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Purpose: To evaluate the quality of the interspace between the prostate and rectum and assess the effect on the dose to the rectum by measuring the spacer quality score (SQS) before and after implanting a hydrogel rectal spacer. Methods and Materials: Thirty patients with prostate cancer were treated with stereotactic ablative body radiation therapy as part of the SPORT clinical trial. Each patient had a 10 mL polyethylene glycol hydrogel spacer inserted transperineally. Computed tomography scans were acquired before and after spacer insertion, 10MV flattening filter free (FFF) stereotactic ablative body radiation therapy (SABR) treatment plans were generated using each image set. To calculate the SQS, the prostate-rectal interspace (PRI) was measured in the anterior-posterior orientation, parallel to the anatomic midline at the prostate base, apex, and midgland on the prespacer and postspacer computed tomography. Measurements were taken in 3 transverse positions between the prostate and the rectum, and PRI scores of 0, 1, and 2 were assigned if the interspace between prostate and rectum was

Abstract Prostate cancer (PCa) is a common and fatal type of cancer in men. Metastatic PCa (mPCa) is a major factor contributing to its lethality, although the mechanisms remain poorly understood. PTEN is one of the most frequently deleted genes in mPCa. Here we show a frequent genomic co-deletion of PTEN and STAT3 in liquid biopsies of patients with mPCa. Loss of Stat3 in a Pten-null mouse prostate model leads to a reduction of LKB1/pAMPK with simultaneous activation of mTOR/CREB, resulting in metastatic disease. However, constitutive activation of Stat3 led to high LKB1/pAMPK levels and suppressed mTORC1/CREB pathway, preventing mPCa development. Metformin, one of the most widely prescribed therapeutics against type 2 diabetes, inhibits mTORC1 in liver and requires LKB1 to mediate glucose homeostasis. We find that metformin treatment of STAT3/AR-expressing PCa xenografts resulted in significantly reduced tumor growth accompanied by diminished mTORC1/CREB, AR and PSA levels. PCa xenografts with deletion of STAT3/AR nearly completely abrogated mTORC1/CREB inhibition mediated by metformin. Moreover, metformin treatment of PCa patients with high Gleason grade and type 2 diabetes resulted in undetectable mTORC1 levels and upregulated STAT3 expression. Furthermore, PCa patients with high CREB expression have worse clinical outcomes and a significantly increased risk of PCa relapse and metastatic recurrence. In summary, we have shown that STAT3 controls mPCa via LKB1/pAMPK/mTORC1/CREB signaling, which we have identified as a promising novel downstream target for the treatment of lethal mPCa.

Background: Emerging data suggest that dose-sparing several key cardiac regions is prognostically beneficial in lung cancer radiotherapy. The cardiac substructures are challenging to contour due to their complex geometry, poor soft tissue definition on computed tomography (CT) and cardiorespiratory motion artefact. A neural network was previously trained to generate the cardiac substructures using three-dimensional radiotherapy planning CT scans (3D-CT). In this study, the performance of that tool on the average intensity projection from four-dimensional (4D) CT scans (4D-AVE), now commonly used in lung radiotherapy, was evaluated. Materials and Methods: The 4D-AVE of n=20 patients completing radiotherapy for lung cancer 2015–2020 underwent manual and automated cardiac substructure segmentation. Manual and automated substructures were compared geometrically and dosimetrically. Two senior clinicians also qualitatively assessed the auto-segmentation tool’s output. Results: Geometric comparison of the automated and manual segmentations exhibited high levels of similarity across parameters, including volume difference (11.8% overall) and Dice similarity coefficient (0.85 overall), and were consistent with 3D-CT performance. Differences in mean (median 0.2 Gy, range −1.6–0.3 Gy) and maximum (median 0.4 Gy, range −2.2–0.9 Gy) doses to substructures were generally small. Nearly all structures (99.5 %) were deemed to be appropriate for clinical use without further editing. Conclusions: Cardiac substructure auto-segmentation using a deep learning-based tool trained on a 3D-CT dataset was feasible on the 4D-AVE scan, meaning this tool is suitable for use on 4D-CT radiotherapy planning scans. Application of this tool would increase the practicality of routine clinical cardiac substructure delineation, and enable further cardiac radiation effects research.

Abstract Purpose Boosting dominant intra-prostatic lesions (DILs) has the potential to increase the therapeutic ratio in prostate cancer radiotherapy. In this study, employing 5-fraction stereotactic ablative radiotherapy (SABR) volumetric modulated arc therapy (VMAT) to deliver 40 Gy to the prostate clinical target volume (CTV) while boosting the DIL up to 50 Gy was evaluated for patients before and after rectal spacer insertion. Materials and methods 24 Computed Tomography (CT) scans of 12 prostate cancer patients with unfavourable intermediate or high risk prostate cancer were employed in this study. At least two treatment plans were generated for each patient to compare pre- and post-spacer insertion plans. Plans were evaluated for target coverage, organs-at-risk doses, and the achievable boost dose level. Results The CTV coverage was significantly better in plans with a spacer, V40Gy 98.4% versus 97.0% (p = 0.012). Using spacers significantly reduced rectal dose in all 12 patients in this study. It was possible to boost DIL to 50 Gy to without violating dose constraints in 6 of 12 patients and to 47.5 Gy in 3 patients post-spacer insertion. For 3 patients (25%) it was not possible to boost DIL above 45 Gy even with a spacer in situ. Without a spacer, for 6 patient (50%) clinically acceptable plan were only achieved when the DIL dose was lowered to 45 Gy. In five of these 6 patients the dose limiting structure was the urethra (urethra planning risk volume V45Gy [cc] ≤ 0.1 cc constraint). Conclusions Clinically acceptable plans for 5 fraction SABR, 40 Gy to the prostate CTV, with a SIB to DIL (45–50 Gy) were achieved. The boost dose achieved was DIL location dependent and primarily affected by DIL’s proximity to the urethra. Compared to plans before spacer insertion, higher DIL dose were achieved with spacer in situ for 25% of the patients. Moreover, significant reduction in rectal dose and better target coverage were also achieved for all patients with spacers in situ.

The development of gene signatures is key for delivering personalized medicine, despite only a few signatures being available for use in the clinic for cancer patients. Gene signature discovery tends to revolve around identifying a single signature. However, it has been shown that various highly predictive signatures can be produced from the same dataset. This study assumes that the presentation of top ranked signatures will allow greater efforts in the selection of gene signatures for validation on external datasets and for their clinical translation. Particle swarm optimization (PSO) is an evolutionary algorithm often used as a search strategy and largely represented as binary PSO (BPSO) in this domain. BPSO, however, fails to produce succinct feature sets for complex optimization problems, thus affecting its overall runtime and optimization performance. Enhanced BPSO (EBPSO) was developed to overcome these shortcomings. Thus, this study will validate unique candidate gene signatures for different underlying biology from EBPSO on transcriptomics cohorts. EBPSO was consistently seen to be as accurate as BPSO with substantially smaller feature signatures and significantly faster runtimes. 100% accuracy was achieved in all but two of the selected data sets. Using clinical transcriptomics cohorts, EBPSO has demonstrated the ability to identify accurate, succinct, and significantly prognostic signatures that are unique from one another. This has been proposed as a promising alternative to overcome the issues regarding traditional single gene signature generation. Interpretation of key genes within the signatures provided biological insights into the associated functions that were well correlated to their cancer type.

Background: Prostate cancer is the most commonly diagnosed malignancy in the UK. Castrate resistant prostate cancer (CRPC) can be difficult to manage with response to next generation hormonal treatment variable. AR-V7 is a protein biomarker that can be used to predict response to treatment and potentially better inform management in these patients. Our aim was to establish the feasibility of conducting a definitive randomised controlled trial comparing the clinical utility of AR-V7 biomarker assay in personalising treatments for patients with metastatic CRPC within the United Kingdom (UK) National Health Service (NHS). Due to a number of issues the trial was not completed successfully, we aim to discuss and share lessons learned herein. Methods: We conducted a randomised, open, feasibility trial, which aimed to recruit 70 adult men with metastatic CRPC within three secondary care NHS trusts in the UK to be run over an 18-month period. Participants were randomised to personalised treatment based on AR-V7 status (intervention) or standard care (control). The primary outcome was feasibility, which included: recruitment rate, retention and compliance. Additionally, a baseline prevalence of AR-V7 expression was to be estimated. Results: Fourteen participants were screened and 12 randomised with six into each arm over a nine-month period. Reliability issues with the AR-V7 assay meant prevalence was not estimated. Due to limited recruitment the study did not complete to target. Conclusions: Whilst the trial did not complete to target, we have ascertained that men with advanced cancer are willing to take part in trials utilising biomarker guided treatment. A number of issues were identified that serve as important learning points in future clinical trials.

Objectives To identify consensus on patient prioritisation for rectal hydrogel spacer use during radiation therapy for the treatment of prostate cancer in the UK.Design Delphi study consisting of two rounds of online questionnaires, two virtual advisory board meetings and a final online questionnaire.Setting Radical radiation therapy for localised and locally advanced prostate cancer in the UK.Participants Six leading clinical oncologists and one urologist from across the UK.Interventions Rectal hydrogel spacer.Primary and secondary outcome measures None reported.Results The panel reached consensus on the importance of minimising toxicity for treatments with curative intent and that even low-grade toxicity-related adverse events can significantly impact quality of life. There was agreement that despite meeting rectal dose constraints, too many patients experience rectal toxicity and that rectal hydrogel spacers in eligible patients significantly reduces toxicity-related adverse events. However, as a consequence of funding limitations, patients need to be prioritised for spacer use. A higher benefit of spacers can be expected in patients on anticoagulation and in patients with diabetes or inflammatory bowel disease, but consensus could not be reached regarding patient groups expected to benefit less. While radiation therapy regimen is not a main factor determining prioritisation, higher benefit is expected in ultrahypofractionated regimens.Conclusion There is a strong and general agreement that all patients with prostate cancer undergoing radical radiation therapy have the potential to benefit from hydrogel spacers. Currently, not all patients who could potentially benefit can access hydrogel spacers, and access is unequal. Implementation of the consensus recommendations would likely help prioritise and equalise access to rectal spacers for patients in the UK.

Abstract Prostate cancer (PCa) is the most common non-cutaneous cancer in men and a notable cause of cancer mortality when it metastasises. The unfolded protein response (UPR) can be cytoprotective but when acutely activated can lead to cell death. In this study, we sought to enhance the acute activation of the UPR using radiation and ONC201, an UPR activator. Treating PCa cells with ONC201 quickly increased the expression of all the key regulators of the UPR and reduced the oxidative phosphorylation, with cell death occurring 72 h later. We exploited this time lag to sensitize prostate cancer cells to radiation through short-term treatment with ONC201. To understand how priming occurred, we performed RNA-Seq analysis and found that ONC201 suppressed the expression of cell cycle and DNA repair factors. In conclusion, we have shown that ONC201 can prime enhanced radiation response.

Abstract Background In this study, a novel pelvic phantom was developed and used to assess the visibility and presence of artefacts from different types of commercial fiducial markers (FMs) on multi-modality imaging relevant to prostate cancer. Methods and materials The phantom was designed with 3D printed hollow cubes in the centre. These cubes were filled with gel to mimic the prostate gland and two parallel PVC rods were used to mimic bones in the pelvic region. Each cube was filled with gelatine and three unique FMs were positioned with a clinically-relevant spatial distribution. The FMs investigated were; Gold Marker (GM) CIVCO, GM RiverPoint, GM Gold Anchor (GA) line and ball shape, and polymer marker (PM) from CIVCO. The phantom was scanned using several imaging modalities typically used to image prostate cancer patients; MRI, CT, CBCT, planar kV-pair, ExacTrac, 6MV, 2.5MV and integrated EPID imaging. The visibility of the markers and any observed artefacts in the phantom were compared to in-vivo scans of prostate cancer patients with FMs. Results All GMs were visible in volumetric scans, however, they also had the most visible artefacts on CT and CBCT scans, with the magnitude of artefacts increasing with FM size. PM FMs had the least visible artefacts in volumetric scans but they were not visible on portal images and had poor visibility on lateral kV images. The smallest diameter GMs (GA) were the most difficult GMs to identify on lateral kV images. Conclusion The choice between different FMs is also dependent on the adopted IGRT strategy. PM was found to be superior to investigated gold markers in the most commonly used modalities in the management of prostate cancer; CT, CBCT and MRI imaging.

BackgroundSexual dysfunction is a frequent side effect associated with different prostate cancer treatment approaches. It can have a substantial impact on men and their partners and is associated with increased psychological morbidity. Despite this, sexual concerns are often not adequately addressed in routine practice. Evidence-based web-based interventions have the potential to provide ongoing information and sexual well-being support throughout all stages of care. ObjectiveThe aim of this study is to examine the efficacy of a web-based self-management intervention designed to maximize sexual well-being in men living with prostate cancer and explore user perspectives on usability and acceptability. MethodsWe used a single-arm study design, and participants were provided with access to the 5-step intervention for a period of 3 months. The intervention content was tailored based on responses to brief screening questions on treatment type, relationship status, and sexual orientation. Efficacy was assessed by using two-tailed, paired sample t tests for comparing the mean differences between pre- and postintervention measurements for exploring the participants’ self-reported knowledge and understanding, sexual satisfaction, and comfort in discussing sexual issues. Usability and acceptability were determined based on the program use data and a postintervention survey for exploring perceived usefulness. ResultsA total of 109 participants were recruited for this study. Significant postintervention improvements at follow-up were observed in the total scores (out of 20) from the survey (mean 12.23/20 points, SD 2.46 vs mean 13.62/20, SD 2.31; t88=9.570; P=.001) as well as in individual item scores on the extent to which the participants agreed that they had sufficient information to manage the impact that prostate cancer had on their sex life (mean 2.31/4 points, SD 0.86 vs mean 2.57/4, SD 0.85; t88=3.660; P=.001) and had the potential to have a satisfying sex life following treatment (mean 2.38/4 points, SD 0.79 vs mean 3.17/4, SD 0.78; t88=7.643; P=.001). The median number of intervention sessions was 3 (range 1-11), and intervention sessions had a median duration of 22 minutes (range 8-77). Acceptable usability scores were reported, with the highest result observed for the question on the extent to which the intervention provided relevant information. ConclusionsThis study provides evidence on the efficacy of a tailored web-based intervention for maximizing sexual well-being in men living with prostate cancer. The results indicate that the intervention may improve one’s self-perceived knowledge and understanding of how to manage sexual issues and increase self-efficacy or the belief that a satisfactory sex life could be achieved following treatment. The findings will be used to refine the intervention content before testing as part of a larger longitudinal study for examining its effectiveness.

Abstract Background Men with metastatic castrate-resistant prostate cancer can experience an array of treatment-related side effects. Accumulating evidence suggests exercise may alleviate some of these adversities and assist in disease management. However, empirical evidence in advanced prostate cancer patients remains limited. The purpose of this study is to determine whether men with metastatic prostate cancer, who are ineligible for high-intensity exercise, can partake in a home-based, moderate-intensity exercise program and the impact of doing so on quality of life and physical fitness parameters. Methods Thirty men with adenocarcinoma of the prostate and progressive systemic, metastatic disease will be recruited. Clinicians will screen patients against inclusion criteria to determine eligibility. All men enrolled will be prescribed a tailored, home-based, moderate-intensity exercise intervention consisting of aerobic and strengthening components for 12 weeks. Patients will receive supplementary education materials and weekly behavioural change consultations throughout the intervention. The primary outcome will be the feasibility of delivering such an intervention in men with metastatic disease. Secondary endpoints including skeletal events will be monitored for safety, as will the feasibility of patient-reported outcome measures and the sampling time points, generating data pertaining to completion rates and potential effect in future trials. General physical fitness will be assessed during these visits, using timed sit-to-stand testing and a 6-min walking test. Prior to each visit, objective physical activity levels will be captured for 7 days using an accelerometer, to determine the feasibility of this technology and the quality of data obtained. In parallel with the feasibility aspects of the trial, changes compared to baseline will be reported. Direct regular contact will also serve as a feedback loop, should any issues arise. This study has received ethical approval from the Office for Research Ethics Committees Northern Ireland. Conclusions This study aims to determine the potential utility of a home-based exercise intervention in managing side effects associated with advanced prostate cancer and its treatment. This feasibility trial will inform the design and implementation of a larger randomised control trial to determine the efficacy of moderate aerobic and strengthening exercise as an adjuvant therapy in men with metastatic prostate cancer. Collecting such evidence provides further support for exercise in this paradigm and potential for its inclusion as a low-toxicity therapy in standard cancer care, in the longer term. Trial registration ClinicalTrials.gov, NCT03658486 Trial sponsor: Queen’s University Belfast (Reference: B18/15). Contact: Dr. Paula Tighe, Research and Enterprise, Queen’s University Belfast. Telephone: 02890 973,296. Email: p.tighe@qub.ac.uk. The sponsor reviewed the protocol and ethical application prior to submission. Protocol issue: Version 1 (18th May 2018). Authors: MB, MM, SJ and GP.

Patient Reported Outcome Measures (PROMS) are useful metrics in evidence-based clinical care and translational research. Recording treatment-related symptoms and Quality of Life (QoL) can provide information in counselling patients to aid decision-making. This prospective study tested the feasibility of radiographer-led collection of multiple validated PROMS from Prostate Cancer (PCa) patients comparing High Dose Rate Brachytherapy combined with hypo-fractionated external beam radiotherapy (hEBRT) and hEBRT alone.From June to August 2017, 20 men with localised PCa (T1-T3aN0M0) consented to participate in the study. Ten patients received combination treatment (37.5 Gray/15 fractions followed by a 15 Gray implant), and ten patients received monotherapy (60 Gray/20 fractions). PROMS were collected at four time-points (1) at baseline, (2) final fraction of hEBRT, (3) 8 weeks after commencing radiotherapy and (4) 12 weeks after commencing radiotherapy. The PROMS used were EPIC-26, IPSS, IIEFF-5 and SF-12. The difference between the two groups were tested using Mann-Whitney U test and Wilcoxon Signed-Rank Test.All participants completed all PROMS (100% response-rate). The Monotherapy group reported a higher incidence of bowel symptoms compared to the combination group and at Week 12, EPIC-26 bowel summary score demonstrated a statistically significant difference (p = 0.005). The prevalence of erectile dysfunction increased within both groups. Maintenance of QoL was reported throughout treatment.This small study demonstrated feasibility of radiographer-led PROMS collection by 100% completion rate. Streamlining of these tools into integrated technology applications and real time PROMS measurement has the ability to benefit patients and guide clinicians in adapting therapies based on individual need. Keywords: Prostate cancer, Hypo-fractionated, HDR brachytherapy, Patient-reported outcome measures, Quality of life

Background: Hypoxia is associated with a poor prognosis in prostate cancer. This work aimed to derive and validate a hypoxia-related mRNA signature for localized prostate cancer. Method: Hypoxia genes were identified in vitro via RNA-sequencing and combined with in vivo gene co-expression analysis to generate a signature. The signature was independently validated in eleven prostate cancer cohorts and a bladder cancer phase III randomized trial of radiotherapy alone or with carbogen and nicotinamide (CON). Results: A 28-gene signature was derived. Patients with high signature scores had poorer biochemical recurrence free survivals in six of eight independent cohorts of prostatectomy-treated patients (Log rank test P

Abstract Background Traditional CTV-PTV margin recipes are not generally applicable in the situation of stereotactic ablative radiotherapy (SABR) treatments of multiple target volumes with a single isocentre. In this work, we present a novel geometric method of margin derivation based on CBCT-derived anatomical data. Methods Twenty patients with high-risk localized prostate cancer were selected for retrospective review. Individual volumes of interest (prostate, prostate and seminal vesicles and pelvic lymph nodes) were delineated on five representative CBCTs and registered to the planning CT using two registration protocols: bone match or prostate-based soft tissue match. Margins were incrementally expanded around composite CTV structures until 95% overlap was achieved. Results CTV-PTV margins of 5.2, 6.5 and 7.6 mm were required for prostate, prostate and seminal vesicles and pelvic lymph nodes respectively using a prostate matching protocol. For the prostate and seminal vesicle structures, margins calculated using our method displayed good agreement with a conventional margin recipe (within ±1.0 mm). Conclusions We have presented an alternative method of CTV-PTV margin derivation that is applicable to SABR treatments with more than one isocentric target. These results have informed an institutional trial of prostate and pelvic nodal SABR in men with high-risk localized prostate cancer.

Radiotherapy is commonly planned on the basis of physical dose received by the tumour and surrounding normal tissue, with margins added to address the possibility of geometric miss. However, recent experimental evidence suggests that intercellular signalling results in a given cell’s survival also depending on the dose received by neighbouring cells. A model of radiation-induced cell killing and signalling was used to analyse how this effect depends on dose and margin choices. Effective Uniform Doses were calculated for model tumours in both idealised cases with no delivery uncertainty and more realistic cases incorporating geometric uncertainty. In highly conformal irradiation, a lack of signalling from outside the target leads to reduced target cell killing, equivalent to under-dosing by up to 10% compared to large uniform fields. This effect is significantly reduced when higher doses per fraction are considered, both increasing the level of cell killing and reducing margin sensitivity. These effects may limit the achievable biological precision of techniques such as stereotactic radiotherapy even in the absence of geometric uncertainties, although it is predicted that larger fraction sizes reduce the relative contribution of cell signalling driven effects. These observations may contribute to understanding the efficacy of hypo-fractionated radiotherapy. [ABSTRACT FROM AUTHOR]

The article looks at the efficiency of the Cancer Care Ontario (CCO) guideline on active surveillance (AS) for localized prostate cancer treatment, based on the American Society of Clinical Oncology (ASCO) summary. Topics discussed include prostate cancer as the most common cancer in the U.S., with 233,000 men composing of 27 percent of new cases, and ASCO recommendations on AS like covering patients with low-risk prostate cancer and active treatment for medium-risk patients.

Purpose: To endorse Cancer Care Ontario's guideline on Active Surveillance for the Management of Localized Prostate Cancer. The American Society of Clinical Oncology (ASCO) has a policy and set of procedures for endorsing clinical practice guidelines developed by other professional organizations., Methods: The Active Surveillance for the Management of Localized Prostate Cancer guideline was reviewed for developmental rigor by methodologists. The ASCO Endorsement Panel then reviewed the content and the recommendations., Results: The ASCO Endorsement Panel determined that the recommendations from the Active Surveillance for the Management of Localized Prostate Cancer guideline, published in May 2015, are clear, thorough, and based upon the most relevant scientific evidence. ASCO endorsed the Active Surveillance for the Management of Localized Prostate Cancer guideline with added qualifying statements. The Cancer Care Ontario recommendation regarding 5-alpha reductase inhibitors was not endorsed by the ASCO panel., Recommendations: For most patients with low-risk (Gleason score ≤ 6) localized prostate cancer, active surveillance is the recommended disease management strategy. Factors including younger age, prostate cancer volume, patient preference, and ethnicity should be taken into account when making management decisions. Select patients with low-volume, intermediate-risk (Gleason 3 + 4 = 7) prostate cancer may be offered active surveillance. Active surveillance protocols should include prostate-specific antigen testing, digital rectal examinations, and serial prostate biopsies. Ancillary radiologic and genomic tests are investigational but may have a role in patients with discordant clinical and/or pathologic findings. Patients who are reclassified to a higher-risk category (Gleason score ≥ 7) or who have significant increases in tumor volume on subsequent biopsies should be offered active therapy., (© 2016 by American Society of Clinical Oncology.)

Purpose: Active surveillance is increasingly accepted as a treatment option for favorable-risk prostate cancer. Long-term follow-up has been lacking. In this study, we report the long-term outcome of a large active surveillance protocol in men with favorable-risk prostate cancer., Patients and Methods: In a prospective single-arm cohort study carried out at a single academic health sciences center, 993 men with favorable- or intermediate-risk prostate cancer were managed with an initial expectant approach. Intervention was offered for a prostate-specific antigen (PSA) doubling time of less than 3 years, Gleason score progression, or unequivocal clinical progression. Main outcome measures were overall and disease-specific survival, rate of treatment, and PSA failure rate in the treated patients., Results: Among the 819 survivors, the median follow-up time from the first biopsy is 6.4 years (range, 0.2 to 19.8 years). One hundred forty-nine (15%) of 993 patients died, and 844 patients are alive (censored rate, 85.0%). There were 15 deaths (1.5%) from prostate cancer. The 10- and 15-year actuarial cause-specific survival rates were 98.1% and 94.3%, respectively. An additional 13 patients (1.3%) developed metastatic disease and are alive with confirmed metastases (n = 9) or have died of other causes (n = 4). At 5, 10, and 15 years, 75.7%, 63.5%, and 55.0% of patients remained untreated and on surveillance. The cumulative hazard ratio for nonprostate-to-prostate cancer mortality was 9.2:1., Conclusion: Active surveillance for favorable-risk prostate cancer is feasible and seems safe in the 15-year time frame. In our cohort, 2.8% of patients have developed metastatic disease, and 1.5% have died of prostate cancer. This mortality rate is consistent with expected mortality in favorable-risk patients managed with initial definitive intervention., (© 2014 by American Society of Clinical Oncology.)