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Background: 177 Lu-prostate-specific membrane antigen (PSMA)-617 (LuPSMA) is a radionuclide therapy approved for patients with PSMA-avid metastatic castrate-resistant prostate cancer (mCRPC). We evaluated whether alterations in the DNA damage repair (DDR) pathway were associated with outcomes to LuPSMA., Patients and Methods: We identified an institutional cohort of men (n = 134) treated with ≥2 cycles of LuPSMA who had panel-based germline and/or tumor genomic sequencing. Mutations or two-copy losses in any of BRCA1, BRCA2, ATM, CDK12, PALB2, RAD51, and MSH2 were considered DDR defects. The primary outcome was a ≥50% reduction in the prostate-specific antigen (PSA) level during LuPSMA therapy (PSA50); secondary outcomes were PSA progression-free survival (PSA-PFS) and overall survival (OS). Models were adjusted for age, number of prior systemic therapies, sites of metastasis, and log-transformed PSA at cycle 1., Results: Thirty-four patients (25%) harbored DDR alterations, most commonly in BRCA2 and ATM (both n = 13). The presence of a DDR defect was not associated with PSA50 [adjusted odds ratio 0.48 (0.20-1.09), P = 0.08], PSA-PFS [adjusted hazard ratio (HR) 1.29 (0.79-2.10), P = 0.30], or OS [adjusted HR 1.42 (0.74-2.72), P = 0.29], with a non-significant trend toward poorer outcomes among DDR-altered patients., Conclusions: DDR alterations were not associated with outcomes following LuPSMA. This has implications for treatment sequencing in mCRPC, particularly in patients with DDR alterations., (Copyright © 2025 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Black men consistently have higher rates of prostate cancer (PCA)- related mortality. Advances in PCA treatment, screening, and hereditary cancer assessment center around germline testing (GT). Of concern is the significant under-engagement of Black males in PCA GT, limiting the benefit of precision therapy and tailored cancer screening despite longstanding awareness of these disparities. To address these critical disparities, the Socioecological Model (SEM) was employed to develop comprehensive recommendations to overcome barriers and implement equitable strategies to engage Black males in PCA GT., Methods: Clinical/research experts, national organization leaders, and community stakeholders spanning multiple regions in US and Africa participated in developing a framework for equity in PCA GT grounded in the SEM. A novel mixed-methods approach was employed to generate key areas to be addressed and informed statements for consensus consideration utilizing the modified Delphi model. Statements achieving strong consensus (> =75% agreement) were included in final equity frameworks addressing clinical/community engagement and research engagement., Results: All societal levels of the SEM (interpersonal, institutional, community, and policy/advocacy) must deliver information about PCA GT to Black males that address benefits/limitations, clinical impact, hereditary cancer implications, with acknowledgment of mistrust (mean scores [MS] 4.57-5.00). Interpersonal strategies for information delivery included engagement of family/friends/peers/Black role models to improve education/awareness and overcome mistrust (MS 4.65-5.00). Institutional strategies included diversifying clinical, research, and educational programs and integrating community liaisons into healthcare institutions (MS 4.57-5.00). Community strategies included partnerships with healthcare institutions and visibility of healthcare providers/researchers at community events (MS 4.65-4.91). Policy/advocacy included improving partnerships between advocacy and healthcare/community organizations while protecting patient benefits (MS 4.57-5.00). Media strategies were endorsed for the first time at every level (MS 4.56-5.00)., Conclusion: The SEM-based equity frameworks proposed provide the first multidisciplinary strategies dedicated to increase engagement of Black males in PCA GT, which are critical to reduce disparities in PCA-mortality through informing tailored screening, targeted therapy, and cascade testing in families., (© 2024. The Author(s).)

Background: Androgen deprivation therapy (ADT) is a front-line treatment for prostate cancer. In some men, their tumors can become refractory leading to the development of castration-resistant prostate cancer (CRPC). This causes tumors to regrow and metastasize, despite ongoing treatment, and impacts negatively on patient survival. ADT is known to stimulate the accumulation of immunosuppressive cells like protumoral tumor-associated macrophages (TAMs), myeloid-derived suppressor cells and regulatory T cells in prostate tumors, as well as hypofunctional T cells. Protumoral TAMs have been shown to accumulate around tumor blood vessels during chemotherapy and radiotherapy in other forms of cancer, where they drive tumor relapse. Our aim was to see whether such perivascular (PV) TAMs also accumulate in ADT-treated prostate tumors prior to CRPC, and, if so, whether selectively inducing them to express a potent immunostimulant, interferon beta (IFNβ), would stimulate antitumor immunity and delay CRPC., Methods: We used multiplex immunofluorescence to assess the effects of ADT on the distribution and activation status of TAMs, CD8+T cells, CD4+T cells and NK cells in mouse and/or human prostate tumors. We then used antibody-coated, lipid nanoparticles (LNPs) to selectively target a STING agonist, 2'3'-cGAMP (cGAMP), to PV TAMs in mouse prostate tumors during ADT., Results: TAMs accumulated at high density around blood vessels in response to ADT and expressed markers of a protumoral phenotype including folate receptor-beta (FR-β), MRC1 (CD206), CD169 and VISTA. Additionally, higher numbers of inactive (PD-1-) CD8+T cells and reduced numbers of active (CD69+) NK cells were present in these PV tumor areas. LNPs coated with an antibody to FR-β selectively delivered cGAMP to PV TAMs in ADT-treated tumors, where they activated STING and upregulated the expression of IFNβ. This resulted in a marked increase in the density of active CD8+T cells (along with CD4+T cells and NK cells) in PV tumor areas, and significantly delayed the onset of CRPC. Antibody depletion of CD8+T cells during LNP administration demonstrated the essential role of these cells in delay in CRPC induced by LNPs., Conclusion: Together, our data indicate that targeting a STING agonist to PV TAMs could be used to extend the treatment window for ADT in prostate cancer., Competing Interests: Competing interests: No, there are no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The phase 3 CALGB 90203 (Alliance) trial evaluated neoadjuvant chemohormonal therapy for high-risk localized prostate cancer before radical prostatectomy. We dissected the molecular features of post-treated tumors with long-term clinical outcomes to explore mechanisms of response and resistance to chemohormonal therapy., Methods: We evaluated 471 radical prostatectomy tumors, including 294 samples from 166 patients treated with 6 cycles of docetaxel plus androgen deprivation therapy before radical prostatectomy and 177 samples from 97 patients in the control arm (radical prostatectomy alone). Targeted DNA sequencing and RNA expression of tumor foci and adjacent noncancer regions were analyzed in conjunction with pathologic changes and clinical outcomes., Results: Tumor fraction estimated from DNA sequencing was significantly lower in post-treated tumor tissues after chemohormonal therapy compared with controls. Higher tumor fraction after chemohormonal therapy was associated with aggressive pathologic features and poor outcomes, including prostate-specific antigen-progression-free survival. SPOP alterations were infrequently detected after chemohormonal therapy, while TP53 alterations were enriched and associated with shorter overall survival. Residual tumor fraction after chemohormonal therapy was linked to higher expression of androgen receptor-regulated genes, cell cycle genes, and neuroendocrine genes, suggesting persistent populations of active prostate cancer cells. Supervised clustering of post-treated high-tumor-fraction tissues identified a group of patients with elevated cell cycle-related gene expression and poor clinical outcomes., Conclusions: Distinct recurrent prostate cancer genomic and transcriptomic features are observed after exposure to docetaxel and androgen deprivation therapy. Tumor fraction assessed by DNA sequencing quantifies pathologic response and could be a useful trial endpoint or prognostic biomarker. TP53 alterations and high cell cycle transcriptomic activity are linked to aggressive residual disease, despite potent chemohormonal therapy., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Cyclic high-dose testosterone administration, known as bipolar androgen therapy (BAT), is a treatment strategy for patients with metastatic castration-resistant prostate cancer (mCRPC). Here, we report the results of a multicenter, single arm Phase 2 study (NCT03554317) enrolling 45 patients with heavily pretreated mCRPC who received BAT (testosterone cypionate, 400 mg intramuscularly every 28 days) with the addition of nivolumab (480 mg intravenously every 28 days) following three cycles of BAT monotherapy. The primary endpoint of a confirmed PSA 50 response rate was met and estimated at 40% (N = 18/45, 95% CI: 25.7-55.7%, P = 0.02 one-sided against the 25% null hypothesis). Sixteen of the PSA 50 responses were achieved before the addition of nivolumab. Secondary endpoints included objective response rate (ORR), median PSA progression-free survival, radiographic progression-free survival (rPFS), overall survival (OS), and safety/tolerability. The ORR was 24% (N = 10/42). Three of the objective responses occurred following the addition of nivolumab. After a median follow-up of 17.9 months, the median rPFS was 5.6 (95% CI: 5.4-6.8) months, and median OS was 24.4 (95% CI: 17.6-31.1) months. BAT/nivolumab was well tolerated, resulting in only five (11%) drug related, grade-3 adverse events. In a predefined exploratory analysis, clinical response rates correlated with increased baseline levels of intratumoral PD-1 + T cells. In paired metastatic tumor biopsies, BAT induced pro-inflammatory gene expression changes that were restricted to patients achieving a clinical response. These data suggest that BAT may augment antitumor immune responses that are further potentiated by immune checkpoint blockade., (© 2024. The Author(s).)

Improved biomarkers are needed for early cancer detection, risk stratification, treatment selection, and monitoring treatment response. While proteins can be useful blood-based biomarkers, many have limited sensitivity or specificity for these applications. Long INterspersed Element-1 (LINE-1, L1) open reading frame 1 protein (ORF1p) is a transposable element protein overexpressed in carcinomas and high-risk precursors during carcinogenesis with negligible detectable expression in corresponding normal tissues, suggesting ORF1p could be a highly specific cancer biomarker. To explore the potential of ORF1p as a blood-based biomarker, we engineered ultrasensitive digital immunoassays that detect mid-attomolar (10-17 M) ORF1p concentrations in patient plasma samples across multiple cancers with high specificity. Plasma ORF1p shows promise for early detection of ovarian cancer, improves diagnostic performance in a multi-analyte panel, and provides early therapeutic response monitoring in gastric and esophageal cancers. Together, these observations nominate ORF1p as a multi-cancer biomarker with potential utility for disease detection and monitoring.

Androgen deprivation therapy (ADT), a cornerstone of treatment for patients with locally advanced and metastatic prostate cancer, is associated with many adverse effects, including osteoporosis, sexual dysfunction, fatigue, and vasomotor symptoms. It is also associated with loss of muscle mass and increased adiposity. This change in body composition is likely the inciting event in the development of insulin resistance, an independent risk factor for diabetes mellitus and cardiovascular disease. Although the occurrence of insulin resistance during ADT has been reported, it remains unclear whether this insulin resistance is primarily hepatic or muscular. Similarly, the mechanisms that lead to insulin resistance also remain unknown. The ADT & Metabolism Study was designed to address these knowledge gaps, as the elucidation of the predominant site of insulin resistance will allow prevention strategies and the use of targeted, tissue-specific insulin-sensitizing agents in patients undergoing ADT. This prospective, mechanistic, single-center, 24-week, observational cohort study will enroll treatment-naïve adult men with prostate cancer about to undergo surgical or medical ADT for at least 24 weeks (ADT group; n = 50) and a control group of men who had undergone radical prostatectomy and are in remission (non-ADT group, n = 25). The primary outcome is to determine the site of insulin resistance (skeletal muscle or liver) using frequent sampling oral glucose tolerance test at baseline and 12 and 24 weeks after commencement of ADT (ADT group) or after enrollment in the study (non-ADT group). Secondary outcomes will assess changes in hepatic and intramyocellular fat (using magnetic resonance spectroscopy), inflammatory markers, adipokines, free fatty acids, and changes in body composition (assessed using dual-energy x-ray absorptiometry) and their correlation with the development of insulin resistance. Exploratory outcomes will include changes in muscle performance, physical function, physical activity, vitality, and sexual drive., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: PLN has consulted for Boston Scientific, Janssen, Astellas, Bayer, Theranano, Nanocan, and Blue Earth. PLN has received research funding from Janssen, Bayer, and Astellas (all outside of the current work). DCS is a stockholder/shareholder of GI Windows and spouse is owner of Phase V Technologies (neither related to current study)., (Copyright: © 2023 Braga-Basaria et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

BackgroundNeuroendocrine prostate cancer (NEPC) is an aggressive subtype, the presence of which changes the prognosis and management of metastatic prostate cancer.MethodsWe performed analytical validation of a Circulating Tumor Cell (CTC) multiplex RNA qPCR assay to identify the limit of quantification (LOQ) in cell lines, synthetic cDNA, and patient samples. We next profiled 116 longitudinal samples from a prospectively collected institutional cohort of 17 patients with metastatic prostate cancer (7 NEPC, 10 adenocarcinoma) as well as 265 samples from 139 patients enrolled in 3 adenocarcinoma phase II trials of androgen receptor signaling inhibitors (ARSIs). We assessed a NEPC liquid biomarker via the presence of neuroendocrine markers and the absence of androgen receptor (AR) target genes.ResultsUsing the analytical validation LOQ, liquid biomarker NEPC detection in the longitudinal cohort had a per-sample sensitivity of 51.35% and a specificity of 91.14%. However, when we incorporated the serial information from multiple liquid biopsies per patient, a unique aspect of this study, the per-patient predictions were 100% accurate, with a receiver-operating-curve (ROC) AUC of 1. In the adenocarcinoma ARSI trials, the presence of neuroendocrine markers, even while AR target gene expression was retained, was a strong negative prognostic factor.ConclusionOur analytically validated CTC biomarker can detect NEPC with high diagnostic accuracy when leveraging serial samples that are only feasible using liquid biopsies. Patients with expression of NE genes while retaining AR-target gene expression may indicate the transition to neuroendocrine differentiation, with clinical characteristics consistent with this phenotype.FundingNIH (DP2 OD030734, 1UH2CA260389, R01CA247479, and P30 CA014520), Department of Defense (PC190039 and PC200334), and Prostate Cancer Foundation (Movember Foundation - PCF Challenge Award).

The complex genomic landscape of prostate cancer evolves across disease states under therapeutic pressure directed toward inhibiting androgen receptor (AR) signaling. While significantly altered genes in prostate cancer have been extensively defined, there have been fewer systematic analyses of how structural variation shapes the genomic landscape of this disease across disease states. We uniformly characterized structural alterations across 531 localized and 143 metastatic prostate cancers profiled by whole genome sequencing, 125 metastatic samples of which were also profiled via whole transcriptome sequencing. We observed distinct significantly recurrent breakpoints in localized and metastatic castration-resistant prostate cancers (mCRPC), with pervasive alterations in noncoding regions flanking the AR, MYC, FOXA1, and LSAMP genes enriched in mCRPC and TMPRSS2-ERG rearrangements enriched in localized prostate cancer. We defined 9 subclasses of mCRPC based on signatures of structural variation, each associated with distinct genetic features and clinical outcomes. Our results comprehensively define patterns of structural variation in prostate cancer and identify clinically actionable subgroups based on whole genome profiling.

Inherited genetic mutations can significantly increase the risk for prostate cancer (PC), may be associated with aggressive disease and poorer outcomes, and can have hereditary cancer implications for men and their families. Germline genetic testing (hereditary cancer genetic testing) is now strongly recommended for patients with advanced/metastatic PC, particularly given the impact on targeted therapy selection or clinical trial options, with expanded National Comprehensive Cancer Network guidelines and endorsement from multiple professional societies. Furthermore, National Comprehensive Cancer Network guidelines recommend genetic testing for men with PC across the stage and risk spectrum and for unaffected men at high risk for PC based on family history to identify hereditary cancer risk. Primary care is a critical field in which providers evaluate men at an elevated risk for PC, men living with PC, and PC survivors for whom germline testing may be indicated. Therefore, there is a critical need to engage and educate primary care providers regarding the role of genetic testing and the impact of results on PC screening, treatment, and cascade testing for family members of affected men. This review highlights key aspects of genetic testing in PC, the role of clinicians, with a focus on primary care, the importance of obtaining a comprehensive family history, current germline testing guidelines, and the impact on precision PC care. With emerging evidence and guidelines, clinical pathways are needed to facilitate integrated genetic education, testing, and counseling services in appropriately selected patients. There is also a need for providers to understand the field of genetic counseling and how best to collaborate to enhance multidisciplinary patient care., (© 2022 The Authors. CA: A Cancer Journal for Clinicians published by Wiley Periodicals LLC on behalf of American Cancer Society.)

Purpose: Tumor-only genomic testing can uncover somatic and germline pathogenic variants [pathogenic/likely pathogenic (P/LP)] in cancer predisposition genes. We describe the prevalence of P/LPs in BRCA1/2 and PALB2 (B1B2P2) across malignancies and the frequency of clinical germline testing (CGT) in patients with P/LPs in B1B2P2 identified on tumor-only testing., Experimental Design: Among 7,575 patients with cancer tested between 2016 and 2018 with the OncoPanel tumor-only sequencing assay, we characterized P/LP frequencies by tumor type, receipt of CGT prior to or within 12 months after OncoPanel, and factors associated with CGT., Results: 272 (3.6%) patients had OncoPanel-detected P/LPs in B1B2P2: 37.5% of P/LPs were in BRCA-related cancers; the remainder were in non-BRCA tumors. P/LPs were detected in ≥5% of breast, pancreatic, prostate, ovarian, nonmelanoma skin, endometrial, small cell lung, and colorectal cancers. 37.9% of patients with P/LPs received CGT prior to OncoPanel; an additional 10.7% underwent CGT within 12 months of OncoPanel. Among 132 with CGT, 88.6% had ≥1 clinical factor for CGT compared with 47.1% who did not undergo CGT. Patients with BRCA tumors were more likely to have CGT compared with those without (81.4% vs. 29.0%, P < 0.0001). Among patients with CGT, 70.5% (93/132) of P/LPs were germline., Conclusions: Tumor-only genomic testing identified P/LPs in B1B2P2 in 3.6% of patients. 52.9% of patients with tumor-detected P/LPs and without CGT did not meet personal or family history criteria for CGT. In addition, some patients with tumor-detected P/LPs were not referred for CGT, especially those with non-BRCA tumors. Given implications for treatment selection and familial cancer risk, processes to reliably trigger CGT from tumor-genomic findings are needed., (©2022 The Authors; Published by the American Association for Cancer Research.)

Treatment-induced tumor dormancy is a state in cancer progression where residual disease is present but remains asymptomatic. Dormant cancer cells are treatment-resistant and responsible for cancer recurrence and metastasis. Prostate cancer treated with androgen-deprivation therapy (ADT) often enters a dormant state. ADT-induced prostate cancer dormancy remains poorly understood due to the challenge in acquiring clinical dormant prostate cancer cells and the lack of representative models. In this study, we aimed to develop clinically relevant models for studying ADT-induced prostate cancer dormancy. Dormant prostate cancer models were established by castrating mice bearing patient-derived xenografts (PDX) of hormonal naïve or sensitive prostate cancer. Dormancy status and tumor relapse were monitored and evaluated. Paired pre- and postcastration (dormant) PDX tissues were subjected to morphologic and transcriptome profiling analyses. As a result, we established eleven ADT-induced dormant prostate cancer models that closely mimicked the clinical courses of ADT-treated prostate cancer. We identified two ADT-induced dormancy subtypes that differed in morphology, gene expression, and relapse rates. We discovered transcriptomic differences in precastration PDXs that predisposed the dormancy response to ADT. We further developed a dormancy subtype-based, predisposed gene signature that was significantly associated with ADT response in hormonal naïve prostate cancer and clinical outcome in castration-resistant prostate cancer treated with ADT or androgen-receptor pathway inhibitors., Implications: We have established highly clinically relevant PDXs of ADT-induced dormant prostate cancer and identified two dormancy subtypes, leading to the development of a novel predicative gene signature that allows robust risk stratification of patients with prostate cancer to ADT or androgen-receptor pathway inhibitors., (©2022 The Authors; Published by the American Association for Cancer Research.)

Purpose: The clinical impact of concurrent corticosteroid use (CCU) on enzalutamide-treated patients with metastatic castration-resistant prostate cancer (mCRPC) is unknown. We investigated the association of CCU with overall survival (OS), radiographic progression-free survival (rPFS), and time to prostate-specific antigen progression (TTPP) in post-chemotherapy, enzalutamide-treated patients with mCRPC., Patients and Methods: Post hoc analysis of AFFIRM (NCT00974311) with patients (n = 1,199) randomized 2:1 to enzalutamide 160 mg/day or placebo. Treatment group, CCU, and known prognostic factors were evaluated for impact on OS, rPFS, and TTPP using a multivariate Cox proportional hazards model. CCU was defined as "baseline" (use started at baseline) or "on-study" (baseline plus use that was started during the trial)., Results: Enzalutamide significantly improved OS, rPFS, and TTPP independent of baseline CCU but was associated with inferior clinical outcomes when compared with no baseline CCU, including a shorter OS [10.8 months vs. not reached (NR); HR for use vs. no use, 2.13; 95% confidence interval (CI), 1.79-2.54], rPFS (5.2 months vs. 8.0 months; HR, 1.49; 95% CI, 1.29-1.72], and TTPP (4.6 months vs. 5.7 months; HR, 1.50; 95% CI, 1.25-1.81). These findings held in a multivariate analysis adjusting for baseline prognostic factors wherein baseline CCU was independently associated with decreased OS (HR, 1.71; 95% CI, 1.43-2.04; P < 0.0001) and rPFS (HR, 1.28; 95% CI, 1.11-1.48; P = 0.0007)., Conclusions: Patients with mCRPC benefited from enzalutamide treatment independent of CCU, but CCU was associated with worse baseline prognostic factors and outcomes., (©2021 The Authors; Published by the American Association for Cancer Research.)

Purpose: Neuroendocrine prostate cancer (NEPC) is a resistance phenotype that emerges in men with metastatic castration-resistant prostate adenocarcinoma (CR-PRAD) and has important clinical implications, but is challenging to detect in practice. Herein, we report a novel tissue-informed epigenetic approach to noninvasively detect NEPC., Experimental Design: We first performed methylated immunoprecipitation and high-throughput sequencing (MeDIP-seq) on a training set of tumors, identified differentially methylated regions between NEPC and CR-PRAD, and built a model to predict the presence of NEPC (termed NEPC Risk Score). We then performed MeDIP-seq on cell-free DNA (cfDNA) from two independent cohorts of men with NEPC or CR-PRAD and assessed the accuracy of the model to predict the presence NEPC., Results: The test cohort comprised cfDNA samples from 48 men, 9 with NEPC and 39 with CR-PRAD. NEPC Risk Scores were significantly higher in men with NEPC than CR-PRAD (P = 4.3 × 10-7) and discriminated between NEPC and CR-PRAD with high accuracy (AUROC 0.96). The optimal NEPC Risk Score cutoff demonstrated 100% sensitivity and 90% specificity for detecting NEPC. The independent, multi-institutional validation cohort included cfDNA from 53 men, including 12 with NEPC and 41 with CR-PRAD. NEPC Risk Scores were significantly higher in men with NEPC than CR-PRAD (P = 7.5×10-12) and perfectly discriminated NEPC from CR-PRAD (AUROC 1.0). Applying the predefined NEPC Risk Score cutoff to the validation cohort resulted in 100% sensitivity and 95% specificity for detecting NEPC., Conclusions: Tissue-informed cfDNA methylation analysis is a promising approach for noninvasive detection of NEPC in men with advanced prostate cancer., (©2021 American Association for Cancer Research.)

Interventions designed to limit the spread of coronavirus disease 2019 (COVID-19) are having profound effects on the delivery of health care, but data showing the impact on oncology clinical trial enrollment, treatment, and monitoring are limited. We prospectively tracked relevant data from oncology clinical trials at Dana-Farber Cancer Institute from January 1, 2018, to June 30, 2020, including the number of open trials, new patient enrollments, in-person and virtual patient visits, dispensed investigational infusions, dispensed or shipped oral investigational agents, research biopsies, and blood samples. We ascertained why patients came off trials and determined on-site clinical research staffing levels. We used 2-sided Wilcoxon rank sum tests to assess the statistical significance of the reported changes. Nearly all patients on interventional treatment trials were maintained, and new enrollments continued at just under one-half the prepandemic rate. The median number of investigational prescriptions shipped to patients increased from 0 to 74 (range = 22-107) per week from March to June 2020. The median number of telemedicine appointments increased from 0 to 107 (range = 33-267) per week from March to June 2020. Research biopsies and blood collections decreased dramatically after Dana-Farber Cancer Institute implemented COVID-19-related policies in March 2020. The number of research nurses and clinical research coordinators on site also decreased after March 2020. Substantial changes were required to safely continue clinical research during the pandemic, yet we observed no increases in serious adverse events or major violations related to drug dosing. Lessons learned from adapting research practices during COVID-19 can inform industry sponsors and governmental agencies to consider altering practices to increase operational efficiency and convenience for patients., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Purpose: In metastatic castration-resistant prostate cancer (mCRPC) low serum androgens prior to starting abiraterone acetate (AA) is associated with more rapid progression. We evaluated the effect of AA on androgens in castration-resistant prostate cancer (CRPC) metastases and associations of intratumoral androgens with response., Experimental Design: We performed a phase II study of AA plus prednisone in mCRPC. The primary outcome was tissue testosterone at 4 weeks. Exploratory outcomes were association of steroid levels and genomic alterations with response, and escalating AA to 2,000 mg at progression., Results: Twenty-nine of 30 men were evaluable. Testosterone in metastatic biopsies became undetectable at 4 weeks ( P < 0.001). Serum and tissue dehydroepiandrosterone sulfate (DHEAS) remained detectable in many patients and was not increased at progression. Serum and tissue DHEAS in the lowest quartile (pretreatment), serum DHEAS in the lowest quartile (4 weeks), and undetectable tissue DHEAS (on-therapy) associated with rapid progression (20 vs. 48 weeks, P = 0.0018; 20 vs. 52 weeks, P = 0.0003; 14 vs. 40 weeks, P = 0.0001; 20 vs. 56 weeks, P = 0.02, respectively). One of 16 men escalating to 2,000 mg had a 30% PSA decline; 13 developed radiographic progression by 12 weeks. Among patients with high serum DHEAS at baseline, wild-type (WT) PTEN status associated with longer response (61 vs. 33 weeks, P = 0.02)., Conclusions: Low-circulating adrenal androgen levels are strongly associated with an androgen-poor tumor microenvironment and with poor response to AA. Patients with CRPC with higher serum DHEAS levels may benefit from dual androgen receptor (AR)-pathway inhibition, while those in the lowest quartile may require combinations with non-AR-directed therapy., (©2021 The Authors; Published by the American Association for Cancer Research.)

High-risk localized prostate cancer (HRLPC) is associated with a substantial risk of recurrence and disease mortality. Recent clinical trials have shown that intensifying anti-androgen therapies administered before prostatectomy can induce pathologic complete responses or minimal residual disease, called exceptional response, although the molecular determinants of these clinical outcomes are largely unknown. Here, we perform whole-exome and transcriptome sequencing on pre-treatment multi-regional tumor biopsies from exceptional responders (ERs) and non-responders (NRs, pathologic T3 or lymph node-positive disease) to intensive neoadjuvant anti-androgen therapies. Clonal SPOP mutation and SPOPL copy-number loss are exclusively observed in ERs, while clonal TP53 mutation and PTEN copy-number loss are exclusively observed in NRs. Transcriptional programs involving androgen signaling and TGF-β signaling are enriched in ERs and NRs, respectively. These findings may guide prospective validation studies of these molecular features in large HRLPC clinical cohorts treated with neoadjuvant anti-androgens to improve patient stratification., Competing Interests: Declaration of interests I.L. is a consultant for PACT Pharma. G.G. receives research funds from IBM and Pharmacylics and is an inventor on patent applications related to MuTect, ABSOLUTE, MutSig, MSMuTect, MSMutSig, and POLYSOLVER. E.M.V. is a consultant for Tango Therapeutics, Genome Medical, Invitae, Enara Bio, Manifold Bio, Monte Rosa Therapeutics, and Janssen. E.M.V. provides research support to Novartis and Bristol-Myers Squibb. E.M.V. has equity in Tango Therapeutics, Genome Medical, Syapse, Enara Bio, Monte Rosa Therapeutics, Manifold Bio, and Microsoft. E.M.V. receives travel reimbursement from Roche/Genentech. E.M.V. has institutional patents filed on ERCC2 mutations and chemotherapy response, chromatin mutations and immunotherapy response, and methods for clinical interpretation., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

There are no biomarkers predictive of resistance to docetaxel or cabazitaxel validated for patients with metastatic castration-resistant prostate cancer (mCRPC). We assessed the association between ABCB1 amplification and primary resistance to docetaxel or cabazitaxel for patients with mCRPC, using circulating cell-free DNA (cfDNA). Patients with ≥1 plasma sample drawn within 12 months before starting docetaxel (cohort A) or cabazitaxel (cohort B) for mCRPC were identified from the Dana-Farber Cancer Institute IRB approved database. Sparse whole genome sequencing was performed on the selected cfDNA samples and tumor fractions were estimated using the computational tool ichorCNA. We evaluated the association between ABCB1 amplification or other copy number alterations and primary resistance to docetaxel or cabazitaxel. Of the selected 176 patients, 45 samples in cohort A and 21 samples in cohort B had sufficient tumor content. No significant association was found between ABCB1 amplification and primary resistance to docetaxel ( p = 0.58; odds ratio (OR) = 1.49) or cabazitaxel ( p = 0.97; OR = 1.06). No significant association was found between exploratory biomarkers and primary resistance to docetaxel or cabazitaxel. In this study, ABCB1 amplification did not predict primary resistance to docetaxel or cabazitaxel for mCRPC. Future studies including ABCB1 amplification in a suite of putative biomarkers and a larger cohort may aid in drawing definitive conclusions.

Purpose: Enzalutamide is a second-generation androgen receptor (AR) inhibitor that has improved overall survival (OS) in metastatic castration-resistant prostate cancer (CRPC). However, nearly all patients develop resistance. We designed a phase II multicenter study of enzalutamide in metastatic CRPC incorporating tissue and blood biomarkers to dissect mechanisms driving resistance., Patients and Methods: Eligible patients with metastatic CRPC underwent a baseline metastasis biopsy and then initiated enzalutamide 160 mg daily. A repeat metastasis biopsy was obtained at radiographic progression from the same site when possible. Blood for circulating tumor cell (CTC) analysis was collected at baseline and progression. The primary objective was to analyze mechanisms of resistance in serial biopsies. Whole-exome sequencing was performed on tissue biopsies. CTC samples underwent RNA sequencing., Results: A total of 65 patients initiated treatment, of whom 22 (33.8%) had received prior abiraterone. Baseline biopsies were enriched for alterations in AR (mutations, amplifications) and tumor suppression genes ( PTEN, RB1 , and TP53 ), which were observed in 73.1% and 92.3% of baseline biopsies, respectively. Progression biopsies revealed increased AR amplifications (64.7% at progression vs. 53.9% at baseline) and BRCA2 alterations (64.7% at progression vs. 38.5% at baseline). Genomic analysis of baseline and progression CTC samples demonstrated increased AR splice variants, AR-regulated genes, and neuroendocrine markers at progression., Conclusions: Our results demonstrate that a large proportion of enzalutamide-treated patients have baseline and progression alterations in the AR pathway and tumor suppressor genes. We demonstrate an increased number of BRCA2 alterations post-enzalutamide, highlighting the importance of serial tumor sampling in CRPC., (©2021 American Association for Cancer Research.)

Purpose: Cisplatin-based chemotherapy is a first-line treatment for muscle-invasive and metastatic urothelial cancer. Approximately 10% of bladder urothelial tumors have a somatic missense mutation in the nucleotide excision repair (NER) gene, ERCC2 , which confers increased sensitivity to cisplatin-based chemotherapy. However, a significant subset of patients is ineligible to receive cisplatin-based therapy due to medical contraindications, and no NER-targeted approaches are available for platinum-ineligible or platinum-refractory ERCC2 -mutant cases., Experimental Design: We used a series of NER-proficient and NER-deficient preclinical tumor models to test sensitivity to irofulven, an abandoned anticancer agent. In addition, we used available clinical and sequencing data from multiple urothelial tumor cohorts to develop and validate a composite mutational signature of ERCC2 deficiency and cisplatin sensitivity., Results: We identified a novel synthetic lethal relationship between tumor NER deficiency and sensitivity to irofulven. Irofulven specifically targets cells with inactivation of the transcription-coupled NER (TC-NER) pathway and leads to robust responses in vitro and in vivo , including in models with acquired cisplatin resistance, while having minimal effect on cells with intact NER. We also found that a composite mutational signature of ERCC2 deficiency was strongly associated with cisplatin response in patients and was also associated with cisplatin and irofulven sensitivity in preclinical models., Conclusions: Tumor NER deficiency confers sensitivity to irofulven, a previously abandoned anticancer agent, with minimal activity in NER-proficient cells. A composite mutational signature of NER deficiency may be useful in identifying patients likely to respond to NER-targeting agents, including cisplatin and irofulven. See related commentary by Jiang and Greenberg, p. 1833 ., (©2020 American Association for Cancer Research.)

Metastatic castration-resistant prostate cancer is typically lethal, exhibiting intrinsic or acquired resistance to second-generation androgen-targeting therapies and minimal response to immune checkpoint inhibitors 1 . Cellular programs driving resistance in both cancer and immune cells remain poorly understood. We present single-cell transcriptomes from 14 patients with advanced prostate cancer, spanning all common metastatic sites. Irrespective of treatment exposure, adenocarcinoma cells pervasively coexpressed multiple androgen receptor isoforms, including truncated isoforms hypothesized to mediate resistance to androgen-targeting therapies 2,3 . Resistance to enzalutamide was associated with cancer cell-intrinsic epithelial-mesenchymal transition and transforming growth factor-β signaling. Small cell carcinoma cells exhibited divergent expression programs driven by transcriptional regulators promoting lineage plasticity and HOXB5, HOXB6 and NR1D2 (refs. 4-6 ). Additionally, a subset of patients had high expression of dysfunction markers on cytotoxic CD8 + T cells undergoing clonal expansion following enzalutamide treatment. Collectively, the transcriptional characterization of cancer and immune cells from human metastatic castration-resistant prostate cancer provides a basis for the development of therapeutic approaches complementing androgen signaling inhibition.

Purpose: Androgen receptor (AR) inhibition can upregulate c-MET expression, which may be a resistance mechanism driving progression of castration-resistant prostate cancer (CRPC). We conducted a phase I trial investigating the safety and pharmacokinetics of a potent c-MET inhibitor, crizotinib, with the AR antagonist, enzalutamide, in CRPC., Patients and Methods: Employing a 3+3 dose-escalation design, we tested three dose levels of crizotinib (250 mg daily, 200 mg twice a day, and 250 mg twice a day) with standard-dose enzalutamide (160 mg daily). The primary endpoint was rate of dose-limiting toxicities (DLTs). Tolerability and pharmacokinetics profile were secondary endpoints., Results: Twenty-four patients were enrolled in the dose-escalation ( n = 16) and dose-expansion ( n = 8) phases. Two DLTs occurred in dose escalation (grade 3 alanine aminotransferase elevation). The MTD of crizotinib was 250 mg twice a day. Most frequent treatment-related adverse events were fatigue (50%), transaminitis (38%), nausea (33%), and vomiting, constipation, and diarrhea (21% each). Grade ≥3 events (25%) included transaminitis ( n = 2), fatigue ( n = 1), hypertension ( n = 1), pulmonary embolism ( n = 1), and a cardiac event encompassing QTc prolongation/ventricular arrhythmia/cardiac arrest. Median progression-free survival was 5.5 months (95% confidence interval, 2.8-21.2). Pharmacokinetics analysis at the MTD ( n = 12) revealed a mean C max ss of 104 ± 45 ng/mL and AUC τ ss of 1,000 ± 476 ng•h/mL, representing a 74% decrease in crizotinib systemic exposure relative to historical data ( C max ss , 315 ng/mL and AUC τ ss , 3,817 ng•h/mL)., Conclusions: Concurrent administration of enzalutamide and crizotinib resulted in a clinically significant 74% decrease in systemic crizotinib exposure. Further investigation of this combination in CRPC is not planned. Our results highlight the importance of evaluating pharmacokinetics interactions when evaluating novel combination strategies in CRPC., (©2020 American Association for Cancer Research.)

High-grade T1 (HGT1) bladder cancer is the highest risk subtype of non-muscle-invasive bladder cancer with unpredictable outcome and poorly understood risk factors. Here, we examined the association of somatic mutation profiles with nonrecurrent disease (GO, good outcome), recurrence (R), or progression (PD) in a cohort of HGT1 patients. Exome sequencing was performed on 62 HGT1 and 15 matched normal tissue samples. Both tumor only (TO) and paired analyses were performed, focusing on 95 genes known to be mutated in bladder cancer. Somatic mutations, copy-number alterations, mutation load, and mutation signatures were studied. Thirty-three GO, 10 R, 18 PD, and 1 unknown outcome patients were analyzed. Tumor mutational burden (TMB) was similar to muscle-invasive disease and was highest in GO, intermediate in PD, and lowest in R patients ( P = 0.017). DNA damage response gene mutations were associated with higher TMB ( P < 0.0001) and GO ( P = 0.003). ERCC2 and BRCA2 mutations were associated with GO. TP53, ATM, ARID1A, AHR, and SMARCB1 mutations were more frequent in PD. Focal copy-number gain in CCNE1 and CDKN2A deletion was enriched in PD or R ( P = 0.047; P = 0.06). APOBEC (46%) and COSMIC5 (34%) signatures were most frequent. APOBEC-A and ERCC2 mutant tumors (COSMIC5) were associated with GO ( P = 0.047; P = 0.0002). pT1b microstaging was associated with a genomic cluster ( P = 0.05) with focal amplifications of E2F3/SOX4, PVRL4, CCNE1, and TP53 mutations. Findings were validated using external public datasets. These findings require confirmation but suggest that management of HGT1 bladder cancer may be improved via molecular characterization to predict outcome. SIGNIFICANCE: Detailed genetic analyses of HGT1 bladder tumors identify features that correlate with outcome, e.g., high mutational burden, ERCC2 mutations, and high APOBEC-A/ERCC2 mutation signatures were associated with good outcome., (©2020 American Association for Cancer Research.)

Rationale and Objectives: To explore a role for multiparametric MRI (mpMRI) as a biomarker of response to neoadjuvant androgen deprivation therapy (ADT) for prostate cancer (PCa)., Materials and Methods: This prospective study was approved by the institutional review board and was HIPAA compliant. Eight patients with localized PCa had a baseline mpMRI, repeated after 6-months of ADT, followed by prostatectomy. mpMRI indices were extracted from tumor and normal regions of interest (TROI/NROI). Residual cancer burden (RCB) was measured on mpMRI and on the prostatectomy specimen. Paired t-tests compared TROI/NROI mpMRI indices and pre/post-treatment TROI mpMRI indices. Spearman's rank tested for correlations between MRI/pathology-based RCB, and between pathological RCB and mpMRI indices., Results: At baseline, TROI apparent diffusion coefficient (ADC) was lower and dynamic contrast enhanced (DCE) metrics were higher, compared to NROI (ADC: 806 ± 137 × 10 -6 vs. 1277 ± 213 × 10 -6 mm 2 /sec, p = 0.0005; K trans : 0.346 ± 0.16 vs. 0.144 ± 0.06 min -1 , p = 0.002; AUC 90 : 0.213 ± 0.08 vs. 0.11 ± 0.03, p = 0.002). Post-treatment, there was no change in TROI ADC, but a decrease in TROI K trans (0.346 ± 0.16 to 0.188 ± 0.08 min -1 ; p = 0.02) and AUC 90 (0.213 ± 0.08 to 0.13 ± 0.06; p = 0.02). Tumor volume decreased with ADT. There was no difference between mpMRI-based and pathology-based RCB, which positively correlated (⍴ = 0.74-0.81, p < 0.05). Pathology-based RCB positively correlated with post-treatment DCE metrics (⍴ = 0.76-0.70, p < 0.05) and negatively with ADC (⍴ = -0.79, p = 0.03)., Conclusion: Given the heterogeneity of PCa, an individualized approach to ADT may maximize potential benefit. This pilot study suggests that mpMRI may serve as a biomarker of ADT response and as a surrogate for RCB at prostatectomy., (Copyright © 2019 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Despite the development of second-generation antiandrogens, acquired resistance to hormone therapy remains a major challenge in treating advanced prostate cancer. We find that cancer-associated fibroblasts (CAFs) can promote antiandrogen resistance in mouse models and in prostate organoid cultures. We identify neuregulin 1 (NRG1) in CAF supernatant, which promotes resistance in tumor cells through activation of HER3. Pharmacological blockade of the NRG1/HER3 axis using clinical-grade blocking antibodies re-sensitizes tumors to hormone deprivation in vitro and in vivo. Furthermore, patients with castration-resistant prostate cancer with increased tumor NRG1 activity have an inferior response to second-generation antiandrogen therapy. This work reveals a paracrine mechanism of antiandrogen resistance in prostate cancer amenable to clinical testing using available targeted therapies., Competing Interests: Declaration of Interests C.L.S. and J.W. are co-inventors of enzalutamide and apalutamide and may be entitled to royalties. C.L.S. serves on the Board of Directors of Novartis and is a co-founder of ORIC Pharmaceuticals. He is a science advisor to Agios, Beigene, Blueprint, Column Group, Foghorn, Housey Pharma, Nextech, KSQ, Petra, and PMV. W.A. reports consulting for Clovis Oncology, Janssen, MORE Health, and ORIC Pharmaceuticals, and received honoraria from CARET and travel accommodations from GlaxoSmith Kline, Clovis Oncology, and ORIC Pharmaceuticals. D.E.R. reports having consulting or advisory role (uncompensated) from Genentech/Roche, Janssen Oncology, and TRACON Pharma, and received research funding from: AstraZeneca (Inst); Celgene (Inst); Ferring (Inst); Genentech/Roche (Inst); Janssen Oncology (Inst); Medivation/Astellas/Pfizer (Inst); Millennium (Inst); Novartis (Inst); Taiho Pharmaceutical (Inst); Takeda (Inst); TRACON Pharma (Inst). W.R.K. is a coinventor on patent WO2012168930A2 filed by Koninklijke Nederlandse Akademie Van Wetenschappen that covers organoid technology., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine whether SRD5A2 promoter methylation is associated with cancer progression during androgen deprivation therapy (ADT) in CRPC., Patients and Methods: In a Local CRPC cohort, 42 prostatic specimens were collected from patients who were diagnosed as CRPC and underwent transurethral resection of the prostate (TURP) at Massachusetts General Hospital (MGH). In a metastatic CRPC (Met CRPC) cohort, 12 metastatic biopsies were collected from CRPC patients who would be treated with abiraterone plus dutasteride (Clinical Trial NCT01393730). As controls, 36 benign prostatic specimens were collected from patients undergoing prostate reduction surgery for symptoms of bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH). The methylation status of cytosine-phosphate-guanine (CpG) site(s) at SRD5A2 promoter regions was tested., Results: Compared with benign prostatic tissue, CRPC samples demonstrated higher SRD5A2 methylation in the whole promoter region (Local CRPC cohort: P < 0.001; Met CRPC cohort: P <0.05). In Local CRPC cohort, a higher ratio of methylation was correlated with better OS (R2 = 0.33, P = 0.013). Hypermethylation of specific regions (nucleotides -434 to -4 [CpG# -39 to CpG# -2]) was associated with a better OS (11.3±5.8 vs 6.4±4.4 years, P = 0.001) and PFS (8.4±5.4 vs 4.5±3.9 years, P = 0.003) with cutoff value of 37.9%. Multivariate analysis showed that SRD5A2 methylation was associated with OS independently (whole promoter region: P = 0.035; specific region: P = 0.02)., Conclusion: Our study demonstrate that SRD5A2 methylation in promoter regions, specifically at CpG# -39 to -2, is significantly associated with better survival for CRPC patients treated with ADT. Recognition of epigenetic modifications of SRD5A2 may affect the choices and sequence of available therapies for management of CRPC., Competing Interests: The authors have declared that no competing interests exist.

Background: SLCO-encoded transporters have been associated with progression to castration-resistant prostate cancer (CRPC) after initiation of androgen deprivation therapy (ADT). Although expressed at lower levels than in CRPC tissues, SLCO-encoded transporters may also play a role in response of primary prostate cancer (PCa) to ADT and biochemical recurrence., Methods: We systematically explored expression of the 11 human SLCO genes in a large sample of untreated and ADT-treated normal prostate (NP) and primary PCa tissues, including tumors treated with neoadjuvant abiraterone., Results: Transporters with the most recognized role in steroid uptake in PCa, including SLCO2B1 (DHEAS) and 1B3 (testosterone), were consistently detected in primary PCa. SLCO1B3 was nearly 5-fold higher in PCa vs NP with no difference in Gleason 3 vs 4 and no change with ADT. SLCO2B1 was detected at 3-fold lower levels in PCa than NP but was nearly 7-fold higher in Gleason 4 vs Gleason 3 and increased 3-fold following ADT (p < 0.05 for all)., Conclusions: We observed clear differences in SLCO expression in PCa vs NP samples, in Gleason 4 vs Gleason 3 tumors, and in ADT-treated vs untreated tissues. These findings are hypothesis generating due to small sample size, but suggest that baseline and ADT-induced changes in PCa OATP expression may influence steroid uptake and response to ADT, as well as uptake and response to drugs such as abiraterone and docetaxel which are also subject to OATP-mediated transport and are now being routinely combined with ADT in the metastatic castration sensitive setting.

Background: In 2004, docetaxel was shown to prolong the overall survival (OS) of patients with metastatic castration-resistance prostate cancer (mCRPC). Since 2010, five new systemic therapies have been shown to prolong OS in men with mCRPC. We sought to evaluate the aggregate impact of these newer therapies on the OS of patients with mCRPC., Methods: Two cohorts of patients diagnosed with mCRPC between 2004 and 2007, treated with drugs used in the limited treatment era only (A), and between 2010 and 2013, treated also with newer therapies (B), were identified from the Dana-Farber Cancer Institute database. The analysis endpoint was OS within 5 years after mCRPC diagnosis. Kaplan-Meier method assessed time-to-event distributions with median (95% confidence interval (CI)). A piece-wise regression model assessed the association between endpoint and treatment cohorts with estimate of hazard ratio (HR) with 95% CI within two time segments in univariate and multivariable analyses adjusting for relevant covariates., Results: Compared to cohort A (n = 318), cohort B (n = 272) patients in newer therapy era demonstrated an OS advantage (2.8 vs. 2.2 years) with a 41% decreased risk of death (HR = 0.59; 95% CI, 0.47-0.74; P < 0.0001), and a 3-year OS rate of 46% vs. 33%. This benefit was accentuated (median OS 2.7 vs. 2.1 years; HR = 0.46; 95% CI, 0.32-0.67; P < 0.0001) in patients who initially presented with de-novo metastatic disease (de-novo). On multivariable analysis, longer OS was associated with cohort B vs. A and performance status 0 vs. 1., Conclusions: Using a single-institution registry, mCRPC patients treated since 2010 had a significant survival improvement vs. those treated before 2010. Although the median survival was only modestly improved and less than predicted when simply adding each newer drug survival advantage, the cumulative benefit from the new therapies was more pronounced in longer-term survivors and de-novo patients.

Heterogeneity in the genomic landscape of metastatic prostate cancer has become apparent through several comprehensive profiling efforts, but little is known about the impact of this heterogeneity on clinical outcome. Here, we report comprehensive genomic and transcriptomic analysis of 429 patients with metastatic castration-resistant prostate cancer (mCRPC) linked with longitudinal clinical outcomes, integrating findings from whole-exome, transcriptome, and histologic analysis. For 128 patients treated with a first-line next-generation androgen receptor signaling inhibitor (ARSI; abiraterone or enzalutamide), we examined the association of 18 recurrent DNA- and RNA-based genomic alterations, including androgen receptor ( AR ) variant expression, AR transcriptional output, and neuroendocrine expression signatures, with clinical outcomes. Of these, only RB1 alteration was significantly associated with poor survival, whereas alterations in RB1 , AR , and TP53 were associated with shorter time on treatment with an ARSI. This large analysis integrating mCRPC genomics with histology and clinical outcomes identifies RB1 genomic alteration as a potent predictor of poor outcome, and is a community resource for further interrogation of clinical and molecular associations., Competing Interests: Conflict of interest statement: W.A. has consulted for Clovis Oncology, Janssen, ORIC Pharmaceuticals, and MORE Health; has received honorarium from Caret Healthcare; has received travel funds from Clovis Oncology, ORIC Pharmaceuticals, and GlaxoSmithKline; and has received research funding from AstraZeneca, Clovis Oncology, Zenith Epigenetics, and GlaxoSmithKline. G.H., received research funding from Janssen. J.A. is currently employed at AstraZeneca. E.M.V.A. has consulted for Tango Therapeutics, Genome Medical, Invitae, Illumina, Foresite Capital, and Dynamo; has received research support from Novartis and BMS; has equity in Tango Therapeutics, Genome Medical, Syapse, and Microsoft; has received travel reimbursement from Roche/Genentech; and is a coinventor of institutional patents filed on ERCC2 mutations and chemotherapy response, chromatin mutations and immunotherapy response, and methods for clinical interpretation. H.B. has received research funding from Millennium Pharmaceuticals, AbbVie/Stemcentrx, Astellas, Janssen, and Eli Lilly; and is a consultant/advisor for Sanofi Genzyme and Janssen. S.T. is a coinventor for University of Michigan patents on ETS fusion genes, and diagnostic field of use licensed to Hologic/Gen-Probe Inc., which has sublicensed rights to Roche/Ventana Medical Systems; is a consultant for and has received honoraria from Janssen, AbbVie, Sanofi, Almac Diagnostics, and Astellas/Medivation; has performed sponsored research from Astellas/Medivation and GenomeDx; and is an equity holder in and employee of Strata Oncology. J.M. has consulted for AstraZeneca and Janssen; and has received travel support or speaker fees from Astellas, AstraZeneca, Sanofi, and IPSEN. D.B. has received honoraria and travel support from Janssen. H.I.S. has consulted for Astellas, Ferring Pharmaceuticals, Janssen Biotech, Janssen Research and Development, Sanofi Aventis, Clovis Oncology, Merck, and WCG Oncology; is a member of the board of directors for Asterias Biotherapeutics; and has received research support from Illumina Inc., Innocrin, and Janssen. P.W.K. is a board member for Context Therapeutics LLC, has consulted for BIND Biosciences, BN Immunotherapeutics, DRGT, GE Healthcare, Janssen Pharmaceutica, Metamark, New England Research Institutes, OncoCellMDx, Progenity, Sanofi-Aventis, Seer Biosciences Inc., Tarveda Therapeutics, and Thermo Fisher Scientific; serves on data safety monitoring boards for Genentech/Roche and Merck & Co.; and has investment interest in Context Therapeutics, DRGT, Seer Biosciences, Placon, and Tarveda Therapeutics. M.-E.T. has consuled for Janssen. J.S.d. is an advisory board member for AstraZeneca, Astellas, Bayer, Boehringer Ingelheim, Genentech/Roche, Genmab, GSK, Janssen, Merck Serono, Merck Sharp & Dohme, Menarini/Silicon Biosystems, Orion, Pfizer, Sanofi Aventis, and Taiho; and his institution has received funding or other support from AstraZeneca, Astellas, Bayer, Genentech, GSK, Janssen, Merck Serono, MSD, Menarini/Silicon Biosystems, Orion, Sanofi Aventis, and Taiho. P.S.N. is a compensated advisor to Janssen, Astellas, and Roche. M.A.R. is a coinventor on a patent for Gene Fusion Prostate Cancer (Harvard/Michigan) and EZH2 (Michigan) in the area of diagnostics and therapeutics; is a coinventor on a patent filed by Cornell University on AURKA and SPOP mutations in the field of prostate cancer diagnostics; receives royalties on licensing agreements for these inventions; and receives research support from Janssen, Eli Lilly, Millenium, and Sanofi-Aventis. C.L.S. serves on the board of directors of Novartis; is a cofounder of ORIC Pharmaceuticals and coinventor of enzalutamide and apalutamide; is a science advisor to Agios, Beigene, Blueprint, Column Group, Foghorn, Housey Pharma, Nextech, KSQ, Petra, and PMV; and is a cofounder of Seragon, purchased by Genentech/Roche in 2014., (Copyright © 2019 the Author(s). Published by PNAS.)

Background: The pace of drug discovery and approvals has led to expanding treatments for cancer patients. Although extensive research exists regarding barriers to enrollment in oncology clinical trials, there are limited studies evaluating processes to optimize patient education, oral anticancer therapy administration, and adherence for patients enrolled in clinical trials. In this study, we assess the feasibility of a video-based, personalized webpage for patients enrolled in genitourinary oncology clinical trials involving 1 or more oral anticancer therapy., Objective: The primary objective of this trial was to assess the differences in the number of patient-initiated violations in the intervention arm compared with a control arm over 4 treatment cycles. Secondary objectives included patient satisfaction, frequently asked questions by patients on the intervention arm, patient-initiated calls to study team members, and patient-reported stress levels., Methods: Eligible patients enrolling on a therapeutic clinical trial for a genitourinary malignancy were randomized 2:1 to the intervention arm or control arm. Patients randomized to the intervention arm received access to a video-based, personalized webpage, which included videos of patients' own clinic encounters with their providers, instructional videos on medication administration and side effects, and electronic versions of educational documents., Results: A total of 99 patients were enrolled (89 were evaluable; 66 completed 4 cycles). In total, 71% (40/56) of patients in the intervention arm had 1 or more patient-initiated violation compared with 70% (23/33) in the control arm. There was no difference in the total number of violations across 4 cycles between the 2 arms (estimate=-0.0939, 95% CI-0.6295 to 0.4418, P value=.73). Median baseline satisfaction scores for the intervention and control arms were 72 and 73, respectively, indicating high levels of patient satisfaction in both arms. Median baseline patient-reported stress levels were 10 and 13 for the intervention and control arms, respectively, indicating low stress levels in both arms at baseline., Conclusions: This study is among the first to evaluate a video-based, personalized webpage that provides patients with educational videos and video recordings of clinical trial appointments. Despite not meeting the primary endpoint of reduced patient-initiated violations, this study demonstrates the feasibility of a video-based, personalized webpage in clinical trials. Future research assessing this tool might be better suited for realms outside of clinical trials and might consider the use of an endpoint that assesses patient-reported outcomes directly. A major limitation of this study was the lack of prior data for estimating the null hypothesis in this population., (©Rana McKay, Hannah Mills, Lillian Werner, Atish Choudhury, Toni Choueiri, Susanna Jacobus, Amanda Pace, Laura Polacek, Mark Pomerantz, Judith Prisby, Christopher Sweeney, Meghara Walsh, Mary-Ellen Taplin. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 02.05.2019.)

Purpose: This study assesses the action of panobinostat, a histone deacetylase inhibitor (HDACI), in restoring sensitivity to bicalutamide in a castration-resistant prostate cancer (CRPC) model and the efficacy and safety of the panobinostat/bicalutamide combination in CRPC patients resistant to second-line antiandrogen therapy (2 nd LAARx)., Patients and Methods: The CWR22PC xenograft and isogenic cell line were tested for drug interactions on tumor cell growth and on the androgen receptor (AR), AR-splice variant7, and AR targets. A phase I trial had a 3 × 3 panobinostat dose-escalation design. The phase II study randomized 55 patients to panobinostat 40 mg (A arm) or 20 mg (B arm) triweekly ×2 weeks with bicalutamide 50 mg/day in 3-week cycles. The primary endpoint was to determine the percentage of radiographic progression-free (rPF) patients at 36 weeks versus historic high-dose bicalutamide., Results: In the model, panobinostat/bicalutamide demonstrated synergistic antitumor effect while reducing AR activity. The dose-limiting toxicity was not reached. The probability of remaining rPF exceeded protocol-specified 35% in the A arm and 47.5% and 38.5% in the B arm. The probabilities of remaining rPF were 47.5% in the A arm and 38.5% in the B arm, exceeding the protocol-specified threshold of 35%. A arm/B arm: adverse events (AE), 62%/19%; treatment stopped for AEs, 27.5%/11.5%; dose reduction required, 41%/4%; principal A-arm grade ≥3 AEs, thrombocytopenia (31%) and fatigue (14%)., Conclusions: The 40 mg panobinostat/bicalutamide regimen increased rPF survival in CRPC patients resistant to 2 nd LAARx. Panobinostat toxicity was tolerable with dose reductions. Epigenetic HDACI therapy reduces AR-mediated resistance to bicalutamide in CRPC models with clinical benefit in patients. The combination merits validation using a second-generation antiandrogen., (©2018 American Association for Cancer Research.)

Androgen deprivation therapy (ADT) is a mainstay of treatment for prostate cancer (PCa). As androgens stimulate erythropoiesis, ADT is associated with a reduction in hematocrit, which in turn contributes to fatigue and related morbidity. However, the mechanisms involved in ADT-induced reduction in erythropoiesis remain unclear. We conducted a 6-mo prospective cohort study and enrolled men with PCa about to undergo ADT (ADT-Group) and a control group of men who had previously undergone prostatectomy for localized PCa and were in remission (Non-ADT Group). All participants had normal testosterone levels at baseline. Fasting blood samples were collected at baseline, 12 wk, and 24 wk after initiation of ADT; samples were obtained at the same intervals from enrollment in the Non-ADT group. Blood count, iron studies, erythropoietin, erythroferrone, and hepcidin levels were measured. Seventy participants formed the analytical sample (31 ADT, 39 Non-ADT). ADT was associated with a significant reduction in erythrocyte count (estimated mean difference = -0.2×10 6 cells/µl, 95%CI = -0.3 to -0.1×10 6 cells/µl, P < 0.001), hematocrit (-1.9%, 95%CI = -2.7 to -1.1%, P < 0.001), and hemoglobin (-0.6 g/dl, 95%CI = -0.8 to -0.3 g/dl, P < 0.001). Serum hepcidin concentration increased in the ADT-group (18 ng/ml, P < 0.001); however, iron concentrations did not change (-1.1 µg/dl, P = 0.837). Ferritin levels increased in men on ADT (60 ng/ml, P < 0.001). Iron binding capacity, transferrin saturation, erythroferrone, and erythropoietin did not change. Nine men undergoing ADT developed new-onset anemia. In conclusion, reduced proliferation of marrow erythroid progenitors leads to ADT-induced reduction in erythropoiesis. Future studies should evaluate the role of selective androgen receptor modulators in the treatment of ADT-induced anemia.

The standard treatment for metastatic prostate cancer, androgen deprivation therapy (ADT), is designed to suppress androgen receptor (AR) activity. However, men invariably progress to castration-resistant prostate cancer (CRPC), and AR reactivation contributes to progression in most cases. To identify mechanisms that may drive CRPC, we examined a VCaP prostate cancer xenograft model as tumors progressed from initial androgen sensitivity prior to castration to castration resistance and then on to relapse after combined therapy with further AR-targeted drugs (abiraterone plus enzalutamide). AR activity persisted in castration-resistant and abiraterone/enzalutamide-resistant xenografts and was associated with increased expression of the AR gene and the AR-V7 splice variant. We then assessed expression of individual AR-regulated genes to identify those that persisted, thereby contributing to tumor growth, versus those that decreased and may therefore exhibit tumor suppressor activities. The most significantly decreased AR target gene was dipeptidyl peptidase 4 (DPP4) , which encodes a membrane-anchored protein that cleaves dipeptides from multiple growth factors, resulting in their increased degradation. DPP4 mRNA and protein were also decreased in clinical CRPC cases, and inhibition of DPP4 with sitagliptin enhanced the growth of prostate cancer xenografts following castration. Significantly, DPP4 inhibitors are frequently used to treat type 2 diabetes as they increase insulin secretion. Together, these results implicate DPP4 as an AR-regulated tumor suppressor gene whose loss enhances growth factor activity and suggest that treatment with DPP4 inhibitors may accelerate emergence of resistance to ADT. Significance: These findings identify DPP4 as an AR-stimulated tumor suppressor gene that is downregulated during progression to castration-resistant prostate cancer, warning that treatment with DPP4 inhibitors, commonly used to treat type 2 diabetes, may accelerate prostate cancer progression following androgen deprivation therapy. Cancer Res; 78(22); 6354-62. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Background: Tumor content in circulating cell-free DNA (cfDNA) is a promising biomarker, but longitudinal dynamics of tumor-derived and non-tumor-derived cfDNA through multiple courses of therapy have not been well described., Methods: CfDNA from 663 plasma samples from 140 patients with castration-resistant prostate cancer (CRPC) was subject to sparse whole genome sequencing. Tumor fraction (TFx) estimated using the computational tool ichorCNA was correlated with clinical features and responses to therapy., Results: TFx associated with the number of bone metastases (median TFx = 0.014 with no bone metastases, 0.047 with 1-3 bone metastases, 0.190 for 4+ bone metastases; P < 0.0001) and with visceral metastases (P < 0.0001). In multivariable analysis, TFx remained associated with metastasis location (P = 0.042); TFx was positively correlated with alkaline phosphatase (P = 0.0227) and negatively correlated with hemoglobin (Hgb) (P < 0.001), but it was not correlated with prostate specific antigen (PSA) (P = 0.75). Tumor-derived and non-tumor-derived cfDNA track together and do not increase with generalized tissue damage from chemotherapy or radiation at the time scales examined. All new treatments that led to ≥30% PSA decline at 6 weeks were associated with TFx decline when baseline TFx was >7%; however, TFx in patients being subsequently maintained on secondary hormonal therapy was quite dynamic., Conclusion: TFx correlates with clinical features associated with overall survival in CRPC, and TFx decline is a promising biomarker for initial therapeutic response., Trial Registration: Dana-Farber/Harvard Cancer Center (DF/HCC) protocol no. 18-135., Funding: Wong Family Award in Translational Oncology, Dana Farber Cancer Institute Medical Oncology grant, Gerstner Family Foundation, Janssen Pharmaceuticals Inc., and Koch Institute Support (core) grant P30-CA14051 from the National Cancer Institute (NCI).

Background: Understanding the integrated immunogenomic landscape of advanced prostate cancer (APC) could impact stratified treatment selection., Methods: Defective mismatch repair (dMMR) status was determined by either loss of mismatch repair protein expression on IHC or microsatellite instability (MSI) by PCR in 127 APC biopsies from 124 patients (Royal Marsden [RMH] cohort); MSI by targeted panel next-generation sequencing (MSINGS) was then evaluated in the same cohort and in 254 APC samples from the Stand Up To Cancer/Prostate Cancer Foundation (SU2C/PCF). Whole exome sequencing (WES) data from this latter cohort were analyzed for pathogenic MMR gene variants, mutational load, and mutational signatures. Transcriptomic data, available for 168 samples, was also performed., Results: Overall, 8.1% of patients in the RMH cohort had some evidence of dMMR, which associated with decreased overall survival. Higher MSINGS scores associated with dMMR, and these APCs were enriched for higher T cell infiltration and PD-L1 protein expression. Exome MSINGS scores strongly correlated with targeted panel MSINGS scores (r = 0.73, P < 0.0001), and higher MSINGS scores associated with dMMR mutational signatures in APC exomes. dMMR mutational signatures also associated with MMR gene mutations and increased immune cell, immune checkpoint, and T cell-associated transcripts. APC with dMMR mutational signatures overexpressed a variety of immune transcripts, including CD200R1, BTLA, PD-L1, PD-L2, ADORA2A, PIK3CG, and TIGIT., Conclusion: These data could impact immune target selection, combination therapeutic strategy selection, and selection of predictive biomarkers for immunotherapy in APC., Funding: We acknowledge funding support from Movember, Prostate Cancer UK, The Prostate Cancer Foundation, SU2C, and Cancer Research UK.

Background: Patients with high-risk prostate cancer have an increased likelihood of experiencing a relapse following radical prostatectomy (RP). We previously conducted three neoadjuvant androgen-deprivation therapy (ADT) trials prior to RP in unfavorable intermediate and high-risk disease., Methods: In this analysis, we report on the post-RP outcomes of a subset of patients enrolled on these studies. We conducted a pooled analysis of patients with available follow-up data treated on three neoadjuvant trials at three institutions. All patients received intense ADT prior to RP. The primary endpoint was time to biochemical recurrence (BCR). BCR was defined as a PSA ≥ 0.2 ng/mL or treatment with radiation or androgen-deprivation therapy for a rising PSA < 0.2 ng/mL., Results: Overall, 72 patients were included of whom the majority had a Gleason score ≥ 8 (n = 46, 63.9%). Following neoadjuvant therapy, 55.7% of patients (n = 39/70) had pT3 disease, 40% (n = 28) had seminal vesicle invasion, 12.9% (n = 9) had positive margins, and 11.4% (n = 8) had lymph node involvement. Overall, 11 (15.7%) had tumor measuring ≤ 0.5 cm, which included four patients (5.7%) with a pathologic complete response and seven (10.0%) with residual tumor measuring 0.1-0.5 cm. Compared to pretreatment clinical staging, 10 patients (14.3%) had pathologic T downstaging at RP. The median follow-up was 3.4 years. Overall, the 3-year BCR-free rate was 70% (95% CI 57%, 90%). Of the 15 patients with either residual tumor ≤ 0.5 cm or pathologic T downstaging, no patient experienced a recurrence., Conclusion: In this exploratory pooled clinical trials analysis, we highlight that neoadjuvant therapy prior to RP in unfavorable intermediate and high-risk patients may potentially have a positive impact on recurrence rates. Larger studies with longer follow-up periods are warranted to evaluate the impact of neoadjuvant hormone therapy on pathologic and long-term outcomes.

Primary prostate cancer can have extensive microheterogeneity, but its contribution to the later emergence of metastatic castration-resistant prostate cancer (mCRPC) remains unclear. In this study, we microdissected residual prostate cancer foci in radical prostatectomies from 18 men treated with neoadjuvant-intensive androgen deprivation therapy (leuprolide, abiraterone acetate, and prednisone) and analyzed them for resistance mechanisms. Transcriptome profiling showed reduced but persistent androgen receptor (AR) activity in residual tumors, with no increase in neuroendocrine differentiation. Proliferation correlated negatively with AR activity but positively with decreased RB1 expression, and whole-exome sequencing (WES) further showed enrichment for RB1 genomic loss. In 15 cases where 2 or 3 tumor foci were microdissected, WES confirmed a common clonal origin but identified multiple oncogenic alterations unique to each focus. These findings show that subclones with oncogenic alterations found in mCRPC are present in primary prostate cancer and are selected for by neoadjuvant-intense androgen deprivation therapy. In particular, this study indicates that subclonal RB1 loss may be more common than previously appreciated in intermediate- to high-risk primary prostate cancer and may be an early event, independent of neuroendocrine differentiation, in the development of mCRPC. Comprehensive molecular analyses of primary prostate cancer may detect aggressive subclones and possibly inform adjuvant strategies to prevent recurrence. Significance: Neoadjuvant androgen deprivation therapy for prostate cancer selects for tumor foci with subclonal genomic alterations, which may comprise the origin of metastatic castration-resistant prostate cancer. Cancer Res; 78(16); 4716-30. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Nearly all prostate cancer deaths are from metastatic castration-resistant prostate cancer (mCRPC), but there have been few whole-genome sequencing (WGS) studies of this disease state. We performed linked-read WGS on 23 mCRPC biopsy specimens and analyzed cell-free DNA sequencing data from 86 patients with mCRPC. In addition to frequent rearrangements affecting known prostate cancer genes, we observed complex rearrangements of the AR locus in most cases. Unexpectedly, these rearrangements include highly recurrent tandem duplications involving an upstream enhancer of AR in 70%-87% of cases compared with <2% of primary prostate cancers. A subset of cases displayed AR or MYC enhancer duplication in the context of a genome-wide tandem duplicator phenotype associated with CDK12 inactivation. Our findings highlight the complex genomic structure of mCRPC, nominate alterations that may inform prostate cancer treatment, and suggest that additional recurrent events in the non-coding mCRPC genome remain to be discovered., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Context: Androgen deprivation therapy (ADT) for prostate cancer (PCa) is associated with increased cardiovascular mortality and sudden cardiac death, with some events occurring early after initiation of ADT. Testosterone levels are inversely associated with corrected QT (QTc) interval duration; therefore, prolongation of QTc duration could be responsible for some of these events during ADT., Objective: To evaluate changes in QTc duration during ADT., Design and Interventions: A 6-month prospective cohort study that enrolled men with PCa about to undergo ADT (ADT group) and a control group of men who previously underwent prostatectomy for PCa and never received ADT (non-ADT group)., Patients: At study entry, all participants were eugonadal and had no history of cardiac arrhythmias or complete bundle branch block., Outcomes: Difference in change in QTc duration from baseline on a 12-lead electrocardiogram at 6, 12, and 24 weeks after initiation of ADT compared with electrocardiograms performed at the same intervals in the non-ADT group. PR, QRS, and QT interval durations were also evaluated., Results: Seventy-one participants formed the analytical sample (33 ADT and 38 non-ADT). ADT was associated with prolongation of the QTc by 7.4 ms compared with the non-ADT group [95% confidence interval (CI) 0.08 to 14.7 ms; P = 0.048]. ADT was also associated with shortening of the QRS interval by 2.4 ms (95% CI -4.64 to -0.23; P = 0.031). Electrolytes did not change., Conclusions: Men undergoing ADT for PCa experienced prolongation of the QTc. These findings might explain the increased risk of sudden cardiac death seen in these patients.

Context: Previous animal and human research suggests that testosterone has antinociceptive properties. Castration in male rodents increases pain perception which is reversed by testosterone replacement. Pain perception also improves in hypogonadal men with testosterone therapy. However, it remains unclear whether androgen deprivation therapy (ADT) in men with prostate cancer (PCa) is associated with an increase in pain perception., Objectives: To evaluate the effects of ADT on pain perception, depression and quality of life (QOL) in men with PCa., Methods: Thirty-seven men with PCa about to undergo ADT with leuprolide acetate (ADT group) were followed prospectively for six months to evaluate changes in clinical and experimental pain. Forty men who had previously undergone prostatectomy for localized PCa and were in remission served as controls (non-ADT group). All participants were eugonadal at study entry. Primary outcomes were changes in clinical pain (assessed with Brief Pain Inventory questionnaire) and experimental pain (assessed with quantitative sensory testing). Secondary outcomes included evaluation of depression, anxiety levels, and quality of life., Results: Serum testosterone levels significantly decreased in the ADT group but remained unchanged in the non-ADT group. There were no significant changes in pain thresholds, ratings, or other responses to quantitative sensory tests over the 6-month course of the study. Clinical pain did not differ between the two groups, and no changes from baseline were observed in either group. Men undergoing ADT did experience worsening of depression (0.93; 95% CI = 0.04-1.82; P = 0.042) and QOL related to physical role limitation (-18.28; 95% CI = -30.18 to -6.37; P = 0.003)., Conclusion: ADT in men with PCa is associated with worsening of depression scores and QOL but is not associated with changes in clinical pain or pain sensitivity., (Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.)

Purpose: MuscadinePlus (MPX), a commercial preparation of pulverized muscadine grape skin, was evaluated as a therapeutic option for men with biochemically recurrent (BCR) prostate cancer wishing to defer androgen deprivation therapy. Experimental Design: This was a 12-month, multicenter, placebo-controlled, two-dose, double-blinded trial of MPX in 125 men with BCR prostate cancer, powered to detect a PSA doubling time (PSADT) difference of 6 months (low dose) and 12 months (high dose) relative to placebo. Participants were stratified (baseline PSADT, Gleason score) and randomly assigned 1:2:2 to receive placebo, 500 mg MPX (low), or 4,000 mg MPX (high) daily. Correlates included superoxide dismutase-2 ( SOD2 ) genotype, lipid peroxidation, and polyphenol pharmacokinetics. Results: The evaluable population included 112 patients, all treated for at least 6 months and 62% treated for 12 months. No significant difference was found in PSADT change between control and treatment arms ( P = 0.81): control 0.9 months ( n = 20; range, 6.7-83.1), low dose 1.5 months ( n = 52; range, 10.3-87.2), high dose 0.9 months ( n = 40; range, 27.3-88.1). One high-dose patient experienced objective response. No drug-related CTCAE grade 3-4 adverse events were seen. In a preplanned exploratory analysis, PSADT pre-to-post increase was significant in the 27 (26%) genotyped patients with SOD2 Alanine/Alanine genotype (rs4880 T>C polymorphism) on MPX (pooled treatment arms; 6.4 months, P = 0.02), but not in control (1.8 months, P = 0.25). Conclusions: Compared with placebo, MPX did not significantly prolong PSADT in BCR patients over two different doses. Exploratory analysis revealed a patient population with potential benefit that would require further study. Clin Cancer Res; 24(2); 306-15. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Purpose: Programmed cell death ligand-1 (PD-L1)/programmed cell death-1 (PD-1) blockade has been unsuccessful in prostate cancer, with poor immunogenicity and subsequent low PD-L1 expression in prostate cancer being proposed as an explanation. However, recent studies indicate that a subset of prostate cancer may express significant levels of PD-L1. Furthermore, the androgen antagonist enzalutamide has been shown to upregulate PD-L1 expression in prostate cancer preclinical models. In this study, we evaluated the effect of neoadjuvant androgen deprivation therapy with abiraterone acetate plus prednisone and leuprolide (Neo-AAPL) on PD-L1 expression in prostate cancer. Experimental Design: Radical prostatectomy (RP) tissues were collected from 44 patients with intermediate- to high-risk prostate cancer who underwent RP after Neo-AAPL treatment. Untreated prostate cancer tissues were collected from 130 patients, including 44 matched controls for the Neo-AAPL cases. Tumor PD-L1 expression was detected by IHC using validated anti-PD-L1 antibodies. Tumor-infiltrating CD8 + cells were analyzed in trial cases and matched controls. Expression of DNA mismatch repair genes was examined in PD-L1-positive tumors. Results: Neo-AAPL-treated tumors showed a trend toward decreased PD-L1 positivity compared with matched controls (7% vs. 21% having ≥1% positive tumor cells; P = 0.062). Treated tumors also harbored significantly fewer tumor-infiltrating CD8 + cells ( P = 0.029). In 130 untreated prostate cancers, African American ethnicity, elevated serum PSA, and small prostate independently predicted tumor PD-L1 positivity. Loss of MSH2 expression was observed in 1 of 21 PD-L1-positive tumors. Conclusions: A subset of prostate cancer expresses PD-L1, which is not increased by Neo-AAPL treatment, indicating that combining Neo-AAPL treatment with PD-L1/PD-1 blockade may not be synergistic. Clin Cancer Res; 23(22); 6812-22. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Purpose: The combination of docetaxel chemotherapy and androgen deprivation therapy (ADT) has become a standard treatment for patients with metastatic prostate cancer. The recently accrued phase III CALGB 90203 trial was designed to investigate the clinical effectiveness of this treatment approach earlier in the disease. Specimens from this trial offer a unique opportunity to interrogate the acute molecular response to docetaxel and ADT and identify potential biomarkers. Experimental Design: We evaluated baseline clinical data, needle biopsies, and radical prostatectomy (RP) specimens from 52 (of 788) patients enrolled on CALGB 90203 at one high volume center. Pathology review, tumor and germline-targeted DNA sequencing ( n = 72 genes), and expression profiling using NanoString platform ( n = 163 genes) were performed to explore changes in critical prostate cancer pathways linked to aggression and resistance. Results: Three of 52 patients had only microfocal residual cancer at prostatectomy. The most common alterations included TMPRSS2-ERG fusion ( n = 32), TP53 mutation or deletion ( n = 11), PTEN deletion ( n = 6), FOXA1 ( n = 6), and SPOP ( n = 4) mutation, with no significant enrichment in posttreated specimens. We did not observe AR amplification or mutations. The degree of AR signaling suppression varied among treated tumors and there was upregulation of both AR and AR-V7 expression as well as a subset of neuroendocrine and plasticity genes. Conclusions: These data support the feasibility of targeted and temporal genomic and transcriptome profiling of neoadjuvant-treated prostate cancer with limited formalin-fixed paraffin embedded tissue requirement. Characterization of the heterogeneity of treatment response and molecular outliers that arise posttreatment provides new insight into potential early markers of resistance. Clin Cancer Res; 23(22); 6802-11. ©2017 AACR ., (©2017 American Association for Cancer Research.)