bluuebunny/crossref_metadata_2025 huggingface dataset:
Predict: Evaluation of baseline characteristics predictive of distant metastases in patients with castration-resistant prostate cancer—Updated data.
Authors: Freedland Stephen J. , Smith Matthew R. , Concepcion Raoul S. , Pieczonka Christopher Michael , Gartrell Benjamin Adam , Schiffman Zvi , Van Mouwerik Tim , Tyler Robert C. , Chang Nancy N. , Shore Neal D.
Published: February 2018

253

Background: Metrics predicting a positive imaging test for men presumed M0 castration-resistant prostate cancer (CRPC) are not universally accepted/implemented. PREDICT (NCT01981109) evaluates characteristics predictive of a baseline (BL) imaging study positive for distant mets (M1) in men with presumed M0 CRPC, and follows those with confirmed M0 disease to M1 development. Methods: Men with no imaging in the previous 3 months (mos) were enrolled in the registry. Imaging modality to detect mets was at investigator’s discretion. Based on BL imaging, patients were classified as M0 or M1. Results: PREDICT enrolled 224 men, of whom 208 had BL scan/image data; 55 (25%) men presented with undetected M1. Visceral disease was noted in 11% of men presenting with M1 disease; 60% had bone only disease, 18% had nodal only disease and 11% had bone + nodal disease. Bone mets were found in 16% (25/160) of Tc99 scans vs 40% (19/48) of NaF PET (p = 0.0004). Of men with M0 at BL, 37/153 (24%) became M1 at a mean time from study entry of 11.9 mos. Mean follow-up was 28 mos. In these men, the only notable change in laboratory values from BL was PSA (mean: 16 vs 69 ng/mL; p = 0.020) and PSADT (7.7 vs 6.3 mos; p < 0.001). Baseline PSADT was 10.9 (M0) and 5.7 (M1) mos. BL mean laboratory values were significantly higher (p < 0.01) in the M1 vs M0 group for PSA (47 vs 10 ng/mL), alkaline phosphatase (111 vs 77 U/L), and prostatic acid phosphatase (8.2 vs 2.5 ng/mL). Conclusions: A high proportion (25%) of men presented with asymptomatic, occult mets, and 11% of the occult mets involved visceral disease. In men with documented M0 CRPC, approximately a quarter will develop mets in the next 12 mos. Early detection of occult mets will allow patients to initiate therapies shown to improve overall survival. Clinical trial information: NCT01981109.
ARV7/AR ratio and neutrophil-to-lymphocyte ratio (NLR) as predictors of docetaxel benefit in metastatic castration-resistant prostate cancer patients (mCRPC).
Authors: Pérez-Gago Maria Coral , Marín-Aguilera Mercedes , Reig Òscar , Pereira Maria Veronica , Milà Maria , Jimenez Natalia , Victoria Iván , Chic Nuria , Mellado Begona
Published: February 2018

254

Background: The constitutively active androgen receptor (AR) variant 7 (ARV7) has been associated to AR inhibitors resistance, but its role in taxane-benefit has not been stablished. Moreover, the neutrophil-to-lymphocyte ratio (NLR) has been associated with poor outcome in prostate cancer.The PBMC population may contain circulating tumor cells (CTCs) but is mainly constituted by lymphocytes and monocytes, that also express the AR. Here we studied the expression of ARV7 and AR in peripheral blood mononuclear cells (PBMC) and its correlation with NLR and clinical outcome in mCRPC treated with docetaxel. Methods: ARV7 and AR mRNAs were tested by quantitative reverse-transcription PCR. Baseline neutrophil and lymphocyte values and PBMC samples were prospectively collected before treatment initiation. Patients were stratified according to NLR ratio (low NLR: ≤3; high NLR:>3) and to ARV7/ARFL ratio expression (Maxstat Cutoff 1.99). Correlation between NLR and PSA progression-free (PSA-PFS) and overall survival (OS), were measured from the start of docetaxel treatment and calculated by log rank test. Results: Fifty patients were included:25 (50%) had low NLR. Thirty-eight patients (76%) expressed high ARV7/ARFL. No significant correlation between NLR with ARV7, AR and ARV7/AR was observed. High ARV7/ARF ratio correlated to a better PSA-PFS (median PSA-PFS 7.47; HR 0.38, 95%CI 0.17-0.85; P=0.0179) , but not OS. High NLR was associated to a lower OS [Median OS was 9.2 months versus 30.17 months in those with low NLR (HR 2.19, 95% CI 1.17-4.09, p= 0.01)]. When both parameters were combined, high NLR and low ARV7/ARFL ratio were associated to a worse PSA-PFS in comparison with low NLR and high ARV7/ARFL ratiogroup(median PSA-PFS: 4.9 vs. 7.5; p=0.008 and HR 5.08, 95% CI 1.33-19.41, p= 0.08) and OS (median OS: 7.4 vs. 30.5; p=0.001 and HR 22.79, 95% CI 4.29-121.17, p= 0.00). Conclusions: The combination of low ARV7/ARFL high NLR and ratio evaluated in PBMC prior to docetaxel treatment has a predictive impact on response and survival in mCRPC patients.
cfDNA analysis of mCRPC patients expressing mutations in Wnt signaling.
Authors: Shahbandi Ashkan , Ledet Elisa , Christensen Bryce Raymon , Moses Marcus Marie , Steinwald Peter , Chapman Lynne , Cotogno Patrick , Layton Jodi Lyn , Lewis Brian E. , Schiff Joshua , Sartor A. Oliver
Published: February 2018

256

Background: Alterations in Wnt signaling have been shown to play a role in the development of castrate resistant prostate cancer. Cell free DNA (cfDNA) isolated from patient plasma can provide a non-invasive way to further assess this role. The goal of this study was to identify patients with cfDNA alterations in major canonical Wnt signaling components (APC and/or beta-catenin), and relate the emergence of these mutations during treatment to alterations in other common mutations. Methods: 134 clinically progressive metastatic CRPC patients from Tulane Cancer Center underwent cfDNA analysis through Guardant360 test (Guardant Health, Redwood City, CA). This analysis consisted of exonic coverage of 70 genes as well as amplifications in 18 genes, with mutations categorized as either pathologic, non-pathologic or as variants of unknown significance (VUS). Clinical annotation of prior treatment history was recorded. Results: 21.6% (29/134) of the mCRPC patients evaluated had a canonical Wnt signaling (APC and/or CTNNB) alteration. Of these patients, 62.1% (18/29) had mutations identified as pathologic. 77.8% (14/18) of patients identified with a pathologic Wnt mutation were treated with abiraterone and/or enzalutamide prior to Guardant360 testing. To determine potential associations between Wnt signaling alterations and other detected changes in cfDNA, the relationship between Wnt mutations (APC and/or CTNNB1) with pathologic TP53 mutations, AR mutations, BRAF amplifications, and MYC amplifications was assessed using a patient’s latest Guardant360 test. A significant positive association was found between Wnt mutations (n = 18) and MYC amplifications (n = 22), (p = 0.0373). 33.3% (6/18) of patients with a pathologic Wnt mutation were found to have amplification in MYC. Other notable associations included Wnt mutations and AR mutations (n = 74), which approached statistical significance (p = 0.112). Conclusions: While the understanding of the role of Wnt signaling in the treatment of mCRPC is still evolving, co-segregation of Wnt-signaling alterations with other oncogenic alterations, particularly MYC, which has been identified as a target of canonical Wnt signaling, may provide insights with regards to future management of mCRPC.
Determining biomarkers of response to docetaxel for patients with metastatic castration-resistant prostate cancer (mCRPC) using circulating cell-free tumor DNA (ctDNA).
Authors: Khalaf Daniel , Herberts Cameron , Vandekerkhove Gillian , Annala Matti , Beja Kevin , Eigl Bernhard J. , Kollmannsberger Christian K. , Nappi Lucia , Vergidis Joanna , Wyatt Alexander William , Chi Kim N.
Published: February 2018

260

Background: Docetaxel is associated with improved outcomes for mCRPC. There are currently no predictive molecular biomarkers for docetaxel to assist with patient selection. Methods: Patients commencing docetaxel for mCRPC between November 2015 and August 2017 were enrolled on a prospective cohort study evaluating circulating biomarkers. A plasma sample for ctDNA analysis was collected before initiation of docetaxel. Targeted sequencing of 73 prostate cancer-relevant genes was performed on leukocyte DNA (germline) and plasma cell-free DNA. Patient records were reviewed for baseline clinical characteristics, PSA response (≥ 50% decline from baseline), and time to PSA progression (TTPP) (PCWG3 criteria). Results: There were 33 patients enrolled; all patients had received prior abiraterone or enzalutamide and none had received prior taxanes. At baseline, the median age was 69.9 years, 30.3% had ECOG performance status 2, 66.7% had bone metastasis and 9.1% had liver metastases. The PSA response rate (RR) was 39.4% and 33.3% had a TTPP less than 3 months. 82% of patients had a ctDNA fraction >5%. Deleterious BRCA2 or ATM defects were present in 12.1% (4/33) of patients (3 somatic and 1 germline). TP53 alterations were identified in 39.4% (13/33), RB1 loss in 21.2% (7/33), PTEN loss in 21.2% (7/33), and Androgen Receptor (AR) amplification in 42.2% (14/33). PTEN deletion was associated with a trend toward inferior RR and TP53 had no discernible effect on PSA RR (Table). BRCA2/ATM defects were associated with a trend toward a lower rate of PSA progression within 3 months (Table). Conclusions: In this preliminary analysis, TP53 alterations had no discernible effect on efficacy of docetaxel chemotherapy. Accrual is ongoing in order to further clarify whether there is an association between PTEN, RB1, AR and BRCA2/ATM alterations and benefit from docetaxel. [Table: see text]
Prognostic impact of DNA repair germline variants in hormone sensitive prostate cancer stage.
Authors: Kohli Manish , Hart Steven , Lilyquist Jenna , Hu Chunling , Hillman David W. , Lee Kun , Gnanaolivu Rohan David , Polley Eric , Couch Fergus
Published: February 2018

262

Background: Inherited and somatic aberrations in DNA repair genes in castrate resistant prostate cancer (CRPC) are associated with poor prognosis, but respond well to poly ADP ribose polymerase (PARP) inhibitors. We evaluated the prevalence and prognostic impact of harboring germline DNA repair variants in hormone sensitive prostate cancer (HSPC). Methods: Germline DNA from buffy coat was sequenced on HiSeq4000 with a median coverage of 200X for DNA repair variants in 20 genes in HSPC and CRPC patients (pts) enrolled in a hospital registry. Pts were divided into two groups; Group A: pts enrolled at the time of CRPC stage; Group B: treatment naïve HSPC stage pts. The primary endpoints were to determine any impact of harboring DNA repair variants on time to progression from HSPC to CRPC and, from CRPC to death. Group A pts were retrospectively analyzed for time to progression from HSPC to CRPC while Group B patients were followed prospectively for outcomes. Statistical analysis included Cox proportional hazard models and Wilcoxon Rank sum test with significance at p≤0.05. Results: In Group A, 51/562 CRPC pts (9.07%) had variants in the 20 genes (most frequently in BRCA2; n = 15). 44/51 pts with variants and 399/511 without variants had died. Median time of progression from HSPC to CRPC with/without variants was 22.1 vs. 25.1 months (mths); p-value = 0.679. Median time from CRPC to death with/without variants was 32.2 Vs. 27.7 mths (p = 0.6). In HSPC Group B, 14/100 pts were identified with germline variants in ATM (n = 5), CHEK2 (n = 3), BRCA1 (n = 2), BRCA2 (n = 2), RAD50 (n = 1), and MSH2 (n = 1). 31/100 have died and median time to progression from HSPC to CRPC with/without variants was 15.6 vs.11.8 mths, p-value = 0.76. Conclusions: Pts with germline DNA repair variants detected in HSPC stage were not associated with poor prognosis. Presence of additional somatic DNA repair gene aberrations in cell-free DNA, not investigated in this cohort may add to the prevalence of DNA repair gene variations in HSPC and together impact prognosis adversely so as to provide a rationale for PARP inhibitor therapy in select HSPC stage pts.
cfDNA TP53 mutations with treatment history and disease progression in metastatic CRPC.
Authors: Chapman Lynne , Ledet Elisa , Moses Marcus Marie , Shahbandi Ashkan , Steinwald Peter , Christensen Bryce Raymon , Cotogno Patrick , Schiff Joshua , Layton Jodi Lyn , Lewis Brian E. , Sartor A. Oliver
Published: February 2018

263

Background: Cell free DNA (cfDNA) has made it possible to actively monitor alterations of genes during the course of therapy. Herein we evaluate cfDNA pathologic mutations in TP53 after treatment resistance to AR targeted therapy and taxanes in mCRPC. In addition to the presence or absence of pathologic mutations, the quantity of the mutations was characterized as present/absent, quantitatively as > or < 1%, or >or <10%. Methods: A retrospective study was done for 111 patients, with 226 separate cfDNA testing dates. Each cfDNA test was treated as an individual sample; of the 226 tests, 112 were positive for pathologic TP53 mutations, and 114 were negative. Treatment histories were collected and TP53 data analyzed in relation to resistance for abiraterone (abi), enzalutamide (enza), abi + enza, or abi + enza and a taxane. Treatment resistance was categorized as being present for those patients completing therapy with an agent. Results: Patients with pathologic TP53 mutations were more likely to have had progression after a novel hormone and a taxane (P = 0.005). Higher concentrations of TP53 mutational loads as measured by cfDNA concentration of >1% and >10% were more likely to be present in patients progressing after a taxane, abi, and enza. Common alterations associated with TP53 included AR amplifications and mutations, MYC amplifications, and BRCA2 mutations. Conclusions: TP53 mutations in cfDNA of mCRPC are progressively more likely to be present in patients, especially after patients receiving both taxanes and a novel hormonal agent. The predictive and prognostic significance of these changes are being further evaluated.[Table: see text]
Molecular profiles of small cell bladder and prostate cancer and comparisons with small cell lung cancer.
Authors: Dawson Nancy Ann , Geynisman Daniel M. , Burgess Earle Frederick , Somer Bradley G. , Arguello David , Hauke Ralph J. , Vaena Daniel A. , Raghavan Derek , Heath Elisabeth I.
Published: February 2018

264

Background: Small cell bladder cancer (SCBC) and small cell prostate cancer (SCPC) are rare and aggressive cancers. Standard therapy remains a platinum agent combined with etoposide, with few options after recurrence. Advances in molecular genomics and drug development have altered our approach to cancer. These same novel approaches may alter how we approach SCBC and SCPC. The purpose of this study is to identify potential targets and compare molecular profiles of SCBC and SCPC to SCLC. Methods: In total, 21 SCBC and 19 SCPC were identified from a de-identified database (Caris Life Sciences). Specimens were evaluated for genetic aberrations (Sanger or next generation sequencing [NGS], ISH) and/or protein expression (immunohistochemistry [IHC]). Comparisons were made against a de-identified cohort of SCLC (n = 428). Results: Pathogenic/presumed pathogenic mutations in SCBC were found in TP53 (91.7%, 11/12), RB1 (18.2%, 2/11), PTEN (8.3%, 1/12), EGFR (7.7%, 1/13), and PIK3CA (7.1%, 1/14). SCPC genetic aberrations were detected in TP53 (72.7%, 8/11) and RB1 (25.0%, 2/8). No carcinomas in this cohort had a high mutational burden or MSI-high status (0%, 0/7). Amplified genes found in SCBC included DDR2 (50%, 1/2) and EGFR (25.0%, 1/4). In SCPC, gene amplification was found in AKT2 (20%, 1/5), CCNE1 (20%, 1/5), FGFR1 (20%, 1/5), and MYC (20%, 1/5). The highest protein expression rates in SCBC involved MRP1 (100%, 5/5), TOP2A (94.1%, 16/17), and RRM1 (81.3%, 13/16). The highest protein expression rates in SCPC were MRP1 (100%, 6/6), TUBB3 (100%, 9/9), and TOP2A (94.4%, 17/18). Comparisons between SCBC and SCPC with SCLC revealed more similarities than differences. Significant differences were found in RRM1 by IHC between SCBC and SCLC. Also, significant differences were found between SCPC and SCLC in AR and PTEN by IHC. Conclusions: Comparisons of GU small cell carcinomas reveal similarities to SCLC. Both TP53 and RB1 mutations were found in both SCBC and SCPC. Amplification in genes CCNE1 and FGFR1, frequently identified in SCLC, were also found in SCPC. The high protein expression in biomarkers like MRP1 may explain the poor response to cytotoxic chemotherapy. Prospective studies are urgently needed.
3D Organoids from Milligrams of Genitourinary Cancer Patients Tissue Retain Key Features of Original Tumors.
Authors: Wang Yue , Souza Glauco R , Amato Robert J.
Published: February 2018

268

Background: 3D organoid culture, especially that generated from patient samples, is becoming prevalent as 2D cell culture models fail to provide clinical relevance. However, a relatively large amount of starting tissue is still required for this process, and the turnover rate and overall success rate vary greatly if relying solely on spontaneous aggregation. Methods: Here, we report the successful use of magnetic 3D bioprinting to drive organoid formation derived from fresh tumor samples of patients with prostate cancer, renal cell cancer, and urothelial cancer. Results: Only milligrams to tens of milligrams of starting tissues (from fine-needle biopsies, core biopsies, or surgical excision) were used. Most organoids formed overnight, with a very high overall success rate ( > 95%, n = 25). We have demonstrated that these cultures can be maintained, passed, and cryopreserved like conventional 2D cultures. More importantly, we characterized the organoids derived from prostatic adenocarcinomas and neuroendocrine tumors by the means of immunostaining and showed that the organoids expressed the same signature proteins as the originating tumors. This clinical concordance is crucial for downstream translational and biological research. We also showed that these adenocarcinoma cells responded to enzalutamide, an androgen receptor inhibitor that is used clinically to treat prostatic adenocarcinoma. Conclusions: In summary, we have established an efficient and robust system to create patient-derived 3D organoids; molecular characterization shows clinical concordance with original patient tumors; and our system shows great potential in drug screening with patient-derived 3D cultures.
A microRNA-based signature predicting immune-related toxicity (iRAEs) to pembrolizumab in prostate cancer patients.
Authors: Weidhaas Joanne B. , Wilenius Kirk , Scheffler Aaron Wolfe , Higa Juliana , Telesca Donatello , Scholz Mark C.
Published: February 2018

269

Background: The need to predict immune-related adverse events (iRAEs) for patients receiving checkpoint inhibitors is a pressing issue, with up to 25-30% Grade 2 or higher toxicity with single agent therapy, regardless of cancer type. Our group is studying a novel class of inherited mutations that disrupt the normal regulatory process of microRNAs as they function to control the genome. We have previously applied a panel of these mutations to predict iRAEs in melanoma and NSCLC patients receiving anti-PD1/anti-PDL1 therapy. We hypothesize that our mutations will predict iRAEs across cancer types. Here we have investigated their ability to predict iRAEs in a cohort of recurrent or advanced prostate cancer patients receiving Pembrolizumab (Pembro). Methods: We previously trained several statistical classifiers on a set of 86 melanoma and NSCLC patients evaluated for iRAEs. Subjects were classified as experiencing high toxicity (grade 2 or more) versus low toxicity (less than 2). We next tested the performance of the identified biomarkers on a set of 40 prospectively-treated prostate cancer patients who had received at least three cycles of Pembro, 200mg every 3 weeks. Samples were collected via cheek swab and germ-line DNA was isolated for testing. Predictive models of high-grade toxicity were based on 49 common markers between training and test samples. Classifiers were built comparing: classification trees, LASSO-regularized logistic regression, and random forests. All models were tuned at training using leave-one-out cross validation. The final extrapolation test errors were estimated on the prostate cohort as validation data not used in training. Results: Within the melanoma and NSCLC training sample we estimate toxicity with 71% accuracy (85% sensitivity, 43% specificity). We found that our biomarker panel when applied to prostate cancer patients extrapolates quite well, where our biomarkers predict toxicity with 68% accuracy (82% sensitivity, 38% specificity). Conclusions: We have identified a panel of microRNA-based, germ-line biomarkers which predict the risk of iRAEs. This panel appears to predict iRAEs across cancer types, including prostate cancer.
PSMA heterogeneity analysis in patients with metastatic castrate-resistant prostate cancer (mCRPC): Imaging versus CTCs.
Authors: Morris Michael J. , Vogelzang Nicholas J. , Sartor A. Oliver , Armour Alison A. , Messmann Richard Adam , Groaning Michael , Robarts Adam , Tolcher Anthony W. , Gordon Michael S. , Babiker Hani M. , Kuo Phillip , Kearney Megan , Jendrisak Adam , Wang Yipeng , Landers Mark Andrew , Petrylak Daniel Peter
Published: February 2018

272

Background: Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancers, making it an ideal imaging and therapeutic target of interest. The utility of the PSMA-targeted imaging agent 99mTc-EC0652 is being evaluated, along with biomarker analysis of circulating tumor cells (CTCs), in pts with mCRPC in a PSMA-targeted chemotherapeutic study. We now report the PSMA heterogeneity via CTC vs. imaging in the pt population treated to date. Methods: Patients were enrolled in 1 of 2 cohorts: mCRPC taxane naïve or taxane exposed. A total of 48 pts evaluated at the time of the data cut had baseline CT & bone scans performed in addition to a 99mTc-EC0652 SPECT/CT as a measure of imaging-based PSMA expression. 40 of 48 pts provided pre-treatment blood samples evaluable for CTC biomarker analysis, which included PSMA expression & were given percent homologous recombination deficiency (%HRD) scores. Four of the best and four of the worst responders were evaluated in more detail for imaging and CTC-based biomarker analysis as it related to clinical outcome. Results: 35 of 40 pts (88%) had detectable CTCs in their samples. 15 of the 35 (43%) pts had PSMA-positive CTCs. The 4 “non-responders” were on study for an average of 41 days and the 4 “responders” for an average of 256 days. Each group contained 2 taxane exposed & 2 taxane naïve patients. Of the 335 bone lesions analyzed by MDP, CT, 99mTc-EC0652, 333 (99.4%) were characterized as PSMApos based on their 99mTc-EC0652 SPECT/CT scan. Of the 26 soft tissue lesions analyzed by CT, all were characterized as PSMApos based on their 99mTc-EC0652 SPECT/CT scan. Seven (26.9%) of those lesions were CT positive (observed on CT scan). Each group had 2 pts that were CTC-based PSMApos & 2 that were PSMAneg. Their percent homologous recombination deficiency (%HRD) scores were of 0.60 [0.333, 1.0] for “non-responders” & 0.01 [0.0, 0.039] for “responders”. Conclusions: PSMA-based imaging showed a high percentage of positive lesions whereas CTC-based PMSA positivity is lower by comparison (43%). The discordance between the imaging results & CTC-based biomarkers, & the relative therapeutic predictive value, requires additional exploration. Clinical trial information: NCT02202447.
Application of the ASCO Value Framework and ESMO Magnitude of Clinical Benefit Scale to assess the value of abiraterone acetate (AA) and enzalutamide (E) in advanced prostate cancer: clinical value and cost considerations.
Authors: Wong Sarah , Everest Louis , Jiang Di Maria , Saluja Ronak , Chan Kelvin K. , Sridhar Srikala S.
Published: February 2018

276

Background: AA and E improve overall survival (OS) in metastatic castration resistant prostate cancer (mCRPC). AA also improves OS in metastatic castration sensitive disease (mCSPC). However, concerns exist over the cost implications of earlier treatment versus the clinical benefit gained. We aimed to quantify and compare the clinical value of AA and E and their drug costs in both the mCRPC and mCSPC settings. Methods: We identified 6 randomized Phase 3 trials of AA and E in mCRPC and mCSPC. Net clinical benefit was quantified by the ASCO Value Framework version 2 (range < 180) and ESMO MCBS version 1.1 (range 1-5)—both consider benefits in overall survival, progression free survival, and quality of life, against increase in drug toxicity. A higher score indicates greater value. Incremental cancer drug costs were also calculated, using average wholesale price from the REDBOOK and the trials’ reported duration of treatment. Results: (Table). Conclusions: AA and E administered in early mCSPC do not provide consistent increases in net clinical benefit compared to mCRPC, but they incur exponential cost considerations. Alternatives such as chemotherapy, which may provide similar net clinical benefit at less incremental costs, still warrant major consideration for clinicians and patients. Until more information is available to define the optimal sequencing of AA, E and other available treatment modalities, current cost implications may hinder moving these agents to earlier treatment settings.[Table: see text]
The Metastatic Prostate Cancer project (MPCproject): Translational genomics through direct patient engagement.
Authors: Mullane Stephanie Anne , Painter Corrie , Dunphy Michael , Anastasio Elana , Simoncelli Tania , Zarrelli Kristen , Philippakis Anthony , McKay Rana R. , Choueiri Toni K. , Golub Todd , Lander Eric , Wagle Nikhil , Van Allen Eliezer Mendel
Published: February 2018

279

Background: While there has been substantial advancement in the genomic understanding of metastatic prostate cancer (MPC), there is still much to be discovered. Additional progress is dependent upon obtaining a large amount of clinically-annotated genomic data. Therefore, we piloted a direct-to-patient nationwide research initiative where patients can contribute their medical records and biospecimens to accelerate research ( mpcproject.org ). Methods: In collaboration with patients and advocacy groups, we have developed a website ( mpcproject.org ). Participants are asked to complete a 17-question survey about their experiences with prostate cancer and an electronic informed consent. All participants receive a saliva kit for germline DNA and blood kit for circulating tumor DNA (ctDNA). Additionally, medical records are collected and archived tissue samples are requested if available. Ultra low pass whole genome sequencing (ULP-WGS) and whole exome sequencing (WES) are performed on the whole blood samples. WES is performed on saliva samples. Genomic, clinical, and patient-reported data will be shared widely with the research community. Aggregate study results will be reported to patients. Results: As of October 2017, 12 pilot patients aged 47-74 from 7 states, provided informed consent. 7 saliva kits, 4 blood kits, and 2 medical records were received. 4 patients were diagnosed with de novo metastatic disease, 8 reported a family history of breast and/or prostate cancer, 6 reported a secondary malignancy. All blood kits were submitted for ULP-WGS and WES. Updated genomic, clinical, and patient-reported data will be presented. Conclusions: We have provided preliminary evidence that partnering directly with MPC patients enabled the remote collection of saliva and blood samples, medical records, and patient-reported data. At the conclusion of the pilot phase, the MPC Project will open enrollment for all men with metastatic and advanced prostate cancer in the US and Canada.
Evaluation of PUMA and NOXA expression as predictive biomarkers in prostate cancer.
Authors: Clairefond Sylvie , Péant Benjamin , Ouellet Veronique , Barres Veronique , Mes-Masson Anne-Marie , Saad Fred
Published: February 2018

28

Background: PUMA and NOXA are two pro-apoptotic members of the BH3-only subgroup of the BCL-2 family. These two proteins play a role in the initiation of apoptosis. The objective of this study is to analyse their expression by immunofluorescence, alone or in combination, in benign and tumor prostate tissues to determine if there is a correlation between their expression and patient biochemical recurrence (BCR). Methods: Biomarker antibodies were verified for specificity and optimized by western blot and with tissue microarrays (TMA) containing prostate cancer cell lines and cell line derived xenograft tissues. Subsequently, quantification of expression for both biomarkers was performed on six TMA generated from radical prostatectomy samples (285 patients). The TMA were constructed using two cores of benign adjacent to the tumor and two cores of tumor tissue from each patient. Analysis of biomarker expression was semi-automated using the VisiomorphDP software. To optimize the analysis, we developed 2 different immunofluorescence masks: a cocktail of anti-cytokeratin-8 and -18 antibodies to identify epithelial cells and a combination of anti-p63 and anti-cytokeratin high marker weight to discriminate benign glands within tumor cores. Correlation with patient clinical outcome was determined with SPSS V20 software. Results: There was no correlation of PUMA and NOXA expression and BCR in tumor cores and stroma. In contrast, in benign epithelial cells Kaplan-Meier analysis showed a significant association between an extreme (low or high) PUMA expression and BCR (Log rank = 11.349, p = 0.001). Further analysis revealed a significant association between high NOXA expression in benign epithelial cells and BCR (Log rank = 6.133, p = 0.013). The combination of extreme PUMA and high NOXA identified patients with a poor prognosis (Log rank = 16.041, p = 0.000). In a multivariate Cox regression model, PUMA and NOXA proteins were also identified as independent predictive biomarkers of BCR. Conclusions: By studying benign epithelial cells adjacent to the tumor we identified two potential biomarkers that discriminate high-risk patients, independent of Gleason score or pathologic stage.
Sensitization of neuroendocrine prostate cancer by RRx-001.
Authors: Peehl Donna , Zhao Honguan , Ning Shoucheng
Published: February 2018

280

Background: RRx-001 is a first-in-class dinitroazetidine nontoxic anticancer agent. Its actions include upregulation of oxidative stress, depletion of GSH and NADPH, anti-angiogenesis, epigenetic modulation and induction of viral mimicry. In a phase II clinical study (NCT02489903), RRx-001 reversed resistance to reintroduced platinum doublets in small cell lung cancer (SCLC) and other tumor types. RRx001 demonstrated clinical activity with a complete metabolic response of metastatic castration-resistant neuroendocrine prostate cancer (NEPC) after treatment with RRx-001 and reintroduced platinum doublets. Here, we used a preclinical model to further investigate RRx-001 sensitization of NEPC to platinum therapy. Methods: NCI-H660 spheroids were pre-treated with 1 mM RRx-001 or vehicle prior to treatment with carboplatin or docetaxel and cell proliferation was assessed. Cells were also pre-treated with both 1 mM RRx-001 and 10 mM N-acetyl cysteine (NAC) or 1 mM Buthionine-S,R-sulfoximine (BSO) to investigate the role of reactive oxygen species (ROS) in RRx-001 activity. NCI-H660 xenografts were pre-treated with RRx-001 (mimicking clinical activity) or vehicle prior to treatment with carboplatin, and tumor volume and body weight were monitored. Results: RRx-001 pre-treatment significantly decreased the IC50 of carboplatin from ~86 mM to 36 mM in vitro, whereas no significant effect was observed on the IC50 of docetaxel. The ROS inhibitor NAC reversed > 70% of RRx-001 sensitization to carboplatin, while co-pre-treatment with the ROS generator BSO significantly enhanced RRx-001 activity. In vivo, pre-treatment with RRx-001 prior to carboplatin significantly decreased tumor volume compared to vehicle, with ~50% greater reduction in mean tumor volume at 30 days. Body weight was not affected by RRx-001. Conclusions: This preclinical study supports the concept that “priming” with RRx-001 may be an effective therapeutic strategy to resensitize NEPC to initially highly effective platinum doublets. A phase 3 trial is planned, and studies with additional preclinical NEPC models will identify the mechanism of action of RRx-001.
Effect of the leukocyte chemoattractant chemerin on PTEN via CMKLR1 in human prostate cancer.
Authors: Pachynski Russell Kent , Crowder Robert , Shin William , Rennier Keith
Published: February 2018

282

Background: Recent data in preclinical models has shown that phosphatase and tensin homolog (PTEN) loss correlated with decreased tumor immune cell infiltration as well as decreased response to T cell-based immunotherapy. Chemerin ( RARRES2) is a recently identified endogenous leukocyte chemoattractant shown to recruit innate immune cells through its G-protein coupled receptor CMKLR1. RARRES2 is commonly downregulated in prostate and other cancers (eg sarcoma) compared to their normal tissue counterparts. Our previous preclinical studies showed that forced overexpression of chemerin in tumors was capable of recruiting immune effector cells into the tumor microenvironment and suppressing tumor growth. Methods: Here, we investigate the effects of chemerin on tumor cell intrinsic processes by exposing prostate and sarcoma tumor lines to exogenous recombinant chemerin in vitro. Evaluation of PTEN was performed at both the mRNA and protein levels, using both quantitative PCR as well as Western blotting. PTEN immunoprecipitation by and Malachite Green assays were used to determine PTEN activity. In vitro invasion assays were performed to investigate the functional impact of chemerin exposure on tumor intrinsic activity. Knockdown of CMKLR1 using siRNA was performed to determine its role in tumor response. Results: Using both prostate and sarcoma tumor lines, we found exogenous chemerin was able to significantly upregulate PTEN expression at both the mRNA and protein levels in a dose-dependent manner. PTEN phosphatase activity was also significantly increased by chemerin. Exposure to chemerin did not result in increased apoptosis or altered in vitro proliferation. Importantly, chemerin treatment significantly decreased in vitro tumor invasion. Knockdown of CMKLR1 resulted in loss of chemerin-induced PTEN and PTEN activity and restored tumor migration, suggesting a link between this GPCR and PTEN. Conclusions: For the first time to our knowledge, we have shown a link between chemerin and PTEN expression and activity in both prostate and sarcoma tumor lines. This work has potential clinical implications on both tumor cell intrinsic and extrinsic responses to chemerin-based immunotherapeutic strategies.
Evaluation of self-reported symptoms and interference issues in prostate cancer patients.
Authors: Taha Mahdi
Published: February 2018

283

Background: Prostate cancer is a leading cause of global morbidity and mortality and in the next few years is expected to be the leading cause of death among men in the United States. Both the disease and its treatments produce a variety of symptoms that impact prostate cancer outcomes, of which the more common symptoms are in relation to sexual dysfunction. A large body of literature has established that systematic patient reporting of symptoms during routine oncology care leads to clinical benefits. At our comprehensive community cancer center we evaluate patients’ reported symptoms using the Symptom Inventory Tool (SIT), an assessment tool that captures the patients' perceived symptom burden for real-time clinical intervention taken at the point of no intervention and every ≥ 21 days thereafter. Methods: The 27-question SIT is comprised of the M.D. Anderson Symptom Inventory Tool (MDASI), a validated assessment instrument, with 8 supplementary questions and a free-text box added by Cancer Treatment Centers of America. Symptoms are rated “at the worst” on a numeric scale ranging from 0 to 10, as experienced by pts in the past 24 hours. The SIT became an integral part of patient care at CTCA beginning in 2012. Results: Over a 45 month period (9/1/2012 to 05/31/2016), prostate cancer pts at CTCA completed the SIT at intake and again ≥ 21 days after. A total of 2,937 assessments were analyzed. The assessments consisted of 1,065 completed at baseline, 1,065 completed at the 2nd follow up (FU), and 807 completed at 3rd FU or greater. Further analysis of baseline SIT identified the pts who rated the above symptoms as “very burdensome” with a score of ≥ 5. 2nd SIT results from these PC patients revealed that those with a heavier symptoms burden at baseline would be more likely to experience a significant decrease in their symptoms burden than the average PC patient population. Conclusions: The SIT was successful in identifying symptoms burden and interference with life issues in prostate cancer patients. Sexual dysfunction and disturbed sleep were the most common reported symptoms. Early identification of patients with heavy symptom-burden allowed immediate intervention and improvement in approximately a one-fourth to two-thirds of patients.
Integrative transcriptional analysis of enzalutamide-resistant castration resistant prostate cancer cells using RNA sequencing.
Authors: Kim Tae Heon , Kang Minyong , Oh Ji Youn , Kang Yumi
Published: February 2018

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Background: Enzalutamide (ENZ)-resistance is a clinically challaengeable issue for management of castration-resistant prostate cancer (CRPC) patients. Here, we aimed to investigate the distinct features of transcriptional expression in ENZ-resistant CRPC cells using RNA sequencing, focusing on the histone modification enzymes as AR co-regulators. Methods: We chronically treated various concentration of ENZ (1 to 40 µM) for 6 to 9 months to establish ENZ-resistant CRPC cells by using C4-2B cells. To explore the phenotypic features of ENZ-resistant CRPC cells (ENZ-R), we analyzed the gene expression patterns, particularly AR target genes, following ENZ treatment. We performed cell viability assay, clonogenic assay, apotosis assay and tumor sphere formation assay. To examine the distinct features of transcriptional expression in ENZ-resistant CRPC cells, we conducted RNA sequencing and classified the key differential expression genes (DEG) according to Gene Ontology Database. Results: ENZ-R cells showed a higher cell viability and clonogenic proliferation compared to control cells following ENZ treatment. Also, ENZ-R cells showed higher gene expression of AR target gens (KLK2, KLK3, TTMPRSS) than those in control cells after dihydrotestosterone treatment. Of note, ENZ-R cells significantly expressed full length AR as well as AR splicing variant 7. Moreover, RNA sequencing revealed that 367 up-regulated genes and 223 down-regulated genes were identified as DEG compared to control cells. We further analyzed these DEG of histone modification enzyme as AR co-regulators, and therefore; we finally determined the candidate 28 target genes of histone modification enzyme (23 up-regulated and 5 down-regulated genes). We validated the differential expression of these key histone modification enzyme genes in ENZ-R cells by using real-time PCR. Conclusions: In sum, we established the ENZ-R cells and identified the 28 candidate DEG of histone modification enzyme in ENZ-R cells by performing RNA sequencing analysis. Our study can offer the valuable information for exploring the ENZ-resistant mechanisms, particularly focusing on the imbalance of AR co-regulators.
New HSP90 selective inhibitors as therapeutic agents for prostate and bladder cancer.
Authors: Liu Weiya , Jensen Derek , Lee Eugene , Gills Jessie , Holzbeierlein Jeffrey M.
Published: February 2018

285

Background: Hsp90 is a molecular chaperone responsible for folding many of the proteins directly associated with cancer progression and consequently, inhibition of the Hsp90 protein folding machinery results in a combinatorial attack on numerous oncogenic pathways. Hsp90 family consist of four isoforms; Hsp90α, Hsp90β, Grp94 and Trap-1. The development of Hsp90 isoform-selective inhibitors represent an alternative approach towards the treatment of cancer that may limit some of the detriments. We demonstrate novel Hsp90 inhibitors, on prostate and bladder cancer cells, which shows both potent antiproliferative effects and specific selectivity for Hsp90β. Methods: PC3MM2, LNCap-LN3, C4-2b, LAPC4 (prostate cancer) and T24, UC3 (bladder cancer) cancer cells were utilized. Cell Titer-Glo luminescent anti-proliferative assay was used to determine the IC50 numbers after 72h treatment. Trypan Blue Cytotoxicity assay was performed for 24h treatment with increasing concentrations of KUNB inhibitors. Effects of KUNB inhibitors on Hsp90’s client protein degradation were investigated by Western Blot. Results: KUNB31 manifested an IC50 of 3.00 µM against UC3 bladder cancer cells, UC3 cells were then evaluated via western blot analyses of known Hsp90α- and Hsp90β-dependent client proteins following treatment with KUNB31 for 24 hours. The data showed that, KUNB31 would not induce the heat shock response like 17AAG, and did cause Hsp90β related protein degradation (CXCR4). Moreover, Hsp27, PKM2, Her2, Hsf-1and Akt all showed degradation to different extent. KUNB105 exhibited potent anti-proliferative in both prostate and bladder cancer cells. IC50 number was determined as 1.24 µM for PC3MM2, 1.18 µM for LNCap-LN3, 1.03 µM for C4-2b, 2.56 µM for LAPC4, 0.20 µM for T24, and 0.30 µM for UC3 cancer cells. Conclusions: KUNB novel Hsp90β selective inhibitors, exhibit potent anti-proliferative and cytotoxic activity along with client protein degradation, without induction of HSR in prostate and bladder cancer cell lines. KUNB compound’s selective inhibition on Hsp90β isomers supports the development of Hsp90-selective inhibitors as a method to overcome the detriments associated with pan-inhibition in cancer treatment.
Abiraterone acetate in metastatic castration-resistant prostate cancer post-docetaxel: A “real-life” retrospective analysis of outcomes in a Brazilian public health institution.
Authors: Flores Thais Caroline Menegasso , Emerich Carolina da Silva Miranda , Zaffaroni Facundo , Debiasi Márcio , Dutra Carolina
Published: February 2018

287

Background: Abiraterone acetate (AA) is a selective inhibitor of CYP17 and showed to improve overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) patients progressing after docetaxel in the COU-AA-301 trial. AA is not widely available for patients treated at the public health system (SUS) and real-life data regarding this treatment in Brazil are lacking. This study aims to describe the epidemiological profile and outcomes of patients diagnosed with mCRPC who progressed after docetaxel treated with AA in a Brazilian public health institution. Methods: We retrospectively reviewed clinical data of patients with mCRPC who progressed after docetaxel and were treated with AA (1000mg/d PO) plus prednisone (5mg/BID PO) from January 2015 to December 2016 in our instituition. Patient demographic and clinical characteristics were described using summary statistics. Kaplan-Meyer method was used to estimate OS and time to prostate-specific antigen (PSA) progression for AA treatment. Results: 37 patients were included for analysis. Median age was 71 yo. Median PSA at AA start was 57 ng/mL (range 0.10-6,676.00), Gleason score was > 7 in 59.5% and ≤7 in 32.4%. 75.7% of patients had symptomatic bone metastasis requiring opioids. At a median follow up of 68 months, the median duration of treatment was 5 months with a median OS of 13 months and a median time to PSA progression of 4 months. Gleason score did not correlate with outcomes (p = 0.56). Although patients who had a prior hormone therapy (PHT) > 12mo had better OS (15mo) when compared to those with PHT < 12 (10mo), this difference was not statistically significant (p = 0.26). AA was well tolerated and disease progression was the main reason for AA discontinuation (86.8%). Conclusions: This analysis shows that AA is an effective and safe treatment option for patients in public health system in a developing country, with comparable outcomes to COU 301 trial in OS, showing benefits regardless Gleason and PHT status. These patients did not receive later lines of treatment, and this could have impacted OS in this study. The incorporation of AA in the SUS should be considered.
Overcoming resistance to antiandrogens with a TGF-β RI inhibitor in preclinical mouse model of PCa.
Authors: Paller Channing Judith , Pu Hong , Begemann Diane , Nakazawa Mary , Kyprianou Natasha
Published: February 2018

288

Background: Epithelial-mesenchymal transition (EMT) is a significant contributor to PCa metastatic progression and therapeutic resistance in patients treated with the androgen receptor (AR) directed therapies. We previously demonstrated that aberrant TGF-β signaling accelerates prostate tumor progression in the TRAMP mouse model of tumorigenesis via selective effects on EMT. Methods: We hypothesize that the combination of the TGF-β receptor inhibitor, galunisertib (G), and enzalutamide (E) will perturb the interactive signaling between TGF-β and AR signaling affecting the phenotypic landscape of EMT. This perturbation may be exploited in our mouse model, towards enhanced anti-tumor efficacy in advanced castration-resistant PCa (CRPC). We treated 2-week old mice for two weeks with the G (75mg/kg) and/or E (30mg/kg) in combination and as single agents. Results: Treatment with G alone or in combination with E resulted in a significant reduction in prostate tumor weight without affecting total body weight. Immunohistochemical (IHC) and Western blot analysis showed that, while treatment with the G alone led to increased apoptosis and decreased cell proliferation, combination of G and E had significantly higher efficacy in inducing apoptosis and inhibiting cell proliferation than either E or G alone. As expected treatment with the G decreased the levels of nuclear Smad4 protein; the combination of G and E further decreased nuclear Smad4 expression. Furthermore the combination of G and E reversed phenotypic EMT to MET (mesenchymal-epithelial-transition), as assessed by the increase in E-cadherin among the prostate tumor cell populations. IHC and Western blot analysis also revealed that the combined treatment of G and E led to a significant decrease in nuclear AR levels compared to E-only-treated or vehicle-control tumors. Conclusions: These results provide significant insights as to the therapeutic impact of G to effectively impair the TGF-β signaling and overcome resistance of PCa patients to E by reversing EMT to potentially sensitize tumors to the antiandrogen effect. This study has major translational relevance; the combination of G and E may lead to synergistic anti-tumor impact in patients with CRPC.