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101 result(s) for "Reiter, Robert E."
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18F-fluciclovine PET-CT and 68Ga-PSMA-11 PET-CT in patients with early biochemical recurrence after prostatectomy: a prospective, single-centre, single-arm, comparative imaging trial
National Comprehensive Cancer Network guidelines consider 18F-fluciclovine PET-CT for prostate cancer biochemical recurrence localisation after radical prostatectomy, whereas European Association of Urology guidelines recommend prostate-specific membrane antigen (PSMA) PET-CT. To the best of our knowledge, no prospective head-to-head comparison between these tests has been done so far. The aim of this study was to compare prospectively paired 18F-fluciclovine and PSMA PET-CT scans for localising biochemical recurrence of prostate cancer after radical prostatectomy in patients with low prostate-specific antigen (PSA) concentrations (<2·0 ng/mL). This was a prospective, single-centre, open-label, single-arm comparative study done at University of California Los Angeles (Los Angeles, CA, USA). Patients older than 18 years of age with prostate cancer biochemical recurrence after radical prostatectomy and PSA levels ranging from 0·2 to 2·0 ng/mL without any prior salvage therapy and with a Karnofsky performance status of at least 50 were eligible. Patients underwent 18F-fluciclovine (reference test) and PSMA (index test) PET-CT scans within 15 days. Detection rate of biochemical recurrence at the patient level and by anatomical region was the primary endpoint. A statistical power analysis demonstrated that a sample size of 50 patients was needed to show a 22% difference in detection rates in favour of PSMA (test for superiority). Each PET scan was interpreted by three independent masked readers and a consensus majority interpretation was generated (two vs one) to determine positive findings. This study is registered with ClinicalTrials.gov, number NCT03515577, and is complete. Between Feb 26, 2018, and Sept 20, 2018, 143 patients were screened for eligibility, of whom 50 patients were enrolled into the study. Median follow-up was 8 months (IQR 7–9). The primary endpoint was met; detection rates were significantly lower with 18F-fluciclovine PET-CT (13 [26%; 95% CI 15–40] of 50) than with PSMA PET-CT (28 [56%; 41–70] of 50), with an odds ratio (OR) of 4·8 (95% CI 1·6–19·2; p=0·0026) at the patient level; in the subanalysis of the pelvic nodes region (four [8%; 2–19] with 18F-fluciclovine vs 15 [30%; 18–45] with PSMA PET-CT; OR 12·0 [1·8–513·0], p=0·0034); and in the subanalysis of any extrapelvic lesions (none [0%; 0–6] vs eight [16%; 7–29]; OR non-estimable [95% CI non-estimable], p=0·0078). With higher detection rates, PSMA should be the PET tracer of choice when PET-CT imaging is considered for subsequent treatment management decisions in patients with prostate cancer and biochemical recurrence after radical prostatectomy and low PSA concentrations (≤2·0 ng/mL). Further research is needed to investigate whether higher detection rates translate into improved oncological outcomes. None.
Androgen deprivation therapy use and duration with definitive radiotherapy for localised prostate cancer: an individual patient data meta-analysis
Randomised trials have investigated various androgen deprivation therapy (ADT) intensification strategies in men receiving radiotherapy for the treatment of prostate cancer. This individual patient data meta-analysis of relevant randomised trials aimed to quantify the benefit of these interventions in aggregate and in clinically relevant subgroups. For this meta-analysis, we performed a systematic literature search in MEDLINE, Embase, trial registries, the Web of Science, Scopus, and conference proceedings to identify trials with results published in English between Jan 1, 1962, and Dec 30, 2020. Multicentre randomised trials were eligible if they evaluated the use or prolongation of ADT (or both) in men with localised prostate cancer receiving definitive radiotherapy, reported or collected distant metastasis and survival data, and used ADT for a protocol-defined finite duration. The Meta-Analysis of Randomized trials in Cancer of the Prostate (MARCAP) Consortium was accessed to obtain individual patient data from randomised trials. The primary outcome was metastasis-free survival. Hazard ratios (HRs) were obtained through stratified Cox models for ADT use (radiotherapy alone vs radiotherapy plus ADT), neoadjuvant ADT extension (ie, extension of total ADT duration in the neoadjuvant setting from 3–4 months to 6–9 months), and adjuvant ADT prolongation (ie, prolongation of total ADT duration in the adjuvant setting from 4–6 months to 18–36 months). Formal interaction tests between interventions and metastasis-free survival were done for prespecified subgroups defined by age, National Comprehensive Cancer Network (NCCN) risk group, and radiotherapy dose. This meta-analysis is registered with PROSPERO, CRD42021236855. Our search returned 12 eligible trials that provided individual patient data (10 853 patients) with a median follow-up of 11·4 years (IQR 9·0–15·0). The addition of ADT to radiotherapy significantly improved metastasis-free survival (HR 0·83 [95% CI 0·77–0·89], p<0·0001), as did adjuvant ADT prolongation (0·84 [0·78–0·91], p<0·0001), but neoadjuvant ADT extension did not (0·95 [0·83–1·09], p=0·50). Treatment effects were similar irrespective of radiotherapy dose, patient age, or NCCN risk group. Our findings provide the strongest level of evidence so far to the magnitude of the benefit of ADT treatment intensification with radiotherapy for men with localised prostate cancer. Adding ADT and prolonging the portion of ADT that follows radiotherapy is associated with improved metastasis-free survival in men, regardless of risk group, age, and radiotherapy dose delivered; however, the magnitude of the benefit could vary and shared decision making with patients is recommended. University Hospitals Seidman Cancer Center, Prostate Cancer Foundation, and the American Society for Radiation Oncology.
Transcriptional profiling of matched patient biopsies clarifies molecular determinants of enzalutamide-induced lineage plasticity
The androgen receptor (AR) signaling inhibitor enzalutamide (enza) is one of the principal treatments for metastatic castration-resistant prostate cancer (CRPC). Several emergent enza clinical resistance mechanisms have been described, including lineage plasticity in which the tumors manifest reduced dependency on the AR. To improve our understanding of enza resistance, herein we analyze the transcriptomes of matched biopsies from men with metastatic CRPC obtained prior to treatment and at progression ( n  = 21). RNA-sequencing analysis demonstrates that enza does not induce marked, sustained changes in the tumor transcriptome in most patients. However, three patients’ progression biopsies show evidence of lineage plasticity. The transcription factor E2F1 and pathways linked to tumor stemness are highly activated in baseline biopsies from patients whose tumors undergo lineage plasticity. We find a gene signature enriched in these baseline biopsies that is strongly associated with poor survival in independent patient cohorts and with risk of castration-induced lineage plasticity in patient-derived xenograft models, suggesting that tumors harboring this gene expression program may be at particular risk for resistance mediated by lineage plasticity and poor outcomes. Lineage plasticity is increasingly recognized as an emergent resistance mechanism after treatment with androgen receptor signalling inhibitors. To understand determinants of resistance, the authors analyzed the transcriptomes of patient tumor biopsies before enzalutamide treatment and at progression and identified a gene expression program associated with lineage plasticity risk and poor outcomes.
Monoclonal antibody targeting of N-cadherin inhibits prostate cancer growth, metastasis and castration resistance
The transition from androgen-dependent to castration-resistant prostate cancer is a lethal event. N-cadherin seems to be a major cause underlying this transition, and targeting this adhesion molecule may have positive clinical benefit. The transition from androgen-dependent to castration-resistant prostate cancer (CRPC) is a lethal event of uncertain molecular etiology. Comparing gene expression in isogenic androgen-dependent and CRPC xenografts, we found a reproducible increase in N-cadherin expression, which was also elevated in primary and metastatic tumors of individuals with CRPC. Ectopic expression of N-cadherin in nonmetastatic, androgen-dependent prostate cancer models caused castration resistance, invasion and metastasis. Monoclonal antibodies against the ectodomain of N-cadherin reduced proliferation, adhesion and invasion of prostate cancer cells in vitro . In vivo , these antibodies slowed the growth of multiple established CRPC xenografts, blocked local invasion and metastasis and, at higher doses, led to complete regression. N-cadherin–specific antibodies markedly delayed the time to emergence of castration resistance, markedly affected tumor histology and angiogenesis, and reduced both AKT serine-threonine kinase activity and serum interleukin-8 (IL-8) secretion. These data indicate that N-cadherin is a major cause of both prostate cancer metastasis and castration resistance. Therapeutic targeting of this factor with monoclonal antibodies may have considerable clinical benefit.
MEK-ERK signaling is a therapeutic target in metastatic castration resistant prostate cancer
BackgroundMetastatic castration resistant prostate cancer (mCRPC) is incurable and progression after drugs that target the androgen receptor-signaling axis is inevitable. Thus, there is an urgent need to develop more effective treatments beyond hormonal manipulation. We sought to identify activated kinases in mCRPC as therapeutic targets for existing, approved agents, with the goal of identifying candidate drugs for rapid translation into proof of concept Phase II trials in mCRPC.MethodsTo identify evidence of activation of druggable kinases in these patients, we compared mRNA expression from metastatic biopsies of patients with mCRPC (n = 101) to mRNA expression in localized prostate from TCGA and used this analysis to infer differential kinase activity. In addition, we assessed the differential phosphorylation levels for key MAPK pathway kinases between mCRPC and localized prostate cancers.ResultsTranscriptomic profiling of 101 patients with mCRPC as compared to patients with localized prostate cancer identified evidence of hyperactive ERK1, and whole genome sequencing revealed frequent amplifications of members of the MAPK pathway in 32% of this cohort. Next, we confirmed elevated levels of phosphorylated ERK1/2 in castration resistant prostate cancer as compared to untreated primary prostate cancer. We observed that the presence of detectable phosphorylated ERK1/2 in the primary tumor is associated with biochemical failure after radical prostatectomy independent of clinicopathologic features. ERK1 is the immediate downstream target of MEK1/2, which is druggable with trametinib, an approved therapeutic for melanoma. Trametinib elicited a profound biochemical and clinical response in a patient who had failed multiple prior treatments for mCRPC.ConclusionsWe conclude that pharmacologic targeting of the MEK/ERK pathway may be a viable treatment strategy for patients with refractory metastatic prostate cancer. An ongoing Phase II trial tests this hypothesis.
Preclinical evaluation of PSMA expression in response to androgen receptor blockade for theranostics in prostate cancer
BackgroundProstate-specific membrane antigen (PSMA)-directed radioligand therapy (RLT) is a promising yet not curative approach in castration-resistant (CR) prostate cancer (PC). Rational combination therapies may improve treatment efficacy. Here, we explored the effect of androgen receptor blockade (ARB) on PSMA expression visualized by PET and its potential additive effect when combined with 177Lu-PSMA RLT in a mouse model of prostate cancer.MethodsMice bearing human CRPC (C4-2 cells) xenografts were treated with 10 mg/kg enzalutamide (ENZ), with 50 mg/kg bicalutamide (BIC), or vehicle (control) for 21 days. PSMA expression was evaluated by 68Ga-PSMA11 PET/CT and quantified by flow cytometry of tumor fine needle aspirations before treatment and on days 23, 29, 34, and 39 post-therapy induction. For the RLT combination approach, mice bearing C4-2 tumors were treated with 10 mg/kg ENZ or vehicle for 21 days before receiving either 15 MBq (84 GBq/μmol) 177Lu-PSMA617 or vehicle. DNA damage was assessed as phospho-γH2A.X foci in tumor biopsies. Reduction of tumor volume on CT and survival were used as study endpoints.ResultsTumor growth was delayed by ARB while 68Ga-PSMA11 uptake increased up to 2.3-fold over time when compared to controls. ABR-induced upregulation of PSMA expression was confirmed by flow cytometry. Phospho-γH2A.X levels increased 1.8- and 3.4-fold at 48 h in response to single treatment ENZ or RLT and ENZ+RLT, respectively. Despite significantly greater DNA damage and persistent increase of PSMA expression at the time of RLT, no additional tumor growth retardation was observed in the ENZ+RLT group (vs. RLT only, p = 0.372 at day 81). Median survival did not improve significantly when ENZ was combined with RLT.ConclusionARB-mediated increases in PSMA expression in PC xenografts were evident by 68Ga-PSMA11 PET imaging and flow cytometry. 177Lu-PSMA617 effectively decreased C4-2 tumor size. However, while pre-treatment with ARB increased DNA damage significantly, it did not result in synergistic effects when combined with RLT.
Efficacy of a preprostatectomy multi-modal penile rehabilitation regimen on recovery of postoperative erectile function
To evaluate the efficacy of a novel, multi-modal, preoperative approach to postprostatectomy penile rehabilitation (PR), we performed a retrospective review of patients who underwent nerve-sparing robotic-assisted laparoscopic prostatectomy (NS-RALP). All patients were evaluated at a comprehensive, academic sexual medicine clinic between 2016 and 2017. The “prehabilitation” PR group (n = 106) consisted of men who were seen in the pre-op period and began tadalafil and l-citrulline 2 weeks prior to surgery. Vacuum erectile device (VED) therapy was started at 1-month post-op. These interventions were continued throughout the 12-month follow-up period. Individuals refractory to these therapies could start treatment with intracavernosal injections. The postprostatectomy PR group (n = 25) consisted of men who were not seen in the pre-op period and started the above therapies immediately following their first visit. A higher percentage of men in the prehabilitation group reported return of erectile function within 12 months (56% vs. 24%, P = 0.007). The prehabilitation group also showed better compliance with PR (PDE5i [96% vs. 64%, P < 0.001], l-citrulline [93% vs. 49%, P < 0.001], and VED [55% vs. 20%, P < 0.001]). Seventy-eight percent of men who attended 4–5 follow-up visits reported return of erectile function. Our results suggest that men undergoing a preoperative protocol show superior recovery of erectile function following NS-RALP. Further studies with prospective designs are warranted.
Dynamic contrast-enhanced (DCE) MR imaging: the role of qualitative and quantitative parameters for evaluating prostate tumors stratified by Gleason score and PI-RADS v2
PurposeTo investigate the role of qualitative and quantitative DCE-MRI parameters in prostate cancer (PCa) stratified by whole-mount histopathology (WMHP) Gleason score (GS) and PI-RADSv2.MethodsThis retrospective study included 323 PCa tumors in 254 men, who underwent 3T MRI prior to prostatectomy, 7/2009-12/2016. Qualitative DCE curve types included type 1 (progressive), type 2 (plateau) and type 3 (washout). Quantitative DCE-MRI pharmacokinetic (PK) parameters included Ktrans (influx volume transfer coefficient), Kep (efflux reflux rate constant) and iAUC (initial area under the curve). DCE-MRI features of true positive lesions were evaluated for overall, index, transition zone (TZ) and peripheral zone (PZ), based on GS grade (low = 6, high > 6) and PI-RADSv2 score using SPSSv24.ResultsThere were 57 (17.6%) low-grade and 266 (82.4%) high-grade PCa lesions. PI-RADSv2 3, 4 and 5 included 106, 120 and 97 lesions, respectively. 251 (77.7%) and 72 (22.3%) lesions were located in PZ and TZ, respectively. High-grade lesions had significantly higher proportion of Type 3 curves compared to low-grade lesions in overall (70.3% vs. 54.4%) and TZ (73.5% vs. 43.5%). As PI-RADSv2 increased, the proportion of type 3 curve significantly increased for overall (80.4–51.9%), index (80.4–54.7%) and PZ (78.7–52.1%) lesions. Among PK parameters, Ktrans (0.43 vs 0.32) and iAUC (8.99 vs 6.9) for overall PCa, Ktrans (0.43 vs 0.31) and iAUC (9 vs 6.67) for PZ PCa, and iAUC (8.94 vs 7.42) for index PCa were significantly higher for high-grade versus low-grade lesions. Also, Ktrans (0.51–0.34), Kep (1.75–1.29) and iAUC (9.79–7.6) for overall PCa, Ktrans (0.53–0.32), Kep (1.81–1.26) and iAUC (9.83–7.34) for PZ PCa; and Kep (1.79–1.17) and iAUC (11.3–8.45) for index PCa increased significantly with a higher PI-RADSv2 score.ConclusionsThe results of study show the possible utility of qualitative and quantitative DCE-MRI parameters for assessment of PCa GS and PI-RADSv2 categorization.
Textured-Based Deep Learning in Prostate Cancer Classification with 3T Multiparametric MRI: Comparison with PI-RADS-Based Classification
The current standardized scheme for interpreting MRI requires a high level of expertise and exhibits a significant degree of inter-reader and intra-reader variability. An automated prostate cancer (PCa) classification can improve the ability of MRI to assess the spectrum of PCa. The purpose of the study was to evaluate the performance of a texture-based deep learning model (Textured-DL) for differentiating between clinically significant PCa (csPCa) and non-csPCa and to compare the Textured-DL with Prostate Imaging Reporting and Data System (PI-RADS)-based classification (PI-RADS-CLA), where a threshold of PI-RADS ≥ 4, representing highly suspicious lesions for csPCa, was applied. The study cohort included 402 patients (60% (n = 239) of patients for training, 10% (n = 42) for validation, and 30% (n = 121) for testing) with 3T multiparametric MRI matched with whole-mount histopathology after radical prostatectomy. For a given suspicious prostate lesion, the volumetric patches of T2-Weighted MRI and apparent diffusion coefficient images were cropped and used as the input to Textured-DL, consisting of a 3D gray-level co-occurrence matrix extractor and a CNN. PI-RADS-CLA by an expert reader served as a baseline to compare classification performance with Textured-DL in differentiating csPCa from non-csPCa. Sensitivity and specificity comparisons were performed using Mcnemar’s test. Bootstrapping with 1000 samples was performed to estimate the 95% confidence interval (CI) for AUC. CIs of sensitivity and specificity were calculated by the Wald method. The Textured-DL model achieved an AUC of 0.85 (CI [0.79, 0.91]), which was significantly higher than the PI-RADS-CLA (AUC of 0.73 (CI [0.65, 0.80]); p < 0.05) for PCa classification, and the specificity was significantly different between Textured-DL and PI-RADS-CLA (0.70 (CI [0.59, 0.82]) vs. 0.47 (CI [0.35, 0.59]); p < 0.05). In sub-analyses, Textured-DL demonstrated significantly higher specificities in the peripheral zone (PZ) and solitary tumor lesions compared to the PI-RADS-CLA (0.78 (CI [0.66, 0.90]) vs. 0.42 (CI [0.28, 0.57]); 0.75 (CI [0.54, 0.96]) vs. 0.38 [0.14, 0.61]; all p values < 0.05). Moreover, Textured-DL demonstrated a high negative predictive value of 92% while maintaining a high positive predictive value of 58% among the lesions with a PI-RADS score of 3. In conclusion, the Textured-DL model was superior to the PI-RADS-CLA in the classification of PCa. In addition, Textured-DL demonstrated superior performance in the specificities for the peripheral zone and solitary tumors compared with PI-RADS-based risk assessment.
Prostate cancer multiparametric magnetic resonance imaging visibility is a tumor-intrinsic phenomena
Multiparametric magnetic resonance imaging (mpMRI) is an emerging standard for diagnosing and prognosing prostate cancer, but ~ 20% of clinically significant tumors are invisible to mpMRI, as defined by the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) score of one or two. To understand the biological underpinnings of tumor visibility on mpMRI, we examined the proteomes of forty clinically significant tumors ( i.e. , International Society of Urological Pathology (ISUP) Grade Group 2)—twenty mpMRI-visible and twenty mpMRI-invisible, with matched histologically normal prostate. Normal prostate tissue was indistinguishable between patients with visible and invisible tumors, and invisible tumors closely resembled the normal prostate. These data indicate that mpMRI-visibility arises when tumor evolution leads to large-magnitude proteomic divergences from histologically normal prostate.