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BACKGROUND The outcome to treatment administered to patients with metastatic castration-resistant prostate cancer (mCRPC) greatly differs between individuals, underlining the need for biomarkers guiding treatment decision making. OBJECTIVE To investigate the prognostic value of circulating tumor cell (CTC) enumeration and dynamics, in the context of second-line endocrine therapies (ie, abiraterone acetate or enzalutamide), irrespective of prior systemic therapies. DESIGN, SETTINGS, AND PARTICIPANTS In a prospective, multicentre study blood samples for CTC enumeration were collected from patients with mCRPC at baseline (n = 174). In patients who responded for minimally 10-12 weeks a follow-up sample was collected. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS For baseline analysis, patients were stratified in

Individual patients' survival varies greatly in metastatic castration-resistant prostate cancer. Retrospective analysis of 368 patients treated with docetaxel and starting abiraterone acetate revealed 5 adverse prognostic factors: hemoglobin < 12 g/dL, > 10 metastases, ECOG performance status >= 2, radiographic progression, and time since diagnosis < 90 months. A prognostic model stratifies patients into 3 groups with different estimated survival, which can aid in patient counseling.Abiraterone acetate (AA) increases overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel. However, survival time varies substantially between individuals. Our goal was to identify prognostic factors that better estimate OS. Materials and Methods: This is a retrospective multicentric analysis of 368 patients with mCRPC starting AA with prednisone after docetaxel. Cox proportional hazards statistics were applied. A multivariate model was constructed based on significant univariate predictors by using a manual stepwise forward and backward selection strategy. Model performance was determined by using receiver operating characteristic (ROC) curves. Results: Univariate analysis identified 20 significant OS predictors. A multivariate model was constructed, based on 220 patients, incorporating 5 independent risk factors for decreased OS at the time of AA initiation: hemoglobin 10 metastases (HR 1.80), ECOG performance status >= 2 (HR 1.88), radiographic progression (HR 1.50), and time since diagnosis < 90 months (HR 1.66, all P

Background With the recent introduction of novel treatment options, real-world data from patients with metastatic castration-resistant prostate cancer (mCRPC) are required to better understand the impact on routine clinical practice. This study primarily aimed to describe the time to treatment failure (TTF) of mCRPC patients treated with abiraterone acetate plus prednisone or the corticosteroid of choice (AAP) in the pre-chemotherapy setting. Other relevant outcomes, clinical and treatment characteristics of these patients were also evaluated. Methods This retrospective, observational study collected data from chemotherapy-naïve mCRPC patients treated with AAP from four European countries. Kaplan-Meier curves were used to estimate TTF, progression-free survival (PFS), and time to first skeletal-related event. The impact of baseline characteristics on TTF and PFS was explored using univariate and multivariate Cox proportional hazard models. Log-rank test was used to assess the potential role of duration of response to ADT in predicting response to AAP treatment. Results Data from 481 eligible patients (Belgium: 68; France: 61; Germany: 150; UK: 202) were analysed. At AAP initiation, the median age of patients was 75.0 years (interquartile range [IQR]: 69.0–81.0), and the median PSA was 56.2 ng/mL (IQR: 22.2–133.1), with over 50% of patients presenting an ECOG score of 0 or 1. Visceral metastases were present in 7.5% of patients; an exclusion criterion in the COU-AA-302 clinical trial. The median TTF with AAP was 10.0 months (95%CI: 9.2–11.1) and the median PFS was 10.8 months (95%CI: 9.6–11.8). Shorter TTF was significantly associated with higher ALP (> 119 units/L), higher PSA (> 56.2 ng/mL), or poorer ECOG PS scores at AAP initiation (p

Purpose: To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from patients with metastatic castration-resistant prostate cancer (mCRPC) starting a new line of AR signaling inhibitors (ARSi). Experimental Design: Between March 2014 and April 2017, we recruited patients with mCRPC (n = 168) prior to ARSi in a cohort study encompassing 10 European centers. Blood samples were collected for comprehensive profiling of CellSearch-enriched circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). Targeted CTC RNA sequencing (RNA-seq) allowed the detection of eight AR splice variants (ARV). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss of heterozygosity, mutations, and structural rearrangements in ctDNA. Clinical or radiologic progression-free survival (PFS) was estimated by Kaplan–Meier analysis, and independent associations were determined using multivariable Cox regression models. Results: Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumor burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value [HR 1.88; 95% confidence interval (CI), 1.18–3.00; P = 0.008], and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs. 7.51 vs. 2.62 months; P < 0.0001), which was validated in an independent mCRPC cohort (n = 202) starting first-line ARSi (median, 14.3 vs. 6.39 vs. 2.23 months; P < 0.0001). Conclusions: In an all-comer cohort, tumor burden estimates and TP53 outperform any AR perturbation to infer prognosis. See related commentary by Rebello et al., p. 1699

BackgroundThere are multiple existing and emerging therapeutic avenues for metastatic prostate cancer, with a common denominator, which is the need for predictive biomarkers. Circulating tumor DNA (ctDNA) has the potential to cost-efficiently accelerate precision medicine trials to improve clinical efficacy and diminish costs and toxicity. However, comprehensive ctDNA profiling in metastatic prostate cancer to date has been limited.MethodsA combination of targeted- and low-pass whole genome sequencing was performed on plasma cell-free DNA and matched white blood cell germline DNA in 364 blood samples from 217 metastatic prostate cancer patients.ResultsctDNA was detected in 85.9% of baseline samples, correlated to line of therapy and was mirrored by circulating tumor cell enumeration of synchronous blood samples. Comprehensive profiling of the androgen receptor (AR) revealed a continuous increase in the fraction of patients with intra-ARstructural variation, from 15.4% during first line mCRPC therapy to 45.2% in fourth line, indicating a continuous evolution of AR during the course of the disease. Patients displayed frequent alterations in DNA repair deficiency genes (18.0%). Additionally, the microsatellite instability phenotype was identified in 3.81% of eligible samples (≥0.1 ctDNA fraction). Sequencing of non-repetitive intronic- and exonic regions ofPTEN, RB1andTP53detected biallelic inactivation in 47.5%, 20.3% and 44.1% of samples with ≥0.2 ctDNA fraction, respectively. Only one patient carried a clonal high-impact variant without a detectable second hit. Intronic high-impact structural variation was twice as common as exonic mutations inPTENand RB1. Finally, 14.6% of patients presented false positive variants due to clonal hematopoiesis, commonly ignored in commercially available assays.ConclusionsctDNA profiles appear to mirror the genomic landscape of metastatic prostate cancer tissue and may cost-efficiently provide somatic information in clinical trials designed to identify predictive biomarkers. However, intronic sequencing of the interrogated tumor suppressors challenge the ubiquitous focus on coding regions and is vital, together with profiling of synchronous white blood cells, to minimize erroneous assignments which in turn may confound results and impede true associations in clinical trials.

Background: Abiraterone acetate (AA) is licensed for treating metastatic castration-resistant prostate cancer (mCRPC). Real-world data on oncological outcome after AA are scarce. The current study assesses efficacy and safety of AA in mCRPC patients previously treated with docetaxel who started treatment during the Belgian compassionate use program (January 2011 July 2012). Patients and methods: Records from 368 patients with mCRPC from 23 different Belgian hospitals who started AA 1000 mg per day with 10 mg prednisone or equivalent were retrospectively reviewed (September 2013 December 2014). Prostate-specific antigen (PSA) response (decrease >= 50%), time to PSA progression (increase >50% over PSA nadir in case of PSA response/ >25% in absence of PSA response), time to radiographic progression (on bone scans or for soft tissue lesions using Response Evaluation Criteria In Solid Tumors 1.1), overall survival and adverse event rate (Common Terminology Criteria for Adverse Events v4.03) were analyzed. Kaplan-Meier statistics were applied. Results: Overall, 92 patients (25%) had an Eastern Cooperative Oncology Group performance status >= 2. Median age was 73 years, median PSA was 103 ng/dl. PSA response was observed in 131 patients (37.4%). Median time to PSA and radiographic progression was 4.1 months (95% CI: 3.6 /1.6) and 5.8 months (5.3-6.4), respectively. Median overall survival was 15.1 months (13.6-16.6). Most common grade 3 to 4 adverse events were anemia (13.9%), hypokalemia (7.3%), fatigue (6.8%), and pain (6.3%). Median duration of AA treatment was 5.3 months (interquartile range: 2.8-10.3). The main study limitation is its retrospective design. Conclusions: These real-world data on post-docetaxel AA efficacy are in line with the COU-AA-301 trial. Importantly, incidence of severe anemia and hypokalemia is up to 50% higher than reported in previous studies. (c) 2016 Elsevier Inc. All rights reserved.

The clinical impact of ET-743 (trabectedin; Yondelis) in women with leiomyosarcoma and undifferentiated uterine sarcoma in patients previously treated with chemotherapy is investigated. Current data show a clinical benefit in 2/5 patients, of which 1 had a partial remission during 9 months. Pooling the treatment outcomes with literature data, a response in 5 (38%) of 13 patients and a clinical benefit in 7 (54%) of 13 patients for all high-grade uterine sarcomas is calculated. When only uterine leiomyosarcomas are concerned, response rate is 5 (45%) of 11 patients with a clinical benefit in 7 (64%) of 11 patients. These results on the use of ET-743 in uterine sarcoma patients support the conductance of larger trials.

5049 Background: A heterogeneous landscape of patients with metastatic castration-resistant prostate cancer (mCRPC) exists in current clinical practice. We investigated the prognostic value of CTC enumeration and dynamics, in the context of second-line endocrine therapies (i.e. abiraterone or enzalutamide). Methods: In a prospective, multicentre study blood samples were collected from patients with mCRPC at baseline (n = 147) and follow-up (n = 95/147(64.6%)). At baseline, patients were stratified in favourable ( < 5 CTCs/7.5mL) and unfavourable (≥5 CTCs/7.5mL) groups, whereas at follow-up, in those demonstrating a stable, in- or decreasing CTC count. PFS and OS were compared between groups. PSA changes at 10-12 weeks were evaluable in 83 patients. Results: Patients with ≥5 CTCs/7.5 mL (n = 59) at baseline had a shorter PFS (3.9 vs. 11.3 months, p< 0.0001) and OS (9.34 months vs. not reached, p< 0.0001). Patients demonstrating increasing CTCs (n = 21) on therapy had a shorter PFS (4.03 vs. 10.36 vs. 13.08 months, p < 0.0001) and OS (11.2 months vs. not reached, p < 0.0001), compared to patients with decreasing (n = 41) and stable (n = 33) CTCs, respectively. Multivariate Cox regression showed that the number of CTCs (HR (95%CI): 1.0054 (1.0006–1.010), p= 0.0260) and an increasing follow-up CTC count (HR (95%CI): 2.8987 (1.2856–6.536), p= 0.0103) were independent predictors of PFS. CTC increase was the sole independent predictor for OS (HR (95%CI): 7.3512 (1.7953–30.101), p= 0.0055). At 10-12 weeks, a PSA response of ≥30% and ≥50% was achieved in 46/83 (55.4%) and 33/83 (39.8%) patients, respectively, which was statistically different between chemo-naive or -pretreated patients (≥30%: p= 0.0395), patients with increasing, stable or decreasing CTC counts (≥30%: p= 0.0019; ≥50%: p= 0.0032), and patients with increasing or stable/decreasing CTC counts (≥30%: p= 0.0006; ≥50%: p= 0.0014). Conclusions: CTC levels are associated with PFS and OS in mCRPC patients, starting a new line of endocrine therapy. Follow-up CTC enumeration is associated with PSA response and its dynamics is an independent predictor of PFS and OS, thereby demonstrating the pharmacodynamic properties of CTCs.

239 Background: In the COU-AA-302 trial, abiraterone acetate plus prednisone (AAP) resulted in extension of radiographic progression-free survival (rPFS) and overall survival in chemotherapy-naïve mCRPC patients compared to prednisone alone. However, limited data on AAP treatment and outcomes is available in the real-world in this setting. The aim of this study is to describe the duration of AAP treatment in routine clinical practice in mCRPC patients prior to chemotherapy. Methods: The study was designed as a retrospective chart review of mCRPC patients identified through oncology and urology practice in Belgium, France, Germany and the UK. This first analysis reports baseline patient characteristics at AAP initiation for the first 224 patients. Treatment duration, PFS and rPFS were estimated using Kaplan-Meier curves. Potential factors associated with treatment duration were explored using the log-rank test. Results: Data from 224 mCRPC patients treated with AAP (Belgium: 67; Germany: 150; UK: 7; none from France) across 19 centres was considered in this initial analysis. At baseline, the median age was 75.5 years (interquartile range [IQR]: 69.0-82.0) and the median PSA level was 50.0 ng/mL (IQR: 21.0-121.0). Patients with visceral metastases (9.8%) and ECOG 2-3 (9.4%) were included in this study, in contrast to those included in the COU-AA-302 study. Median duration of AAP treatment was 11.6 months (95% confidence interval [CI]: 10.2-12.8), whilst median PFS and rPFS were 11.9 months (95% CI: 10.8-13.3) and 16.5 months (95% CI: 13.5-20.0), respectively. Reasons for discontinuing AAP involved PSA progression (52.2%), radiographic progression (38.9%), symptomatic progression (27.8%), non-toxic death (19.4%) and toxicity (2.2%). Treatment duration was significantly longer in mCRPC patients with either baseline ECOG status 0, lower PSA, alkaline phosphatase, aspartate aminotransferase, or lactate dehydrogenase levels (p < 0.05). Conclusions: The results of this study suggest similar treatment duration and rPFS for mCRPC patients in this real-life cohort with poorer clinical features compared to those observed in the COU-AA-302 trial population.

Substance P (SP) is an immunoregulatory tachykinin which augments antigen- and mitogen-induced lymphocyte proliferation via signaling through the neurokinin-1 receptor (NK1-R). Non-neuronal cells of the immune system such as monocytes, T lymphocytes and eosinophils can be a source of SP. We have investigated if antigen-presenting dendritic cells (DC) produce SP. DC were grown from bone marrow precursors using a cocktail of GM-CSF, IL-4 and Flt-3 ligand. Reverse transcriptase-PCR amplification using primers for the mouse preprotachykinin-A gene and direct DNA sequencing of amplified products from purified DC demonstrated the presence of the gamma-transcript of the gene, coding for SP and neurokinin A. At the protein level, mouse DC expressed SP as determined by an enzyme immunoassay and confirmed by immunostaining. The functional role of endogenous SP release was determined. During the interaction with syngeneic or allogeneic DC, the addition of a specific NK1-R antagonist partly reduced proliferation in responding T lymphocytes. This was confirmed by using responders derived from NK1-R-deficient mice. In the absence of DC, proliferation of T cells induced by direct TCR ligation and soluble CD28 was partly dependent on signaling through NK1-R, revealing an autocrine effect of SP production by T cells. In conclusion, these results demonstrate that endogenously produced SP contributes to T cell proliferation induced by DC or TCR / CD28 stimulation.

Tachykinins released from sensory airway nerves have been shown to increase vascular permeability and plasma-protein extravasation (PPE) in rodent airways. We previously demonstrated that in Fisher (F344) rats, tachykinins cause bronchoconstriction mainly by indirect mechanisms involving the activation of NK1 receptor and mast cells, whereas in the less responsive BDE rats tachykinins have a direct NK2 receptor-mediated effect on bronchial smooth muscle. Using Evans blue dye as an intravascular marker, we demonstrated that F344 rats are hyperresponsive for the PPE induced by substance P (SP) and capsaicin. The NK1 receptor antagonist RP 67,580 reduced the neurogenic PPE in both strains, whereas the NK2 receptor antagonist SR 48,968 had no effect, indicating that only NK1 receptors are involved in the PPE. Pretreatment with the 5-HT antagonist methysergide decreased the neurogenic PPE in F344 rats but not in BDE rats. In F344 rats depleted of mast-cell mediators with compound 48/80, the SP-induced PPE was significantly reduced. Pretreatment with the H1 antagonist mepyramine and the H2 antagonist cimetidine caused a similar reduction in SP-induced PPE in main bronchi of both strains. Pretreatment with atropine, indomethacin, or the leukotriene antagonist ICI 198,615 did not affect the SP-induced PPE. In conclusion, neurogenic PPE in rat airways involves the activation of NK1 receptors. In F344 but not in BDE rats, an additional indirect mechanism involving 5-HT release and mast-cell activation participates in the neurogenic PPE.

e16057 Background: To assess efficacy and safety of abiraterone acetate (AA) in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel who started treatment during the AA compassionate use program (January 2011 - July 2012). Methods: We retrospectively analyzed records from 368 patients from 23 different Belgian hospitals. All patients had mCRPC, received prior chemotherapy and started AA at the standard dose of 1000mg per day with 10mg prednisone or equivalent. Principal outcomes measured were prostate-specific antigen (PSA) response (defined as a decrease ≥ 50%), time to PSA progression (defined as an increase > 50% over PSA nadir in case of PSA response or > 25% in the absence of PSA response), time to radiographic progression (according to Response Evaluation Criteria In Solid Tumors 1.1 criteria), overall and cancer-specific survival and occurrence of adverse events (according to Common Terminology Criteria for Adverse Events v4.03). Kaplan-Meier stati...

Temozolomide (TMZ) has demonstrated activity and acceptable toxicity for the treatment of recurrent high-grade gliomas in prospective phase II studies. Limited information is available on TMZ when prescribed outside a clinical trial. We conducted a retrospective study to evaluate the activity and safety of TMZ that was prescribed for the treatment of recurrent glioma in the context of a compassionate use program in Belgium. Data were obtained on 117 adult patients (from five hospitals) who received TMZ as first or second line chemotherapy. The recommended starting dose of TMZ was 200 mg/m2 x5d q28d for chemonaive patients and 150 mg/m2 x5d q28d for pre-treated patients. Toxicity was generally mild. Thrombocytopenia was the most frequent treatment related adverse event (grade 3/4 in 17% of patients). Its occurrence was correlated with a starting dose of 200 mg/m2/d and stresses the need to monitor toxicity. The overall objective response rate (complete and partial response) was 29 and 34% of patients achieved an objective disease stabilization. The median progression-free survival was 104 days (95% CI: 85-123) and the median overall survival was 215 days (95% CI: 161 269). In multivariate analysis a 'deep localization' of the glioma (as opposed to a cortico-subcortical localization) and 'the preceding history of a low-grade glioma' were respectively identified as a negative and positive independent prognostic variable for survival. No significant difference in terms of response or median survival was observed between patients with anaplastic astrocytoma or oligo-astrocytoma and chemonaive glioblastoma multiforme. This retrospective study indicates that the reported activity and toxicity profile of TMZ for the treatment of patients with recurrent glioma is reproducible outside the setting of a prospective clinical trial.

A gram-negative alkaline phosphatase- and pyrrolidone peptidase-positive rod-shaped bacterium (CCUG 45702) was isolated from two aerobic blood cultures from a female cancer patient. No identification could be reached using phenotypic techniques. Amplification of the tRNA intergenic spacers revealed fragments with lengths of 116, 133, and 270 bp, but no such pattern was present in our reference library. Sequencing of the 16S rRNA gene revealed its identity as Moraxella atlantae , a species isolated only rarely and published only once as causing infection. In retrospect, the phenotypic characteristics fit the identification as M. atlantae (formerly known as CDC group M-3). Comparative 16S rRNA sequence analysis indicates that M. atlantae , M. lincolnii , and M. osloensis might constitute three separate genera within the Moraxellaceae . After treatment with amoxicillin-clavulanic acid for 2 days, fever subsided and the patient was dismissed.