Hyaluronan Metabolism in Urologic Cancers.

Hyaluronan (HA) is one of the major components of the extracellular matrix in tumor tissue. Recent reports have made it clear that the balance of HA synthesis and degradation is critical for tumor progression. HA is synthesized on the cytoplasmic surface of the plasma membrane by hyaluronan synthases (HAS) and extruded into the extracellular space. Excessive HA production in cancer is associated with enhanced HA degradation in the tumor microenvironment, leading to the accumulation of HA fragments with small molecular weight. These perturbations in both HA synthesis and degradation may play important roles in tumor progression. Recently, it has become increasingly clear that small HA fragments can induce a variety of biological events, such as angiogenesis, cancer-promoting inflammation, and tumor-associated immune suppression. Progression of urologic malignancies, particularly of prostate and bladder cancers, as well as of certain types of kidney cancer show markedly perturbed metabolism of tumor-associated HA. This review highlights the recent research findings regarding HA metabolism in tumor microenvironments with a special focus on urologic cancers. It also will discuss the potential implications of these findings for the development of novel therapeutic interventions for the treatment of prostate, bladder, and kidney cancers.

Micro-Ultrasound Guided Transperineal Prostate Biopsy: A Clinic-Based Procedure.

Prostate cancer is the most common solid malignancy in men and requires a biopsy for diagnosis. This manuscript describes a freehand micro-ultrasound guided transperineal technique performed under local anesthesia, which maintains accuracy, keeps patients comfortable, has low adverse events, and minimizes the need for disposables. Prior micro-ultrasound-guided transperineal techniques required general or spinal anesthesia. The key steps described in the protocol include (1) the placement of the local anesthesia, (2) micro-ultrasound imaging, (3) and the visualization of the anesthetic/biopsy needle while uncoupled from the insonation plane. A retrospective review of 100 patients undergoing this technique demonstrated a 68% clinically significant cancer detection rate. Pain scores were prospectively collected in a subset of patients (N = 20) and showed a median procedural pain score of 2 out of 10. The 30 day Grade III adverse event rate was 3%; one of these events was probably related to the prostate biopsy. Overall, we present a simple, accurate, and safe technique for performing a micro-ultrasound-guided transperineal prostate biopsy.

Applications of Exosomes in Diagnosing Muscle Invasive Bladder Cancer.

Muscle Invasive Bladder Cancer (MIBC) is a subset of bladder cancer with a significant risk for metastases and death. It accounts for nearly 25% of bladder cancer diagnoses. A diagnostic work-up for MIBC is inclusive of urologic evaluation, radiographic imaging with a CT scan, urinalysis, and cystoscopy. These evaluations, especially cystoscopy, are invasive and carry the risk of secondary health concerns. Non-invasive diagnostics such as urine cytology are an attractive alternative currently being investigated to mitigate the requirement for cystoscopy. A pitfall in urine cytology is the lack of available options with high reliability, specificity, and sensitivity to malignant bladder cells. Exosomes are a novel biomarker source which could resolve some of the concerns with urine cytology, due to the high specificity as the surrogates of tumor cells. This review serves to define muscle invasive bladder cancer, current urine cytology methods, the role of exosomes in MIBC, and exosomes application as a diagnostic tool in MIBC. Urinary exosomes as the specific populations of extracellular vesicles could provide additional biomarkers with specificity and sensitivity to bladder malignancies, which are a consistent source of cellular information to direct clinicians for developing treatment strategies. Given its strong presence and differentiation ability between normal and cancerous cells, exosome-based urine cytology is highly promising in providing a perspective of a patient's bladder cancer.

High Levels of PD-L1+ and Hyal2+ Myeloid-derived Suppressor Cells in Renal Cell Carcinoma.

Renal cell carcinoma (RCC) patients frequently have increased number of immunosuppressive myeloid cells in circulation. High number of myeloid-derived suppressor cells (MDSCs) in the blood are associated with immune suppression as well as with cancer-related inflammation which drives the mobilization of myeloid cells to tumor tissue. Here, we show that peripheral blood from a previously untreated RCC patient has increased the number of monocytic CD33+CD11b+ MDSCs, which also co-expressed PD-L1 and membrane-bound enzyme hyaluronidase 2 (Hyal2). PD-L1 expression is associated with immune suppression, whereas expression of Hyal2 is associated with inflammation, because Hyal2+ myeloid cells can degrade the extracellular hyaluronan (HA), leading to the accumulation of pro-inflammatory HA fragments with low molecular weight. These findings implicate the potential involvement of monocytic MDSCs in both tumor-associated immune suppression and cancer-related inflammation. Analysis of organotypic tumor-tissue slice cultures prepared from cancer tissue of the same patient revealed the significant presence of PD-L1+ HLA-DR+ macrophage-like or dendritic cell-like antigen-presenting cells in tumor stroma. Interestingly, stroma-associated PD-L1+ cells frequently have intracellular hyaluronan. Collectively, data presented in this study suggest that the interplay between tumor-recruited myeloid cells and stromal HA may contribute to the inflammation and immune tolerance in kidney cancer.

Detection of PD-L1-Expressing Myeloid Cell Clusters in the Hyaluronan-Enriched Stroma in Tumor Tissue and Tumor-Draining Lymph Nodes.

Expression of the transmembrane protein PD-L1 is frequently upregulated in cancer. Because PD-L1-expressing cells can induce apoptosis or anergy of T lymphocytes through binding to the PD1 receptor, the PD-L1-mediated inhibition of activated PD1+ T cells is considered a major pathway for tumor immune escape. However, the mechanisms that regulate the expression of PD-L1 in the tumor microenvironment are not fully understood. Analysis of organotypic tumor tissue slice cultures, obtained from mice with implanted syngeneic tumors (MBT2 bladder tumors in C3H mice, Renca kidney, and CT26 colon tumors in BALB/c mice), as well as from patients with cancer, revealed that tumor-associated hyaluronan (HA) supports the development of immunosuppressive PD-L1+ macrophages. Using genetically modified tumor cells, we identified epithelial tumor cells and cancer-associated mesenchymal fibroblast-like cells as a major source of HA in the tumor microenvironment. These HA-producing tumor cells, and particularly the vimentin-positive fibroblast-like cells of bone marrow origin, directly interact with tumor-recruited myeloid cells to form large stromal congregates/clusters that are highly enriched for both HA and PD-L1. Furthermore, similar cell clusters composed of HA-producing fibroblast-like cells and PD-L1+ macrophages were detected in tumor-draining, but not in distant, lymph nodes. Collectively, our findings indicate that the formation of multiple large HA-enriched stromal clusters that support the development of PD-L1-expressing APCs in the tumor microenvironment and draining lymph nodes could contribute to the immune escape and resistance to immunotherapy in cancer.

Utilization and outcomes of metastasectomy for patients with metastatic urothelial cancer: An analysis of the national cancer database.

BACKGROUND: Surgical resection of oligometastatic disease has been shown to be associated with an improved survival in other malignancies, though its role is not established in metastatic urothelial carcinoma (mUC). We sought to examine utilization trends of metastasectomy in mUC and associated outcomes using the NCDB database. METHODS: We queried the NCDB from 2004 to 2016 for patients with metastatic urothelial carcinoma who had undergone metastasectomy. The annual utilization trend of metastasectomy was evaluated by linear regression. We compared overall survival (OS) between propensity score matched patients who had undergone metastasectomy and those who had not using two-sided log-rank and Cox regression models. We also performed sensitivity analyses on subcohorts of mUC. RESULTS: The utilization rate of metastasectomy in mUC was 7% and did not change significantly over time. Patients who received metastasectomy on average were younger, had >cT3 disease, had radical surgery to the primary tumor, and received systemic therapy. After propensity score matching, metastasectomy was not associated with an OS benefit for mUC patients (HR, 0.94; 95% CI, 0.83 to 1.07; P=0.38). Stratified subgroup analysis based on systemic therapy, radical surgery to primary tumor, clinical N stage, and primary location of disease did not show an OS benefit of metastasectomy. CONCLUSION: Metastasectomy is uncommonly used, though utilization has persisted over more than a decade. Despite selection biases and residual confounding favoring patients undergoing metastasectomy, we found similar OS among these individuals and those who did not undergo metastasectomy.

Predicting Complete Response to Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer.

Muscle-invasive bladder cancer is a life-threatening disease best managed with multimodal therapy. Neoadjuvant chemotherapy prior to cystectomy significantly improves survival with the greatest benefit noted in patients with a complete pathologic response noted at cystectomy. While radical cystectomy is currently an important part of the treatment plan, surgical morbidity remains high. Accurate prediction of complete responses to chemotherapy would enable avoiding the morbidity of radical cystectomy. Multiple clinical, pathologic, molecular, and radiographic predictors have been evaluated. Clinical and standard pathologic findings have not been found to be accurate predictors of complete response. To date, tumor genomic findings have been the most promising and have led to multiple clinical trials to evaluate if bladder preservation is possible in select patients. Radiomics has shown initial promise with larger validation series needed. These predictors can be further characterized as treatment specific and non-treatment specific. With the potential changing landscape of neoadjuvant therapy prior to radical cystectomy and the limitations of individual predictors of a complete response, a panel of several biomarkers may enhance patient selection for bladder preservation. The aim of this review is to summarize predictors of complete response to neoadjuvant chemotherapy.

Robot-Assisted Radical Nephroureterectomy.

First proposed by Kimball and Ferris in 1933 for the treatment of papillary tumors in the upper urinary tract, radical nephroureterectomy (RNU) with bladder cuff excision remains the gold standard for management of high-risk upper tract urothelial carcinoma involving the proximal ureter and/or pelvicaliceal system. Over three decades since the first description of laparoscopic RNU, minimally invasive approaches to RNU have continued to evolve and become increasingly utilized. More recently, robot-assisted RNU (RARNU) has increasingly become a viable approach. Specifically, RARNU affords a reduction in perioperative morbidity and improved convalescence as a minimally invasive approach, all while adhering to traditional open surgical principles and providing surgeons with improved technical ergonomics and streamlined operating room logistics, particularly with the advent of the da Vinci Xi platform. In this study, we describe our approach to transperitoneal RARNU, including indications, operating room setup, step-by-step surgical technique, and perioperative care.

Association between nuclear grade of renal cell carcinoma and the aorta-lesion-attenuation-difference.

INTRODUCTION AND BACKGROUND: Several features noted on renal mass biopsy (RMB) can influence treatment selection including tumor histology and nuclear grade. However, there is poor concordance between renal cell carcinoma (RCC) nuclear grade on RMB compared to nephrectomy specimens. Here, we evaluate the association of nuclear grade with aorta-lesion-attenuation-difference (ALAD) values determined on preoperative CT scan. METHODS AND MATERIALS: A retrospective review of preoperative CT scans and surgical pathology was performed on patients undergoing nephrectomy for solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate low-grade (nuclear grade 1 and 2) and high-grade (nuclear grade 3 and 4) tumors was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis. Sub-group analysis by histologic sub-type was also performed. RESULTS: A total of 368 preoperative CT scans in patients with RCC on nephrectomy specimen were reviewed. Median patient age was 61 years (IQR 52-68). The majority of patients were male, 66% (243/368). Tumor histology was chromophobe RCC in 7.6%, papillary RCC in 15.5%, and clear cell RCC in 76.9%. The majority, 69.3% (253/365) of tumors, were stage T1a. Nuclear grade was grade 1 in 5.46% (19/348), grade 2 in 64.7% (225/348), grade 3 in 26.2% (91/348), and grade 4 in 3.2% (11/348). Nephrographic ALAD values for grade 1, 2, 3, and 4 were 73.7, 46.5, 36.4, and 43.1, respectively (p = 0.0043). Nephrographic ALAD was able to differentiate low-grade from high-grade RCC with a sensitivity of 32%, specificity of 89%, PPV of 86%, and NPV of 36%. ROC analysis demonstrated the predictive utility of nephrographic ALAD to predict high- versus low-grade RCC with an AUC of 0.60 (95% CI 0.51-0.69). CONCLUSION: ALAD was significantly associated with nuclear grade in our nephrectomy series. Strong specificity and PPV for the nephrographic phrase demonstrate a potential role for ALAD in the pre-operative setting that may augment RMB findings in assessing nuclear grade of RCC. Although this association was statistically significant, the clinical utility is limited at this time given the results of the statistical analysis (relatively poor ROC analysis). Sub-group analysis by histologic subtype yielded very similar diagnostic performance and limitations of ALAD. Further studies are necessary to evaluate this relationship further.

Validation of aorta-lesion-attenuation difference on preoperative contrast-enhanced computed tomography scan to differentiate between malignant and benign oncocytic renal tumors.

OBJECTIVES: We previously noted that the aorta-lesion-attenuation difference (ALAD) determined on CT scan discriminated well between chromophobe RCC and oncocytoma. The current evaluation seeks to validate these initial findings in a second cohort of nephrectomy patients. METHODS: A retrospective review of preoperative CT scans and surgical pathology was performed on patients undergoing nephrectomy for small, solid renal masses. ALAD was calculated by measuring the difference in Hounsfield units (HU) between the aorta and the lesion of interest on the same image slice on preoperative CT scan. The discriminative ability of ALAD to differentiate malignant pathology from oncocytoma was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) using ROC analysis. RESULTS: Twenty-one preoperative CT scans and corresponding pathology reports were reviewed and included in the validation cohort. ALAD values were calculated during the excretory and nephrographic phases. Compared to the training cohort, patients in the validation cohort were significantly older (62 versus 59 years old), had larger tumors (3.7 versus 2.7 cm), and higher stage disease (59% versus 79% T1a disease). Nephrographic ALAD was able to differentiate malignant pathology from oncocytoma in the training and validation cohorts with a sensitivity of 84% versus 73%, specificity of 86% and 67%, PPV of 98% versus 91%, and NPV of 33% versus 35%. The AUC for malignant pathology versus oncocytoma in the validation cohort was 0.72 (95% CI 0.63-0.82). Nephrographic ALAD was able to differentiate chromophobe RCC from oncocytoma in the training and validation cohorts with a sensitivity of 100% versus 67%, specificity of 86% versus 67%, PPV of 75% versus 43%, and NPV of 100% versus 84%. The AUC for chromophobe RCC versus oncocytoma in the validation cohort was 0.72 (95% CI 0.48-0.96). CONCLUSIONS: The ability of ALAD to discriminate between chromophobe RCC and oncocytoma was diminished in the validation cohort compared to the training cohort, but remained significant. The current findings support further investigation in the role of ALAD in the management of patients with indeterminate diagnoses of oncocytic neoplasm.

Hyal2 Expression in Tumor-Associated Myeloid Cells Mediates Cancer-Related Inflammation in Bladder Cancer.

The increased presence of myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAM) in tumor tissue has been extensively reported. However, their role in the regulation of hyaluronan (HA) metabolism in the tumor microenvironment has not been established. Here we describe a novel function of tumor-associated myeloid cells related to the enhanced breakdown of extracellular HA in human bladder cancer tissue, leading to the accumulation of small HA fragments with molecular weight (MW) <20 kDa. Increased fragmentation of extracellular HA and accumulation of low molecular weight HA (LMW-HA) in tumor tissue was associated with elevated production of multiple inflammatory cytokines, chemokines, and angiogenic factors. The fragmentation of HA by myeloid cells was mediated by the membrane-bound enzyme hyaluronidase 2 (Hyal2). Increased numbers of Hyal2+CD11b+ myeloid cells were detected in the tumor tissue as well as in the peripheral blood of patients with bladder cancer. Coexpression of CD33 suggested that these cells belong to monocytic myeloid-derived suppressor cells. The HA-degrading function of Hyal2-expressing MDSCs could be enhanced by exposure to tumor-conditioned medium, and IL1ß was identified as one of the factors involved in the stimulation of Hyal2 activity. CD44-mediated signaling played an important role in the regulation of HA-degrading activity of Hyal2-expressing myeloid cells, as the engagement of CD44 receptor with specific mAb triggered translocation of Hyal2 enzyme to the cellular surface and stimulated secretion of IL1ß. Taken together, this work identifies Hyal2-expressing tumor-associated myeloid cells as key players in the accumulation of LMW-HA in the tumor microenvironment and cancer-related inflammation and angiogenesis. SIGNIFICANCE: This study identifies Hyal2-expressing tumor-associated myeloid cells of monocyte-macrophage lineage as contributors to hyaluronan degradation in bladder cancer tissue, leading to accumulation of inflammatory and proangiogenic low molecular weight hyaluronan fragments.

Validation of MRI quantitative susceptibility mapping of superparamagnetic iron oxide nanoparticles for hyperthermia applications in live subjects.

The use of magnetic fluid hyperthermia (MFH) for cancer therapy has shown promise but lacks suitable methods for quantifying exogenous irons such as superparamagnetic iron oxide (SPIO) nanoparticles as a source of heat generation under an alternating magnetic field (AMF). Application of quantitative susceptibility mapping (QSM) technique to prediction of SPIO in preclinical models has been challenging due to a large variation of susceptibility values, chemical shift from tissue fat, and noisier data arising from the higher resolution required to visualize the anatomy of small animals. In this study, we developed a robust QSM for the SPIO ferumoxytol in live mice to examine its potential application in MFH for cancer therapy. We demonstrated that QSM was able to simultaneously detect high level ferumoxytol accumulation in the liver and low level localization near the periphery of tumors. Detection of ferumoxytol distribution in the body by QSM, however, required imaging prior to and post ferumoxytol injection to discriminate exogenous iron susceptibility from other endogenous sources. Intratumoral injection of ferumoxytol combined with AMF produced a ferumoxytol-dose dependent tumor killing. Histology of tumor sections corroborated QSM visualization of ferumoxytol distribution near the tumor periphery, and confirmed the spatial correlation of cell death with ferumoxytol distribution. Due to the dissipation of SPIOs from the injection site, quantitative mapping of SPIO distribution will aid in estimating a change in temperature in tissues, thereby maximizing MFH effects on tumors and minimizing side-effects by avoiding unwanted tissue heating.

An Examination of the Relationship between Mental Distress, Functional and Psychosocial Quality of Life Indicators in a Population Based Sample of Prostate Cancer Survivors Who Received Curative Treatment.

INTRODUCTION: Although survival rates are highest among prostate cancer survivors compared to any other forms of cancer, nearly 60% suffer from mental distress. Here we examine urinary function and psychosocial stressors and their association with poor mental health in a younger group of prostate cancer survivors who have undergone curative treatment. METHODS: The study includes 128 men (47 to 70 years old) who received active treatment for prostate cancer, and completed a survivorship online survey between 2017 and 2018. Psychological distress was assessed with Kessler Psychological Distress Scale. International Prostate Symptom Score subscales (incomplete urinary emptying, frequency, intermittency, urgency, weak stream, straining and nocturia) and number of current prostate cancer survivorship stressors were predictors. Multivariate logistic regression was used to fit the model while controlling for months of survivorship since diagnosis, the presence or absence of surgery, radiation or hormone therapy treatment, current medication for depression and demographics. RESULTS: A total of 19.5% of men scored positive for current mental health issues. Prostate cancer survivors who reported increased number of current survivorship stressors (OR 1.48, 95% CI 1.09-2.01), had higher frequency of urination (OR 2.05, 95% CI 1.15-3.64), history of radiation treatment (OR 7.15, 95% CI 1.02-50.35) and were currently on prescribed medication for depression (OR 33.47, 95% CI 3.80-294.87) had higher odds for screening positive for psychological distress compared with their counterparts. CONCLUSIONS: These results corroborate recent findings showing an intersection between urological oncology and poor mental health during survivorship, and warrant the development of multidisciplinary teams in addressing survivorship issues in this population.

Complication rate after cystectomy following pelvic radiotherapy: an international, multicenter, retrospective series of 682 cases.

PURPOSE: Conflicting evidence exists on the complication rates after cystectomy following previous radiation (pRTC) with only a few available series. We aim to assess the complication rate of pRTC for abdominal-pelvic malignancies. METHODS: Patients treated with radical cystectomy following any previous history of RT and with available information on complications for a minimum of 1 year were included. Univariable and multivariable logistic regression models were used to assess the relationship between the variable parameters and the risk of any complication. RESULTS: 682 patients underwent pRTC after a previous RT (80.5% EBRT) for prostate, bladder (BC), gynecological or other cancers in 49.1%, 27.4%, 9.8% and 12.9%, respectively. Overall, 512 (75.1%) had at least one post-surgical complication, classified as Clavien ≥ 3 in 29.6% and Clavien V in 2.9%. At least one surgical complication occurred in 350 (51.3%), including bowel leakage in 6.2% and ureteric stricture in 9.4%. A medical complication was observed in 359 (52.6%) patients, with UTI/pyelonephritis being the most common (19%), followed by renal failure (12%). The majority of patients (86%) received an incontinent urinary diversion. In multivariable analysis adjusted for age, gender and type of RT, patients treated with RT for bladder cancer had a 1.7 times increased relative risk of experiencing any complication after RC compared to those with RT for prostate cancer (p = 0.023). The type of diversion (continent vs non-continent) did not influence the risk of complications. CONCLUSION: pRTC carries a high rate of major complications that dramatically exceeds the rates reported in RT-naïve RCs.

Surgical Approach Does Not Impact Margin Status After Partial Nephrectomy for Large Renal Masses.

PURPOSE: While surgical approach has recently been associated with positive surgical margin (PSM) after partial nephrectomy (PN) for small (<4 cm) renal masses, its impact on margin status for large (>4 cm) masses is unclear. We sought to evaluate the relationship between margin and surgical approach in patients undergoing PN for large renal masses. MATERIALS AND METHODS: Using the National Cancer Database (NCDB), we identified patients undergoing PN for pathological T1b and T2a renal-cell carcinoma diagnosed from 2010 to 2013. Conversions to open surgery were also included in our analysis. The primary outcome was surgical margin status. Multivariable regression modeling was performed to identify factors associated with PSM. A propensity score matching analysis was then performed to evaluate the impact of margin status on overall survival (OS). RESULTS: Of the 7495 patients undergoing PN for pT1b and pT2a renal masses over the study period, 504 (6.7%) had PSM. On multivariable analysis, surgical approach (laparoscopic or robot assisted vs open) was not significantly associated with surgical margin (p = 0.12 and p = 0.44, respectively). Tumor stage (T2a vs T1b) also showed no significant association (p = 0.18). A subsequent multivariable analysis using clinical staging showed that surgical approach (p = 0.28 and p = 0.54, respectively), tumor stage (p = 0.78), and conversion-to-open surgery (p = 0.98) had no significant association with PSM. Propensity score matched analysis showed that PSM was not significantly associated with OS (hazard ratio 0.95 [95% confidence interval 0.47-1.92] p = 0.88). CONCLUSION: In a contemporary nation-wide cohort, surgical approach was not associated with an increased risk of PSM for large, noninvasive renal masses. Furthermore, increased size from T1b to T2a was not associated with an increased risk of PSM. These data suggest that surgical approach should be selected by surgeon comfort level with an individual tumor, rather than the size of the tumor itself.

Urinary pH and the risk of recurrence in patients with non-muscle invasive bladder cancer.

INTRODUCTION: To evaluate the effect of urine pH on tumor recurrence rates in patients undergoing surveillance after initial diagnosis of non-muscle invasive bladder cancer (NMIBC). MATERIALS AND METHODS: All patients diagnosed with NMIBC at a tertiary referral center from January 2004 to March 2015 were reviewed. Our primary outcome was time to first recurrence after transurethral resection of bladder tumor (TURBT). Patients were analyzed according to the average urine pH of all urinalysis data over the surveillance period from TURBT to first recurrence. Kaplan-Meier survival analysis was used to determine differences in median time to recurrence. Cox proportional hazards regression was used to assess independent predictors of cancer recurrence. RESULTS: A total of 252 patients were included, of which 155 patients had average pH ≤ 6 (median pH 5.5) and 97 patients had average pH > 6 (median pH 6.8), p < 0.001. There was no significant difference in median time to recurrence between low/acidic pH (≤ 6) and high/basic pH (> 6) groups (28 months versus 17 months, respectively, p = 0.3444). Similarly, urine pH did not affect the risk of recurrence in a subgroup analysis stratified by smoking status. On multivariable Cox regression analysis, there was no association between average pH and recurrence among high grade tumors (HR = 1.33, 95% CI = 0.76 to 2.34, p = 0.3186), or low grade tumors (HR = 1.013, 95% CI = 1.01 to 1.58, p = 0.96). CONCLUSIONS: There was no association between urine pH and risk of tumor recurrence, regardless of smoking status. These findings suggest that modification of urine pH is unlikely to decrease the frequency of tumor recurrence in patients with NMIBC.

The Role of Gut Microbiome in the Pathogenesis of Prostate Cancer: A Prospective, Pilot Study.

OBJECTIVE: To elucidate potential biomarkers or mechanistic principles involved with the gut microbiota and its impact on prostate cancer pathogenesis. MATERIALS AND METHODS: We performed a prospective case-control pilot study evaluating the gut microbiome of 20 men with either benign prostatic conditions (n = 8) or intermediate or high risk clinically localized prostate cancer (Gleason ≥4 + 3 cN0M0) (n = 12) undergoing care at tertiary referral center from September 1, 2015 to March 1, 2016. Key exclusion criteria included recent antibiotic use, significant gastrointestinal disorders, hormonal or systemic therapy for prostate cancer. Computational genomics analysis was performed on collected stool samples using MetaPhlAn2 and HUMAnN2 platforms. Linear discriminant analysis effect size method was used to support high-dimensional class comparisons to find biologically relevant features. Kruskal-Wallis sum-rank test was used to detect features with significant differential abundance with respect to class, with biological consistency investigated using a set of pairwise tests among subclasses using the Wilcoxon rank-sum test, both to an α ≤0.05. RESULTS: Higher relative abundance of Bacteriodes massiliensis was seen in prostate cancer cases compared to controls. Faecalibacterium prausnitzii and Eubacterium rectalie had higher relative abundance among controls. Biologically significant differences were also found in relative gene, pathway, and enzyme abundance. CONCLUSION: Biologically significant differences exist in the gut microbial composition of men with prostate cancer compared to benign controls. These differences may play a role in the pathobiology of prostate cancer, and warrant further exploration.