Background Abiraterone acetate plus prednisolone (herein referred to as abiraterone) or enzalutamide added at the start of androgen deprivation therapy improves outcomes for patients with metastatic prostate cancer. Here, we aimed to evaluate long-term outcomes and test whether combining enzalutamide with abiraterone and androgen deprivation therapy improves survival. Methods We analysed two open-label, randomised, controlled, phase 3 trials of the STAMPEDE platform protocol, with no overlapping controls, conducted at 117 sites in the UK and Switzerland. Eligible patients (no age restriction) had metastatic, histologically-confirmed prostate adenocarcinoma; a WHO performance status of 0-2; and adequate haematological, renal, and liver function. Patients were randomly assigned (1:1) using a computerised algorithm and a minimisation technique to either standard of care (androgen deprivation therapy; docetaxel 75 mg/m(2) intravenously for six cycles with prednisolone 10 mg orally once per day allowed from Dec 17, 2015) or standard of care plus abiraterone acetate 1000 mg and prednisolone 5 mg (in the abiraterone trial) orally or abiraterone acetate and prednisolone plus enzalutamide 160 mg orally once a day (in the abiraterone and enzalutamide trial). Patients were stratified by centre, age, WHO performance status, type of androgen deprivation therapy, use of aspirin or non-steroidal anti-inflammatory drugs, pelvic nodal status, planned radiotherapy, and planned docetaxel use. The primary outcome was overall survival assessed in the intention-to-treat population. Safety was assessed in all patients who started treatment. A fixed-effects meta-analysis of individual patient data was used to compare differences in survival between the two trials. STAMPEDE is registered with ClinicalTrials.gov (NCT00268476) and ISRCTN (ISRCTN78818544). Findings Between Nov 15, 2011, and Jan 17, 2014, 1003 patients were randomly assigned to standard of care (n=502) or standard of care plus abiraterone (n=501) in the abiraterone trial. Between July 29, 2014, and March 31, 2016, 916 patients were randomly assigned to standard of care (n=454) or standard of care plus abiraterone and enzalutamide (n=462) in the abiraterone and enzalutamide trial. Median follow-up was 96 months (IQR 86-107) in the abiraterone trial and 72 months (61-74) in the abiraterone and enzalutamide trial. In the abiraterone trial, median overall survival was 76.6 months (95% CI 67.8-86.9) in the abiraterone group versus 45.7 months (41.6-52.0) in the standard of care group (hazard ratio [HR] 0.62 [95% CI 0.53-0.73]; p<0.0001). In the abiraterone and enzalutamide trial, median overall survival was 73.1 months (61.9-81.3) in the abiraterone and enzalutamide group versus 51.8 months (45.3-59.0) in the standard of care group (HR 0.65 [0.55-0.77]; p<0.0001). We found no difference in the treatment effect between these two trials (interaction HR 1.05 [0.83-1.32]; p interaction=0.71) or between-trial heterogeneity (I-2 p=0.70). In the first 5 years of treatment, grade 3-5 toxic effects were higher when abiraterone was added to standard of care (271 [54%] of 498 vs 192 [38%] of 502 with standard of care) and the highest toxic effects were seen when abiraterone and enzalutamide were added to standard of care (302 [68%] of 445 vs 204 [45%] of 454 with standard of care). Cardiac causes were the most common cause of death due to adverse events (five [1%] with standard of care plus abiraterone and enzalutamide [two attributed to treatment] and one (<1%) with standard of care in the abiraterone trial). Interpretation Enzalutamide and abiraterone should not be combined for patients with prostate cancer starting longterm androgen deprivation therapy. Clinically important improvements in survival from addition of abiraterone to androgen deprivation therapy are maintained for longer than 7 years. Copyright (c) 2023 The Author(s). Published by Elsevier Ltd.

Metastatic and high-risk localized prostate cancer respond to hormone therapy but outcomes vary. Following a pre-specified statistical plan, we used Cox models adjusted for clinical variables to test associations with survival of multi-gene expression-based classifiers from 781 patients randomized to androgen deprivation with or without abiraterone in the STAMPEDE trial. Decipher score was strongly prognostic (p<2×10-5) and identified clinically-relevant differences in absolute benefit, especially for localized cancers. In metastatic disease, classifiers of proliferation, PTEN or TP53 loss and treatment-persistent cells were prognostic. In localized disease, androgen receptor activity was protective whilst interferon signaling (that strongly associated with tumor lymphocyte infiltration) was detrimental. Post-Operative Radiation-Therapy Outcomes Score was prognostic in localized but not metastatic disease (interaction p=0.0001) suggesting the impact of tumor biology on clinical outcome is context-dependent on metastatic state. Transcriptome-wide testing has clinical utility for advanced prostate cancer and identified worse outcomes for localized cancers with tumor-promoting inflammation.

Background STAMPEDE has previously reported that radiotherapy (RT) to the prostate improved overall survival (OS) for patients with newly diagnosed prostate cancer with low metastatic burden, but not those with high-burden disease. In this final analysis, we report long-term findings on the primary outcome measure of OS and on the secondary outcome measures of symptomatic local events, RT toxicity events, and quality of life (QoL). Methods and findings Patients were randomised at secondary care sites in the United Kingdom and Switzerland between January 2013 and September 2016, with 1:1 stratified allocation: 1,029 to standard of care (SOC) and 1,032 to SOC+RT. No masking of the treatment allocation was employed. A total of 1,939 had metastatic burden classifiable, with 42% low burden and 58% high burden, balanced by treatment allocation. Intention-to-treat (ITT) analyses used Cox regression and flexible parametric models (FPMs), adjusted for stratification factors age, nodal involvement, the World Health Organization (WHO) performance status, regular aspirin or nonsteroidal anti-inflammatory drug (NSAID) use, and planned docetaxel use. QoL in the first 2 years on trial was assessed using prospectively collected patient responses to QLQ-30 questionnaire. Patients were followed for a median of 61.3 months. Prostate RT improved OS in patients with low, but not high, metastatic burden (respectively: 202 deaths in SOC versus 156 in SOC+RT, hazard ratio (HR) = 0·64, 95% CI 0.52, 0.79, p < 0.001; 375 SOC versus 386 SOC+RT, HR = 1.11, 95% CI 0.96, 1.28, p = 0·164; interaction p < 0.001). No evidence of difference in time to symptomatic local events was found. There was no evidence of difference in Global QoL or QLQ-30 Summary Score. Long-term urinary toxicity of grade 3 or worse was reported for 10 SOC and 10 SOC+RT; long-term bowel toxicity of grade 3 or worse was reported for 15 and 11, respectively. Conclusions Prostate RT improves OS, without detriment in QoL, in men with low-burden, newly diagnosed, metastatic prostate cancer, indicating that it should be recommended as a SOC. Trial registration ClinicalTrials.gov NCT00268476 , ISRCTN.com ISRCTN78818544 .

Background Genomic copy number alterations commonly occur in prostate cancer and are one measure of genomic instability. The clinical implication of copy number change in advanced prostate cancer, which defines a wide spectrum of disease from high-risk localised to metastatic, is unknown. Methods We performed copy number profiling on 688 tumour regions from 300 patients, who presented with advanced prostate cancer prior to the start of long-term androgen deprivation therapy (ADT), in the control arm of the prospective randomised STAMPEDE trial. Patients were categorised into metastatic states as follows; high-risk non-metastatic with or without local lymph node involvement, or metastatic low/high volume. We followed up patients for a median of 7 years. Univariable and multivariable Cox survival models were fitted to estimate the association between the burden of copy number alteration as a continuous variable and the hazard of death or disease progression. Results The burden of copy number alterations positively associated with radiologically evident distant metastases at diagnosis ( P =0.00006) and showed a non-linear relationship with clinical outcome on univariable and multivariable analysis, characterised by a sharp increase in the relative risk of progression ( P =0.003) and death ( P =0.045) for each unit increase, stabilising into more modest increases with higher copy number burdens. This association between copy number burden and outcome was similar in each metastatic state. Copy number loss occurred significantly more frequently than gain at the lowest copy number burden quartile ( q =4.1 × 10 −6 ). Loss of segments in chromosome 5q21-22 and gains at 8q21-24, respectively including CHD1 and cMYC occurred more frequently in cases with higher copy number alteration (for either region: Kolmogorov–Smirnov distance, 0.5; adjusted P <0.0001). Copy number alterations showed variability across tumour regions in the same prostate. This variance associated with increased risk of distant metastases (Kruskal-Wallis test P =0.037). Conclusions Copy number alteration in advanced prostate cancer associates with increased risk of metastases at diagnosis. Accumulation of a limited number of copy number alterations associates with most of the increased risk of disease progression and death. The increased likelihood of involvement of specific segments in high copy number alteration burden cancers may suggest an order underlying the accumulation of copy number changes. Trial registration ClinicalTrials.gov NCT00268476 , registered on December 22, 2005. EudraCT 2004-000193-31 , registered on October 4, 2004.

Abiraterone acetate plus prednisolone (AAP) previously demonstrated improved survival in STAMPEDE, a multiarm, multistage platform trial in men starting long-term hormone therapy for prostate cancer. This long-term analysis in metastatic patients was planned for 3 years after the first results. Standard-of-care (SOC) was androgen deprivation therapy. The comparison randomised patients 1:1 to SOC-alone with or without daily abiraterone acetate 1000 mg + prednisolone 5 mg (SOC + AAP), continued until disease progression. The primary outcome measure was overall survival. Metastatic disease risk group was classified retrospectively using baseline CT and bone scans by central radiological review and pathology reports. Analyses used Cox proportional hazards and flexible parametric models, accounting for baseline stratification factors. One thousand and three patients were contemporaneously randomised (November 2011 to January 2014): median age 67 years; 94% newly-diagnosed; metastatic disease risk group: 48% high, 44% low, 8% unassessable; median PSA 97 ng/mL. At 6.1 years median follow-up, 329 SOC-alone deaths (118 low-risk, 178 high-risk) and 244 SOC + AAP deaths (75 low-risk, 145 high-risk) were reported. Adjusted HR = 0.60 (95% CI: 0.50-0.71; P = 0.31 x 10(-9)) favoured SOC + AAP, with 5-years survival improved from 41% SOC-alone to 60% SOC + AAP. This was similar in low-risk (HR = 0.55; 95% CI: 0.41-0.76) and high-risk (HR = 0.54; 95% CI: 0.43-0.69) patients. Median and current maximum time on SOC + AAP was 2.4 and 8.1 years. Toxicity at 4 years postrandomisation was similar, with 16% patients in each group reporting grade 3 or higher toxicity. A sustained and substantial improvement in overall survival of all metastatic prostate cancer patients was achieved with SOC + abiraterone acetate + prednisolone, irrespective of metastatic disease risk group.

5021 Background: Men with advanced hormone-sensitive prostate cancer (HSPC) starting long term androgen deprivation therapy (ADT) follow a highly variable clinical course. Treatment intensification with docetaxel or AR targeted therapies improves outcomes but there is a risk of overtreatment, especially in non-metastatic (M0) or metastatic (M1) low volume disease. We established a framework for biomarker evaluation in the STAMPEDE trial. We aimed to evaluate the feasibility and clinical utility of assessing the burden of copy number (CN) aberrations in newly diagnosed advanced HSPC. We hypothesised that increased percentage genome altered (PGA) would associate with higher disease burden and worse prognosis. Methods: We implemented a scalable strategy using low coverage whole genome sequencing (lpWGS) of formalin fixed paraffin embedded (FFPE) diagnostic core biopsies from STAMPEDE participants randomised to the standard of care ADT arm, between 2005 and 2016. Tissue was retrieved from 136 trial sites. 315 cases were randomly selected, aiming for a biomarker population of 300, anticipating an assay failure rate ̃5%. We defined 40% as the minimum histopathologically determined tumor cellularity (TC) for inclusion. We performed a survival analysis investigating PGA at diagnosis as a continuous measure with fractional polynomial specification in Cox models adjusting for disease burden, Gleason grade, pre-ADT PSA (log-transformed), age at randomisation and TC. We pre-specified that all hypothesis tests required evidence at the 5% significance level to consider rejecting the null hypothesis. Results: We successfully CN profiled 300/315 cases. There were no significantly different baseline clinico-pathological features between the full trial comparison n = 3106 and final biomarker population n = 300, 290/300 cases were de novo presentations. PGA in the core with highest Gleason grade and TC was median 18% (range 0%-75%; n = 300). PGA was significantly higher in M1 (n = 169) compared to M0 (n = 131) cases (median: 21% vs 14%; p = 0.00006). 284/300 were subclassified by disease burden into M0 node negative and node positive, and M1 low and high volume. PGA was significantly associated with increased disease burden (p = 0.00002). Increased PGA was significantly and non-linearly associated with an increased hazard of failure-free survival (p = 0.004), progression-free survival (p = 0.002), metastatic progression-free survival (p = 0.003), overall survival (p = 0.045) and prostate cancer-specific survival (p = 0.011). Conclusions: Evaluation of the burden of CN aberrations in archival, poor quality FFPE diagnostic tissue from men randomised in the STAMPEDE trial is feasible using lpWGS and has potential clinical utility to identify better prognosis advanced HSPC patients, who may not require treatment intensification.

IMPORTANCE Prostate radiotherapy (RT) improves survival in men with low-burden metastatic prostate cancer. However, owing to the dichotomized nature of metastatic burden criteria, it is not clear how this benefit varies with bone metastasis counts and metastatic site. OBJECTIVE To evaluate the association of bone metastasis count and location with survival benefit from prostate RT. DESIGN, SETTING, AND PARTICIPANTS This exploratory analysis of treatment outcomes based on metastatic site and extent as determined by conventional imaging (computed tomography/magnetic resonance imaging and bone scan) evaluated patients with newly diagnosed metastatic prostate cancer randomized within the STAMPEDE trial's metastasis M1 RT comparison. The association of baseline bone metastasis counts with overall survival (OS) and failure-free survival (FFS) was assessed using a multivariable fractional polynomial interaction procedure. Further analysis was conducted in subgroups. INTERVENTIONS Patients were randomized to receive either standard of care (androgen deprivation therapy with or without docetaxel) or standard of care and prostate RT. MAIN OUTCOMES AND MEASURES The primary outcomes were OS and FFS. RESULTS A total of 1939 of 2061 men were included (median [interquartile range] age, 68 [63-73] years); 1732 (89%) had bone metastases. Bone metastasis counts were associated with OS and FFS benefit from prostate RT. Survival benefit decreased continuously as the number of bone metastases increased, with benefit most pronounced up to 3 bone metastases. A plot of estimated treatment effect indicated that the upper 95% CI crossed the line of equivalence (hazard ratio [HR], 1) above 3 bone metastases without a detectable change point. Further analysis based on subgroups showed that the magnitude of benefit from the addition of prostate RT was greater in patients with lowmetastatic burden with only nonregional lymph nodes (M1a) or 3 or fewer bone metastases without visceral metastasis (HR for OS, 0.62; 95% CI, 0.46-0.83; HR for FFS, 0.57; 95% CI, 0.47-0.70) than among patients with 4 or more bone metastases or any visceral/other metastasis (HR for OS, 1.08; 95% CI, 0.91-1.28; interaction P =.003; HR for FFS, 0.87; 95% CI, 0.76-0.99; interaction P =.002). CONCLUSIONS AND RELEVANCE In this exploratory analysis of a randomized clinical trial, bone metastasis count and metastasis location based on conventional imaging were associated with OS and FFS benefit from prostate RT in M1 disease.

5076 Background: Treatment intensification with docetaxel or abiraterone improved survival for advanced prostate cancer starting androgen deprivation therapy (ADT) in the Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy (STAMPEDE, NCT00268476) trial. However, survival and time-to-progression is highly variable on ADT, introducing the risk of unnecessary toxicity from additional treatments for some patients. Here we test the prognostic association of proliferation index using Ki67 scores in the control arm of the STAMPEDE population of high-risk localised (M0) and metastatic (M1) prostate cancer. Methods: Pre-ADT diagnostic needle biopsies were obtained from 517 men randomized in STAMPEDE arm A between 2006 and 2015. These were assessed for proliferation using an analytically optimised Ki67 immunohistochemistry assay. Ki67 was tested for associations with baseline clinico-pathological variables (Grade group, pre-ADT serum PSA and imaging metastatic burden) in univariable linear-regression models, and for associations with survival outcomes in multivariable Cox-regression models adjusted for these and additional confounding variables. Primary outcome measure was overall survival, secondary outcomes were prostate cancer-specific, failure-free, progression-free and metastatic progression-free survival. Results: Ki67 was available for 475 patients who received ADT only for at least 2 years ± radiotherapy. Of 202 M0, 74 were node positive. Of 273 M1, 116, 127 and 30 were respectively low, high and unknown radiological M1 volume. Ki67 score associated with higher Gleason (p=7.15x10 -11 ) and presence of extra-pelvic metastases (p=1.41x10 -8 ). Increasing Ki67 scores showed a strong linear association with poorer overall survival, with an estimated 2% increase in the hazard of death per percentage increase in the score (adjusted HR=1.02, 95% CI 1.01-1.02; p=1.04x10 -5 ). There was also strong evidence that Ki67 associated positively with all secondary outcomes, including prostate cancer-specific survival (adjusted p=5.50x10 -6 ) and metastatic progression-free survival (adjusted p=3.50x10 -9 ). Conclusions: Ki67 immuno-score is strongly prognostic in clinically advanced prostate cancer independent of Gleason score and the other clinicopathological variables tested in this study. Ki67 is a clinically scalable assay that could improve selection for treatment intensification and provide a tool for screening patients most likely to benefit from further molecular investigation.

PURPOSE The STAMPEDE trial recruits men with newly diagnosed, high-risk, hormone-sensitive prostate cancer. To ascertain the feasibility of targeted next-generation sequencing (tNGS) and the prevalence of baseline genomic aberrations, we sequenced tumor and germline DNA from patients with metastatic prostate cancer (mPCa) starting long-term androgen-deprivation therapy (ADT). METHODS In a 2-stage approach, archival, formalin-fixed, paraffin-embedded (FFPE) prostate tumor core biopsy samples were retrospectively subjected to 2 tNGS assays. Prospective enrollment enabled validation using tNGS in tumor and germline DNA. RESULTS In stage 1, tNGS data were obtained from 185 tumors from 287 patients (65%); 98% had de novo mPCa. We observed PI3K pathway aberrations in 43%, due to PTEN copy-number loss (34%) and/or activating mutations in PIK3 genes or AKT (18%) and TP53 mutation or loss in 33%. No androgen receptor (AR) aberrations were detected; RB1 loss was observed in < 1%. In stage 2, 93 (92%) of 101 FFPE tumors (biopsy obtained within 8 months) were successfully sequenced prospectively. The prevalence of DNA damage repair (DDR) deficiency was 14% (somatic) and 5% (germline). BRCA2 mutations and mismatch repair gene mutations were exclusive to high-volume disease. Aberrant DDR (22% v 15%), Wnt pathway (16% v 4%), and chromatin remodeling (16% v 8%) were all more common in high-volume compared with low-volume disease, but the small numbers limited statistical comparisons. CONCLUSION Prospective genomic characterization is feasible using residual diagnostic tumor samples and reveals that the genomic landscapes of de novo high-volume mPCa and advanced metastatic prostate cancer have notable similarities (PI3K pathway, DDR, Wnt, chromatin remodeling) and differences (AR, RB1). These results will inform the design and conduct of biomarker-directed trials in men with metastatic hormone-sensitive prostate cancer.

Background: Prostate radiotherapy (RT) is a first-line option for newly diagnosed men with low-burden metastatic prostate cancer. The current criterion to define this clinical state is based on manual bone metastasis counts, butenumeration of bone metastases is limited by interobserver variations, and it does not account for metastasis volume or lesional coalescence. The automated bone scan index (aBSI) is a quantitative method of evaluating bone metastatic burden in a standardised and reproducible manner. Objective: To evaluate whether aBSI has utility as a predictive imaging biomarker to define a newly diagnosed metastatic prostate cancer population that might benefit from the addition of prostate RT to standard of care (SOC) systemic therapy. Design, setting, and participants: This is an exploratory analysis of men with newly diagnosed metastatic prostate cancer randomised in a 1:1 ratio to either SOC or SOC + prostate RT within the STAMPEDE "M1 vertical bar RT comparison". Intervention: The SOC was lifelong androgen deprivation therapy, with up-front docetaxel permitted from December 2015. Men allocated RT received either a daily or a weekly schedule that was nominated before randomisation. Outcome measurements and statistical analysis: Baseline bone scans were evaluated retrospectively to calculate aBSI. We used overall (OS) and failure-free (FFS) survival as the end points. Treatment-aBSI interaction was evaluated using the multivariable fractional polynomial interaction (MFPI) and subpopulation treatment effect pattern plot. Further analysis was done in aBSI quartiles using Cox regression models adjusted for stratification factors. Results and limitations: : Baseline bone scans for 660 (SOC: 323 and SOC + RT: 337) of 2061 men randomised within the "M1 vertical bar RT comparison" met the software requirements for aBSI calculation. The median age was 68 yr, median PSA was 100 ng/mL, median aBSI was 0.9, and median follow-up was 39 mo. Baseline patient characteristics including aBSI were balanced between the treatment groups. Using the MFPI procedure, there was evidence of aBSI-treatment interaction for OS (p = 0.04, MFPI procedure) and FFS (p < 0.01, MFPI procedure). Graphical evaluation of estimated treatment effect plots showed that the OS and FFS benefit from prostate RT was greatest in patients with a low aBSI. Further analysis in quartiles based on aBSI supported this finding. Conclusions: A low automated bone scan index is predictive of survival benefit associated with prostate RT in menwith newly diagnosed metastatic prostate cancer. Patient summary: The widely used bone scan can be evaluated using an automated technique to potentially select men with newly diagnosed metastatic prostate cancer who might benefit from prostate radiotherapy. (c) 2020 The Authors. Published by Elsevier B.V. on behalf of European Association of Urology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Background: Abiraterone acetate received licencing for use in only "high-risk" metastatic hormone-naive prostate cancer (mHNPC) following the LATITUDE trial findings. However, a "risk"-related effect was not seen in the STAMPEDE trial. There remains uncertainty as to whether men with LATITUDE "low-risk" M1 disease benefit from androgen deprivation therapy (ADT) combined with abiraterone acetate and prednisolone (AAP). Objective: Evaluation of heterogeneity of effect between LATITUDE high- and low-risk M1 prostate cancer patients receiving ADT +AAP in the STAMPEDE trial. Design, setting, and participants: A post hoc subgroup analysis of the 2017 STAMPEDE "abiraterone comparison". Staging scans for M1 patients contemporaneously randomised to ADT or ADT +AAP within the STAMPEDE trial were evaluated centrally and blind to treatment assignment. Stratification was by risk according to the criteria set out in the LATITUDE trial. Exploratory subgroup stratification incorporated the CHAARTED criteria. Outcome measurements and statistical analysis: The primary outcome measure was overall survival (OS) and the secondary outcome measure was failure-free survival (FFS). Further exploratory analysis evaluated clinical skeletal-related events, progression-free survival (PFS), and prostate cancer-specific death. Standard Cox-regression and Kaplan-Meier survival estimates were employed for analysis. Results and limitations: A total of 901 M1 STAMPEDE patients were evaluated after exclusions. Of the patients, 428 (48%) were identified as having a low risk and 473 (52%) a high risk. Patients receiving ADT + AAP had significantly improved OS (low-risk hazard ratio [HR]: 0.66, 95% confidence interval or CI [0.44-0.98]) and FFS (low-risk HR: 0.24, 95% CI [0.17-0.33]) compared with ADT alone. Heterogeneity of effect was not seen between low- and high-risk groups for OS or FFS. For OS benefit in low risk, the number needed to treat was four times greater than that for high risk. However, this was not observed for the other measured endpoints. Conclusions: Men with mHNPC gain treatment benefit from ADT + AAP irrespective of risk stratification for "risk" or "volume". Patient summary: Coadministration of abiraterone acetate and prednisolone with androgen deprivation therapy (ADT) is associated with prolonged overall survival and disease control, compared with ADT alone, in all men with metastatic disease starting hormone therapy for the first time. (C) 2019 Published by Elsevier B.V. on behalf of European Association of Urology.

Objective To determine the prognostic relevance of non‐regional lymph node ( NRLN ) metastases presenting synchronously with bone metastases in metastatic prostate cancer ( mPC a) for guiding treatment decisions based on oligometastatic definitions. Patients and Methods Patients diagnosed with mPC a between 2004 and 2013 were identified from the Surveillance, Epidemiology and End Results database and were grouped by metastatic sites into only NRLN , only bone, bone + NRLN and other sites ± bone/ NRLN metastases. Multivariate Cox and competing risk regression analyses were performed to compare the risks of all‐cause mortality ( ACM ) and prostate cancer‐specific mortality ( PCSM ) associated with bone + NRLN metastases before and after propensity‐score matching to patients with only bone metastases. This was complemented with landmark and supplementary analyses. Results Of 17 167 patients with mPC a identified, 63.1% presented with only bone metastases, while bone and NRLN metastases co‐occurred in 8.9% of the cohort. On multivariate analyses, after adjusting for potential confounders (clinical and sociodemographic), patients with bone + NRLN metastases had a significantly higher risk of ACM (hazard ratio [ HR ] 1.161, 95% confidence interval [ CI ] 1.084–1.243; P < 0.001) and PCSM (subdistribution HR 1.149, 95% CI 1.067–1.237; P < 0.001) compared with patients with only bone metastases. Landmark analyses limited to survivors of ≥6 and ≥12 months again showed a significantly increased risk of ACM for patients presenting with bone + NRLN metastases compared with patients with only bone metastases. In a subsequent 1:1 propensity‐score‐matched cohort of patients with bone + NRLN metastases and only bone metastases, the bone + NRLN group had higher multivariate‐adjusted hazard rates for ACM ( HR 1.202, 95% CI 1.102–1.311; P < 0.001) and PCSM (subdistribution HR 1.146, 95% CI 1.044–1.259; P = 0.004). Conclusions Patients with concomitant NRLN and bone metastases have a higher risk of death, NRLN and bone metastases therefore representing a high‐risk feature, when compared with patients with bone metastases alone. The current therapeutic stratification of ‘low‐’ vs ‘high‐volume’ disease does not account for this phenomenon, and patients requiring aggressive combination therapy may not receive maximum therapeutic benefit as a consequence.

Background Based on previous findings, we hypothesised that radiotherapy to the prostate would improve overall survival in men with metastatic prostate cancer, and that the benefit would be greatest in patients with a low metastatic burden. We aimed to compare standard of care for metastatic prostate cancer, with and without radiotherapy. Methods We did a randomised controlled phase 3 trial at 117 hospitals in Switzerland and the UK. Eligible patients had newly diagnosed metastatic prostate cancer. We randomly allocated patients open-label in a 1: 1 ratio to standard of care (control group) or standard of care and radiotherapy (radiotherapy group). Randomisation was stratified by hospital, age at randomisation, nodal involvement, WHO performance status, planned androgen deprivation therapy, planned docetaxel use (from December, 2015), and regular aspirin or non-steroidal anti-inflammatory drug use. Standard of care was lifelong androgen deprivation therapy, with up-front docetaxel permitted from December, 2015. Men allocated radiotherapy received either a daily (55 Gy in 20 fractions over 4 weeks) or weekly (36 Gy in six fractions over 6 weeks) schedule that was nominated before randomisation. The primary outcome was overall survival, measured as the number of deaths; this analysis had 90% power with a one-sided a of 2.5% for a hazard ratio (HR) of 0.75. Secondary outcomes were failure-free survival, progression-free survival, metastatic progression-free survival, prostate cancer-specific survival, and symptomatic local event-free survival. Analyses used Cox proportional hazards and flexible parametric models, adjusted for stratification factors. The primary outcome analysis was by intention to treat. Two prespecified subgroup analyses tested the effects of prostate radiotherapy by baseline metastatic burden and radiotherapy schedule. This trial is registered with ClinicalTrials.gov, number NCT00268476. Findings Between Jan 22, 2013, and Sept 2, 2016, 2061 men underwent randomisation, 1029 were allocated the control and 1032 radiotherapy. Allocated groups were balanced, with a median age of 68 years (IQR 63-73) and median amount of prostate-specific antigen of 97 ng/mL (33-315). 367 (18%) patients received early docetaxel. 1082 (52%) participants nominated the daily radiotherapy schedule before randomisation and 979 (48%) the weekly schedule. 819 (40%) men had a low metastatic burden, 1120 (54%) had a high metastatic burden, and the metastatic burden was unknown for 122 (6%). Radiotherapy improved failure-free survival (HR 0.76, 95% CI 0.68-0.84; p<0.0001) but not overall survival (0.92, 0.80-1.06; p=0266). Radiotherapy was well tolerated, with 48 (5%) adverse events (Radiation Therapy Oncology Group grade 3-4) reported during radiotherapy and 37 (4%) after radiotherapy. The proportion reporting at least one severe adverse event (Common Terminology Criteria for Adverse Events grade 3 or worse) was similar by treatment group in the safety population (398 [38%] with control and 380 [39%] with radiotherapy). Interpretation Radiotherapy to the prostate did not improve overall survival for unselected patients with newly diagnosed metastatic prostate cancer. Copyright (c) 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.

227 Background: Patients diagnosed with non-regional lymph nodes (NRLN) in isolation exhibit a more prolonged clinical course than those with bone or visceral metastases in trial data, but evaluation of survival data in general populations is sparse and their presence doesn’t feature in risk estimations based on tumour volume. Methods: The evaluation and prognostic relevance of NRLN metastasis presenting synchronously with osseous or non-ossesous metastasis in hormone-naive prostate cancer was evaluated using the Surveillance, Epidemiology and End-results (SEER) database. Patients with stage M1a-c PCa diagnosed between 2004 and 2009 were identified and included within the analysis. Kaplan Meier was used to estimate overall (OS) and cancer specific survival (CSS) rates in relation to metastatic distribution. Multivariate cox-regression models were used to identify predictors of OS and CSS. Results: Of 4869 metastatic PCa patients identified, osseous metastasis was the most common finding (65.1%); followed by non-osseous (17.5%), osseous + NRLN (7.8%), NRLN (4.9%), non-osseous + osseous (±NRLN) (2.9%) and non-osseous + NRLN (1.8%). Median follow-up was 93 mo. Median OS and CSS were 28 and 34 mo respectively. Patients with osseous + NRLN metastasis had a significantly worse median OS (30 mo vs 25 mo, p = 0.001) and CSS (37 mo vs 29 mo, p < 0.001) compared to osseous only metastasis. On multivariate cox regression, osseous + NRLN metastasis was an independent predictor of OS and CSS when compared to osseous only metastasis (both p-values < 0.01). Conclusions: NRLN metastasis in the presence of osseous metastasis represents a poor prognostic feature when compared to osseous metastasis alone. The current therapeutic stratification of “low vs high volume” disease does not account for this phenomenon and patients requiring aggressive therapy may not receive maximal therapeutic benefit as a consequence.