Role of ecto-5'-nucleotidase in bladder function.

Purinergic signaling plays an important role in regulating bladder contractility and voiding. Abnormal purinergic signaling is associated with lower urinary tract symptoms (LUTS). Ecto-5'-nucleotidase (NT5E) catalyzes dephosphorylation of extracellular AMP to adenosine, which in turn promotes adenosine-A2b receptor signaling to relax bladder smooth muscle (BSM). The functional importance of this mechanism was investigated using Nt5e knockout (Nt5eKO) mice. Increased voiding frequency of small voids revealed by voiding spot assay was corroborated by urodynamic studies showing shortened voiding intervals and decreased bladder compliance. Myography indicated reduced contractility of Nt5eKO BSM. These data support a role for NT5E in regulating bladder function through modulation of BSM contraction and relaxation. However, the abnormal bladder phenotype of Nt5eKO mice is much milder than we previously reported in A2b receptor knockout (A2bKO) mice, suggesting compensatory response(s) in Nt5eKO mouse bladder. To better understand this compensatory mechanism, we analyzed changes in purinergic and other receptors controlling BSM contraction and relaxation in the Nt5eKO bladder. We found that the relative abundance of muscarinic CHRM3 (cholinergic receptor muscarinic 3), purinergic P2X1, and A2b receptors was unchanged, whereas P2Y12 receptor was significantly downregulated, suggesting a negative feedback response to elevated ADP signaling. Further studies of additional ecto-nucleotidases indicated significant upregulation of the nonspecific urothelial alkaline phosphatase ALPL, which might mitigate the degree of voiding dysfunction by compensating for Nt5e deletion. These data suggest a mechanistic complexity of the purinergic signaling network in bladder and imply a paracrine mechanism in which urothelium-released ATP and its rapidly produced metabolites coordinately regulate BSM contraction and relaxation.

Enhanced prostatic Esr1+ luminal epithelial cells in the absence of SRD5A2.

Steroid 5α reductase 2 (SRD5A2) converts testosterone to dihydrotestosterone and is crucial for prostatic development. 5α reductase inhibitors (5ARI) reduce prostate size in benign prostate hyperplasia (BPH) and ameliorate lower urinary tract symptoms secondary to BPH. However, the mechanisms of 5ARI functioning are still not fully understood. Here, we used a Srd5a2-/- mouse model and employed single-cell RNA sequencing to explore the impact of SRD5A2 absence on prostate cellular heterogeneity. Significant alterations in luminal epithelial cell (LE) populations were observed, alongside an increased proportion and proliferative phenotype of estrogen receptor 1 (ESR1)+ LE2 cells, following an SRD5A2-independent ESR1 differentiation trajectory. LE2 cells exhibited enhanced estrogen response gene signatures, suggesting an alternative pathway for prostate growth when SRD5A2 is absent. Human prostate biopsy analysis revealed an inverse correlation between the expressions of SRD5A2 and LE2 markers (ESR1/PKCα), and an inverse correlation between SRD5A2 and the clinical efficiency of 5ARI. These findings provide insights into 5ARI resistance mechanisms and potential alternative therapies for BPH-related lower urinary tract symptoms. © 2024 The Pathological Society of Great Britain and Ireland.

Lifetime Health and Economic Outcomes of Biparametric Magnetic Resonance Imaging as First-Line Screening for Prostate Cancer : A Decision Model Analysis.

BACKGROUND: Contemporary prostate cancer (PCa) screening uses first-line prostate-specific antigen (PSA) testing, possibly followed by multiparametric magnetic resonance imaging (mpMRI) for men with elevated PSA levels. First-line biparametric MRI (bpMRI) screening has been proposed as an alternative. OBJECTIVE: To evaluate the comparative effectiveness and cost-effectiveness of first-line bpMRI versus PSA-based screening. DESIGN: Decision analysis using a microsimulation model. DATA SOURCES: Surveillance, Epidemiology, and End Results database; randomized trials. TARGET POPULATION: U.S. men aged 55 years with no prior screening or PCa diagnosis. TIME HORIZON: Lifetime. PERSPECTIVE: U.S. health care system. INTERVENTION: Biennial screening to age 69 years using first-line PSA testing (test-positive threshold, 4 µg/L) with or without second-line mpMRI or first-line bpMRI (test-positive threshold, PI-RADS [Prostate Imaging Reporting and Data System] 3 to 5 or 4 to 5), followed by biopsy guided by MRI or MRI plus transrectal ultrasonography. OUTCOME MEASURES: Screening tests, biopsies, diagnoses, overdiagnoses, treatments, PCa deaths, quality-adjusted and unadjusted life-years saved, and costs. RESULTS OF BASE-CASE ANALYSIS: For 1000 men, first-line bpMRI versus first-line PSA testing prevented 2 to 3 PCa deaths and added 10 to 30 life-years (4 to 11 days per person) but increased the number of biopsies by 1506 to 4174 and the number of overdiagnoses by 38 to 124 depending on the biopsy imaging scheme. At conventional cost-effectiveness thresholds, first-line PSA testing with mpMRI followed by either biopsy approach for PI-RADS 4 to 5 produced the greatest net monetary benefits. RESULTS OF SENSITIVITY ANALYSIS: First-line PSA testing remained more cost-effective even if bpMRI was free, all men with low-risk PCa underwent surveillance, or screening was quadrennial. LIMITATION: Performance of first-line bpMRI was based on second-line mpMRI data. CONCLUSION: Decision analysis suggests that comparative effectiveness and cost-effectiveness of PCa screening are driven by false-positive results and overdiagnoses, favoring first-line PSA testing with mpMRI over first-line bpMRI. PRIMARY FUNDING SOURCE: National Cancer Institute.

Practical Use of Self-Adjusted Nitrous Oxide During Transrectal Prostate Biopsy: A Double-Blind Randomized Controlled Trial.

PURPOSE: Transrectal prostate biopsy is a common ambulatory procedure that can result in pain and anxiety for some men. Low-dose, adjustable nitrous oxide is increasingly being used to improve experience of care for patients undergoing painful procedures. This study seeks to evaluate the efficacy and safety of low-dose (<45%) nitrous oxide, which has not been previously established for transrectal prostate biopsies. MATERIALS AND METHODS: A single-institution, prospective, double-blind, randomized, controlled trial was conducted on patients undergoing transrectal prostate biopsies. Patients were randomized to receive either self-adjusted nitrous oxide or oxygen, in addition to routine periprostatic bupivacaine block. Nitrous oxide at levels between 20% and 45% were adjusted to patients' desired effect. Patients completed a visual analog scale for anxiety, State Trait Anxiety Inventory, and a visual analog scale for pain immediately before and after biopsy. The blinded operating urologist evaluated ease of procedure. Periprocedural vitals and complications were assessed. Patients were allowed to drive home independently. RESULTS: A total of 133 patients received either nitrous oxide (66) or oxygen (67). There was no statistically significant difference in the primary anxiety end point of State Trait Anxiety Inventory or the visual analog scale for anxiety scores between the nitrous oxide and oxygen groups. However, patients in the nitrous oxide group reported significantly lower visual analog scale for pain scores compared to the oxygen group (P = .026). The operating urologists' rating of tolerance of the procedure was better in the nitrous oxide group (P = .03). There were no differences in biopsy performance time. Complications were similarly low between the 2 groups. CONCLUSIONS: Patient-adjusted nitrous oxide at levels of 20% to 45% is a safe adjunct during transrectal prostate biopsy. Although there was not an observed difference in the primary end point of anxiety, nitrous oxide was associated with lower patient-reported pain scores.

Zonal Growth Pattern of the Prostate Is Affected by Age and Body Mass Index.

PURPOSE: As men age, the prostate continues to grow on average 2.5% per year. While the variable growth rate of the total prostate gland is recognized, the growth rate of different prostate zones remains largely unclear. We evaluated the growth patterns of the prostate zones and identified clinical parameters contributing to the zonal growth rates. MATERIALS AND METHODS: Prostate magnetic resonance imaging (MRI) data and clinical information were obtained retrospectively on 156 patients who had at least 3 prostate MRIs between 2003 and 2018. Different prostate zonal volumes were measured and analyzed. The outcome was analyzed using linear regression. RESULTS: We observed that prostate growth rates vary depending on body mass index (BMI), transition zone index (TZI), the prostate zone and 5-alpha reductase inhibitor (5ARI) use. The peripheral zone volume growth rates increased with age and peaked at 60-70 years of age (p=0.047), while the transition zone volume demonstrates continuous growth without a peak through all ages. BMI and TZI are associated with the growth rate of the peripheral zone (p=0.026, p <0.001, respectively) but not the transition zone growth rate. 5ARI use is significantly associated with the reduction in the transition zone growth rate (p=0.033), not the peripheral zone. In addition, patients with TZI greater than 60% had the most significant reduction in the transition zone growth rate while taking 5ARI (p <0.001). CONCLUSIONS: Transition and peripheral zones of the prostate grow at variable rates. BMI and TZI affect peripheral zone growth rate, while 5ARI use reduces the transition zone growth rate.

Single black men have the worst prognosis with localized prostate cancer.

INTRODUCTION: To determine whether marital status combined with race serve as prognostic factors for survival in localized prostate cancer. MATERIALS AND METHODS: Patients with localized prostate cancer were retrospectively extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Chi-square test was used to investigate the association between marital status combined with race and other variables. Gray's test was used to compare the cumulative incidence function of different variables. Multivariable analysis was conducted to assess prognostic factors after adjusting for other variables. RESULTS: A total of 207,219 patients with localized prostate cancer from the SEER database from 2010 to 2016 were eligible. We found that black or single patients had the highest risk of mortality (p < 0.001). When marital status and race were combined, single black patients had the worst prognosis after adjusting for other variables (hazard ratio = 1.93, 95% confidence interval: 1.58-2.35; p < 0.001). Married status had a prognostic advantage in all races. In the same marital groups, whites and Asians had lower risk of prostate cancer-specific mortality and other-cause mortality than blacks with married and single status (p < 0.001). CONCLUSIONS: Marital status and race serve as prognostic factors for localized prostate cancer. Blacks or single individuals had higher risk of mortality when considered independently, and single black patients had the worst prognosis. Furthermore, married status was an advantage in the same race group, and whites and Asians had lower risk than blacks with married and single status. Accordingly, the interaction between race and marital status on prostate cancer prognosis in clinical practice should be assessed carefully.

High Real-World Medication Adherence and Durable Clinical Benefit in Medicare Patients Treated with 5-Alpha Reductase Inhibitors for Benign Prostatic Hyperplasia.

PURPOSE: Although clinical trials demonstrate 5-alpha reductase inhibitors are efficacious treatments for benign prostatic hyperplasia, they have low reported medication adherence outside of clinical trials. We evaluated real-world drug adherence and clinical outcomes in Medicare patients with lower urinary tract symptoms from benign prostatic hyperplasia managed with 5-alpha reductase inhibitor therapy. MATERIALS AND METHODS: Using health care and pharmacy claims from Partners Healthcare Medicare Accountable Care Organization enrollees (January 2009 to July 2018), we identified men initiating a 5-alpha reductase inhibitor for benign prostatic hyperplasia with more than 1 medication dispensation. Adherence was calculated as an 80% or greater proportion of days covered. A Cox proportional hazards model was used to evaluate the primary outcome of treatment failure, defined as any benign prostatic hyperplasia related surgery. RESULTS: Among 3,107 men initiating 5-alpha reductase inhibitor therapy for benign prostatic hyperplasia and filling at least 2 prescriptions, 74.9% had high medication adherence during the first year. Patients with low adherence had 29% higher hazards of undergoing surgical intervention (95% CI 1.02-1.59, p=0.036) after adjusting for age, benign prostatic hyperplasia severity, presence of hematuria, bladder stones and type of 5-alpha reductase inhibitors. The presence of bladder stones (HR 1.70, 95% CI 1.02-2.86, p=0.04) and finasteride vs dutasteride use (HR 1.41, 95% CI 1.01-1.98, p=0.05) were also risk factors for surgical intervention. CONCLUSIONS: Among Medicare patients 5-alpha reductase inhibitor treatment adherence was high and associated with lower hazards of surgical intervention. 5-Alpha reductase inhibitor therapy may be more feasible for older men with benign prostatic hyperplasia than previously reported and demonstrates modest clinical benefit.

Would You Recommend Prostate-Specific Antigen Screening for This Patient?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center.

Prostate cancer is the third most common cancer type in the United States overall, accounting for 9.5% of new cancer cases and 5% of cancer deaths. The goal of prostate-specific antigen (PSA)-based screening is to identify early-stage disease that can be treated successfully. The U.S. Preventive Services Task Force (USPSTF) reviewed evidence on the benefits and harms of PSA-based screening and treatment of screen-detected prostate cancer. It found that PSA-based screening in men aged 55 to 69 years prevents approximately 1.3 deaths from prostate cancer over 13 years per 1000 men screened and 3 cases of metastatic cancer per 1000 men screened, with no reduction in all-cause mortality. No benefit was found for PSA-based screening in men aged 70 years and older. On the basis of its review, the USPSTF concluded that the decision for men aged 55 to 69 years to have PSA-based screening should be an individual one and should include a discussion of the potential benefits and harms. Here, 2 experts-an internist and a urologist-discuss the key points of a shared decision-making conversation about PSA-based prostate cancer screening, the PSA-based screening strategy that optimizes benefit and minimizes harm, and the PSA threshold at which they would recommend further diagnostic testing.

Metformin: an antiproliferative agent and methylation regulator in treating prostatic disease?

Existing drugs that have been used in clinical practice for other purposes can prove useful for reutilization, since much of the safety profile and pharmacokinetics have been completed. Therefore, the drugs can enter clinical practice for a variety of causes with less regulatory burden. Metformin may prove to be such a drug; it may have a role in other diseases, besides the management of diabetes. In this perspective, we provide our findings and understanding of metformin as an alternative way to treat urological abnormal proliferation. We propose the potential mechanisms into two hallmarks: direct antiproliferative function via insulin-like growth factor (IGF) signaling pathway and epigenetic modulating via adjusting DNA methylation. These specific hallmarks may ultimately contribute to a better understanding of metformin in treating prostatic diseases.

Androgenic to oestrogenic switch in the human adult prostate gland is regulated by epigenetic silencing of steroid 5α-reductase 2.

Benign prostatic hyperplasia is the most common proliferative abnormality of the prostate. All men experience some prostatic growth as they age, but the rate of growth varies among individuals. Steroid 5α-reductase 2 (SRD5A2) is a critical enzyme for prostatic development and growth. Previous work indicates that one-third of adult prostatic samples do not express SRD5A2, secondary to epigenetic modifications. Here we show that the level of oestradiol is dramatically elevated, concomitant with significant upregulation of oestrogen response genes, in prostatic samples with methylation at the SRD5A2 promoter. The phosphorylation of oestrogen receptor-α in prostatic stroma is upregulated when SRD5A2 expression is absent. We show that tumour necrosis factor (TNF)-α suppresses SRD5A2 mRNA and protein expression, and simultaneously promotes expression of aromatase, the enzyme responsible for conversion of testosterone to oestradiol. Concomitant suppression of SRD5A2 and treatment with TNF-α synergistically upregulate the aromatase levels. The data suggest that, in the absence of prostatic SRD5A2, there is an androgenic to oestrogenic switch. These findings have broad implications for choosing appropriate classes of medications for the management of benign and malignant prostatic diseases. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

BRCA1 Interacting Protein COBRA1 Facilitates Adaptation to Castrate-Resistant Growth Conditions.

COBRA1 (co-factor of BRCA1) is one of the four subunits of the negative elongation factor originally identified as a BRCA1-interacting protein. Here, we provide first-time evidence for the oncogenic role of COBRA1 in prostate pathogenesis. COBRA1 is aberrantly expressed in prostate tumors. It positively influences androgen receptor (AR) target gene expression and promoter activity. Depletion of COBRA1 leads to decreased cell viability, proliferation, and anchorage-independent growth in prostate cancer cell lines. Conversely, overexpression of COBRA1 significantly increases cell viability, proliferation, and anchorage-independent growth over the higher basal levels. Remarkably, AR-positive androgen dependent (LNCaP) cells overexpressing COBRA1 survive under androgen-deprivation conditions. Remarkably, treatment of prostate cancer cells with well-studied antitumorigenic agent, 2-methoxyestradiol (2-ME2), caused significant DNA methylation changes in 3255 genes including COBRA1. Furthermore, treatment of prostate cancer cells with 2-ME2 downregulates COBRA1 and inhibition of prostate tumors in TRAMP (transgenic adenocarcinomas of mouse prostate) animals with 2-ME2 was also associated with decreased COBRA1 levels. These observations implicate a novel role for COBRA1 in progression to CRPC and suggest that COBRA1 downregulation has therapeutic potential.

DNA methyl transferase 1 reduces expression of SRD5A2 in the aging adult prostate.

5-α Reductase type 2 (SRD5A2) is a critical enzyme for prostatic development and growth. Inhibition of SRD5A2 by finasteride is used commonly for the management of urinary obstruction caused by benign prostatic hyperplasia. Contrary to common belief, we have found that expression of SRD5A2 is variable and absent in one third of benign adult prostates. In human samples, absent SRD5A2 expression is associated with hypermethylation of the SRD5A2 promoter, and in vitro SRD5A2 promoter activity is suppressed by methylation. We show that methylation of SRD5A2 is regulated by DNA methyltransferase 1, and inflammatory mediators such as tumor necrosis factor α, NF-κB, and IL-6 regulate DNA methyltransferase 1 expression and thereby affect SRD5A2 promoter methylation and gene expression. Furthermore, we show that increasing age in mice and humans is associated with increased methylation of the SRD5A2 promoter and concomitantly decreased protein expression. Artificial induction of inflammation in prostate primary epithelial cells leads to hypermethylation of the SRD5A2 promoter and silencing of SRD5A2, whereas inhibition with tumor necrosis factor α inhibitor reactivates SRD5A2 expression. Therefore, expression of SRD5A2 is not static and ubiquitous in benign adult prostate tissues. Methylation and expression of SRD5A2 may be used as a gene signature to tailor therapies for more effective treatment of prostatic diseases.

Age and Obesity Promote Methylation and Suppression of 5α-Reductase 2: Implications for Personalized Therapy of Benign Prostatic Hyperplasia.

PURPOSE: In men with symptomatic benign prostatic hyperplasia 5α-reductase inhibitors are a main modality of treatment. More than 30% of men do not respond to the therapeutic effects of 5α-reductase inhibitors. We have found that a third of adult prostate samples do not express 5α-reductase type 2 secondary to epigenetic modifications. We evaluated whether 5α-reductase type 2 expression in benign prostatic hyperplasia specimens from symptomatic men was linked to methylation of the 5α-reductase type 2 gene promoter. We also identified associations with age, obesity, cardiac risk factors and prostate specific antigen. MATERIALS AND METHODS: Prostate samples from men undergoing transurethral prostate resection were used. We determined 5α-reductase type 2 protein expression and gene promoter methylation status by common assays. Clinical variables included age, body mass index, hypertension, hyperlipidemia, diabetes, prostate specific antigen and prostate volume. Univariate and multivariate statistical analyses were performed followed by stepwise logistic regression modeling. RESULTS: Body mass index and age significantly correlated with methylation of the 5α-reductase type 2 gene promoter (p <0.05) whereas prostate volume, prostate specific antigen or benign prostatic hyperplasia medication did not correlate. Methylation highly correlated with 5α-reductase protein expression (p <0.0001). In a predictive model increasing age and body mass index significantly predicted methylation status and protein expression (p <0.01). CONCLUSIONS: Increasing age and body mass index correlate with increased 5α-reductase type 2 gene promoter methylation and decreased protein expression in men with symptomatic benign prostatic hyperplasia. These results highlight the interplay among age, obesity and gene regulation. Our findings suggest an individualized epigenetic signature for symptomatic benign prostatic hyperplasia, which may be important to choose appropriate personalized treatment options.

Personalized medicine for the management of benign prostatic hyperplasia.

PURPOSE: Benign prostatic hyperplasia affects more than 50% of men by age 60 years, and is the cause of millions of dollars in health care expenditure for the treatment of lower urinary tract symptoms and urinary obstruction. Despite the widespread use of medical therapy, there is no universal therapy that treats all men with symptomatic benign prostatic hyperplasia. At least 30% of patients do not respond to medical management and a subset require surgery. Significant advances have been made in understanding the natural history and development of the prostate, such as elucidating the role of the enzyme 5α-reductase type 2, and advances in genomics and biomarker discovery offer the potential for a more targeted approach to therapy. We review the current understanding of benign prostatic hyperplasia progression as well as the key genes and signaling pathways implicated in the process such as 5α-reductase. We also explore the potential of biomarker screening and gene specific therapies as tools to risk stratify patients with benign prostatic hyperplasia and identify those with symptomatic or medically resistant forms. MATERIALS AND METHODS: A PubMed® literature search of current and past peer reviewed literature on prostate development, lower urinary tract symptoms, benign prostatic hyperplasia pathogenesis, targeted therapy, biomarkers, epigenetics, 5α-reductase type 2 and personalized medicine was performed. An additional Google Scholar™ search was conducted to broaden the scope of the review. Relevant reviews and original research articles were examined, as were their cited references, and a synopsis of original data was generated with the goal of informing the practicing urologist of these advances and their implications. RESULTS: Benign prostatic hyperplasia is associated with a state of hyperplasia of the stromal and epithelial compartments, with 5α-reductase type 2 and androgen signaling having key roles in the development and maintenance of the prostate. Chronic inflammation, multiple growth factor and hormonal signaling pathways, and medical comorbidities have complex roles in prostate tissue homeostasis as well as its evolution into the clinical state of benign prostatic hyperplasia. Resistance to medical therapy with finasteride may occur through silencing of the 5α-reductase type 2 gene by DNA methylation, leading to a state in which 30% of adult prostates do not express 5α-reductase type 2. Novel biomarkers such as single nucleotide polymorphisms may be used to risk stratify patients with symptomatic benign prostatic hyperplasia and identify those at risk for progression or failure of medical therapy. Several inhibitors of the androgen receptor and other signaling pathways have recently been identified which appear to attenuate benign prostatic hyperplasia progression and may offer alternative targets for medical therapy. CONCLUSIONS: Progressive worsening of lower urinary tract symptoms and bladder outlet obstruction secondary to benign prostatic hyperplasia is the result of multiple pathways including androgen receptor signaling, proinflammatory cytokines and growth factor signals. New techniques in genomics, proteomics and epigenetics have led to the discovery of aberrant signaling pathways, novel biomarkers, DNA methylation signatures and potential gene specific targets. As personalized medicine continues to develop, the ability to risk stratify patients with symptomatic benign prostatic hyperplasia, identify those at higher risk for progression, and seek alternative therapies for those in whom conventional options are likely to fail will become the standard of targeted therapy.

The association of patient and disease characteristics with the overtreatment of low-risk prostate cancer from 2010 to 2016.

BACKGROUND: Although active surveillance is the preferred management for low-risk prostate cancer (PCa), some men remain at risk of overtreatment with definitive local therapy. We hypothesized that baseline characteristics may be associated with overtreatment and represent a potential source of health disparities. We therefore examined the associations of patient and disease characteristics with the surgical overtreatment of low-risk PCa. METHODS: We identified men aged 45-75 years with cT1 cN0 cM0 prostate adenocarcinoma with biopsy Gleason score 6 and PSA < 10 ng/ml from 2010-2016 in the National Cancer Database (NCDB) and who underwent radical prostatectomy (RP). We evaluated the associations of baseline characteristics with clinically insignificant PCa (iPCa) at RP (i.e., "overtreatment"), defined as organ-confined (i.e., pT2) Gleason 3 + 3 disease, using multivariable logistic regression. RESULTS: We identified 36,088 men with low-risk PCa who underwent RP. The unadjusted rate of iPCa decreased during the study period, from 54.7% in 2010 to 40.0% in 2016. In multivariable analyses adjusting for baseline characteristics, older age (OR 0.98, 95% CI 0.97-0.98), later year of diagnosis (OR 0.62, 95% CI 0.57-0.67 for 2016 vs. 2010), Black race (OR 0.85, 95% CI 0.79-0.91), treatment at an academic/research program (OR 0.82, 95% CI 0.73-0.91), higher PSA (OR 0.91, 95% CI 0.90-0.92), and higher number of positive biopsy cores (OR 0.87, 95% CI 0.86-0.88) were independently associated with a lower risk of overtreatment (iPCa) at RP. Conversely, a greater number of biopsy cores sampled (OR 1.01, 95% CI 1.01-1.02) was independently associated with an increased risk of overtreatment (iPCa) at RP. CONCLUSIONS: We observed an ~27% reduction in rates of overtreatment of men with low-risk PCa over the study period. Several patient, disease, and structural characteristics are associated with detection of iPCa at RP and can inform the management of men with low-risk PCa to reduce potential overtreatment.

Models of care and NCCN guideline adherence in very-low-risk prostate cancer.

NCCN Guidelines recommend active surveillance as the primary management option for patients with very-low-risk prostate cancer and an expected survival of less than 20 years, reflecting the favorable prognosis of these men and the lack of perceived benefit of immediate, definitive treatment. The authors hypothesized that care at a multidisciplinary clinic, where multiple physicians have an opportunity to simultaneously review and discuss each case, is associated with increased rates of active surveillance in men with very-low-risk prostate cancer, including those with limited life expectancy. Of 630 patients with low-risk prostate cancer managed at 1 of 3 tertiary care centers in Boston, Massachusetts in 2009, 274 (43.5%) had very-low-risk classification. Patients were either seen by 1 or more individual practitioners in sequential settings or at a multidisciplinary clinic, in which concurrent consultation with 2 or more of the following specialties was obtained: urology, radiation oncology, and medical oncology. Patients seen at a multidisciplinary prostate cancer clinic were more likely to select active surveillance than those seen by individual practitioners (64% vs 30%; P<.001), an association that remained significant on multivariable logistic regression (odds ratio [OR], 4.16; P<.001). When the analysis was limited to patients with an expected survival of less than 20 years, this association remained highly significant (72% vs 34%, P<.001; OR, 5.19; P<.001, respectively). Multidisciplinary care is strongly associated with selection of active surveillance, adherence to NCCN Guidelines and minimization of overtreatment in patients with very-low-risk prostate cancer.

Correction: Metformin inhibits the proliferation of benign prostatic epithelial cells.

[This corrects the article DOI: 10.1371/journal.pone.0173335.].

Conditional survival following radical cystectomy for urothelial carcinoma of the bladder.

INTRODUCTION: Traditional surveillance protocols do not adequately account for the decreasing risk of mortality over time in aggressive malignancies, such as bladder cancer. Rather, the risk of death depends on both the baseline risk of mortality and the time survived since treatment. We therefore evaluated the conditional survival of patients diagnosed with urothelial carcinoma of the bladder (UCB) following radical cystectomy (RC). PATIENTS AND METHODS: We identified patients aged 18 to 75 with Charlson 0-1 and pTany pN0-3 cM0 UCB diagnosed from 2006 to 2015 in the National Cancer Database and treated with RC. The 2- and 5-year conditional overall survival (COS)-i.e., the probability of surviving an additional 2- or 5-years given a specified time survived since treatment-was estimated using the Kaplan-Meier method. Multivariable Cox regression models with landmark time analysis were used to evaluate the associations of baseline characteristics with OS over time. RESULTS: A total of 15,594 patients were included in the study. Median follow-up was 27.8 months. The 2- and 5-year COS for the overall cohort increased through 36 months follow-up and then plateaued. When stratified by pT and pN stage, the COS gain increased with higher pT and pN stage, demonstrating the greatest increase over time for patients with pTany N1-3 disease (5-year COS of 23% at baseline, 58% at 36-months, and 71% at 60-months). In multivariable Cox regression modeling, pT and pN stage were significantly associated with higher all-cause mortality at baseline (HR 3.27 for pT4, HR 2.57 for pT3 vs. ≤pT2; HR 2.26 for pN2-3, HR 1.77 for pN1 vs. pN0), but these associations were attenuated in magnitude with increasing landmark times of 36- and 60-months (HR 1.63 for pT4, HR 1.35 for pT3 vs. ≤pT2; HR 1.34 for pN2-3, HR 1.27 for pN1 vs. pN0). Our study is limited by the retrospective design and the lack of cancer-specific survival data. CONCLUSIONS: Risk of death after RC varies with time elapsed since treatment and disease stage. Accordingly, stage-specific COS may be used to improve prognostication and surveillance protocols.