Radiographic Progression-Free Survival and Clinical Progression-Free Survival as Potential Surrogates for Overall Survival in Men With Metastatic Hormone-Sensitive Prostate Cancer.

PURPOSE: Despite major increases in the longevity of men with metastatic hormone-sensitive prostate cancer (mHSPC), most men still die of prostate cancer. Phase III trials assessing new therapies in mHSPC with overall survival (OS) as the primary end point will take approximately a decade to complete. We investigated whether radiographic progression-free survival (rPFS) and clinical PFS (cPFS) are valid surrogates for OS in men with mHSPC and could potentially be used to expedite future phase III clinical trials. METHODS: We obtained individual patient data (IPD) from 9 eligible randomized trials comparing treatment regimens (different androgen deprivation therapy [ADT] strategies or ADT plus docetaxel in the control or research arms) in mHSPC. rPFS was defined as the time from random assignment to radiographic progression or death from any cause whichever occurred first; cPFS was defined as the time from random assignment to the date of radiographic progression, symptoms, initiation of new treatment, or death, whichever occurred first. We implemented a two-stage meta-analytic validation model where conditions of patient-level and trial-level surrogacy had to be met. We then computed the surrogate threshold effect (STE). RESULTS: IPD from 6,390 patients randomly assigned from 1994 to 2012 from 13 units were pooled for a stratified analysis. The median OS, rPFS, and cPFS were 4.3 (95% CI, 4.2 to 4.5), 2.4 (95% CI, 2.3 to 2.5), and 2.3 years (95% CI, 2.2 to 2.4), respectively. The STEs were 0.80 and 0.81 for rPFS and cPFS end points, respectively. CONCLUSION: Both rPFS and cPFS appear to be promising surrogate end points for OS. The STE of 0.80 or higher makes it viable for either rPFS or cPFS to be used as the primary end point that is surrogate for OS in phase III mHSPC trials with testosterone suppression alone as the backbone therapy and would expedite trial conduct.

Effect of docetaxel added to bicalutamide in Hormone-Naïve non-metastatic prostate cancer with rising PSA, a randomized clinical trial (SPCG-14).

BACKGROUND: Historically, endocrine therapy was used in a range of scenarios in patients with rising PSA, both as a treatment for locally advanced non-metastatic prostate cancer and PSA recurrence following curative intended therapy. In the present study the objective was to investigate if chemotherapy added to endocrine therapy could improve progression-free survival (PFS). MATERIALS AND METHODS: Patients with hormone-naïve, non-metastatic prostate cancer and rising prostate-specific antigen (PSA), enrolled from Sweden, Denmark, the Netherlands, and Finland, were randomized to long-term bicalutamide (150 mg daily) or plus docetaxel (75 mg/m2, q3w, 8-10 cycles) without prednisone, after stratification for the site, prior local therapy or not, and PSA doubling time. The primary endpoint was 5-year PFS analyzed with a stratified Cox proportional hazards regression model on intention to treat basis. RESULTS: Between 2009 and 2018, a total of 348 patients were randomized; 315 patients had PSA relapse after radical treatment, 33 patients had no prior local therapy. Median follow-up was 4.9 years (IQR 4.0-5.1). Adding docetaxel improved PFS (HR 0.68, 95% CI 0.50-0.93; p = 0.015). Docetaxel showed an advantage for patients with PSA relapse after prior local therapy (HR 0.67, 95% CI 0.49-0.94; p = 0.019). One event of neutropenic infection/fever occurred in 27% of the patients receiving docetaxel. Limitations were slow recruitment, lack of enrolling patients without radical local treatment, and too short follow-up for evaluation of overall survival in patients with PSA relapse. CONCLUSION: Docetaxel improved PFS in patients starting bicalutamide due to PSA relapse after local therapy or localized disease without local therapy. Confirmatory studies of the efficacy of docetaxel in the setting of PSA-only relapse in addition to endocrine therapies may be justified if longer follow-up will show increased metastatic-free survival.

Biomarker-Oriented Therapy in Bladder and Renal Cancer.

Treatment of patients with urothelial carcinoma (UC) of the bladder or renal cancer has changed significantly during recent years and efforts towards biomarker-directed therapy are being investigated. Immune checkpoint inhibition (ICI) or fibroblast growth factor receptor (FGFR) directed therapy are being evaluated for non-muscle invasive bladder cancer (NMIBC) patients, as well as muscle-invasive bladder cancer (MIBC) patients. Meanwhile, efforts to predict tumor response to neoadjuvant chemotherapy (NAC) are still ongoing, and genomic biomarkers are being evaluated in prospective clinical trials. Currently, patients with metastatic UC (mUC) are usually treated with second-line ICI, while cisplatin-ineligible patients with programmed death-ligand 1 (PD-L1) positive tumors can benefit from first-line ICI. Platinum-relapsed UC patients harboring FGFR2/3 mutations can be treated with erdafitinib, while enfortumab vedotin has emerged as a novel third-line treatment option for mUC. In metastatic (clear cell) renal cell carcinoma (RCC), ICI was first introduced as second-line treatment after vascular endothelial growth factor receptor-tyrosine kinase inhibition (VEGFR-TKI). Currently, ICIs have also been introduced as first-line treatment in metastatic RCC. Although there is no evidence up to now for beneficial adjuvant treatment after surgery with VEGFR-TKIs in high-risk non-metastatic RCC, several trials are underway investigating the potential beneficial effect of ICIs in this setting.

Patient-reported Quality of Life in Patients with Primary Metastatic Prostate Cancer Treated with Androgen Deprivation Therapy with and Without Concurrent Radiation Therapy to the Prostate in a Prospective Randomised Clinical Trial; Data from the HORRAD Trial.

BACKGROUND: A survival benefit was demonstrated for patients with low-volume metastatic prostate cancer (mPCa) when local radiotherapy was added to androgen deprivation therapy (ADT). OBJECTIVE: To determine the effect of ADT combined with external beam radiotherapy (EBRT) to the prostate on health-related quality of life (HRQoL) of patients with primary bone mPCa. DESIGN, SETTING, AND PARTICIPANTS: The HORRAD trial is a multicentre randomised controlled trial recruiting 432patients with primary bone mPCa between 2004 and 2014. INTERVENTION: Patients were randomised to ADT with EBRT or to ADT alone. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients completed two validated HRQoL questionnaires (European Organization for Research and Treatment of Cancer [EORTC] Quality of Life Questionnaire Core Module (QLQ-C30) and EORTC Quality of Life Questionnaire Prostate Module [QLQ-PR25]) at baseline and at 3, 6, 12, and24 mo after the initiation of treatment. The effect of both treatments was evaluated based on mixed-effect models. RESULTS AND LIMITATIONS: Patient characteristics and HRQoL scores at baseline were similar in both arms. At baseline, 98% of patients completed the questionnaires, compared with 58% at 24 mo. Patients reported significantly more diarrhoea (difference between the groups 10.8; 95% confidence interval [CI] 7.3-14.2), bowel symptoms (4.5; 95% CI 2.1-6.8), and urinary symptoms (11.9; 95% CI 8.9-14.8) after EBRT and ADT compared with ADT alone (all between-arm difference p < 0.001). Urinary complaints levelled at 6 mo. At 2 yr, only bowel symptom scores were significantly different (8.0; 95% CI 4.8-11.1, p ≤ 0.001), but 68% of patients in the radiotherapy group did not report clinically relevant worsening of their bowel symptom scores. CONCLUSIONS: Patients with bone mPCa reported temporary modest urinary and bowel symptoms after combined treatment with EBRT of the prostate and ADT compared with ADT alone. For some patients (22%), deterioration of bowel functions remains at 2 yr, whereas general HRQoL does not deteriorate.. PATIENT SUMMARY: This study investigated the effect of radiotherapy to the prostate added to hormonal therapy on patient-reported health-related quality of life (HRQoL) in patients with primary bone metastatic prostate cancer. Most patients reported only temporary urinary and bowel symptoms. In 22% of patients, bowel symptoms remained at 2 yr, whereas general HRQoL did not deteriorate.

Cystic renal-epithelial derived induced pluripotent stem cells from polycystic kidney disease patients.

Autosomal-dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease, leading to kidney failure in most patients. In approximately 85% of cases, the disease is caused by mutations in PKD1. How dysregulation of PKD1 leads to cyst formation on a molecular level is unknown. Induced pluripotent stem cells (iPSCs) are a powerful tool for in vitro modeling of genetic disorders. Here, we established ADPKD patient-specific iPSCs to study the function of PKD1 in kidney development and cyst formation in vitro. Somatic mutations are proposed to be the initiating event of cyst formation, and therefore, iPSCs were derived from cystic renal epithelial cells rather than fibroblasts. Mutation analysis of the ADPKD iPSCs revealed germline mutations in PKD1 but no additional somatic mutations in PKD1/PKD2. Although several somatic mutations in other genes implicated in ADPKD were identified in cystic renal epithelial cells, only few of these mutations were present in iPSCs, indicating a heterogeneous mutational landscape, and possibly in vitro cell selection before and during the reprogramming process. Whole-genome DNA methylation analysis indicated that iPSCs derived from renal epithelial cells maintain a kidney-specific DNA methylation memory. In addition, comparison of PKD1+/- and control iPSCs revealed differences in DNA methylation associated with the disease history. In conclusion, we generated and characterized iPSCs derived from cystic and healthy control renal epithelial cells, which can be used for in vitro modeling of kidney development in general and cystogenesis in particular.

Prostate Radiotherapy for Metastatic Hormone-sensitive Prostate Cancer: A STOPCAP Systematic Review and Meta-analysis.

BACKGROUND: Many trials are evaluating therapies for men with metastatic hormone-sensitive prostate cancer (mHSPC). OBJECTIVE: To systematically review trials of prostate radiotherapy. DESIGN, SETTING, AND PARTICIPANTS: Using a prospective framework (framework for adaptive meta-analysis [FAME]), we prespecified methods before any trial results were known. We searched extensively for eligible trials and asked investigators when results would be available. We could then anticipate that a definitive meta-analysis of the effects of prostate radiotherapy was possible. We obtained prepublication, unpublished, and harmonised results from investigators. INTERVENTION: We included trials that randomised men to prostate radiotherapy and androgen deprivation therapy (ADT) or ADT only. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Hazard ratios (HRs) for the effects of prostate radiotherapy on survival, progression-free survival (PFS), failure-free survival (FFS), biochemical progression, and subgroup interactions were combined using fixed-effect meta-analysis. RESULTS AND LIMITATIONS: We identified one ongoing (PEACE-1) and two completed (HORRAD and STAMPEDE) eligible trials. Pooled results of the latter (2126 men; 90% of those eligible) showed no overall improvement in survival (HR=0.92, 95% confidence interval [CI] 0.81-1.04, p=0.195) or PFS (HR=0.94, 95% CI 0.84-1.05, p=0.238) with prostate radiotherapy. There was an overall improvement in biochemical progression (HR=0.74, 95% CI 0.67-0.82, p=0.94×10-8) and FFS (HR=0.76, 95% CI 0.69-0.84, p=0.64×10-7), equivalent to ∼10% benefit at 3yr. The effect of prostate radiotherapy varied by metastatic burden-a pattern consistent across trials and outcome measures, including survival (<5, ≥5; interaction HR=1.47, 95% CI 1.11-1.94, p=0.007). There was 7% improvement in 3-yr survival in men with fewer than five bone metastases. CONCLUSIONS: Prostate radiotherapy should be considered for men with mHSPC with a low metastatic burden. PATIENT SUMMARY: Prostate cancer that has spread to other parts of the body (metastases) is usually treated with hormone therapy. In men with fewer than five bone metastases, addition of prostate radiotherapy helped them live longer and should be considered.

Effect on Survival of Androgen Deprivation Therapy Alone Compared to Androgen Deprivation Therapy Combined with Concurrent Radiation Therapy to the Prostate in Patients with Primary Bone Metastatic Prostate Cancer in a Prospective Randomised Clinical Trial: Data from the HORRAD Trial.

BACKGROUND: The cornerstone of standard treatment for patients with primary bone metastatic prostate cancer (mPCa) is androgen deprivation therapy (ADT). Retrospective studies suggest a survival benefit for treatment of the primary prostatic tumour in mPCa, but to date, no randomised-controlled-trials (RCTs) have been published addressing this issue. OBJECTIVE: To determine whether overall survival is prolonged by adding local treatment of the primary prostatic tumour with external beam radiation therapy (EBRT) to ADT. DESIGN, SETTING, AND PARTICIPANTS: The HORRAD trial is a multicentre RCT recruiting 432 patients with prostate-specific antigen (PSA) >20ng/ml and primary bone mPCa on bone scan between 2004 and 2014. INTERVENTION: Patients were randomised to either ADT with EBRT (radiotherapy group) or ADT alone (control group). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Primary endpoint was overall survival. Secondary endpoint was time to PSA progression. Crude and adjusted analyses were applied to evaluate treatment effect. RESULTS AND LIMITATIONS: Median PSA level was 142ng/ml and 67% of patients had more than five osseous metastases. Median follow up was 47 mo. Median overall survival was 45 mo (95% confidence interval [CI], 40.4-49.6) in the radiotherapy group and 43 mo (95% CI: 32.6-53.4) in the control group (p=0.4). No significant difference was found in overall survival (hazard ratio [HR]: 0.90; 95% CI: 0.70-1.14; p=0.4). Median time to PSA progression in the radiotherapy group was 15 mo (95% CI: 11.8-18.2), compared with 12 mo (95% CI: 10.6-13.4) in the control group. The crude HR (0.78; 95% CI: 0.63-0.97) was statistically significant (p=0.02). CONCLUSIONS: The current RCT comparing ADT to ADT with EBRT to the prostate in patients with primary bone mPCa did not show a significant difference in overall survival, although the CI cannot exclude a substantial survival benefit. Further research is needed to confirm our findings. PATIENT SUMMARY: This study investigated the effect of adding radiation therapy to the prostate to hormonal therapy in prostate cancer patients with metastasis to the bone at diagnosis. In our patient group, additional radiotherapy did not improve overall survival. Further research is needed to confirm our findings. TWITTER SUMMARY: Adding radiotherapy to the prostate in patients with bone metastatic prostate cancer does not improve overall survival.

Identifying cystogenic paracrine signaling molecules in cyst fluid of patients with polycystic kidney disease.

In autosomal dominant polycystic kidney disease (ADPKD) paracrine signaling molecules in cyst fluid can induce proliferation and cystogenesis of neighboring renal epithelial cells. However, the identity of this cyst-inducing factor is still unknown. The aim of this study was to identify paracrine signaling proteins in cyst fluid using a 3D in vitro cystogenesis assay. We collected cyst fluid from 15 ADPKD patients who underwent kidney or liver resection (55 cysts from 13 nephrectomies, 5 cysts from 2 liver resections). For each sample, the ability to induce proliferation and cyst formation was tested using the cystogenesis assay (RPTEC/TERT1 cells in Matrigel with cyst fluid added for 14 days). Kidney cyst fluid induced proliferation and cyst growth of renal epithelial cells in a dose-dependent fashion. Liver cyst fluid also induced cystogenesis. Using size exclusion chromatography, 56 cyst fluid fractions were obtained of which only the fractions between 30 and 100 kDa showed cystogenic potential. Mass spectrometry analysis of samples that tested positive or negative in the assay identified 43 candidate cystogenic proteins. Gene ontology analysis showed an enrichment for proteins classified as enzymes, immunity proteins, receptors, and signaling proteins. A number of these proteins have previously been implicated in ADPKD, including secreted frizzled-related protein 4, S100A8, osteopontin, and cysteine rich with EGF-like domains 1. In conclusion, both kidney and liver cyst fluids contain paracrine signaling molecules that drive cyst formation. Using size exclusion chromatography and mass spectrometry, we procured a candidate list for future studies. Ultimately, cystogenic paracrine signaling molecules may be targeted to abrogate cystogenesis in ADPKD.

Algorithm for Bosniak 2F Cyst in Kidney Donation.

BACKGROUND The Bosniak system for radiological classification of renal cysts offers a tool for surgical decision-making in clinical practice. Although 95% of Bosniak 2F cysts remain benign, a consensus on the management of Bosniak 2F cysts in kidney donation has not been developed. CASE REPORT We present a donor with a Bosniak 2F cyst, who successfully donated her kidney after partial resection of the Bosniak 2F cyst. Postoperative pathology examination of the partially resected cystic wall revealed a multilocular cystic renal cell carcinoma. Postoperative pathology examination revealed a multilocular cystic renal cell carcinoma. Resection of the Bosniak 2F cyst provides 2 advantages: the recipient receives a new donor kidney and will be free of dialysis, and the donor will be free of surveillance. CONCLUSIONS We present a practical guideline for kidney donors with Bosniak 2F cysts, balancing the risk of tumor transmission or recurrence with the benefit associated with organ transplantation, without compromising the risk of the donor and recipient. Further evaluation of this algorithm by longer follow-up and more studies is needed to prove its safety.

Bosniak Classification for Complex Renal Cysts Reevaluated: A Systematic Review.

PURPOSE: We systematically evaluated the Bosniak classification system with malignancy rates of each Bosniak category, and assessed the effectiveness related to surgical treatment and oncologic outcome based on recurrence and/or metastasis. MATERIALS AND METHODS: In a systematic review according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) criteria, we selected 39 publications for inclusion in this analysis and categorized them into 1) surgical cohorts-all cysts treated surgically and 2) radiological cohorts-cysts with surgical treatment or radiological followup. RESULTS: A total of 3,036 complex renal cysts were categorized into Bosniak II, IIF, III and IV. In surgical and radiological cohorts pooled estimates showed a malignancy prevalence of 0.51 (0.44, 0.58) in Bosniak III and 0.89 (0.83, 0.92) in Bosniak IV cysts, respectively. Stable Bosniak IIF cysts showed a malignancy rate of less than 1% during radiological followup (surveillance). Bosniak IIF cysts, which showed reclassification to the Bosniak III/IV category during radiological followup (12%), showed malignancy in 85%, comparable to Bosniak IV cysts. The estimated surgical number needed to treat to avoid metastatic disease of Bosniak III and IV cysts was 140 and 40, respectively. CONCLUSIONS: The effectiveness of the Bosniak classification system for complex renal cysts was high in categories II, IIF and IV, but low in category III, and 49% of Bosniak III cysts was overtreated because of a benign outcome. This surgical overtreatment combined with the excellent outcome for Bosniak III cysts may suggest that surveillance is a rational alternative to surgery. This will require further study to assess whether surveillance of Bosniak III cysts will prove safe.

Intermittent versus continuous cyproterone acetate in bone metastatic prostate cancer: results of a randomized trial.

BACKGROUND: To compare intermittent treatment (IT) versus continuous treatment (CT) using cyproterone acetate (CPA) in bone metastatic prostate cancer patients, we conducted an open-label, multicenter randomized trial. Continuous androgen deprivation therapy is the standard treatment in metastatic prostate cancer. Intermittent treatment might maintain efficacy while toxicity and costs are reduced. METHODS: Patients received CPA 100 mg tid in the prephase. Patients with a PSA decline of ≥ 90 % or PSA <4 ng/ml were randomized. If patients were progressive, LHRH analogues were added. Primary end point was time to PSA progression. RESULTS: A total of 366 patients were recruited; 258 reached a good response after 3 or 6 months and were randomized. A total of 131 patients randomized to IT and 127 to CT. Patients on IT had an average of 1.7 episodes on CPA, before LHRH analogues were started. The mean time without treatment in IT was 463 days versus 422 days on treatment. There were statistical significant differences between IT and CT in 3 of the 5 functional scales of EORTC QLQ C 30; however, the clinical relevance of this finding appears modest. Symptom and potency scales showed significant advantages for IT. There were no differences in time to PSA progression on CPA, time to PSA and/or clinical progression on LHRH analogues and time to cancer-specific and overall survival. CONCLUSIONS: IT by CPA is associated with less symptoms and modest advantages in QOL domains. There were no differences in time to PSA progression, clinical progression or survival.

Complications of initial prostate biopsy in a European randomized screening trial.

BACKGROUND: Transrectal prostate needle biopsy (PNB) is a standard procedure for the diagnosis of prostate cancer. We recently found an increasing frequency of hospitalization with infectious complications associated with PNB over time. OBJECTIVE: To perform an updated analysis of overall complication rates in a large screening population over the past 18 years and to examine possible predictors of complications on initial PNB. DESIGN, SETTING AND PARTICIPANTS: From 1993-2011, 7216 men underwent initial lateralized sextant PNB in European Randomized Study of Screening for Prostate Cancer (ERSPC) Rotterdam. After 2 weeks a questionnaire was administered to 6962 men regarding PNB-related complications. Outcome Measurements & Statistical Analysis: Overall complication rates as well as specific complications (hematuria for >3 days, hematospermia, significant pain after biopsy, fever, and hospitalizations) were prospectively recorded. Multivariable logistic regression models were performed to assess the relationship between age, comorbidities, and prostate volume with specific complications. RESULTS AND LIMITATIONS: A total of 4674 (67.1%) men reported any sequelae after initial PNB, with hematospermia as the most frequent (53.8%), followed by hematuria (24.3%). Significant pain (4.8%), fever (4.1%), and hospital admission (0.7%) were reported less frequently. Hematospermia was significantly more likely in younger men with fewer comorbidities and smaller prostate volume; whereas hematuria was significantly more frequent among men with increasing comorbidities and prostate volume. In addition, pain was inversely associated with age and was also reported less frequently during later years of biopsy. Limitations of our study include the use of sextant biopsies and a relatively healthy population, while strengths include the large sample size and data on patient-specific covariates. CONCLUSION: Many men experience minor complications after initial PNB, although the frequency of specific complications such as hematospermia and hematuria differed based upon factors such as prostate volume and comorbidities. Overall, these data are useful to counsel patients who are undergoing their first PNB on the frequency of complications in a screening population.

Postoperative radiotherapy after radical prostatectomy for high-risk prostate cancer: long-term results of a randomised controlled trial (EORTC trial 22911).

BACKGROUND: We report the long-term results of a trial of immediate postoperative irradiation versus a wait-and-see policy in patients with prostate cancer extending beyond the prostate, to confirm whether previously reported progression-free survival was sustained. METHODS: This randomised, phase 3, controlled trial recruited patients aged 75 years or younger with untreated cT0-3 prostate cancer (WHO performance status 0 or 1) from 37 institutions across Europe. Eligible patients were randomly assigned centrally (1:1) to postoperative irradiation (60 Gy of conventional irradiation to the surgical bed for 6 weeks) or to a wait-and-see policy until biochemical progression (increase in prostate-specific antigen >0·2 µg/L confirmed twice at least 2 weeks apart). We analysed the primary endpoint, biochemical progression-free survival, by intention to treat (two-sided test for difference at α=0.05, adjusted for one interim analysis) and did exploratory analyses of heterogeneity of effect. This trial is registered with ClinicalTrials.gov, number NCT00002511. FINDINGS: 1005 patients were randomly assigned to a wait-and-see policy (n=503) or postoperative irradiation (n=502) and were followed up for a median of 10·6 years (range 2 months to 16·6 years). Postoperative irradiation significantly improved biochemical progression-free survival compared with the wait-and-see policy (198 [39·4%] of 502 patients in postoperative irradiation group vs 311 [61·8%] of 503 patients in wait-and-see group had biochemical or clinical progression or died; HR 0·49 [95% CI 0·41-0·59]; p<0·0001). Late adverse effects (any type of any grade) were more frequent in the postoperative irradiation group than in the wait-and-see group (10 year cumulative incidence 70·8% [66·6-75·0] vs 59·7% [55·3-64·1]; p=0.001). INTERPRETATION: Results at median follow-up of 10·6 years show that conventional postoperative irradiation significantly improves biochemical progression-free survival and local control compared with a wait-and-see policy, supporting results at 5 year follow-up; however, improvements in clinical progression-free survival were not maintained. Exploratory analyses suggest that postoperative irradiation might improve clinical progression-free survival in patients younger than 70 years and in those with positive surgical margins, but could have a detrimental effect in patients aged 70 years or older. FUNDING: Ligue Nationale contre le Cancer (Comité de l'Isère, Grenoble, France) and the European Organisation for Research and Treatment of Cancer (EORTC) Charitable Trust.

Current vaccination strategies for prostate cancer.

CONTEXT: The first therapeutic cancer vaccine demonstrating effectiveness in a phase 3 study was approved by the US Food and Drug Administration on 29 April 2010. The pivotal trial demonstrated overall survival (OS) benefit in patients treated with antigen-loaded leukapheresis cells compared with a control infusion. Results of other prostate cancer (PCa) vaccination strategies are awaited, as this approach may herald a new era in the care for patients with advanced PCa. OBJECTIVE: Consider effectiveness and safety of vaccination strategies in the treatment of PCa. EVIDENCE ACQUISITION: We searched three bibliographic databases (January 1995 through October 2010) for randomised phase 2 and 3 studies of vaccination strategies for PCa based on predetermined relevant Medical Subject Heading terms and free text terms. EVIDENCE SYNTHESIS: Data from 3 randomised phase 3 and 10 randomised phase 2 vaccination trials are discussed with respect to clinical outcome in terms of progression-free survival and OS, toxicity, prostate-specific antigen (PSA) response, and immunologic response. Three phase 3 trials (D9901, D9902A, and D9902B) that enrolled a total of 737 patients, all controlled and double-blinded, tested the efficacy of sipuleucel-T. The largest of these three trials, called Immunotherapy for Prostate Adenocarcinoma Treatment (IMPACT), has demonstrated safety and effectiveness of sipuleucel-T (now marketed as Provenge) as measured by prolonged survival of 512 asymptomatic patients with metastatic castration-resistant PCa (mCRPC). The study showed a 4.1-mo median survival benefit in the sipuleucel-T vaccine-treated group compared with the control group (25.8 vs 21.7 mo; hazard ratio [HR]: 0.78; 95% confidence interval [CI], 0.62-0.98; p=0.032) and extended 3-yr survival (31.7% vs 23.0%). In contrast, two phase 3 vaccination trials with a whole-tumour-cell mixture of two PCa cell lines (GVAX) and testing GVAX either alone or in combination with chemotherapy versus chemotherapy alone (VITAL1 and 2) were terminated prematurely based on futility and increased deaths. Other phase 2 vaccination trials testing different types of vaccines in castration-resistant PCa patients have been reported with variable outcomes. Notably, a controlled, double-blind, randomised phase 2 vaccine trial of PROSTVAC-VF, a recombinant viral vector containing complementary DNA encoding PSA, in 125 patients with chemotherapy-naïve, minimally symptomatic mCRPC also demonstrated safety but no significant effect on the time to disease progression. In comparison with controls (n=40), PROSTVAC-VF-treated patients (n=82) experienced longer median survival of 8.5 mo (25.1 vs 16.6 mo; HR: 0.56; 95% CI, 0.37-0.85; p=0.0061) and extended 3-yr survival (30% vs 17%). In general, PCa vaccines are perceived to have less toxicity compared with current cytotoxic or targeted therapies. Evaluation of clinical efficacy of different vaccination strategies (eg, protein-, peptide- and DNA-based vaccines) in the context of properly designed and controlled phase 3 studies is warranted. CONCLUSIONS: Cancer vaccines represent a new paradigm in the treatment of PCa. The IMPACT trial showed improved survival but no difference in time to disease progression in mCRPC patients with minimal tumour burden. Observations in phase 2 and 3 trials pave the way for other vaccination approaches for this disease, raise questions regarding the most appropriate clinical trial designs, and underscore the importance of identifying biomarkers for antitumour effect to better implement such therapies.