocomial COVID-19 were coined as 'COVID-19 cold' sites. CONCLUSION: Reconfiguring management pathways for patients with prostate cancer is recommended if significant delay (>3-6 months) in surgical management is unavoidable. The mapped pathways provide guidance for such patients. The IPC processes proposed provide a framework for providing RP within an environment with low COVID-19 risk during the outbreak or when the disease remains endemic. The broader concepts could be adapted to other indications beyond prostate cancer surgery.

Social Determinants Predict Outcomes in Data From a Multi-Ethnic Cohort of 20,899 Patients Investigated for COVID-19.

Importance: The COVID-19 pandemic exploits existing inequalities in social determinants of health (SDOH) in disease burden and access to healthcare. Few studies have examined these emerging disparities using indicators of SDOH. Objective: To evaluate predictors of COVID-19 test positivity, morbidity, and mortality and their implications for inequalities in SDOH and for future policies and health care improvements. Design, Setting, and Participants: A cross sectional analysis was performed on all patients tested for COVID-19 on the basis of symptoms with either a history of travel to at risk regions or close contact with a confirmed case, across the Mount Sinai Health System (MSHS) up until April 26th 2020. Main Outcomes and Measures: Primary outcome was death from COVID-19 and secondary outcomes were test positivity, and morbidity (e.g., hospitalization and intubation caused by COVID-19). Results: Of 20,899 tested patients, 8,928 tested positive, 1,701 were hospitalized, 684 were intubated, and 1,179 died from COVID-19. Age, sex, race/ethnicity, New York City borough (derived from first 3 digits of zip-code), and English as preferred language were significant predictors of test positivity, hospitalization, intubation and COVID-19 mortality following multivariable logistic regression analyses. Conclusions and Relevance: People residing in poorer boroughs were more likely to be burdened by and die from COVID-19. Our results highlight the importance of integrating comprehensive SDOH data into healthcare efforts with at-risk patient populations.

Estimated Costs Associated With Radiation Therapy for Positive Surgical Margins During Radical Prostatectomy.

Importance: Prostate cancer is the most common malignant neoplasm among men and is the one with the highest positive surgical margin (PSM) rate. This high rate is due to the difficulty in balancing the risk of extraprostatic disease and excising periprostatic structures, which ultimately affects patients' quality of life. In the case of a PSM, the appropriateness of adjuvant radiation therapy (aRT) should be discussed. The financial burden of PSMs on health systems has not been investigated. Objective: To estimate the financial costs associated with a PSM during radical prostatectomy on the basis of the odds of undergoing aRT. Design, Setting, and Participants: This cohort study used data on men with prostate cancer from the US National Cancer Database (January 1, 2010, through December 31, 2015). Data were requested in March 2019, accessed in April 2019, and analyzed in August 2019. Exposure: Treatment with radical prostatectomy followed by aRT, if indicated. Main Outcomes and Measures: The attributable risk fraction of PSMs on undergoing aRT was estimated from a logistic regression with aRT administration as the outcome. The analysis was adjusted for patients' socioeconomic and demographic characteristics and tumor characteristics. The aRT cost for the year 2019 was calculated using the Medicare Physician Fee Schedule and the Hospital Outpatient Prospective Payment System. The fraction of this cost attributable to a PSM was estimated according to its attributable risk fraction. Results: In total, 230 175 men were identified (median [interquartile range] age at diagnosis, 62.0 [56.0-67.0] years). Overall, 22.8% of the patients had a PSM. Patients with PSMs were more likely than those without PSMs to be older (median [interquartile range] age, 62.0 [56.0-66.0] years vs 62.0 [57.0-67.0] years) and nonwhite (9320 patients [17.8%] vs 29 872 patients [16.8%]), to have higher comorbidity scores (1604 patients [3.1%] vs 4884 patients [2.7%] with a Charlson-Deyo Comorbidity Index score ≥2) and worse tumor characteristics (category T3 and T4 disease, 26 394 patients [50.3%] vs 36 040 patients [20.3%]), and to have lower socioeconomic indicators (median annual income <$30 000, 5708 patients [10.9%] vs 17 874 patients [10.1%]; proportion of individuals without a high school degree in the area ≥29%, 6925 patients [13.2%] vs 22 648 patients [12.7%]). In addition, PSMs were documented more frequently at nonacademic institutions than academic ones (31 702 patients [60.5%] vs 20 714 patients [39.5%]). A total of 11 585 patients (5.0%) underwent aRT, and 7698 of them (3.3%) had a PSM at the final pathology examination. When controlling for patients' socioeconomic and demographic characteristics and tumor characteristics, men with PSMs were more likely than those with negative margins to undergo aRT, with an odds ratio of 3.79 (95% CI, 3.63-3.96; P < .001). The attributable risk fraction of the presence of a PSM on aRT was 44% (95% CI, 42%-45%). The attributable cost of a PSM was calculated as $17 356 (95% CI, $16 567-$17 751). Assuming 60 000 prostatectomies in 2019 and similar trends of PSM and aRT, the overall health burden attributable to PSMs was calculated to be $52 068 000 (95% CI, $49 701 000-$53 253 000). Conclusions and Relevance: The estimated aRT cost attributable to the presence of a PSM was $17 356, resulting in $52 068 000 in spending on aRT in 2019. Strategies to reduce PSMs could be associated with a reduction in the overall health costs of surgically treated PCa.

DCE-MRI of the prostate using shutter-speed vs. Tofts model for tumor characterization and assessment of aggressiveness.

PURPOSE: To quantify Tofts model (TM) and shutter-speed model (SSM) perfusion parameters in prostate cancer (PCa) and noncancerous peripheral zone (PZ) and to compare the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to Prostate Imaging and Reporting and Data System (PI-RADS) classification for the assessment of PCa aggressiveness. MATERIALS AND METHODS: Fifty PCa patients (mean age 60 years old) who underwent MRI at 3.0T followed by prostatectomy were included in this Institutional Review Board-approved retrospective study. DCE-MRI parameters (Ktrans , ve , kep [TM&SSM] and intracellular water molecule lifetime τi [SSM]) were determined in PCa and PZ. Differences in DCE-MRI parameters between PCa and PZ, and between models were assessed using Wilcoxon signed-rank tests. Receiver operating characteristic (ROC) analysis for differentiation between PCa and PZ was performed for individual and combined DCE-MRI parameters. Diagnostic performance of DCE-MRI parameters for identification of aggressive PCa (Gleason ≥8, grade group [GG] ≥3 or pathology stage pT3) was assessed using ROC analysis and compared with PI-RADSv2 scores. RESULTS: DCE-MRI parameters were significantly different between TM and SSM and between PZ and PCa (P < 0.037). Diagnostic performances of TM and SSM for differentiation of PCa from PZ were similar (highest AUC TM: Ktrans +kep 0.76, SSM: τi +kep 0.80). PI-RADS outperformed TM and SSM DCE-MRI for identification of Gleason ≥8 lesions (AUC PI-RADS: 0.91, highest AUC DCE-MRI: Ktrans +τi SSM 0.61, P = 0.002). The diagnostic performance of PI-RADS and DCE-MRI for identification of GG ≥3 and pT3 PCa was not significantly different (P > 0.213). CONCLUSION: SSM DCE-MRI did not increase the diagnostic performance of DCE-MRI for PCa characterization. PI-RADS outperformed both TM and SSM DCE-MRI for identification of aggressive cancer. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:837-849.

A Multidimensional Analysis of Prostate Surgery Costs in the United States: Robotic-Assisted versus Retropubic Radical Prostatectomy.

BACKGROUND: The economic value of robotic-assisted laparoscopic prostatectomy (RALP) in the United States is still not well understood because of limited view analyses. OBJECTIVES: The objective of this study was to examine the costs and benefits of RALP versus retropubic radical prostatectomy from an expanded view, including hospital, payer, and societal perspectives. METHODS: We performed a model-based cost comparison using clinical outcomes obtained from a systematic review of the published literature. Equipment costs were obtained from the manufacturer of the robotic system; other economic model parameters were obtained from government agencies, online resources, commercially available databases, an advisory expert panel, and the literature. Clinical point estimates and care pathways based on National Comprehensive Cancer Network guidelines were used to model costs out to 3 years. Hospital costs and costs incurred for the patients' postdischarge complications, adjuvant and salvage radiation treatment, incontinence and potency treatment, and lost wages during recovery were considered. Robotic system costs were modeled in two ways: as hospital overhead (hospital overhead calculation: RALP-H) and as a function of robotic case volume (robotic amortization calculation: RALP-R). All costs were adjusted to year 2014 US dollars. RESULTS: Because of more favorable clinical outcomes over 3 years, RALP provided hospital ($1094 savings with RALP-H, $341 deficit with RALP-R), payer ($1451), and societal ($1202) economic benefits relative to retropubic radical prostatectomy. CONCLUSIONS: Monte-Carlo probabilistic sensitivity analysis demonstrated a 38% to 99% probability that RALP provides cost savings (depending on the perspective). Higher surgical consumable costs are offset by a decreased hospital stay, lower complication rate, and faster return to work.

Defining a standard set of patient-centered outcomes for men with localized prostate cancer.

BACKGROUND: Value-based health care has been proposed as a unifying force to drive improved outcomes and cost containment. OBJECTIVE: To develop a standard set of multidimensional patient-centered health outcomes for tracking, comparing, and improving localized prostate cancer (PCa) treatment value. DESIGN, SETTING, AND PARTICIPANTS: We convened an international working group of patients, registry experts, urologists, and radiation oncologists to review existing data and practices. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The group defined a recommended standard set representing who should be tracked, what should be measured and at what time points, and what data are necessary to make meaningful comparisons. Using a modified Delphi method over a series of teleconferences, the group reached consensus for the Standard Set. RESULTS AND LIMITATIONS: We recommend that the Standard Set apply to men with newly diagnosed localized PCa treated with active surveillance, surgery, radiation, or other methods. The Standard Set includes acute toxicities occurring within 6 mo of treatment as well as patient-reported outcomes tracked regularly out to 10 yr. Patient-reported domains of urinary incontinence and irritation, bowel symptoms, sexual symptoms, and hormonal symptoms are included, and the recommended measurement tool is the Expanded Prostate Cancer Index Composite Short Form. Disease control outcomes include overall, cause-specific, metastasis-free, and biochemical relapse-free survival. Baseline clinical, pathologic, and comorbidity information is included to improve the interpretability of comparisons. CONCLUSIONS: We have defined a simple, easily implemented set of outcomes that we believe should be measured in all men with localized PCa as a crucial first step in improving the value of care. PATIENT SUMMARY: Measuring, reporting, and comparing identical outcomes across treatments and treatment centers will provide patients and providers with information to make informed treatment decisions. We defined a set of outcomes that we recommend being tracked for every man being treated for localized prostate cancer.

Primary treatments for clinically localised prostate cancer: a comprehensive lifetime cost-utility analysis.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Multiple treatment alternatives exist for localised prostate cancer, with few high-quality studies directly comparing their comparative effectiveness and costs. The present study is the most comprehensive cost-effectiveness analysis to date for localised prostate cancer, conducted with a lifetime horizon and accounting for survival, health-related quality-of-life, and cost impact of secondary treatments and other downstream events, as well as primary treatment choices. The analysis found minor differences, generally slightly favouring surgical methods, in quality-adjusted life years across treatment options. However, radiation therapy (RT) was consistently more expensive than surgery, and some alternatives, e.g. intensity-modulated RT for low-risk disease, were dominated - that is, both more expensive and less effective than competing alternatives. OBJECTIVE: To characterise the costs and outcomes associated with radical prostatectomy (open, laparoscopic, or robot-assisted) and radiation therapy (RT: dose-escalated three-dimensional conformal RT, intensity-modulated RT, brachytherapy, or combination), using a comprehensive, lifetime decision analytical model. PATIENTS AND METHODS: A Markov model was constructed to follow hypothetical men with low-, intermediate-, and high-risk prostate cancer over their lifetimes after primary treatment; probabilities of outcomes were based on an exhaustive literature search yielding 232 unique publications. In each Markov cycle, patients could have remission, recurrence, salvage treatment, metastasis, death from prostate cancer, and death from other causes. Utilities for each health state were determined, and disutilities were applied for complications and toxicities of treatment. Costs were determined from the USA payer perspective, with incorporation of patient costs in a sensitivity analysis. RESULTS: Differences across treatments in quality-adjusted life years across methods were modest, ranging from 10.3 to 11.3 for low-risk patients, 9.6-10.5 for intermediate-risk patients and 7.8-9.3 for high-risk patients. There were no statistically significant differences among surgical methods, which tended to be more effective than RT methods, with the exception of combined external beam + brachytherapy for high-risk disease. RT methods were consistently more expensive than surgical methods; costs ranged from $19 901 (robot-assisted prostatectomy for low-risk disease) to $50 276 (combined RT for high-risk disease). These findings were robust to an extensive set of sensitivity analyses. CONCLUSIONS: Our analysis found small differences in outcomes and substantial differences in payer and patient costs across treatment alternatives. These findings may inform future policy discussions about strategies to improve efficiency of treatment selection for localised prostate cancer.

Assessment of required nodal yield in a high risk cohort undergoing extended pelvic lymphadenectomy in robotic-assisted radical prostatectomy and its impact on functional outcomes.

OBJECTIVES: To establish a minimal lymph node yield (LNY) necessary for accurate staging in a high risk cohort, since no consensus exists as to the optimal extent of pelvic lymph node dissection (PLND) needed during radical prostatectomy in high risk patients. To investigate the impact of an extended PLND on urinary and sexual function. PATIENTS AND METHODS: In all, 760 men underwent robotic-assisted radical prostatectomy from January 2010 to May 2011 by a single surgeon (AKT). Low and intermediate risk groups (as defined by the D'Amico classification) underwent a minimum of a limited PLND (obturator/external iliac packets) and high risk patients underwent an extended PLND (as limited plus hypogastric, triangle of Marcille and common iliac packets up to the level of the ureteric crossing). In order to analyse LNY for staging purposes, the high risk group (n = 82) was subdivided into patients with ≥13 LNY vs <13 LNY and the incidence of lymph node (LN) invasion was compared between these groups. To study the impact of extended PLND on functional outcomes, we evaluated patients from our total cohort who were preoperatively potent (Sexual Health Inventory for Men ≥17), continent and who received bilateral nerve-sparing surgery. Return to potency at 26 weeks postoperatively was defined as a score of ≥3 on questions 2 and 3 of the Sexual Health Inventory for Men questionnaire, and continence was defined as zero pads per day or one pad for security per day. RESULTS: Median LNYs in the low, intermediate and high risk groups were (interquartile range [IQR]) 5 (2-10), 7 (3-12) and 13 (6-20) (P < 0.001); LN positivity was 0% (0 of 309), 0.8% (3 of 369) and 13.4% (11 of 82) in the three respective groups (P < 0.001). Median LNYs (IQR) among the high risk LN positive and negative patients were 20 (13-22) and 11 (5-18) (P = 0.05); 5% of the patients had positive LNs in the <13 LNY group vs 21% of patients in the >13 LNY group (P = 0.036). Median (IQR) console time was significantly different, at 120 min (95-137) for the ≥13 LNY group vs 100 min (85-120) for the <13 LNY group (P = 0.04). Among patients who fitted the inclusion criteria for functional outcomes (n = 561), 55.2% (16 of 29) with ≥20 LNs removed recovered potency at a median follow-up of 6 months postoperatively vs 70% of patients with <20 LNs (301 of 430) (P = 0.020). There was no significant difference in continence recovery between the groups. CONCLUSIONS: High risk patients should undergo an extended dissection with at least 13 LNs removed for accurate staging. Extended PLND with LNYs of ≥20 is associated with worse potency outcomes. With LN positivity occurring rarely in low risk patients, extended PLND may be of little oncological benefit but with significant functional compromise in this cohort.

Biobanking after robotic-assisted radical prostatectomy: a quality assessment of providing prostate tissue for RNA studies.

BACKGROUND: RNA quality is believed to decrease with ischaemia time, and therefore open radical prostatectomy has been advantageous in allowing the retrieval of the prostate immediately after its devascularization. In contrast, robotic-assisted laparoscopic radical prostatectomies (RALP) require the completion of several operative steps before the devascularized prostate can be extirpated, casting doubt on the validity of this technique as a source for obtaining prostatic tissue. We seek to establish the integrity of our biobanking process by measuring the RNA quality of specimens derived from robotic-assisted laparoscopic radical prostatectomy. METHODS: We describe our biobanking process and report the RNA quality of prostate specimens using advanced electrophoretic techniques (RNA Integrity Numbers, RIN). Using multivariate regression analysis we consider the impact of various clinicopathological correlates on RNA integrity. RESULTS: Our biobanking process has been used to acquire 1709 prostates, and allows us to retain approximately 40% of the prostate specimen, without compromising the histopathological evaluation of patients. We collected 186 samples from 142 biobanked prostates, and demonstrated a mean RIN of 7.25 (standard deviation 1.64) in 139 non-stromal samples, 73% of which had a RIN ≥ 7. Multivariate regression analysis revealed cell type--stromal/epithelial and benign/malignant--and prostate volume to be significant predictors of RIN, with unstandardized coefficients of 0.867(p = 0.001), 1.738(p < 0.001) and -0.690(p = 0.009) respectively. A mean warm ischaemia time of 120 min (standard deviation 30 min) was recorded, but multivariate regression analysis did not demonstrate a relationship with RIN within the timeframe of the RALP procedure. CONCLUSIONS: We demonstrate the robustness of our protocol--representing the concerted efforts of dedicated urology and pathology departments--in generating RNA of sufficient concentration and quality, without compromising the histopathological evaluation and diagnosis of patients. The ischaemia time associated with our prostatectomy technique using a robotic platform does not negatively impact on biobanking for RNA studies.

Residency training program paradigms for teaching robotic surgical skills to urology residents.

The advent of laparoscopic and robotic techniques for management of urologic malignancies marked the beginning of an ever-expanding array of minimally invasive options available to cancer patients. With the popularity of these treatment modalities, there is a growing need for trained surgical oncologists who not only have a deep understanding of the disease process and adept surgical skills, but also show technical mastery in operating the equipment used to perform these techniques. Establishing a robotic prostatectomy program is a tremendous undertaking for any institution, as it involves a huge cost, especially in the purchasing and maintenance of the robot. Residency programs often face many challenges when trying to establish a balance between costs associated with robotic surgery and training of the urology residents, while maintaining an acceptable operative time. Herein we describe residency training program paradigms for teaching robotic surgical skills to urology residents. Our proposed paradigm outlines the approach to compensate for the cost involved in robotic training establishment without compromising the quality of education provided. With the potential advantages for both patients and surgeons, we contemplate that robotic-assisted surgery may become an integral component of residency training programs in the future.

Bayesian neural networks for bivariate binary data: an application to prostate cancer study.

Prostate cancer is one of the most common cancers in American men. The cancer could either be locally confined, or it could spread outside the organ. When locally confined, there are several options for treating and curing this disease. Otherwise, surgery is the only option, and in extreme cases of outside spread, it could very easily recur within a short time even after surgery and subsequent radiation therapy. Hence, it is important to know, based on pre-surgery biopsy results how likely the cancer is organ-confined or not. The paper considers a hierarchical Bayesian neural network approach for posterior prediction probabilities of certain features indicative of non-organ confined prostate cancer. In particular, we find such probabilities for margin positivity (MP) and seminal vesicle (SV) positivity jointly. The available training set consists of bivariate binary outcomes indicating the presence or absence of the two. In addition, we have certain covariates such as prostate specific antigen (PSA), gleason score and the indicator for the cancer to be unilateral or bilateral (i.e. spread on one or both sides) in one data set and gene expression microarrays in another data set. We take a hierarchical Bayesian neural network approach to find the posterior prediction probabilities for a test and validation set, and compare these with the actual outcomes for the first data set. In case of the microarray data we use leave one out cross-validation to access the accuracy of our method. We also demonstrate the superiority of our method to the other competing methods through a simulation study. The Bayesian procedure is implemented by an application of the Markov chain Monte Carlo numerical integration technique. For the problem at hand, our Bayesian bivariate neural network procedure is shown to be superior to the classical neural network, Radford Neal's Bayesian neural network as well as bivariate logistic models to predict jointly the MP and SV in a patient in both the data sets as well as in the simulation study.