Cardiovascular Effects of GnRH Antagonists Compared With Agonists in Prostate Cancer: A Systematic Review.

Background: Androgen deprivation therapy is the cornerstone of treatment for patients with advanced prostate cancer. Meta-analysis of small, oncology-focused trials suggest gonadotropin-releasing hormone (GnRH) antagonists may be associated with fewer adverse cardiovascular outcomes compared with GnRH agonists. Objectives: This study sought to determine whether GnRH antagonists were associated with fewer major adverse cardiovascular events compared with GnRH agonists. Methods: Electronic databases were searched for all prospective, randomized trials comparing GnRH antagonists with agonists. The primary outcome was a major adverse cardiovascular event as defined by the following standardized Medical Dictionary for Regulatory Activities terms: "myocardial infarction," "central nervous system hemorrhages and cerebrovascular conditions," and all-cause mortality. Bayesian meta-analysis models with random effects were fitted. Results: A total of 11 eligible studies of a maximum duration of 3 to 36 months (median = 12 months) enrolling 4,248 participants were included. Only 1 trial used a blinded, adjudicated event process, whereas potential bias persisted in all trials given their open-label design. A total of 152 patients with primary outcome events were observed, 76 of 2,655 (2.9%) in GnRH antagonist-treated participants and 76 of 1,593 (4.8%) in agonist-treated individuals. Compared with GnRH agonists, the pooled OR of GnRH antagonists for the primary endpoint was 0.57 (95% credible interval: 0.37-0.86) and 0.58 (95% credible interval: 0.32-1.08) for all-cause death. Conclusions: Despite the addition of the largest, dedicated cardiovascular outcome trial, the volume and quality of available data to definitively answer this question remain suboptimal. Notwithstanding these limitations, the available data suggest that GnRH antagonists are associated with fewer cardiovascular events, and possibly mortality, compared with GnRH agonists.

Statin Use and Survival Among Men Receiving Androgen-Ablative Therapies for Advanced Prostate Cancer: A Systematic Review and Meta-analysis.

Importance: Epidemiological evidence supports a role for statins in improving survival in advanced prostate cancer, particularly among men receiving androgen-ablative therapies. Objective: To study the association between statin use and survival among men with prostate cancer receiving androgen deprivation therapy (ADT) or androgen receptor axis-targeted therapies (ARATs). Data Sources: This systemic review and meta-analysis used sources from MEDLINE, EMBASE, Epub Ahead of Print, Cochrane Clinical Trials, Cochrane Systematic Reviews, and Web of Science from inception to September 6, 2022. Study Selection: Observational studies reporting associations of concurrent statin use and survival outcomes (in hazard ratios [HRs]). Data Extraction and Synthesis: Two authors independently abstracted all data. Summary estimates pooled multivariable HRs with 95% CIs using the generic inverse variance method with random-effects modeling. A priori specified subgroup and sensitivity analyses were undertaken, and heterogeneity, study quality, and publication bias were evaluated. Confidence in the evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Main Outcomes and Measures: Overall mortality and prostate cancer-specific mortality (PCSM). Results: Twenty-five cohorts of 119 878 men (65 488 statin users [55%]) with more than 74 416 deaths were included. Concurrent statin use was associated with a 27% reduction in the risk of overall mortality (HR, 0.73 [95% CI, 0.66-0.82]; I2 = 83%) and a 35% reduction in the risk of PCSM (HR, 0.65 [95% CI, 0.58-0.73]; I2 = 74%), with substantial heterogeneity in both estimates. Subgroup analyses identified a PCSM advantage associated with statins for men receiving ARATs compared with ADT alone (HR, 0.40 [95% CI, 0.30-0.55] vs 0.68 [95% CI, 0.60-0.76]; P = .002 for difference). Confidence in the evidence was rated low for both outcomes. Conclusions and Relevance: The findings of this meta-analysis show that concurrent statin use was associated with reduced overall mortality and PCSM among men receiving androgen-ablative therapies for advanced prostate cancer. These findings are limited by the observational nature of the data and residual unexplained interstudy heterogeneity. Randomized clinical trials are warranted to validate these results.

Effect of 18F-DCFPyL PET/CT on the Management of Patients with Recurrent Prostate Cancer: Results of a Prospective Multicenter Registry Trial.

Background The high positivity rate of prostate-specific membrane antigen (PSMA) PET in the setting of biochemical failure (BCF), even when conventional imaging is negative, is promising. Purpose To assess the disease detection rate of PSMA-based PET/CT with fluorine 18-DCFPyL as a radiotracer and the PET-directed management change in men with suspected limited recurrent prostate cancer. Materials and Methods This prospective multicenter registry (Ontario PSMA-PET Registry for Recurrent Prostate Cancer, or PREP) enrolled men with BCF after primary therapy (radical prostatectomy plus or minus salvage radiation therapy or primary radiation therapy) and zero to four disease sites at conventional imaging (CT and bone scintigraphy). The positivity rate of PSMA PET according to serum prostate-specific antigen (PSA) level; frequency of local-egional, oligometastatic, and extensive metastatic recurrence; and rate of change in management after PET findings were recorded. The nonparametric Mood median test was used to assess the association between serum PSA level and change in management. Results A total of 1289 men (median age, 71 years [interquartile range, 65-75 years]) were evaluated. PSMA PET helped detect disease in 841 of 1289 men (65%) and in 615 of 999 men (62%) with negative conventional imaging. The recurrence detection rates according to serum PSA level at enrollment were 38% (160 of 424 men), 63% (107 of 171 men), and 83% (573 of 692 men) for PSA under 0.5 ng/mL, 0.5-1.0 ng/mL, and above 1.0 ng/mL, respectively. At PSMA PET, 399 of 1289 men (31%) had local-regional recurrence, 314 (24%) had oligometastatic disease, and 128 (10%) had extensive metastases. Following PET examination, a change in planned management was recorded in 748 of 1289 men (58%), and in 371 of 1250 men (30%), there was a change in management intent, more commonly from palliative to potentially curative intent (255 of 1289 men [20%]). Conclusion Prostate-specific membrane antigen PET helped detect additional sites of disease compared with conventional imaging in approximately 60% of men with biochemical failure and suspected low-volume metastatic disease, resulting in frequent change in management, including a change from palliative to curative or radical intent therapy in 20% of men. Long-term follow-up is needed to determine whether this impacts disease control. Clinical trial registration no. NCT03718260 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Civelek in this issue.

Genetic Factors Associated with Prostate Cancer Conversion from Active Surveillance to Treatment.

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion (MAST3, p = 6.9×10-7 and GAB2, p = 2.0×10-6). Moreover, increasing values of a previously validated 269-variant genetic risk score (GRS) for PC was positively associated with conversion (e.g., comparing the highest to the two middle deciles gave a hazard ratio [HR] = 1.13; 95% Confidence Interval [CI]= 0.94-1.36); whereas, decreasing values of a 36-variant GRS for prostate-specific antigen (PSA) levels were positively associated with conversion (e.g., comparing the lowest to the two middle deciles gave a HR = 1.25; 95% CI, 1.04-1.50). These results suggest that germline genetics may help inform and individualize the decision of AS-or the intensity of monitoring on AS-versus treatment for the initial management of patients with low-risk PC.

Prostate cancer mortality and metastasis under different biopsy frequencies in North American active surveillance cohorts.

BACKGROUND: Active surveillance (AS) is an accepted means of managing low-risk prostate cancer. Because of the rarity of downstream events, data from existing AS cohorts cannot yet address how differences in surveillance intensity affect metastasis and mortality. This study projected the comparative benefits of different AS schedules in men diagnosed with prostate cancer who had Gleason score (GS) ≤6 disease and risk profiles similar to those in North American AS cohorts. METHODS: Times of GS upgrading were simulated based on AS data from the University of Toronto, Johns Hopkins University, the University of California at San Francisco, and the Canary Pass Active Surveillance Cohort. Times to metastasis and prostate cancer death, informed by models from the Scandinavian Prostate Cancer Group 4 trial, were projected under biopsy surveillance schedules ranging from watchful waiting to annual biopsies. Outcomes included the risk of metastasis, the risk of death, remaining life-years (LYs), and quality-adjusted LYs. RESULTS: Compared with watchful waiting, AS biopsies reduced the risk of prostate cancer metastasis and prostate cancer death at 20 years by 1.4% to 3.3% and 1.0% to 2.4%, respectively; and 5-year biopsies reduced the risk of metastasis and prostate cancer death by 1.0% to 2.4% and 0.6% to 1.6%, respectively. There was little difference between annual and 5-year biopsy schedules in terms of LYs (range of differences, 0.04-0.16 LYs) and quality-adjusted LYs (range of differences, -0.02 to 0.09 quality-adjusted LYs). CONCLUSIONS: Among men diagnosed with GS ≤6 prostate cancer, obtaining a biopsy every 3 or 4 years appears to be an acceptable alternative to more frequent biopsies. Reducing surveillance intensity for those who have a low risk of progression reduces the number of biopsies while preserving the benefit of more frequent schedules.

Combining urinary DNA methylation and cell-free microRNA biomarkers for improved monitoring of prostate cancer patients on active surveillance.

PURPOSE: Prostate cancer (CaP) patients with low-grade tumors are enrolled in active surveillance (AS) programs and monitored with digital rectal exams (DREs), prostate-specific antigen (PSA) tests, and periodic invasive biopsies. Patients are "reclassified" with higher-risk disease if they show signs of disease progression. However, AS patients who will reclassify cannot be easily identified upfront and suffer morbidities associated with biopsy. Biomarkers derived from noninvasively obtained specimens such as serum or urine samples are promising alternatives to monitor patients with clinically insignificant cancer. Previously, we have characterized and validated a urinary DNA methylation panel and a serum miRNA panel for the prediction of patient reclassification in 2 independent AS cohorts. In this exploratory study, we have investigated cell-free miRNAs in the urinary supernatant combined with urinary DNA methylation markers to form an integrative panel for prediction of AS patient reclassification. METHODS: Post-DRE urine was collected from 103 CaP patients on active surveillance. Urinary sediment DNA methylation levels of selected genes were previously analyzed using qPCR-based MethyLight assay. Using qRT-PCR, we analyzed the urinary supernatants for relative quantities of 10 miRNAs previously shown to be associated with AS reclassification. Logistic regression and Receiver Operating Characteristics curve analyses were performed to assess the predictive ability of miRNAs and DNA methylation biomarkers. RESULTS: We identified a 3-marker panel, consisting of miR-24, miR-30c and CRIP3 methylation, that was significant for prediction of patient reclassification (Odds ratio = 2.166, 95% confidence interval = 1.22-3.847) with a negative predictive value of 90.9%. Our 3-marker panel also demonstrated additive value to PSA for prediction of patient reclassification (c-statistic = 0.717, ROC bootstrapped 1000 iteration P = 0.041). CONCLUSION: A urinary integrated panel of methylation and miRNA markers is a promising approach to identify AS patients at risk for reclassification. Our 3-marker panel, with its high negative predictive value, would be beneficial to identify and preclude AS patients with truly indolent cancer and to personalize monitoring strategies for AS patients.

A Phase 1 Pilot Study of Preoperative Radiation Therapy for Prostate Cancer: Long-Term Toxicity and Oncologic Outcomes.

PURPOSE: Neoadjuvant radiation therapy (RT) improves disease control in various cancers and has become an established oncologic treatment strategy. During 2001 to 2004, we conducted a phase 1 pilot study assessing the role of short-course preoperative RT (PreORT) for men with unfavorable intermediate- and high-risk localized prostate cancer. Herein, we present long-term follow-up toxicity and oncologic outcomes. METHODS AND MATERIALS: Eligible patients had histologically proven prostate cancer, cT1-T2N0M0 disease, prostate-specific antigen >15 to 35 ng/mL regardless of Gleason score, or prostate-specific antigen 10 to 15 ng/mL with Gleason score ≥7. Patients received 25 Gy in 5 consecutive daily fractions (5 Gy per fraction) to the prostate only, followed by radical prostatectomy within 14 days after RT completion. Primary outcomes were intraoperative morbidity and late genitourinary (GU) and gastrointestinal toxicities. RESULTS: In total, 15 patients were enrolled; 14 patients completed PreORT followed by radical prostatectomy, which also included bilateral lymph node dissections in 13 cases. Median follow-up was 12.2 years (range, 6.7-16.3). Late GU toxicity was common, with 2 patients (13.3%) experiencing G2 toxicity and 6 patients (40%) G3 toxicity. There were no patients with G4 to G5 late GU toxicity. Late gastrointestinal toxicity was infrequent, with only 1 patient (6.7%) experiencing transient G2 proctitis. At last follow-up, 8 (53.3%) and 6 (40%) patients experienced biochemical and metastatic disease recurrence, respectively. CONCLUSIONS: The use of PreORT in men with high-risk prostate cancer is associated with unexpected high rates of late GU toxicity. Future studies examining the role of RT preradical prostatectomy must cautiously select RT technique and dose schedule. Importantly, long-term follow-up data are essential to fully determine the therapeutic index of PreORT in the management of localized disease.

Cannabinoid WIN 55,212-2 induces cell cycle arrest and apoptosis, and inhibits proliferation, migration, invasion, and tumor growth in prostate cancer in a cannabinoid-receptor 2 dependent manner.

BACKGROUND: Cannabinoids have demonstrated anticarcinogenic properties in a variety of malignancies, including in prostate cancer. In the present study, we explored the anti-cancer effects of the synthetic cannabinoid WIN 55,212-2 (WIN) in prostate cancer. METHODS: Established prostate cancer cells (PC3, DU145, LNCaP) were treated with varying concentrations of WIN. Cell proliferation was determined by the MTS assay. The anti-migration and anti-invasive potential of WIN was examined by the wound healing assay and the matrigel invasion assay. Cell cycle analysis was performed by flow cytometry, and mechanistic studies were performed by Western blot. Athymic mice (n = 10) were inoculated with human PC3 cells. Once tumors reached 100 mm3 , animals were randomized into two groups: saline control and WIN (5 mg/kg), delivered by intraperitoneal injection three times per week for 3 weeks. RESULTS: WIN significantly reduced prostate cancer cell proliferation, migration, invasion, induced apoptosis, and arrested cells in Go/G1 phase in a dose-dependent manner. Mechanistic studies revealed these effects were mediated through a pathway involving cell cycle regulators p27, Cdk4, and pRb. Pre-treatment with a CB2 antagonist, AM630, followed by treatment with WIN resulted in a reversal of the anti-proliferation and cell cycle arrest previously seen with WIN alone. In vivo, administration of WIN resulted in a reduction in the tumor growth rate compared to control (P < 0.05). CONCLUSIONS: The following study provides evidence supporting the use of WIN as a novel therapeutic for prostate cancer.

Correction to: Number-needed-to-treat analysis of clinical progression in patients with metastatic castration-resistant prostate cancer in the STRIVE and TERRAIN trials.

It has been highlighted that in the original article [1] there was a typesetting mistake in the Results - NNT in Strive section. This Correction article states the incorrect and correct sentence.

Number-needed-to-treat analysis of clinical progression in patients with metastatic castration-resistant prostate cancer in the STRIVE and TERRAIN trials.

BACKGROUND: This analysis estimated the number needed to treat with enzalutamide versus bicalutamide to achieve one additional patient with chemotherapy-naïve metastatic castration-resistant prostate cancer who would obtain clinical benefit regarding progression-free survival, radiographic progression-free survival, or no prostate-specific antigen progression at 1 and 2 years following treatment initiation. METHODS: Clinical event rates were obtained from the STRIVE (NCT01664923) and TERRAIN (NCT01288911) trials, and the number needed to treat was the inverse of the absolute rate difference between the event rates of enzalutamide and bicalutamide. The 95% Confidence Interval of the number needed to treat was derived from the 95% Confidence Interval of the event rate difference. RESULTS: Using STRIVE data (patients with metastatic disease: n = 128 enzalutamide; n = 129 bicalutamide) comparing enzalutamide with bicalutamide at 1 and 2 years, the numbers needed to treat to achieve one additional patient with chemotherapy-naïve metastatic castration-resistant prostate cancer with progression-free survival were 2.0 and 2.8, respectively; with radiographic progression-free survival, 2.6 and 3.0, respectively; and without prostate-specific antigen progression, 1.8 and 2.4, respectively. Using TERRAIN data (n = 184 enzalutamide; n = 191 bicalutamide) comparing enzalutamide with bicalutamide at 1 and 2 years, the numbers needed to treat to achieve one additional patient with progression-free survival were 4.3 and 3.7, respectively; with radiographic progression-free survival, 10.0 and 2.8, respectively; and without prostate-specific antigen progression, 2.1 and 3.2, respectively. CONCLUSIONS: The combined data from TERRAIN and STRIVE demonstrated that treating chemotherapy-naïve metastatic castration-resistant prostate cancer with enzalutamide leads to more patients without clinical progression at 1 and 2 years than with bicalutamide. TRIAL REGISTRATION: STRIVE (NCT01664923; registration date: August 10, 2012) and TERRAIN (NCT01288911; registration date: February 1, 2011).

Clinically Localized Prostate Cancer: AUA/ASTRO/SUO Guideline. Part II: Recommended Approaches and Details of Specific Care Options.

PURPOSE: This guideline is structured to provide a clinical framework stratified by cancer severity to facilitate care decisions and guide the specifics of implementing the selected management options. The summary presented herein represents Part II of the two-part series dedicated to Clinically Localized Prostate Cancer: AUA/ASTRO/SUO Guideline discussing risk stratification and care options by cancer severity. Please refer to Part I for discussion of specific care options and outcome expectations and management. MATERIALS AND METHODS: The systematic review utilized in the creation of this guideline was completed by the Agency for Healthcare Research and Quality and through additional supplementation by ECRI Institute. This review included articles published between January 2007 and March 2014 with an update search conducted through August 2016. When sufficient evidence existed, the body of evidence for a particular treatment was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. Additional information is provided as Clinical Principles and Expert Opinions (table 2 in supplementary unabridged guideline, http://jurology.com/). RESULTS: The AUA (American Urological Association), ASTRO, and SUO (Society of Urologic Oncology) formulated an evidence-based guideline based on a risk stratified clinical framework for the management of localized prostate cancer. CONCLUSIONS: This guideline attempts to improve a clinician's ability to treat patients diagnosed with localized prostate cancer, but higher quality evidence in future trials will be essential to improve the level of care for these patients. In all cases, patient preferences should be considered when choosing a management strategy.

Comparative Analysis of Biopsy Upgrading in Four Prostate Cancer Active Surveillance Cohorts.

Background: Active surveillance (AS) is increasingly accepted for managing low-risk prostate cancer, yet there is no consensus about implementation. This lack of consensus is due in part to uncertainty about risks for disease progression, which have not been systematically compared or integrated across AS studies with variable surveillance protocols and dropout to active treatment. Objective: To compare risks for upgrading from a Gleason score (GS) of 6 or less to 7 or more across AS studies after accounting for differences in surveillance intervals and competing treatments and to evaluate tradeoffs of more versus less frequent biopsies. Design: Joint statistical model of longitudinal prostate-specific antigen (PSA) levels and risks for biopsy upgrading. Setting: Johns Hopkins University (JHU); Canary Prostate Active Surveillance Study (PASS); University of California, San Francisco (UCSF); and University of Toronto (UT) AS studies. Patients: 2576 men aged 40 to 80 years with a GS between 2 and 6 and clinical stage T1 or T2 prostate cancer enrolled between 1995 and 2014. Measurements: PSA levels and biopsy GSs. Results: After variable surveillance intervals and competing treatments were accounted for, estimated risks for biopsy upgrading were similar in the PASS and UT studies but higher in UCSF and lower in JHU studies. All cohorts had a delay of 3 to 5 months in detecting upgrading with biennial biopsies starting after a first confirmatory biopsy versus annual biopsies. Limitation: The model does not account for possible misclassification of biopsy GS. Conclusion: Men in different AS studies have different risks for biopsy upgrading after variable surveillance protocols and competing treatments are accounted for. Despite these differences, the consequences of more versus less frequent biopsies seem to be similar across cohorts. Biennial biopsies seem to be an acceptable alternative to annual biopsies. Primary Funding Source: National Cancer Institute.

Clinically Localized Prostate Cancer: AUA/ASTRO/SUO Guideline. Part I: Risk Stratification, Shared Decision Making, and Care Options.

PURPOSE: This guideline is structured to provide a clinical framework stratified by cancer severity to facilitate care decisions and guide the specifics of implementing the selected management options. The summary presented represents Part I of the two-part series dedicated to Clinically Localized Prostate Cancer: AUA/ASTRO/SUO Guideline discussing risk stratification and care options by cancer severity. MATERIALS AND METHODS: The systematic review utilized in the creation of this guideline was completed by the Agency for Healthcare Research and Quality and through additional supplementation by ECRI Institute. This review included articles published between January 2007 and March 2014 with an update search conducted through August 2016. When sufficient evidence existed, the body of evidence for a particular treatment was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. Additional information is provided as Clinical Principles and Expert Opinions (table 2 in supplementary unabridged guideline, http://jurology.com/). RESULTS: The AUA (American Urological Association), ASTRO, and SUO (Society of Urologic Oncology) formulated an evidence-based guideline based on a risk stratified clinical framework for the management of localized prostate cancer. CONCLUSIONS: This guideline attempts to improve a clinician's ability to treat patients diagnosed with localized prostate cancer, but higher quality evidence in future trials will be essential to improve the level of care for these patients. In all cases, patient preferences should be considered when choosing a management strategy.

Total energy expenditure and vigorous-intensity physical activity are associated with reduced odds of reclassification among men on active surveillance.

BACKGROUND: Research examining the association between physical activity (PA) and prostate cancer (PCa) has accumulated; however, few studies have examined this association in the context of active surveillance. The current study examines this among men initially diagnosed with favorable-risk PCa and managed by active surveillance at Sunnybrook Health Sciences Centre in Canada and the Royal Marsden Hospital in the United Kingdom. METHODS: Participants completed a questionnaire on daily participation in non-leisure, transport, and recreational PA. A logistic regression was employed using PA as the independent variable and whether the patient reclassified to higher-risk PCa while on active surveillance as the dependent variable. Demographic and lifestyle covariates were incorporated in the analysis to assess potential confounding and effect modification. RESULTS: Men from both hospitals presented with similar clinical and demographic characteristics. Total PA was inversely associated with odds of reclassification while on active surveillance (p-trend = 0.027). A weaker inverse association was observed with recreational PA (p-trend = 0.30). Men who participated in weekly vigorous PA were less likely to reclassify than those who did not (odds ratio (95% confidence interval): 0.42 (0.20-0.85)). CONCLUSIONS: Total and vigorous PA were inversely associated with odds of reclassification in two active surveillance cohorts. Given the limitations of this study, more robust prospective observational studies involving objective PA measures are warranted to confirm findings.

Evaluating Metformin as a Potential Chemosensitizing Agent when Combined with Docetaxel Chemotherapy in Castration-resistant Prostate Cancer Cells.

BACKGROUND/AIM: Docetaxel, the first-line chemotherapy for metastatic castration-resistant prostate cancer (mCRPC), provides certain survival benefits, but is associated with significant toxicity. A novel therapeutic approach for mCRPC is combining docetaxel with a chemosensitizing agent. We hypothesized that metformin, a potential chemosensitizer, would improve docetaxel efficacy in CRPC cells. MATERIALS AND METHODS: MTS assays were used to determine the effect of metformin-docetaxel treatment on PC3 and DU145 cell viability. Wound-healing and ATP concentration assays were used to evaluate cell migration and intracellular ATP levels following metformin-docetaxel treatment. Western blotting was used for mechanistic evaluation. RESULTS: Metformin-docetaxel treatment significantly reduced PC3 cell viability. Metformin-docetaxel treatment did not significantly affect cell migration or intracellular ATP levels. Western blotting revealed metformin-docetaxel treatment did not significantly change AMPK or P-AMPK expression patterns. CONCLUSION: Metformin may be an effective chemosensitizer for certain types of CRPC cells, but further investigation is needed.

The Effect of Metformin Use during Docetaxel Chemotherapy on Prostate Cancer Specific and Overall Survival of Diabetic Patients with Castration Resistant Prostate Cancer.

PURPOSE: Docetaxel is the first line chemotherapy currently used to treat patients with symptomatic metastatic castration resistant prostate cancer. Although it provides survival benefits, it is associated with significant side effects. Novel therapeutic options are needed for patients with metastatic castration resistant prostate cancer and an approach is combining docetaxel with chemosensitizing agents. Metformin has been shown to improve the survival of patients with breast, lung and endometrial cancer receiving chemotherapy, and enhance chemotherapeutic efficacy in breast cancer and colon cancer cells. However, to our knowledge the chemosensitizing effect of metformin in prostate cancer has not been explored. Therefore, the hypothesis for our study was that diabetic patients with metastatic castration resistant prostate cancer who were administered metformin during docetaxel chemotherapy would have improved prostate cancer specific and overall survival. MATERIALS AND METHODS: This retrospective cohort study used data from several Ontario administrative health care databases. Men older than 65 years diagnosed with metastatic castration resistant prostate cancer and treated with docetaxel were stratified into groups based on diabetes status and use of antidiabetic medications. We evaluated the effect of metformin use with docetaxel on prostate cancer specific survival and overall survival using Kaplan-Meier survival curves, the log rank test and multivariate Cox proportional HRs. RESULTS: Survival curves showed that metformin use with docetaxel did not improve prostate cancer specific survival (p = 0.9562) or overall survival (p = 0.9927). HRs showed no significant effect of metformin use with docetaxel on prostate cancer specific survival (HR = 0.96, p = 0.66) or overall survival (HR = 0.94, p = 0.39). CONCLUSIONS: Metformin use during docetaxel chemotherapy did not significantly improve prostate cancer specific or overall survival in diabetic patients with metastatic castration resistant prostate cancer. This study indicates that metformin may not be an effective chemosensitizer for metastatic castration resistant prostate cancer.

New Rates of Interventions to Manage Complications of Modern Prostate Cancer Treatment in Older Men.

BACKGROUND: Interventions to treat complications from prostate cancer (PCa) treatment are common and affect the course of a patient's life. OBJECTIVE: To examine rates of complications other than urinary incontinence and impotence for older patients treated for PCa. DESIGN, SETTING, AND PARTICIPANTS: Population-based retrospective cohort study of patients aged 65-79 yr receiving radical prostatectomy or radiotherapy (RT) from 2001 to 2008 in the US Surveillance Epidemiology and End Results and Medicare linked databases. OUTCOME MEASURES AND STATISTICAL ANALYSIS: Complications were organised in three categories: urologic procedures, rectal-anal procedures, and major surgeries. We analysed the role of primary treatment on the number of complications using negative binomial regression. RESULTS AND LIMITATIONS: Among 60476 men, 14492 underwent primary surgery and 45984 underwent primary RT; 33418 (55%) experienced at least one complication (mean: 2.6 complications per patient). For both groups, complications peaked within 2 yr of treatment but continued at a steady rate for 10 yr. Patients treated with radiation had higher rates of urologic procedures (adjusted relative rate [aRR]: 1.25; 95% confidence interval [CI], 1.2-1.3; p<0.0001) and rectal-anal procedures (aRR: 1.4; 95% CI, 1.4-1.5; p<0.0001) but a lower rate of major surgeries (aRR: 0.9; 95% CI, 0.8-0.9; p<0.0001) compared with those having surgery. Because patients treated with RT were older and more comorbid, selection bias limits the strength of conclusions that can be drawn from this data. CONCLUSIONS: Complications are common following PCa cancer treatment and occur many years after treatment. The primary treatment is an important predictor of complication rates that may inform treatment decisions and long-term survivorship plans. PATIENT SUMMARY: We examined complications after prostate cancer treatment in a large American population. Patients treated with radiotherapy rather than surgery had higher rates of complications requiring urologic procedures and rectal-anal procedures but lower rates of open surgeries. However, we were only able to examine men aged >65 yr, and this, along with the observational study technique, means that these results may not apply to all patients and that factors beyond those that we could measure may have affected these results.

Identification and Validation of a Five MicroRNA Signature Predictive of Prostate Cancer Recurrence and Metastasis: A Cohort Study.

BACKGROUND: MicroRNA (miRNA) have been shown to be important in regulating gene expression in prostate cancer. We used next generation miRNA sequencing to conduct a whole miRNome analysis to identify miRNAs associated with prostate cancer metastasis. METHODS: We conducted discovery and validation analyses of miRNAs among a total of 546 men who underwent surgery for prostate cancer using the development of metastasis as an endpoint. Genome wide analysis was conducted among the discovery group (n=31) to identify new miRNAs associated with prostate cancer metastasis. Selected miRNAs were then analyzed using qPCR on prostatectomy specimens from an independent cohort (n=515) to determine whether their expression could predict the development of metastasis after surgery. To examine the biology underlying these associations, we created prostate cancer cell lines which overexpressed miR-301a for in vitro and in vivo functional assays. RESULTS: We identified 33 miRNAs associated with prostate cancer metastasis and selected a panel comprising miRs-301a, 652, 454, 223 and 139 which strongly predicted metastasis (AUC=95.3%, 95%C.I.:84%-99%). Among the validation cohort, the 15-year metastasis-free survival was 77.5% (95% C.I.:63.9%-86.4%) for patients with a high miRNA panel score and 98.8% (95% C.I.:94.9%-99.7%, p<0.0001 for difference) for those with a low score. After adjusting for grade, stage, and PSA, the hazard ratio for metastasis was 4.3 (95% C.I.: 1.7-11.1, p=0.002) for patients with a high miRNA panel score, compared to those with a low score. Prostate cancer cell lines overexpressing miR-301a had in significantly higher tumor growth and metastasis in a xenograft mouse model. CONCLUSIONS: A panel of miRNAs is associated with prostate cancer metastasis. These could be used as potential new prognostic factors in the surgical management of prostate cancer.

A combination of desmopressin and docetaxel inhibit cell proliferation and invasion mediated by urokinase-type plasminogen activator (uPA) in human prostate cancer cells.

BACKGROUND: This study was designed to assess the effectiveness of a combination treatment using both desmopressin and docetaxel in prostate cancer treatment. Desmopressin is a well-known synthetic analogue of the antidiuretic hormone vasopressin. It has recently been demonstrated to inhibit tumor progression and metastasis in in vivo models. Docetaxel is widely used for the treatment of castration resistant prostate cancer (CRPC) patients. However, durable responses have been uncommon to date. In this study, we investigated the anti-tumor effect of desmopressin in combination with docetaxel in vitro and in vivo. METHODS: Two prostate cancer cells (PC3, LNCaP) were treated with different concentrations of desmopressin alone, docetaxel alone, and a combination of desmopressin and docetaxel. Cell proliferation was determined by MTS assay. The anti-invasive and anti-migration potential of desmopressin and in combination with docetaxel were examined by wound healing assay, migration chamber assay, and matrigel invasion assay. RESULTS: The combination of desmopressin and docetaxel resulted in a significant inhibition of PC3 and LNCaP cell proliferation (p < 0.01). Additionally, cell migration and invasion were also inhibited by the combination when compared to that of either treatment alone in PC3 cells (p < 0.01). The anti-tumor effect of this combination treatment was associated with down-regulation of both urokinase-type plasminogen activator (uPA) and matrix metalloproteinase (MMP-2 and MMP-9) in PC3 cells. CONCLUSIONS: We are the first to elucidate the anti-tumor and anti-metastatic potential of desmopressin in combination with docetaxel in a prostate cancer model via the uPA-MMP pathway. Our finding could potentially contribute to the therapeutic profile of desmopressin and enhance the efficacy of docetaxel based treatment for CRPC.

Capsaicin reduces the metastatic burden in the transgenic adenocarcinoma of the mouse prostate model.

BACKGROUND: Capsaicin, the active compound in chili peppers, has demonstrated anti- carcinogenic properties in vitro in a number of malignancies, including the prostate. In the present study, we investigate the chemopreventive potential of capsaicin on prostate cancer using the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. The TRAMP is a murine model that resembles the progression of human disease. METHODS: Thirty-five 6-week-old TRAMP x C57BL/6 mice were randomized between treatment with capsaicin (5 mg/kg body weight) or control (saline) three times a week by oral gavage until 30 weeks of age. Body weight of animals was recorded thrice weekly. At termination, all tumors were extracted, recorded, and analyzed for histopathological analysis. To understand the effect of capsaicin on migration and invasion, in vitro experiments were carried out using PC3 cells. RESULTS: Mice in the control group expressed an overall trend of higher-grade disease with 37.5% poorly differentiated (PD), 18.75% moderately differentiated (MD), and 44% of well-differentiated (WD) adenocarcinoma, compared to the capsaicin-treated group with only 27.7% PD, 61.0% of WD, and 11.1% of intraepithelial neoplasia (PIN). The treatment group demonstrated a higher incidence of noncancerous PIN lesions compared to the control group. The capsaicin group also demonstrated a significant reduction (P < 0.05) in the metastatic burden compared to the controls, which correlated to a reduction in p27(Kip) (1) expression and neuroendocrine differentiation in prostate tumors. Furthermore, there were no differences in body weight between groups overtime, and no pathological toxicities in the liver and gastrointestinal tract with capsaicin consumption. In vitro studies revealed a dose-dependent reduction in the invasion and migration capacity of PC3 cells. CONCLUSION: The following study provides evidence supporting the safety and chemopreventive effects of capsaicin in the TRAMP model.