Genomic Hallmarks and Structural Variation in Metastatic Prostate Cancer.

While mutations affecting protein-coding regions have been examined across many cancers, structural variants at the genome-wide level are still poorly defined. Through integrative deep whole-genome and -transcriptome analysis of 101 castration-resistant prostate cancer metastases (109X tumor/38X normal coverage), we identified structural variants altering critical regulators of tumorigenesis and progression not detectable by exome approaches. Notably, we observed amplification of an intergenic enhancer region 624 kb upstream of the androgen receptor (AR) in 81% of patients, correlating with increased AR expression. Tandem duplication hotspots also occur near MYC, in lncRNAs associated with post-translational MYC regulation. Classes of structural variations were linked to distinct DNA repair deficiencies, suggesting their etiology, including associations of CDK12 mutation with tandem duplications, TP53 inactivation with inverted rearrangements and chromothripsis, and BRCA2 inactivation with deletions. Together, these observations provide a comprehensive view of how structural variations affect critical regulators in metastatic prostate cancer.

Blood-based tests for multicancer early detection (PATHFINDER): a prospective cohort study.

BACKGROUND: Multicancer early detection (MCED) blood tests can detect a cancer signal from circulating cell-free DNA (cfDNA). PATHFINDER was a prospective cohort study investigating the feasibility of MCED testing for cancer screening. METHODS: In this prospective cohort study done in oncology and primary care outpatient clinics at seven US health networks, a convenience sample of adults aged 50 years or older without signs or symptoms of cancer consented to MCED testing. We collected blood, analysed cfDNA, and returned results to participants' doctors. If a methylation signature indicative of cancer was detected, predicted cancer signal origin(s) informed diagnostic assessment. The primary outcome was time to, and extent of, diagnostic testing required to confirm the presence or absence of cancer. This trial is registered at ClinicalTrials.gov, NCT04241796, and is completed. FINDINGS: Between Dec 12, 2019, and Dec 4, 2020, we recruited 6662 participants. 4204 (63·5%) of 6621 participants with analysable results were women, 2417 (36·5%) were men, and 6071 (91·7%) were White. A cancer signal was detected in 92 (1·4%) of 6621 participants with analysable results. 35 (38%) participants were diagnosed with cancer (true positives) and 57 (62%) had no cancer diagnosis (false positives). Excluding two participants whose diagnostic assessments began before MCED test results were reported, median time to diagnostic resolution was 79 days (IQR 37-219): 57 days (33-143) in true-positive and 162 days (44-248) in false-positive participants. Most participants had both laboratory tests (26 [79%] of 33 with true-positive results and 50 [88%] of 57 with false-positive results) and imaging (30 [91%] of 33 with true-positive results and 53 [93%] of 57 with false-positive results). Fewer procedures were done in participants with false-positive results (17 [30%] of 57) than true-positive results (27 [82%] of 33) and few had surgery (one with a false-positive result and three with a true-positive result). INTERPRETATION: This study supports the feasibility of MCED screening for cancer and underscores the need for further research investigating the test's clinical utility. FUNDING: GRAIL.

Lutetium-177-PSMA-617 for Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Metastatic castration-resistant prostate cancer remains fatal despite recent advances. Prostate-specific membrane antigen (PSMA) is highly expressed in metastatic castration-resistant prostate cancer. Lutetium-177 (177Lu)-PSMA-617 is a radioligand therapy that delivers beta-particle radiation to PSMA-expressing cells and the surrounding microenvironment. METHODS: We conducted an international, open-label, phase 3 trial evaluating 177Lu-PSMA-617 in patients who had metastatic castration-resistant prostate cancer previously treated with at least one androgen-receptor-pathway inhibitor and one or two taxane regimens and who had PSMA-positive gallium-68 (68Ga)-labeled PSMA-11 positron-emission tomographic-computed tomographic scans. Patients were randomly assigned in a 2:1 ratio to receive either 177Lu-PSMA-617 (7.4 GBq every 6 weeks for four to six cycles) plus protocol-permitted standard care or standard care alone. Protocol-permitted standard care excluded chemotherapy, immunotherapy, radium-223 (223Ra), and investigational drugs. The alternate primary end points were imaging-based progression-free survival and overall survival, which were powered for hazard ratios of 0.67 and 0.73, respectively. Key secondary end points were objective response, disease control, and time to symptomatic skeletal events. Adverse events during treatment were those occurring no more than 30 days after the last dose and before subsequent anticancer treatment. RESULTS: From June 2018 to mid-October 2019, a total of 831 of 1179 screened patients underwent randomization. The baseline characteristics of the patients were balanced between the groups. The median follow-up was 20.9 months. 177Lu-PSMA-617 plus standard care significantly prolonged, as compared with standard care, both imaging-based progression-free survival (median, 8.7 vs. 3.4 months; hazard ratio for progression or death, 0.40; 99.2% confidence interval [CI], 0.29 to 0.57; P<0.001) and overall survival (median, 15.3 vs. 11.3 months; hazard ratio for death, 0.62; 95% CI, 0.52 to 0.74; P<0.001). All the key secondary end points significantly favored 177Lu-PSMA-617. The incidence of adverse events of grade 3 or above was higher with 177Lu-PSMA-617 than without (52.7% vs. 38.0%), but quality of life was not adversely affected. CONCLUSIONS: Radioligand therapy with 177Lu-PSMA-617 prolonged imaging-based progression-free survival and overall survival when added to standard care in patients with advanced PSMA-positive metastatic castration-resistant prostate cancer. (Funded by Endocyte, a Novartis company; VISION ClinicalTrials.gov number, NCT03511664.).

Transcriptional profiling identifies an androgen receptor activity-low, stemness program associated with enzalutamide resistance.

The androgen receptor (AR) antagonist enzalutamide is one of the principal treatments for men with castration-resistant prostate cancer (CRPC). However, not all patients respond, and resistance mechanisms are largely unknown. We hypothesized that genomic and transcriptional features from metastatic CRPC biopsies prior to treatment would be predictive of de novo treatment resistance. To this end, we conducted a phase II trial of enzalutamide treatment (160 mg/d) in 36 men with metastatic CRPC. Thirty-four patients were evaluable for the primary end point of a prostate-specific antigen (PSA)50 response (PSA decline ≥50% at 12 wk vs. baseline). Nine patients were classified as nonresponders (PSA decline <50%), and 25 patients were classified as responders (PSA decline ≥50%). Failure to achieve a PSA50 was associated with shorter progression-free survival, time on treatment, and overall survival, demonstrating PSA50's utility. Targeted DNA-sequencing was performed on 26 of 36 biopsies, and RNA-sequencing was performed on 25 of 36 biopsies that contained sufficient material. Using computational methods, we measured AR transcriptional function and performed gene set enrichment analysis (GSEA) to identify pathways whose activity state correlated with de novo resistance. TP53 gene alterations were more common in nonresponders, although this did not reach statistical significance (P = 0.055). AR gene alterations and AR expression were similar between groups. Importantly, however, transcriptional measurements demonstrated that specific gene sets-including those linked to low AR transcriptional activity and a stemness program-were activated in nonresponders. Our results suggest that patients whose tumors harbor this program should be considered for clinical trials testing rational agents to overcome de novo enzalutamide resistance.

Delivering exercise medicine to cancer survivors: has COVID-19 shifted the landscape for how and who can be reached with supervised group exercise?

PURPOSE: Due to stay-at-home orders during COVID-19, we transitioned supervised, group, in-person resistance training interventions in two clinical trials in cancer survivors to live, online delivery using video-conferencing technology. We describe the feasibility, preliminary efficacy, and safety of live online group training and compare to in-person training. METHODS: Adherence (% sessions attended), retention (% participants completing intervention), and safety (# adverse events) data of resistance training groups from two randomized controlled trials in cancer survivors that participated before or during the COVID-19 pandemic were collated. Participants were post-treatment breast cancer survivors and their spouses (n = 62) and prostate cancer survivors (n = 32) (age range: 38-82 years). During COVID-19, delivery of supervised, group resistance exercise sessions was delivered live online via video-conference. Preliminary evidence for training efficacy was assessed by chair stand performance over the 6-month intervention. RESULTS: Feasibility of online resistance training was better than in-person for both studies (adherence: 86% vs 82% and 91% vs. 81% and retention 95% vs. 80% and 92% vs. 84% for online and in-person classes). Improvements in chair stand time were similar in prostate cancer and spouse groups that trained online vs. in-person, except for breast cancer survivors who improved more with in-person training (7% vs. 14% for online vs. in-person). Safety was similar between formats (12 vs. 11 adverse events for online vs. in-person). CONCLUSION: Supervised, in-person group resistance training can be feasibly adapted for live, online delivery and could help broaden approaches to exercise delivery in cancer survivors, including older adults. TRIAL REGISTRATION: The studies described in this commentary were registered on ClinicalTrials.gov on August 3, 2018 (NCT03630354) and on October 30, 2018 (NCT03741335).

LSD1 activates a lethal prostate cancer gene network independently of its demethylase function.

Medical castration that interferes with androgen receptor (AR) function is the principal treatment for advanced prostate cancer. However, clinical progression is universal, and tumors with AR-independent resistance mechanisms appear to be increasing in frequency. Consequently, there is an urgent need to develop new treatments targeting molecular pathways enriched in lethal prostate cancer. Lysine-specific demethylase 1 (LSD1) is a histone demethylase and an important regulator of gene expression. Here, we show that LSD1 promotes the survival of prostate cancer cells, including those that are castration-resistant, independently of its demethylase function and of the AR. Importantly, this effect is explained in part by activation of a lethal prostate cancer gene network in collaboration with LSD1's binding protein, ZNF217. Finally, that a small-molecule LSD1 inhibitor-SP-2509-blocks important demethylase-independent functions and suppresses castration-resistant prostate cancer cell viability demonstrates the potential of LSD1 inhibition in this disease.

Feasibility and Acceptability of a Remotely Delivered, Web-Based Behavioral Intervention for Men With Prostate Cancer: Four-Arm Randomized Controlled Pilot Trial.

BACKGROUND: Diet and exercise may be associated with quality of life and survival in men with prostate cancer. OBJECTIVE: This study aimed to determine the feasibility and acceptability of a remotely delivered web-based behavioral intervention among men with prostate cancer. METHODS: We conducted a multi-site 4-arm pilot randomized controlled trial of a 3-month intervention (TrueNTH Community of Wellness). Eligibility included self-reported prostate cancer diagnosis, having a personal device that connected to the internet, age ≥18 years, and ability to read English and receive text messages and emails. Men receiving chemotherapy or radiation, or those who reported contraindications to exercise, could participate with physician clearance. Participants were randomized (1:1:1:1) to additive intervention levels: website; website and personalized diet and exercise prescription; website, personalized prescription, Fitbit, and text messages; and website, personalized prescription, Fitbit, text messages, and 2 30-minute phone calls-one with an exercise trainer and one with a registered dietician. Primary outcomes were feasibility (accrual and attrition) and acceptability (survey data and website use). We described self-reported diet and exercise behavior at the time of enrollment, 3 months, and 6 months as secondary outcomes. RESULTS: In total, 202 men consented and were randomized between August 2017 and September 2018 (level 1: 49, level 2: 51, level 3: 50, level 4: 52). A total of 160 men completed the onboarding process and were exposed to their randomly assigned intervention (38, 38, 42, and 42 in levels 1, 2, 3, and 4, respectively). The follow-up rate was 82.7% (167/202) at 3 months and 77.2% (156/202) at 6 months. Participants had a median age of 70 years and were primarily White and college educated. Website visit frequency over the 3-month intervention period increased across levels (median: 2, 9, 11, and 16 visits for levels 1, 2, 3, and 4, respectively). Most were satisfied or very satisfied with the intervention (20/39, 51%; 27/42, 64%; 23/44, 52%; and 27/42, 64% for levels 1, 2, 3, and 4, respectively). The percentage of men who reported being very satisfied was highest among level 4 participants (10/42, 24% vs 4/39, 10%; 5/42, 12%; and 5/44, 11% for levels 1, 2, and 3, respectively). Dissatisfaction was highest in level 1 (5/39, 13% vs 1/42, 2%; 3/44, 7%; and 2/42, 5% for levels 2, 3, and 4, respectively). We observed small improvements in diet and physical activity at 3 months among men in level 4 versus those in level 1. CONCLUSIONS: A web-based, remotely delivered, tailored behavioral intervention for men with prostate cancer is feasible. Future studies are warranted to increase the effect of the intervention on patient behavior while maintaining sustainability and scalability as well as to design and implement interventions for more diverse populations. TRIAL REGISTRATION: ClinicalTrials.gov NCT03406013; http://clinicaltrials.gov/ct2/show/NCT03406013.

Recycling Discarded Drugs: Improving Access to Oral Antineoplastic Drugs.

It is common for patients to have limited access to oral antineoplastics or to discontinue treatment because of cost. Such oral treatments are also discontinued because of toxicity, disease progression, or death, resulting in unused portions of these medications. Policies for the subsequent use or destruction of unused drugs exist, but none completely address the need for methods of recycling back to the patients in need. This article addresses this wastefulness and ways to minimize it so that more patients benefit.

A phase II randomized placebo-controlled double-blind study of salvage radiation therapy plus placebo versus SRT plus enzalutamide with high-risk PSA-recurrent prostate cancer after radical prostatectomy (SALV-ENZA).

BACKGROUND: In men with a rising PSA following radical prostatectomy, salvage radiation therapy (SRT) offers a second chance for cure. Hormonal therapy can be combined with SRT in order to increase prostate tumor control, albeit with associated higher rates of treatment side effects. This trial studies the effectiveness of SRT combined with hormonal therapy using a more potent anti-androgen with a favorable side effect profile. Enzalutamide, a next generation selective androgen receptor antagonist, is approved by the Food and Drug Administration for the treatment of metastatic castrate-resistant prostate cancer (CRPC) where it has been shown to improve overall survival in combination with androgen deprivation therapy. The primary objective of this study is to evaluate the efficacy of combination SRT and enzalutamide for freedom-from-PSA-progression. Secondary objectives include time to local recurrence within the radiation field, metastasis-free survival and safety as determined by frequency and severity of adverse events. METHODS/DESIGN: This is a randomized, double-blind, phase II, prospective, multicenter study in adult males with biochemically recurrent prostate cancer following radical prostatectomy. Following registration, enzalutamide 160 mg or placebo by mouth (PO) once daily will be administered for 6 months. Following two months of study drug, external beam radiotherapy to 66.6-70.2 Gray (Gy) will be administered to the prostate bed over 7-8 weeks while continuing daily placebo/enzalutamide. This is followed by two additional months of placebo/enzalutamide. DISCUSSION: The SALV-ENZA trial is the first phase II placebo-controlled double-blinded randomized study to test SRT in combination with a next generation androgen receptor antagonist in men with high-risk recurrent prostate cancer after radical prostatectomy. The primary hypothesis of this study is that clinical outcomes will be improved by the addition of enzalutamide compared to standard-of-care SRT alone and pave the path for phase III evaluation of this combination. TRIAL REGISTRATIONS: ClinicaltTrials.gov Identifier: NCT02203695 Date of Registration: 06/16/2014. Date of First Participant Enrollment: 04/16/2015.

Implementing a comprehensive translational oncology platform: from molecular testing to actionability.

BACKGROUND: In order to establish the workflows required to implement a real-time process involving multi-omic analysis of patient samples to support precision-guided therapeutic intervention, a tissue acquisition and analysis trial was implemented. This report describes our findings to date, including the frequency with which mutational testing led to precision-guided therapy and outcome for those patients. METHODS: Eligible patients presenting to Oregon Health and Science University Knight Cancer Institute were enrolled on the study. Patients with biopsy proven metastatic or locally advanced unresectable prostate cancer, breast cancer, pancreatic adenocarcinoma, or refractory acute myelogenous leukemia receiving standard of care therapy were eligible. Metastatic site biopsies were collected and analyzed using the Knight Diagnostic Lab GeneTrails comprehensive solid tumor panel (124 genes). CLIA certified genomic information was made available to the treating physician. RESULTS: Between 1/26/2017 and 5/30/2018, 38 patients were enrolled, with 28 successfully undergoing biopsy. Of these, 25 samples yielded sufficient tumor for analysis. The median biopsy cellularity and number of cores collected were 70% (15-90%) and 5 (2-20), respectively. No procedure-related complications occurred. GeneTrails analysis revealed that 22 of 25 (88%) tumor samples harbored at least one potentially actionable mutation, and 18 (72%) samples harbored 2 or more potentially actionable mutations. The most common genetic alterations identified involved: DNA damage repair genes, cell cycle regulating genes, PIK3CA/Akt/mTOR pathway, and FGF gene family. To date, CLIA certified genomic results were used by treating physicians for precision-guided therapy in 5 (23%) patients. CONCLUSION: We report the feasibility of real-time tissue acquisition and analysis to support a successful translational oncology platform. The workflow will provide the foundation to improve access and accrual to biomarker driven precision oncology trials.

DNA Repair Gene Alterations and PARP Inhibitor Response in Patients With Metastatic Castration-Resistant Prostate Cancer.

Background: PARP inhibition is a promising therapeutic strategy for the treatment of men with metastatic castration-resistant prostate cancer whose tumors harbor homologous recombination DNA repair gene alterations. However, questions remain for many practicing clinicians about which patients are ideally suited for PARP inhibitor treatment. This report details our institutional experience using PARP inhibitor therapy in patients whose tumors harbored specific DNA repair gene alterations. Patients and Methods: We performed a retrospective chart review to identify patients at Oregon Health & Science University who were treated with PARP inhibition. We identified 8 patients and determined the impact of the specific DNA repair gene alterations on tumor response and time on treatment with PARP inhibition. Results: A number of DNA repair gene alterations were identified. Three patients had pathogenic BRCA2 mutations and one had a BRCA2 mutation of uncertain significance. Conversely, the 4 other patients' tumors harbored alterations in other DNA repair genes, none of which were clearly pathogenic. A statistically significant difference in benefit was seen between patients whose tumors harbored BRCA2 gene alterations and those whose tumors did not, as measured by >50% decline in prostate-specific antigen levels (100% vs 0%; P=.03) and duration on therapy (31.4 vs 6.4 weeks; P=.03). Conclusions: Our results demonstrate that not all DNA repair alterations are equally predictive of PARP inhibitor response. Importantly, all responding patients had tumors harboring BRCA2 DNA repair alterations, including one without a known pathogenic mutation. Conversely, among the 4 nonresponders, several DNA repair alterations in genes other than BRCA2 were identified that were not clearly pathogenic. This demonstrates the need to carefully examine the functional relevance of the DNA repair alterations identified, especially in genes other than BRCA2, when considering patients for PARP inhibitor treatment.

Custirsen (OGX-011) combined with cabazitaxel and prednisone versus cabazitaxel and prednisone alone in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel (AFFINITY): a randomised, open-label, international, phase 3 trial.

BACKGROUND: Docetaxel and cabazitaxel improve overall survival compared with mitoxantrone in patients with metastatic castration-resistant prostate cancer. Custirsen (OGX011) is a second generation highly specific antisense oligonucleotide that inhibits the production of clusterin, an antiapoptotic protein that is upregulated in response to chemotherapy and that confers treatment resistance. We aimed to assess whether custirsen in combination with cabazitaxel and prednisone increases overall survival in patients with metastatic castration-resistant prostate cancer previously treated with docetaxel. METHODS: In this randomised, open-label, international, phase 3 trial, men with radiographically documented metastatic castration-resistant prostate cancer that had progressed after docetaxel treatment with a Karnofsky performance status of more than 70% and who were fit for chemotherapy, were recruited from 95 cancer treatment centres in eight countries. Patients were randomly assigned (1:1) centrally using permuted blocks (block size 8) to receive cabazitaxel plus prednisone (cabazitaxel 25 mg/m2 intravenously every 21 days plus oral prednisone 10 mg daily) with or without custirsen (640 mg intravenously on days 1, 8, and 15, plus three previous loading doses) until disease progression, unacceptable toxicity, or the completion of ten treatment cycles. Randomisation was stratified by use of opioids for prostate cancer-related pain at screening, disease progression following first-line docetaxel treatment established by radiographic evidence, and previous treatment with abiraterone or enzalutamide. The co-primary endpoints were overall survival in all randomly assigned patients and in a poor-prognosis subgroup. All analyses were intention to treat with the exception of safety, which was reported for patients who received any assigned treatment. The trial has been completed and the results presented here are the final analysis. This trial is registered with Clinicaltrials.gov, number NCT01578655. FINDINGS: Between Sept 9, 2012, and Sept 29, 2014, 795 patients were screened for enrolment. 635 men were eligible for inclusion and were randomly assigned (n=317 in the cabazitaxel and prednisone plus custirsen group and n=318 in the cabazitaxel and prednisone group). Median follow up was 28·3 months (IQR 24·4-34·5) for the custirsen group and 29·8 months (IQR 25·3-35·2) for the control group. Median overall survival in all randomly assigned patients did not differ between the two groups (14·1 months [95% CI 12·7-15·9] in the curtisen group vs 13·4 months [12·1-14·9] in the control group; hazard ratio [HR] 0·95 [95% CI 0·80-1·12]; log-rank p=0·53). In the poor prognosis subgroup, median overall survival also did not differ between the two treatment groups (11·0 months [95% CI 9·3-13·3] in the custursin group vs 10·9 months [8·2-12·4] in the control group; HR 0·97 [95% CI 0·80-1·21]; two-sided p=0·80). The most frequently reported grade 3 or worse adverse events in the custirsen versus control groups were neutropenia (70 [22%] of 315 vs 61 [20%] of 312), anaemia (68 [22%] vs 49 [16%]), fatigue (23 [7%] vs 18 [6%]), asthenia (16 [5%] vs 8 [3%]), bone pain (16 [5%] vs 5 [2%]), and febrile neutropenia (16 [5%] vs 9 [3%]). Serious adverse events were reported in 155 (49%) versus 132 (42%). 27 patients died within 30 days of treatment in the cabazitaxel and prednisone plus custirsen group, seven of which were deemed to be treatment related, versus 17 in the cabazitaxel and prednisone group, eight of which were deemed to be treatment related. Of the 21 deaths reported, 15 were reported as complications related to study treatment, either chemotherapy (eight and three, respectively) or study drug (none and four, respectively). INTERPRETATION: We noted no survival benefit in men with metastatic castration-resistant prostate cancer with the addition of custirsen to cabazitaxel and prednisone treatment. Cabazitaxel and prednisone remains the standard of care for patients with metastatic castration-resistant prostate cancer progressing after docetaxel chemotherapy. FUNDING: OncoGenex Pharmaceuticals.

Enzalutamide in metastatic prostate cancer before chemotherapy.

BACKGROUND: Enzalutamide is an oral androgen-receptor inhibitor that prolongs survival in men with metastatic castration-resistant prostate cancer in whom the disease has progressed after chemotherapy. New treatment options are needed for patients with metastatic prostate cancer who have not received chemotherapy, in whom the disease has progressed despite androgen-deprivation therapy. METHODS: In this double-blind, phase 3 study, we randomly assigned 1717 patients to receive either enzalutamide (at a dose of 160 mg) or placebo once daily. The coprimary end points were radiographic progression-free survival and overall survival. RESULTS: The study was stopped after a planned interim analysis, conducted when 540 deaths had been reported, showed a benefit of the active treatment. The rate of radiographic progression-free survival at 12 months was 65% among patients treated with enzalutamide, as compared with 14% among patients receiving placebo (81% risk reduction; hazard ratio in the enzalutamide group, 0.19; 95% confidence interval [CI], 0.15 to 0.23; P<0.001). A total of 626 patients (72%) in the enzalutamide group, as compared with 532 patients (63%) in the placebo group, were alive at the data-cutoff date (29% reduction in the risk of death; hazard ratio, 0.71; 95% CI, 0.60 to 0.84; P<0.001). The benefit of enzalutamide was shown with respect to all secondary end points, including the time until the initiation of cytotoxic chemotherapy (hazard ratio, 0.35), the time until the first skeletal-related event (hazard ratio, 0.72), a complete or partial soft-tissue response (59% vs. 5%), the time until prostate-specific antigen (PSA) progression (hazard ratio, 0.17), and a rate of decline of at least 50% in PSA (78% vs. 3%) (P<0.001 for all comparisons). Fatigue and hypertension were the most common clinically relevant adverse events associated with enzalutamide treatment. CONCLUSIONS: Enzalutamide significantly decreased the risk of radiographic progression and death and delayed the initiation of chemotherapy in men with metastatic prostate cancer. (Funded by Medivation and Astellas Pharma; PREVAIL ClinicalTrials.gov number, NCT01212991.).

Clinical Outcomes of Chemotherapy Naïve Men with Metastatic Castration Resistant Prostate Cancer and Low Baseline Prostate Specific Antigen Treated with Enzalutamide vs Placebo.

PURPOSE: Metastatic castration resistant prostate cancer with low baseline prostate specific antigen represents an early stage in the natural history of castration resistant prostate cancer progression (low volume disease), low prostate specific antigen producing disease or disease that is less dependent on androgen receptor biology (high volume disease). We analyzed outcomes in men with low prostate specific antigen and a high disease burden who received the oral androgen receptor inhibitor enzalutamide in the PREVAIL (Safety and Efficacy Study of Oral MDV3100 in Chemotherapy-Naive Patients with Progressive Metastatic Prostate Cancer) study. MATERIALS AND METHODS: In this exploratory analysis low baseline prostate specific antigen was defined as less than 10 ng/ml. Post hoc analyses included radiographic progression-free and overall survival in the once daily enzalutamide and placebo arms. Patients were stratified post hoc by high volume disease, defined as more than 4 bone metastases and/or visceral disease, and low volume disease, defined as 4 or fewer bone metastases with no visceral disease. RESULTS: Of 1,717 patients enrolled in PREVAIL 242 (14.1%) had low baseline prostate specific antigen, including 110 with high volume disease. Enzalutamide decreased the risk of radiographic progression relative to placebo in patients with low baseline prostate specific antigen (HR 0.20, 95% CI 0.10-0.42). This decrease was irrespective of tumor burden (high volume disease HR 0.17, 95% CI 0.06-0.51 and low volume disease HR 0.25, 95% CI 0.09-0.70). Median overall survival was not reached in patients with low baseline prostate specific antigen in either treatment arm. CONCLUSIONS: Chemotherapy naïve men with metastatic castration resistant prostate cancer and low baseline prostate specific antigen irrespective of disease burden may benefit from enzalutamide. This indicates that targeting the androgen receptor signaling pathway is a therapeutic option in similar patients.

Docetaxel and mitoxantrone before radical prostatectomy in men with high-risk prostate cancer: 10-year follow-up and immune correlates.

The aims of this study were to report the clinical outcomes in a cohort of men with high-risk prostate cancer treated with neoadjuvant docetaxel and mitoxantrone 10 years after treatment, identify pretreatment clinical parameters that may be predictors of recurrence, and describe tumor-infiltrating leukocytes present in radical prostatectomy specimens. We conducted a phase I/II study of neoadjuvant docetaxel and mitoxantrone before radical prostatectomy in high-risk localized prostate cancer to determine the feasibility of this combination and predictors of prostate cancer recurrence after cytotoxic chemotherapy. After 10 years of follow-up, 34 (63%) of 54 participants experience a recurrence. In univariate analysis, prostate-specific antigen (PSA) density (P=0.01), pathological stage (P=0.03), lymph node status (P<0.0001), seminal vesicle invasion (P=0.003), and tissue vascular endothelial growth factor (VEGF) expression (P=0.016) were significantly associated with recurrence. In multivariate analysis, only lymph node status, PSA density, and VEGF expression were significant predictors of disease recurrence. We used a tissue microarray for the first 50 participants to characterize the tumor-infiltrating lymphocytes and evaluate them for association with recurrence. We measured CD3, CD4, CD8, FoxP3, CD20, CD15, CD68, and CD163 by immunohistochemistry in both tumor and normal prostate specimens, but did not find an association between immunophenotype and recurrence. There was a significantly different density of CD68 and CD163 cells between normal and tumor tissue. Lymph node status, PSA density, and tissue VEGF expression predict recurrence after chemotherapy for high-risk prostate cancer. Additional studies are needed to determine the potential benefit of chemotherapy in the neoadjuvant setting.

Cyclooxygenase-2 (COX-2) inhibition for prostate cancer chemoprevention: double-blind randomised study of pre-prostatectomy celecoxib or placebo.

OBJECTIVE: To evaluate the biological effects of selective cyclooxygenase-2 inhibition on prostate tissue in patients undergoing radical prostatectomy (RP). PATIENTS AND METHODS: Patients with localised prostate cancer were randomised to receive either celecoxib 400 mg twice daily or placebo for 4 weeks before RP. Specimens were analysed for levels of apoptosis, prostaglandins, and androgen receptor (AR). Effects on serum prostate-specific antigen (PSA) and postoperative opioid use were also measured. RESULTS: In all, 28 of 44 anticipated patients enrolled and completed treatment. One patient in the celecoxib arm had a myocardial infarction postoperatively. For this reason, and safety concerns in other studies, enrolment was halted. The apoptosis index (AI) in tumour cells was 0.29% [95% confidence interval (CI) 0.11-0.47%] vs 0.39% (95% CI 0.00-0.84%) in the celecoxib and placebo arms, respectively (P = 0.68). The AI in benign cells was 0.18% (95% CI 0.03-0.32%) vs 0.13% (95% CI 0.00-0.28%) in the celecoxib and placebo arms, respectively (P = 0.67). Prostaglandin E2 and AR levels were similar in cancerous and benign tissues when comparing the two arms. The median baseline PSA level was 6.0 and 6.2 ng/mL for the celecoxib and placebo groups, respectively, and did not significantly change after celecoxib treatment. There was no difference in postoperative opiate usage between arms. CONCLUSION: Celecoxib had no effect on apoptosis, prostaglandins or AR levels in cancerous or benign prostate tissues. These findings coupled with drug safety concerns should serve to limit interest in these selective drugs as chemopreventive agents.

CT-Guided Bone Biopsies in Metastatic Castration-Resistant Prostate Cancer: Factors Predictive of Maximum Tumor Yield.

PURPOSE: To evaluate the success rate of CT-guided bone biopsies in metastatic castration-resistant prostate cancer (mCRPC) and to investigate associated technical, imaging, and clinical parameters affecting diagnostic yields. MATERIALS AND METHODS: Eighty CT-guided bone biopsy specimens were obtained from 72 men (median age, 68 y; range, 49-89 y) enrolled in a multicenter trial to identify mechanisms of resistance in mCRPC. Successful biopsy was determined by histologic confirmation of tumor cells and successful isolation of RNA for molecular analysis. RESULTS: The overall success rate of CT-guided bone biopsies was 69% (55/80) based on histology and 64% (35/55) based on isolation of molecular material for RNA sequencing. Biopsies performed in lesions with areas of radiolucency had significantly higher diagnostic yields compared with lesions of predominantly dense sclerosis (95% vs 33%; P = .002) and lesions of predominantly subtle sclerosis (95% vs 65%; P = .04). Success rates increased in lesions with density ≤ 475 HU (79% for ≤ 475 HU vs 33% for > 475 HU; P = .001) and in lesions with ill-defined margins (76% for ill-defined margins vs 36% for well-circumscribed margins; P = .005). Alkaline phosphatase was the only clinical parameter to correlate significantly with diagnostic yield (83% for > 110 U/L vs 50% for ≤ 110 U/L; P = .001). CONCLUSIONS: Image-guided bone tumor biopsies can be successfully used to acquire cellular and molecular material for analyses in patients with osteoblastic prostate cancer metastases. Diagnostic yields are significantly increased in lesions with areas of radiolucency, density ≤ 475 HU, ill-defined margins, and interval growth and in patients with alkaline phosphatase > 110 U/L.

Management of Castration-Resistant, Taxane-Resistant Prostate Cancer.

Metastatic castration-resistant prostate cancer that is progressing despite docetaxel chemotherapy is difficult to treat and often aggressive. If not previously used, modern androgen signaling inhibitors have established clinical activity in this setting. Cabazitaxel and radium-223 have also been shown to extend survival in appropriately selected patients. Carboplatin-containing chemotherapy regimens have not been studied in randomized trials with a survival endpoint, but they have demonstrated activity in phase II trials and are occasionally considered in the post-docetaxel setting. Recent identification of potentially exploitable targets in the molecular makeup of advanced prostate cancer has created opportunities for clinical trials of novel targeted agents, with poly(ADP-ribose) polymerase inhibitors yielding compelling early results in molecularly selected patients. Much remains to be done to improve the lot of patients with docetaxel-unresponsive metastatic castration-resistant prostate cancer.