The Complementary Roles of Open and Endovascular Repair of Extent I -III Thoracoabdominal Aortic Aneurysms in a United Kingdom Aortic Centre

OBJECTIVE

A multidisciplinary approach offering both open surgical (OSR) and complex endovascular repair (cEVAR) is essential if patients with thoraco-abdominal aortic aneurysms (TAAAs) are to receive optimal care. This study reports early and mid-term outcomes of elective and non-elective OSR and cEVAR for extent I - III TAAA in a UK aortic centre.

METHODS

Retrospective study of consecutive patients treated between January 2009 and December 2021. Primary endpoint was 30 day/in hospital mortality. Secondary end point was Kaplan-Meier estimates of mid-term survival. Data are presented as median (IQR).

RESULTS

In total, 296 patients (176 men; median age 71 years [IQR 65, 76]; aneurysm diameter 66 mm [61, 75]) underwent repair (222 elective, 74 non-elective). OSR patients (n = 66) were significantly younger with a higher incidence of heritable disease and chronic dissection, while cEVAR patients (n = 230) had a significantly higher prevalence of coronary, pulmonary, and renal disease. Overall, in hospital mortality after elective and non-elective repair was 3.2% (n = 7) and 23.0% (n = 17), respectively, with no significant difference between treatment modalities (elective OSR 6.5% vs. cEVAR 2.3%; p = .14; non-elective OSR 25.0% vs. cEVAR 20.3%; p = .80). Major non-fatal complications occurred in 15.3% (33/215) after elective repair (OSR 39.5%, 17/43, vs. cEVAR 9.3%, 16/172; p < .001) and 14% (8/57) after non-elective repair (OSR 26.7%, 4/15, vs. cEVAR 9.5%, 4/42; p = .19). Median follow up was 52 months (IQR 23, 78). Estimated survival ± standard error at one, three, and five years for the entire cohort was 89.6 ± 2.0%, 76.6 ± 2.9%, and 69.0% ± 3.2% after elective repair, and 67.6 ± 5.4%, 52.1 ± 6.0%, and 41.0 ± 6.2% after non-elective repair. There was no difference in five year survival comparing modalities after elective repair for patients less than 70 years, and those with post-dissection aneurysms.

CONCLUSION

A multidisciplinary approach offering OSR and cEVAR can deliver comprehensive care for extent I - III TAAA with low early mortality and good mid-term survival. Further studies are required to determine the optimal complementary roles of each treatment modality.

EphrinB2: Expression of a novel potential target in renal cell carcinoma

Introduction

Renal cell carcinoma (RCC) is primarily managed by surgery with the use of systemic targeted therapy in a metastatic setting. Newer targeted therapeutic options are evolving; Eph-ephrin is a potential new pathway. The therapeutic potential of targeting the EphB4-EphrinB2 pathway has been demonstrated in many solid tumors; however, its expression in RCC has only been evaluated in a few studies with limited cases. We herein determine the immunohistochemical expression of EphrinB2 in RCC.

Methods

A tissue microarray comprising 110 cases of different histological subtypes of RCC and 10 normal kidney tissues were stained with monoclonal anti-EphrinB2 antibody (Abcam, AB201512). The tumor and endothelial cells expressing the EphrinB2 were examined and its expression was correlated with sex, histological subtypes, and tumor nodes metastasis (TNM) stage.

Results

Twenty cases of urothelial carcinoma and two unsatisfactory conventional clear cell RCC cases were excluded, and EphrinB2 expression was interpreted in the remaining 88 tumors. EphrinB2 was expressed in 42 out of 88 tumors (47.7%) and was negative in the normal renal parenchyma. There was a statistically significant difference in the expression of EphrinB2 in males (55%) and females (32%). However, no such difference of expression was noted for the histological subtypes and the stages. Half (51%) of Stage 1 (n = 30) and Stage 2 (n = 11) tumors showed EphrinB2 positivity.

Conclusions

EphrinB2 is expressed in approximately half of RCC cases. EphrinB2 expression in the early stage cancer might indicate its induction as an early event.

Controlling C2C12 Cytotoxicity on Liquid Metal Embedded Elastomer (LMEE)

Liquid metal embedded elastomers (LMEEs) are highly stretchable composites comprised of microscopic droplets of eutectic gallium-indium (EGaIn) liquid metal embedded in a soft rubber matrix. They have a unique combination of mechanical, electrical, and thermal properties that make them attractive for potential applications in flexible electronics, thermal management, wearable computing, and soft robotics. However, the use of LMEEs in direct contact with human tissue or organs requires an understanding of their biocompatibility and cell cytotoxicity. In this study, we investigate the cytotoxicity of C2C12 cells in contact with LMEE composites composed of EGaIn droplets embedded with a polydimethylsiloxane (PDMS) matrix. In particular, we examine the influence of EGaIn volume ratio and shear mixing time during synthesis on cell proliferation and viability. We also examine the special case of electrically-conductive LMEE composites in which a percolating network of EGaIn droplets is created through "mechanical sintering." This study in C2C12 cytotoxicity represents a first step in determining whether LMEE is safe for use in implantable biomedical devices and biohybrid systems. This article is protected by copyright. All rights reserved.

EphrinB2 Inhibition and Pembrolizumab in Metastatic Urothelial Carcinoma

PURPOSE

Patients with metastatic urothelial carcinoma have poor prognosis after failure of standard first-line chemotherapy. Immune check point programmed death 1-programmed death ligand 1 antibodies have low response rates and thus there exists a major unmet need.

MATERIALS AND METHODS

In this phase II trial, patients with metastatic urothelial carcinoma that recurred or progressed after platinum-based chemotherapy received soluble EphB4-human serum albumin (sEphB4-HSA) in combination with pembrolizumab. The primary end points were tolerability and overall survival (OS). The secondary end points were progression-free survival (PFS), objective response rate (ORR), duration of response, and toxicity. The expression of sEphB4-HSA target EphrinB2 was correlated with outcomes.

RESULTS

Seventy patients were enrolled. The median follow up was 22.9 months (range, 1.3-54.7). The regimen had acceptable toxicity. In the intent-to-treat analysis (N = 70), the median OS was 14.6 months (95% CI, 9.2 to 21.5). Twenty-six (37%) patients had an objective response (95% CI, 26 to 48). The median PFS was 4.1 (95% CI, 1.5 to 5.7) months. Forty-six (66%) patients expressed EphrinB2, and among them, the median OS was 21.5 months (95% CI, 12.4 to not reached), the ORR was 52% (95% CI, 37 to 67), including a complete response rate of 24% (11 of 46; 95% CI, 12 to 36). The median PFS was 5.7 (95% CI, 2.7 to 27.9) months. Response was maintained at 6, 12, and 24 months in 88%, 74%, and 69% of the patients, respectively.

CONCLUSION

The combination of sEphB4-HSA and pembrolizumab appears synergistic with improved OS and ORR compared with historical data for programmed death 1/programmed death ligand 1 monotherapy.

Patient Engagement by the Tobacco Quitline After Electronic Referrals

INTRODUCTION

Referrals through the electronic health record (EHR) system provide an efficient evidence-based method to connect patients to the Tobacco Quitline. However, patients frequently do not respond to Quitline phone calls or accept services. The goal of this study was to characterize factors associated with successful engagement with Quitline following e-referrals by physicians in Maryland.

AIMS AND METHODS

This is a cross-sectional study with hierarchical data modeling. Data for 1790 patients e-referred in 2018-2019 by the University of Maryland Medical System (UMMS) were analyzed. Patients' engagement was assessed using a generalized estimating equation multivariable regression model for ordinal outcomes at two levels: Picking up a phone call from Quitline (1-800-QUIT-NOW) and enrollment in tobacco cessation programs.

RESULTS

Older age, female gender, black race, low socioeconomic status, and provider's skills were significantly associated with successful outcomes of Quitline referral. The engagement with Quitline was higher in black non-Hispanic patients compared to other racial/ethnic groups (phone call response odds ratio [OR] = 1.99, 95% confidence interval [CI] = 1.35% to 2.93% and service acceptance OR = 1.89, 95% CI = 1.28% to 2.79%). Patients residing in socioeconomically deprived areas were more likely to respond to Quitline phone calls compared to those from affluent neighborhoods (OR = 1.52, 95% CI = 1.03% to 2.25%). Patients referred by faculty or attending physicians were more likely to respond compared to those referred by residents (OR = 1.23, 95% CI 1.04, 1.44, p = .0141).

CONCLUSIONS

Multiple factors impact successful engagement with Quitline. Additional means to improve Quitline engagement success may include focused messaging on tobacco cessation benefits to patients, and skillful counseling by the provider.

IMPLICATIONS

Implementation of the clinical decision support (CDS) tool for electronic referrals to the Tobacco Quitline at the UMMS was successful in providing evidence-based free service to elderly patients and socioeconomically disadvantaged racial and ethnic minorities. The CDS also served to engage physicians in conversation about tobacco use and cessation with every tobacco-using patient. Curricular content for physicians in training should be enriched to expand tobacco use and treatment.

Diagnostic Performance and Advanced Imaging Reduction With Digital Tomosynthesis in Scaphoid Fracture Management

BACKGROUND

Management of scaphoid fractures often requires advanced imaging to achieve accurate diagnoses and appropriate treatment. Digital tomosynthesis (DTS) is a cross-sectional imaging modality that may be used to substitute magnetic resonance imaging or computed tomographic scans. The purpose of this study is to: (1) determine the diagnostic accuracy of DTS in occult scaphoid fractures; and (2) report on the reduction of other advanced imaging when using DTS.

METHODS

From May 2014 to October 2017, the charts of all patients who underwent scaphoid tomogram were retrospectively reviewed. The diagnostic accuracy of DTS for occult fracture was compared with 2-week follow-up plain films. To measure the reduction in utilization of advanced imaging, it was determined whether DTS eliminated the need for advanced imaging by providing adequate information regarding the clinical question.

RESULTS

A total of 78 patients underwent scaphoid tomography in this time frame: 39 for occult fracture, 33 for fracture union, 5 for fracture morphology, and 1 for hardware positioning. For the detection of occult fracture, DTS had a sensitivity of 100%, specificity of 83%, positive predictive value of 64%, and negative predictive value of 100%. Advanced imaging was not used in 35 of the remaining 39 patients based on the results obtained by DTS. In patients who did receive advanced imaging, 83% of tomograms provided conclusive diagnostic information.

CONCLUSIONS

Digital tomosynthesis increases the diagnostic sensitivity of occult scaphoid fractures, reducing unnecessary immobilization and advanced imaging. Digital tomosynthesis provides clinical detail beyond plain film, which reduces the need to obtain advanced imaging when assessing union, fracture pattern, and hardware placement.

Living with a left ventricular assist device: Capturing recipients experiences using group concept mapping software

Background

Left ventricular assist device (LVAD) implantation significantly impacts on a recipient’s symptoms and quality of life. Capturing their experiences and post implant journey is an important part of clinical practice, research and device design evolution. Patient reported outcome measures (PROMs) are a useful tool for capturing that experience. However, patient reported outcome measures need to reflect recipients’ experiences. Discussions with a patient partner group found that none of the frequently used cardiology PROMs captured their unique experiences.

Aims

To capture the experiences and important issues for LVAD recipients. Develop a conceptual map of domains and items that should be reflected in patient reported outcomes.

Methods

Group concept mapping (GCM) web-based software was used to remotely capture and structure recipients’ experiences across a wide geographical area. GCM is a semi-quantitative mixed method consisting of 3 stages: item generation, item sorting and rating (importance, relevance and frequency). Patient partners were involved in all aspects of the study design and development.

Results

18 LVAD recipients consented to take part. 101 statements were generated and multi-dimensional scaling, and hierarchical cluster analysis identified 9 clusters. Cluster themes included: Activities, Partner/family support, Travel, Mental wellbeing, Equipment and clothing, Physical and cognitive limitations, LVAD Restrictions, LVAD Challenges and positive impact of the LVAD (LVAD Positives). LVAD Positives were scored highest across all the rating variables, e.g., frequency (2.85), relevance (2.44) and importance (2.21). Other domains rated high for importance included physical and cognitive limitations (2.19), LVAD restrictions (2.11), Partner/family support (2.02), and Equipment and clothing (2.01).

Conclusion

Online GCM software facilitated the inclusion of geographically dispersed recipients and provided useful insights into the experiences of LVAD recipients. The conceptual framework identifies important domains and items that should be prioritised and included in patient reported outcomes in future research, LVAD design evolution, and clinical practice.

Feasibility of using CT radiomic signatures for predicting CD8-T cell infiltration and PD-L1 expression in renal cell carcinoma

Objectives

To identify computed tomography (CT)-based radiomic signatures of cluster of differentiation 8 (CD8)-T cell infiltration and programmed cell death ligand 1 (PD-L1) expression levels in patients with clear-cell renal cell carcinoma (ccRCC).

Methods

Seventy-eight patients with pathologically confirmed localized ccRCC, preoperative multiphase CT and tumor resection specimens were enrolled in this retrospective study. Regions of interest (ROI) of the ccRCC volume were manually segmented from the CT images and processed using a radiomics panel comprising of 1708 metrics. The extracted metrics were used as inputs to three machine learning classifiers: Random Forest, AdaBoost, and ElasticNet to create radiomic signatures for CD8-T cell infiltration and PD-L1 expression, respectively.

Results

Using a cut-off of 80 lymphocytes per high power field, 59 % were classified to CD8 highly infiltrated tumors and 41 % were CD8 non highly infiltrated tumors, respectively. An ElasticNet classifier discriminated between these two groups of CD8-T cells with an AUC of 0.68 (95 % CI, 0.55-0.80). In addition, based on tumor proportion score with a cut-off of > 1 % tumor cells expressing PD-L1, 76 % were PD-L1 positive and 24 % were PD-L1 negative. An Adaboost classifier discriminated between PD-L1 positive and PD-L1 negative tumors with an AUC of 0.8 95 % CI: (0.66, 0.95). 3D radiomics metrics of graylevel co-occurrence matrix (GLCM) and graylevel run-length matrix (GLRLM) metrics drove the performance for CD8-Tcell and PD-L1 classification, respectively.

Conclusions

CT-radiomic signatures can differentiate tumors with high CD8-T cell infiltration with moderate accuracy and positive PD-L1 expression with good accuracy in ccRCC.

Abstract 5186: Higher levels of circulating exhausted T-cells at pre- and post-infusion negatively associated with clinical efficacy in tisagenlecleucel (Tisa-cel) treated relapsed/refractory large B-cell lymphoma (r/r LBCL) patients (pts) in JULIET trial

Background: JULIET, a pivotal phase II trial of Tisa-cel, an anti-CD19 CAR-T cell therapy in pts with r/r LBCL demonstrated durable activity with a manageable safety profile (Schuster et al., 2021). We sequentially characterized peripheral blood T cell functionality by immunophenotyping and correlated with efficacy endpoints.

Methods: Immunophenotypic characterization of both non-CAR-T and CAR-T cells was performed by flow cytometry in 378 blood samples from 111 pts collected at enrollment and within the first month post Tisa-cel infusion. Proportions of T cell subsets were identified by maturation (CCR7/CD45RA/CD45RO) and exhaustion (PD1/LAG3/TIM3) markers and then correlated with durable clinical response (Complete Response (CR) ≥ 6 mo vs. Non-response (NR)/Relapse), PFS and OS.

Results: At enrollment, low T cell levels (&lt;14.5% of PBMCs or &lt;170 cells/uL) observed in 30% (31/105) pts were associated with NR/relapse (27/31) and with significantly shorter PFS and OS, compared to those with higher levels (median (m)PFS: 2.1 vs. 9 mo, p=0.0006; mOS: 6 vs. 28.5 mo, p=0.003). NR/relapse pts had higher levels of exhausted T cell subsets in both CD4 (LAG3+, LAG3+PD1+) and CD8 (PD1+, LAG3+, LAG3+PD1+) cells at enrollment. High levels (&gt;median) of these subsets also had significantly shorter PFS and OS, with LAG+PD1+CD8+ ranked on top (mPFS: 2 vs. 34 mo; mOS: 4.6 mo vs. not reached, both p&lt;0.0001) and remained significant in multivariate Cox models including LDH and Myc status (PFS: HR=3.1 [1.9 - 5.3]; OS: HR=2.8 [1.6 - 4.8]; both p&lt;0.001). Hierarchical clustering showed concordant increase of all non-CAR-T exhausted subsets in NR/relapse pts, separating them from ongoing CRs. The trend continued at day 28 (D28), with almost all exhausted CD4 and CD8 subsets in both non-CAR-T and CAR-T cells being consistently higher in NR/Relapse compared to ongoing CRs. In addition, high levels of exhausted subsets in non-CAR-T cells at D28 were associated with shorter PFS and OS, with the strongest trend in PD1+, LAG3+, LAG3+PD1+ of CD8 and CD4 cells. Survival analyses for CAR-T exhausted subsets were less informative due to small sample size. Of note, several LAG3+ and LAG3+PD1+ subsets of CAR-T and non-CAR-T cells were also higher in NR/relapse at CAR-T peak expansion. In contrast, no obvious differences were observed for T cell memory subsets from both CAR-T and non-CAR-T cells across multiple timepoints.

Conclusions: Decreased circulating T cells at enrollment, and increased circulating exhausted T cells in non-CAR-T (at enrollment and D28) and CAR-T (at D28) compartments, were associated with poor response and survival, suggesting these flow measurements may serve as surrogate for overall T cell function, which is critical for optimal Tisa-cel efficacy and early prognostication in LBCL.

Citation Format: Ulrich Jäger, Xia Han, Davide Germano, David Quinn, Dalia Gaddis, Aisha Masood, Tanya Mulvey, Jennifer Mataraza, Michael R. Bishop, Gilles Salles, Richard Maziarz, Stephen Schuster. Higher levels of circulating exhausted T-cells at pre- and post-infusion negatively associated with clinical efficacy in tisagenlecleucel (Tisa-cel) treated relapsed/refractory large B-cell lymphoma (r/r LBCL) patients (pts) in JULIET trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5186.

Non-Invasive Profiling of Advanced Prostate Cancer via Multi-Parametric Liquid Biopsy and Radiomic Analysis

Integrating liquid biopsies of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) with other minimally invasive measures may yield more comprehensive disease profiles. We evaluated the feasibility of concurrent cellular and molecular analysis of CTCs and cfDNA combined with radiomic analysis of CT scans from patients with metastatic castration-resistant PC (mCRPC). CTCs from 22 patients were enumerated, stained for PC-relevant markers, and clustered based on morphometric and immunofluorescent features using machine learning. DNA from single CTCs, matched cfDNA, and buffy coats was sequenced using a targeted amplicon cancer hotspot panel. Radiomic analysis was performed on bone metastases identified on CT scans from the same patients. CTCs were detected in 77% of patients and clustered reproducibly. cfDNA sequencing had high sensitivity (98.8%) for germline variants compared to WBC. Shared and unique somatic variants in PC-related genes were detected in cfDNA in 45% of patients (MAF > 0.1%) and in CTCs in 92% of patients (MAF > 10%). Radiomic analysis identified a signature that strongly correlated with CTC count and plasma cfDNA level. Integration of cellular, molecular, and radiomic data in a multi-parametric approach is feasible, yielding complementary profiles that may enable more comprehensive non-invasive disease modeling and prediction.

Using group concept mapping software to develop a conceptual framework of left ventricular assist device recipients' experiences

Background

Advanced Heart failure (AHF) carries a high mortality rate. Heart transplantation is one therapeutic option, but low donation rates limits its availability. A left ventricular assist device (LVAD) is an alternative therapy which helps relieve symptoms, while improving prognosis and quality of life. However, lack of donors also means that the LVAD becomes a destination therapy by default.(1) Living with an LVAD requires significant psychological, social and physical adaptation for the recipients' and their families.(2) Patient reported outcome measures (PROMs) are one way of capturing these concerns and ongoing problems. Discussions with a patient and public involvement group found a range of issues not currently captured by available PROMS.

Aim

To develop a conceptual framework which reflects the experiences of LVAD recipients' and evaluate their importance for inclusion in PROMs using a research web platform.

Method

Participants were recruited from a regional transplant centre which covers a wide geographical area in the UK. Ethical approval was obtained and participants were recruited through routine LVAD clinics. Group concept mapping (GCM) is a semi-quantitative mixed methods approach that can be used to capture and quantify recipients' experiences.(3) Groupwisdom concept mapping software was used as the electronic data collection platform.(4) GCM consists of 3 stages: statement generation, thematic statement sorting, and rating statements for importance, relevance and frequency of impact. Multidimensional scaling and hierarchical cluster analysis produces visual representations of recipients' experiences as a points and cluster map, and scoring of statements produces relative importance of items across the clusters.

Results

18 LVAD recipients consented to take part. 101 items and 9 clusters were generated. Clusters represented: Activities; Partner/family dependency; Travel; Mental well-being; LVAD challenges; Equipment and clothing; Physical and cognitive limitations; Restrictions, and LVAD positives. LVAD Positives and LVAD restrictions were rated high for frequency, relevance and importance. Physical and cognitive limitations was rated high for importance and frequency. Equipment was rated high for relevance and frequency, and Challenges was rated high for relevance.

Conclusion

GCM and the online software is a useful tool for developing a conceptual framework and mapping key areas of importance for LVAD recipients, especially, when prioritising important patient reported outcome domains for use in clinical practice, future research and design evolution. Using an electronic platform allowed us to reach participants dispersed over a wide geographical area.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): British Heart FoundationNational Institute for Health Research Cluster Rating Map for Importance

40 Cattle-Related Trauma: A 5 Year Retrospective Review in An Adult Major Trauma Centre

Aim

Bovine injuries are a common and significant cause of trauma, often requiring admission and operative treatment. We review all bovine related injuries over five years, both emergency and GP referrals at an adult major trauma centre in England.

Method

Retrospective evaluation was undertaken using keywords through radiology referrals and hospital admissions speciality databases. Demographics were collected as well as the mechanism and the situation of injury; trauma scores were calculated using: Injury Severity Score (ISS) and Probability of Survival (Ps19).

Results

Sixty-seven patients were identified retrospectively over 5 years, 44 emergency patients (including 23 major traumas) and 23 GP referrals. Combined (Emergency & GP) mean age 52 years old. 67% male. Mean ISS 11. Most common combined mechanism of injury, kicked (n = 23). In emergency patients, trampling injuries were most common. 86% of the trampled patients were major traumas. Indirect injuries mainly involved farm gates (92%). 73% of bull-related injuries were major traumas. In emergency patients’ fractures were the most common primary injury (n = 20), upper limb followed by spine. In GP, soft tissue injuries were the most common. 70% of the emergency referrals required admission and 50% operations. Only one GP referral required an operation. Two patients had a Ps19 score &lt;90. There were two mortalities.

Conclusions

Cattle related injuries are a significant cause of severe morbidity and mortality. They are under-reported. Patterns of injury are similar to high velocity road traffic collisions and bull-related injuries or trampling in particular, should alert the clinician to more significant trauma.

1232 Trust-Wide Assessment of Delirium in Post-Operative Elective Surgery

Aim

Delirium is an acute change in cognition and associated with adverse patient outcomes. The incidence of post-operative delirium after elective non-cardiac surgery is unknown. We aimed to assess the incidence of post-operative delirium in this group and the effect on patient outcomes.

Method

Patients aged 65 and over who underwent elective non-cardiac surgery were identified on post-operative day three. Delirium screening was performed in real time using the validated 4-AT assessment tool. A retrospective review of the patients’ preoperative and perioperative record was conducted to collect demographics and identify risk factors for delirium. Outcome data was collected at 30 days. Patients with a positive delirium score (&gt;4) underwent a more in-depth assessment and managing teams given a delirium management pack.

Results

75 (39 male) consecutive patients were screened over a period of 4 months. Median age 77 years and 18% had frailty assessed as “vulnerable”. The majority of patients (37.3%) underwent thoracic surgery, followed by hepatobiliary (17.3%), gynaecological (17.3%), colorectal (12%), maxillofacial (9.3%) and ENT (4%). 5.3% (4) of patients had a positive 4-AT screen. No patients had a formal delirium screen or diagnosis in the initial 48 hours. The median length of stay for patients with a positive screen was 8.5 days (IQR 7.5-12) compared to 8 days (IQR 5-13) for patients with a negative screen.

Conclusions

Reassuringly, rate of post-operative delirium following elective operations in our Trust are low (5%). Larger numbers of patients are required to assess the impact this has on patient outcomes and identify correlation with risk factors.

Pathophysiology of severe primary graft dysfunction in orthotopic heart transplantation

BACKGROUND

A series of insults on the donor heart result in pathophysiological changes that manifest as primary graft dysfunction (PGD) post-orthotopic heart transplantation. The objectives of this study were: (i) describe the pathophysiology of severe PGD using an established cardiovascular model; and (ii) the evolution of the pathophysiology during recovery from severe PGD.

METHODS

Hemodynamic data from 20 consecutive patients with severe PGD (need for mechanical circulatory support, MCS) at baseline (T0), 6 h (T6) and "recovery" (explant of support), and 20 consecutive patients without severe PGD were used to model the pathophysiology using the cardiovascular model described by Burkhoff and Dickstein.

RESULTS

There was a progressive (from T0 to T6) up- and leftward shift in the diastolic pressure-volume relationship, especially of the right ventricle (RV), resulting in reduced capacitance. RV end-systolic elastance (Ees) was significantly elevated in severe PGD but preload-recruitable stroke work (PRSW) was significantly lower compared to patients without severe PGD. "Recovery" (after liberation from MCS) was associated with improvement in RV Ees, chamber capacitance and PRSW, although they remained significantly lower than patients without severe PGD.

CONCLUSION

Severe PGD of the dominant right heart failure phenotype is characterized by reduced chamber capacitance, increased "stiffness" and impaired contractility. Complete normalization was not required for successful weaning of MCS.

Outcomes of temporary mechanical circulatory support in cardiogenic shock due to end-stage heart failure

Background

There are few reports of mechanical circulatory support (MCS) in patients with cardiogenic shock (CS) due to end-stage heart failure (ESHF). We evaluated our institutional MCS strategy and compared the outcomes of INTERMACS 1 and 2 patients with CS due to ESHF.

Methods

Retrospective analysis of prospectively collected data (November 2014 to July 2019) from a single centre. ESHF was defined by a diagnosis of HF prior to presentation with CS. Other causes of CS (eg: acute myocardial infarction) were excluded. We compared the clinical course, complications and 90-day survival of patients with CS due to ESHF in INTERMACS profile 1 and 2.

Results

We included 60 consecutive patients with CS due to ESHF Differences in baseline characteristics were consistent with the INTERMACS profiles. The duration of MCS was similar between INTERMACS 1 and 2 patients (14 (10–33) vs 15 (7–23) days, p = 0.439). There was no significant difference in the number of patients with complications that required intervention. Compared to INTERMACS 2, INTERMACS 1 patients had more organ dysfunction on support and significant lower 90-day survival (66% vs 34%, p = 0.016).

Conclusion

Our temporary MCS strategy, including earlier intervention in patients with CS due to ESHF at INTERMACS 2 was associated with less organ dysfunction and better 90-day survival compared to INTERMACS 1 patients.

Abstract 5379: Non-invasive profiling of advanced prostate cancer via multi-parametric liquid biopsy and radiomics

Introduction: Biomarkers of treatment response in advanced prostate cancer (PC) are urgently needed. Liquid biopsy profiling and radiomic imaging enable non-invasive, repeatable tumor profiling, and combining these modalities could yield powerful new predictive tools. We tested the feasibility of concurrent, multi-parametric molecular analysis of circulating tumor cells (CTCs) and matched plasma cell-free DNA (cfDNA), combined with radiomic analysis of CT scans from the same patients.

Methods: Under IRB-approved informed consent, blood was collected from 23 patients with metastatic castrate resistant PC (mCRPC). CTCs were enumerated using the RareCyte and CellSearch platforms, and individual single CTCs and white blood cells (WBCs) were retrieved using RareCyte's integrated robotic micropipette. DNA was extracted from single cells (scDNA), as well as from matched cfDNA and buffy coats (bcDNA), then sequenced using Ampliseq HD Pan-cancer panel. Concurrent radiomic analysis was performed on bone metastatic lesions identified on CT scans from the same patients, and manually segmented regions of interest were queried for a variety of texture metrics.

Results: Of 19 patients with both CellSearch and RareCyte enumeration, CTCs were detected in 12 by CellSearch (63%; median: 3/7.5 mL; range 1-343/ 7.5 mL) and in 14 by RareCyte (74%; median: 1/7.5 mL; range 1-363/7.5 mL). Using matched bcDNA as a gold standard, sensitivity and positive predictive value of germline SNP detection were 74% and 93% for scDNA, and 98% and 99% for cfDNA. A total of 48 and 18 somatic alterations were identified across the cohort in CTCs and cfDNA, respectively, including mutations in AR, TP53, CCND3, FGFR1, ALK, and ROS1. Of 14 patients whose single CTCs were recovered by RareCyte, 12 (86%) had detectable somatic mutations in scDNA, and 7 (50%) had detectable somatic mutations in matched cfDNA. While some mutations were concordant between matched scDNA and cfDNA, most were distinct. Radiomic entropy in CT scans was associated with CellSearch CTC-counts (AUC of 0.74) using the FDA-cleared prognostic threshold of &lt;5 vs. ≥5 CTCs/7.5ml.

Conclusion: We successfully piloted an integrated, multi-parametric analysis of matched single CTCs, WBCs, plasma cfDNA, and buffy coats, along with matched radiomic analysis of CT scans in patients with mCRPC. Germline variants were detected more readily in cfDNA, whereas somatic mutations in commonly altered genes were detected more frequently in CTCs. CellSearch CTC count, an FDA cleared prognostic biomarker, correlated with radiomic entropy, the first such association to our knowledge between liquid biopsy and radiographic readouts. The results demonstrate the feasibility of this approach and its potential to generate comprehensive molecular data and new biomarker profiles. Prospective validation in a large PC cohort is underway.

Citation Format: Gareth J. Morrison, Jonathan Buckley, D. Gigi Ostrow, Bino Varghese, Nolan Ericson, Steven Cen, Alexander Cunha, Yi-Tsung Lu, Tad George, Jeffrey Smith, David Quinn, Vinay Duddalwar, Timothy Triche, Amir Goldkorn. Non-invasive profiling of advanced prostate cancer via multi-parametric liquid biopsy and radiomics [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5379.

Abstract CT172: Pharmacodynamic and gene expression profiling of patients treated with BLZ945 + spartalizumab demonstrates on-target peripheral and tumor immune microenvironment modulation

Background: The colony stimulating factor 1 receptor (CSF-1R) signaling pathway promotes tumor progression via the recruitment, differentiation, and survival of immuno-suppressive tumor-associated macrophages (TAMs). Blocking CSF-1R signaling may lead to the depletion of TAMs and increased T-cell activation. BLZ945 is an oral, highly selective and potent kinase inhibitor of CSF-1R, which can cross the blood-brain barrier. By reducing TAMs and promoting a pro-inflammatory microenvironment, BLZ945 may stimulate T-cell responses, thereby sensitizing solid tumors to anti–PD-1 therapy. Methods: BLZ945X2101 is an ongoing Ph I/II study investigating the use of BLZ945 as single agent and in combination with spartalizumab (anti–PD-1) in advanced solid tumors. Eligible pts (aged ≥18 years, ECOG 0–1) with advanced/metastatic solid tumors received BLZ945 (300 mg–1600 mg QD and 600 mg BID) Q1W, 7d on/7d off (150 mg–300 mg QD), or 4d on/10d off (300 mg–1200 mg QD and 600 mg BID); or BLZ945 (150 mg–1400 mg QD, 600 mg–800 mg BID) Q1W or 4d on/10d off (300 mg–1200 mg) plus spartalizumab at a fixed dose of 400 mg IV, Q4W. Baseline and on-treatment tumor samples were collected. Here we report flow cytometric, soluble ligand and gene expression profiling analyses as evidence of on-target pharmacodynamic effects of BLZ945 + spartalizumab in treated patients. Results: In total, paired samples for 61 pts for flow cytometry, samples from 30 pts for CSF-1 plasma and paired samples from 35 pts for RNAseq analysis were analyzed. BLZ945 (+/-spartalizumab) induced increases in plasma CSF-1 and decreased peripheral intermediate and nonclassical monocytes, at all doses and schedules tested. Gene expression profiling by RNAseq in paired biopsies showed downregulation of macrophage associated genes in patients treated with both single-agent BLZ945 and BLZ945 + spartalizumab. In patients treated with the BLZ945 + spartalizumab combination, upregulation of cytokine, chemokine, and HLA genes was observed. Signs of antitumor activity were observed in several tumor types including glioblastoma and head and neck cancer. Conclusions: Flow cytometric, soluble ligand and gene expression profiling demonstrated BLZ945-mediated CSF-1R blockade in the periphery and tumor microenvironment in patients with advanced cancers. Ongoing analyses include identification of transcriptomic signatures associated with response. These data support further clinical development of BLZ945 ± spartalizumab in advanced cancers (NCT02829723).

Citation Format: Jincheng Wu, Chia-Chi Lin, Marta Gil-Martin, Aung Naing, Liqiong Fan, Fang Yang, David Quinn, Pei-Jung Tu, Cornelia Quadt, Jennifer Mataraza. Pharmacodynamic and gene expression profiling of patients treated with BLZ945 + spartalizumab demonstrates on-target peripheral and tumor immune microenvironment modulation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT172.

Cardiac Power Output Index and Severe Primary Graft Dysfunction After Heart Transplantation

OBJECTIVES

To evaluate the value of cardiac power output index (CPOi) in predicting severe primary graft dysfunction (PGD) after heart transplantation (defined as mechanical circulatory support [MCS] and/or mortality <30 days after transplant).

DESIGN

Observational cohort study.

SETTING

A heart transplant center in the United Kingdom.

PARTICIPANTS

Consecutive patients who underwent heart transplantation from January 2014 to December 2019 (n = 160). Twenty patients were excluded, as MCS was instituted immediately after transplant.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic data on return to the intensive care unit (time 0, T0) and at 6 hours (T6) were collected to calculate CPOi at both points in 140 consecutive patients-22 patients developed severe PGD. The CPOi at T0 correlated with donor-recipient predicted heart mass and inversely with inotrope score. Patients who developed severe PGD had significantly lower CPOi at T0 and T6. The areas under the receiver operating characteristic curve for CPOi at T0 and T6 for the development of severe PGD were 0.90 and 0.92, respectively. Adjusting for vasoactive-inotrope score did not improve discrimination. The probability of severe PGD if CPOi at T0 <0.34 W/m² and T6 <0.33 W/m² was 79%, but was only 2% if both CPOi at T0 and T6 were >0.34 W/m² and >0.33 W/m², respectively. After adjusting for baseline differences, CPOi at T6 (odds ratio 0.78; 95% CI 0.67-0.91, p = .001) was significantly associated with severe PGD.

CONCLUSION

Low CPOi at T0 is associated with severe PGD. Serial assessment of CPOi increases the diagnostic probability of severe PGD.

Evaluating Changes in Immune Function and Bone Microenvironment During Radium-223 Treatment of Patients with Castration-Resistant Prostate Cancer

The effects of radium-223 on the immune system and the bone tumor microenvironment are incompletely understood. The authors describe mechanisms by which radium-223 may interact with the immune system, specifically through STAT-3 and impact on tumor and circulating lymphocyte populations. They review mechanisms through which effects of radium-223 and androgen-targeted therapy on bone microenvironment could be better elucidated. These knowledge gaps currently limit development of optimal combination therapy approaches for radium-223. Tissue based studies are currently underway in a prospective clinical trial to enhance therapeutic perspective on radium-223 treatment in the prostate cancer landscape.

Cancer transcriptomic profiling from rapidly enriched circulating tumor cells

Transcriptomic profiling of metastatic cancer can illuminate mechanisms of progression and lead to new therapies, but standard biopsy is invasive and reflects only a single metastatic site. In contrast, circulating tumor cell (CTC) profiling is noninvasive and repeatable, reflecting the dynamic and systemic nature of advanced disease. To date, transcriptomic profiling of CTCs has not delivered on its full potential, because white blood cells (WBCs) vastly outnumber CTCs. Current profiling strategies either lack cancer sensitivity and specificity or require specialized CTC capture protocols that are not readily scalable to large patient cohorts. Here, we describe a new strategy for rapid CTC enrichment and transcriptomic profiling using commercially available WBC depletion, microfluidic enrichment and RNA sequencing. When applied to blood samples from patients with advanced prostate cancer (PC), transcriptomes from enriched samples cluster with cancer positive controls and previously undetectable prostate-specific transcripts become readily measurable. Gene set enrichment analysis reveals multiple significantly enriched signaling pathways associated with PC, as well as novel pathways that merit further study. This accessible and scalable approach yields cancer-specific transcriptomic data and can be applied repeatedly and noninvasively in large cancer patient cohorts to discover new therapeutic targets in advanced disease.

Protocol for a multi-centre, definitive randomised controlled trial of the effectiveness of Individual Placement and Support for employment support among people with alcohol and drug dependence

BACKGROUND

Unemployment is highly prevalent in populations with alcohol and drug dependence and the employment support offered in addiction-treatment programmes is ineffective. Individual Placement and Support (IPS) is an evidence-based intervention for competitive employment. IPS has been extensively studied in severe mental illness and physical disabilities, but there have been no formal randomised controlled trials (RCTs) in alcohol and drug dependence. The Individual Placement and Support for Alcohol and Drug Dependence (IPS-AD) study should determine whether IPS for patients with alcohol use disorder (AUD), opioid use disorder (OUD) and other drug use disorder is effective.

DESIGN/METHODS

The IPS-AD study is a seven-site, pragmatic, two-arm, parallel-group, superiority RCT. IPS-AD includes a realist process evaluation. Eligible patients (adult, unemployed or economically inactive for at least 6 months and wishing to obtain open job market employment and enrolled in ongoing community treatment-as-usual (TAU; the control condition) in England for AUD, OUD and other drug use disorders) will be randomised (1:1) to receive TAU and any standard employment support, or TAU plus IPS (the experimental condition) for 9 months with up to 4 months of in-work support. The primary outcome measure will be competitive employment status (at least 1 day (7 h)) during an 18-month follow-up, determined by patient-level, trial-data-linkage with national tax and state benefit databases. From meta-analysis, an 18% target difference on this measure of vocational effectiveness (for the experimental intervention) and a two-sided 5% level of statistical significance, will require a minimum target sample of 832 participants to achieve 90% power for a pre-registered, mixed-effects, multi-variable logistic regression model. A maximum-likelihood multiple-imputation approach will manage missing outcome data. IPS-AD has six vocational secondary outcome measures during the 18-month follow-up: (1) total time in competitive employment (and corresponding National Insurance contributions and tax paid); (2) time from randomisation to first competitive employment; (3) number of competitive job appointments; (4) job tenure (length of longest held competitive employment); (5) sustained employment (tenure in a single appointment for at least 13 weeks); and (6) job search self-efficacy. A primary cost-benefit analysis and a secondary cost-effectiveness analysis will be done using the primary outcome and secondary vocational outcomes, respectively and will include addiction treatment and social and health outcomes and their associated reference costs. The process evaluation will address IPS implementation and delivery.

DISCUSSION

The IPS-AD study is the first large-scale, multi-site, definitive, superiority RCT of IPS for people with alcohol and drug dependence. Findings from the study will have substantial implications for service delivery.

TRIAL REGISTRATION

ISRCTN Registry, ID: ISRCTN24159790. Registered on 1 February 2018.

Programmed Death 1 and Programmed Death Ligand 1 Inhibitors in Advanced and Recurrent Urothelial Carcinoma: Meta-analysis of Single-Agent Studies

We performed a systematic review and meta-analysis on the response rates of patients with treatment-refractory urothelial carcinoma treated with programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) inhibitors. We reviewed the literature for prospective studies evaluating PD-1/PD-L1 inhibitors in refractory urothelial carcinoma patients, which formed the basis for US Food and Drug Administration approval of 5 different antagonistic antibodies targeting PD-1 or PD-L1 (atezolizumab, durvalumab, avelumab, nivolumab, and pembrolizumab). We considered studies examining PD-1/PD-L1-treated patients, which we identified using the following key terms in the Pubmed, Scopus, Web of Science, ClinicalTrial.gov, and Cochrane Library databases. Eligible studies had ≥ 20 patients each and reported response rates, duration of response, and overall survival (OS). We performed fixed and random-effects meta-analyses to model the point estimates for objective response rate and complete response. The median progression-free survival (PFS) and OS for studies reporting these statistics were evaluated. We found 10 eligible studies that met our inclusion criteria, providing extractable numerators and denominators for response rates, PFS, and OS for 1934 patients with metastatic urothelial carcinoma. The objective response rate was 18% (95% confidence interval, 15-22) for second-line or later therapies. The random-effects estimate for complete response was 4% (95% confidence interval, 3-5), including all disease locations and all PD-1 and PD-L1 inhibitors. Median OS and PFS were < 13 months and 3 months, respectively, across all studies, irrespective of PD-L1 expression. We found that the estimated response rates of agents included in this meta-analysis seem to be more favorable than other salvage therapies.

Impact of FDG PET Imaging for Expanding Patient Eligibility and Measuring Treatment Response in a Genome-Driven Basket Trial of the Pan-HER Kinase Inhibitor, Neratinib

PURPOSE

To determine whether FDG PET can expand eligibility in biomarker-selected clinical trials by providing a means to quantitate response in patients with non-assessable disease by RECIST.

EXPERIMENTAL DESIGN

SUMMIT (NCT01953926) is a multicenter phase II "basket" trial of the Pan-HER kinase inhibitor, neratinib. Patients had advanced ERBB2 (HER2)-mutant solid tumors, ≥1 measurable lesion, preferably defined unidimensionally by RECIST v1.1, or alternatively metabolically by PET Response Criteria (PRC). The primary aim was to determine the proportion of additional breast cancer patients accrued using PRC who would have otherwise been ineligible based on RECIST criteria alone. The secondary aim was to determine the concordance of response versus non-response between RECIST and PRC.

RESULTS

Eighty-one patients with HER2-mutant metastatic breast cancer were accrued; 77 were evaluable for response by RECIST and/or PRC. 63 (82%) were RECIST-evaluable and 14 (18%) were accrued using PRC alone. Bone-only disease (n = 11; 79%) was the most common reason for classification as non-measurable by RECIST. Twenty-nine patients were accrued and followed using both criteria, of which 25 (86%; 95% confidence interval, 68%-96%) were concordant for response versus non-response as defined by RECIST and PRC.

CONCLUSIONS

PRC allowed patients with non-RECIST measurable disease access to therapy and facilitated more rapid accrual of patients to this trial of a rare biomarker. PRC and RECIST both provided methods of response assessment and were generally concordant. Thus, PRC was useful as a supplement to RECIST criteria. This provides a rationale for including FDG PET measurements in future clinical trials involving rare tumors or rare genomically defined subpopulations of more common cancers.

Measuring Changes in Electrical Impedance During Cell-Mediated Mineralization

Background: The fundamental electrical properties of bone have been attributed to the organic collagen and the inorganic mineral component; however, contributions of individual components within bone tissue toward the measured electrical properties are not known. In our study, we investigated the electrical properties of cell-mediated mineral deposition process and compared our results with cell-free mineralization. Materials and Methods: Saos-2 cells encapsulated within gelatin methacrylate (GelMA) hydrogels were chemically stimulated in osteogenic medium for a period of 4 weeks. The morphology, composition, and mechanical properties of the mineralized constructs were characterized using bright-field imaging, scanning electron microscopy (SEM) energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy (FITR), nuclear magnetic resonance spectroscopy (NMR), micro-CT, immunostaining, and mechanical compression tests. In parallel, a custom-made device was used to measure the electrical impedance of mineralized constructs. All results were compared with cell-free GelMA hydrogels mineralized through the simulated body fluid approach. Results: Results demonstrate a decrease in the electrical impedance of deposited mineral in both cell-mineralized and cell-free mineralized samples. Conclusions: This study establishes a model system to investigate in vivo and in vitro mineralization processes.

Multiparametric liquid biopsy analysis in metastatic prostate cancer

Molecular profiling of prostate cancer with liquid biopsies, such as circulating tumor cells (CTCs) and cell-free nucleic acid analysis, yields informative yet distinct data sets. Additional insights may be gained by simultaneously interrogating multiple liquid biopsy components to construct a more comprehensive molecular disease profile. We conducted an initial proof-of-principle study aimed at piloting this multiparametric approach. Peripheral blood samples from men with metastatic castrate-resistant prostate cancer were analyzed simultaneously for CTC enumeration, single-cell copy number variations, CTC DNA and matched cell-free DNA mutations, and plasma cell-free RNA levels of androgen receptor (AR) and AR splice variant (ARV7). In addition, liquid biopsies were compared with matched tumor profiles when available, and a second liquid biopsy was drawn and analyzed at disease progression in a subset of patients. In this manner, multiparametric liquid biopsy profiles were successfully generated for each patient and time point, demonstrating the feasibility of this approach and highlighting shared as well as unique cancer-relevant alterations. With further refinement and validation in large cohorts, multiparametric liquid biopsies can optimally integrate disparate but clinically informative data sets and maximize their utility for molecularly directed, real-time patient management.

Differential growth and shape formation in plant organs

Morphogenesis is a phenomenon by which a wide variety of functional organs are formed in biological systems. In plants, morphogenesis is primarily driven by differential growth of tissues. Much effort has been devoted to identifying the role of genetic and biomolecular pathways in regulating cell division and cell expansion and in influencing shape formation in plant organs. However, general principles dictating how differential growth controls the formation of complex 3D shapes in plant leaves and flower petals remain largely unknown. Through quantitative measurements on live plant organs and detailed finite-element simulations, we show how the morphology of a growing leaf is determined by both the maximum value and the spatial distribution of growth strain. With this understanding, we develop a broad scientific framework for a morphological phase diagram that is capable of rationalizing four configurations commonly found in plant organs: twisting, helical twisting, saddle bending, and edge waving. We demonstrate the robustness of these findings and analyses by recourse to synthetic reproduction of all four configurations using controlled polymerization of a hydrogel. Our study points to potential approaches to innovative geometrical design and actuation in such applications as building architecture, soft robotics and flexible electronics.

Smoke-Free Multi-unit Housing Policies Show Promise in Reducing Secondhand Smoke Exposure Among Racially and Ethnically Diverse, Low-Income Seniors

Secondhand smoke (SHS) exposure is a public health issue for residents of multi-unit housing (MUH) properties. We evaluated the impact of smoke-free policy implementation on reported SHS exposure among racially, ethnically diverse seniors living in low-income MUH properties. In Spring 2013 and Summer 2014, we surveyed residents (n = 960) at 15 MUH properties in Broward and Miami-Dade Counties, Florida. The percentage of residents reporting SHS exposure within their apartments from elsewhere in or around their building decreased from 31.1 %, before policy implementation, to 23.6 % at follow-up (p = 0.02). In multivariate analysis of non-smoking residents after policy implementation, residents who reported having one or more comorbidities were two times more likely to report SHS exposure (aOR 2.23, 95 % CI 1.12-4.40). Considering the vulnerability of low-income seniors to SHS exposure, our findings are relevant to residents, property owners/managers, and public health professionals making decisions about smoke-free policies for MUH properties in which seniors reside.

Low-dimensional dynamical characterization of human performance of cancer patients using motion data

BACKGROUND

Biomechanical characterization of human performance with respect to fatigue and fitness is relevant in many settings, however is usually limited to either fully qualitative assessments or invasive methods which require a significant experimental setup consisting of numerous sensors, force plates, and motion detectors. Qualitative assessments are difficult to standardize due to their intrinsic subjective nature, on the other hand, invasive methods provide reliable metrics but are not feasible for large scale applications.

METHODS

Presented here is a dynamical toolset for detecting performance groups using a non-invasive system based on the Microsoft Kinect motion capture sensor, and a case study of 37 cancer patients performing two clinically monitored tasks before and after therapy regimens. Dynamical features are extracted from the motion time series data and evaluated based on their ability to i) cluster patients into coherent fitness groups using unsupervised learning algorithms and to ii) predict Eastern Cooperative Oncology Group performance status via supervised learning.

FINDINGS

The unsupervised patient clustering is comparable to clustering based on physician assigned Eastern Cooperative Oncology Group status in that they both have similar concordance with change in weight before and after therapy as well as unexpected hospitalizations throughout the study. The extracted dynamical features can predict physician, coordinator, and patient Eastern Cooperative Oncology Group status with an accuracy of approximately 80%.

INTERPRETATION

The non-invasive Microsoft Kinect sensor and the proposed dynamical toolset comprised of data preprocessing, feature extraction, dimensionality reduction, and machine learning offers a low-cost and general method for performance segregation and can complement existing qualitative clinical assessments.

A universal standard for the validation of blood pressure measuring devices: Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Collaboration Statement

: In the last 30 years, several organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on Blood Pressure (BP) Monitoring and the International Organization for Standardization (ISO) have developed protocols for clinical validation of BP measuring devices. However, it is recognized that science, as well as patients, consumers and manufacturers would be best served if all BP measuring devices were assessed for accuracy according to an agreed single validation protocol that had global acceptance. Therefore, an international initiative was taken by AAMI, ESH and ISO experts who agreed to develop a universal standard for device validation. This statement presents the key aspects of a validation procedure, which were agreed by the AAMI, ESH and ISO representatives as the basis for a single universal validation protocol. As soon as the AAMI/ESH/ISO standard is fully developed, this will be regarded as the single universal standard and will replace all other previous standards/protocols.

CT-based texture characterization of lymphadenopathy in urothelial carcinoma: Prediction of treatment response

514

Background: Promising treatments are emerging for urothelial carcinoma, although there is no reliable method for predicting treatment response on an individual basis. Extraction of quantitative tumor-texture features from clinical radiologic images may distinguish between cancers which may be more responsive to treatment. Our purpose is to analyze CT-based textural features of urothelial cancer lymph node metastases prior to treatment and classify them to categories for response. Methods: In this IRB approved retrospective study, 36 patients with a proven diagnosis of urothelial cancer who were scheduled to have chemotherapy (Eribulin) and had pre- and post-treatment imaging were included. A total of 66 abnormally enlarged lymph nodes (> 1.5 cm short-axis) were identified. Using RECIST 1.1 as treatment standard, lymph nodes were categorized into 3 categories: Complete or partial response (CR, PR), Stable disease (SD), and Progressive disease (PD). Texture analysis was performed using six different textural methods ranging from 1st order statistical methods such as histogram analysis to higher-order methods such as image-frequency analysis. Depending on data normality, ANOVA or Kruskal Wallis test were used to assess signal difference across CR/PR, SD, and PD categories univariately. Classification Tree (CART) was used to explore potential multivariate prediction model. Results: 34 lymph nodes were categorized as CR/PR, 19 categorized as SD, and 13 categorized as PD. Univarate data analysis showed that of the various textural, histogram-based metrics: Correlation, Variance, Standard deviation, Sum/difference of averages, Homogeneity/Dissimilarity have statistically significantly difference across response categories (p<0.05). CART analysis show preliminary evidence of predicting PD with 85% sensitivity but 54% false positive. Conclusions: CT-based textural features can differentiate between urothelial cancers which are more likely to respond to treatment. Validation with larger sample size and inclusion of data from other sites of metastases will aid in the identification of reliable imaging-texture based biomarkers for treatment stratification.

Overall survival and immune responses with sipuleucel-T and enzalutamide: STRIDE study

246

Background: STRIDE (NCT01981122) is the first study comparing concurrent (con) vs sequential (seq) enzalutamide (enz) with sipuleucel-T (sip-T) in patients (pts) with metastatic castration-resistant prostate cancer. Pts were followed until death or for 3 years. Methods: Fifty-two pts were randomized 1:1 to 3 sip-T infusions and enz started 2 wks before (n = 25, con) or 10 wks after (n = 27, seq) sip-T. Enz was continued for 52 wks or until disease progression (DP)/toxicity. Time to clinical outcomes was estimated by Kaplan-Meier analysis. Results: Median age (years): con 66; seq 72 (p = 0.01). Baseline characteristics and laboratory values were similar between arms. K-M estimated median follow up: 40.2 months. Clinical trial information: NCT01981122. Conclusions: Long-term follow-up suggests sip-T+enz is well-tolerated with no new safety concerns. Though not powered for such, con vs seq rx did not result in differences in OS or DP; differences in PSA responses cannot be excluded. Larger studies could better evaluate the clinical impact of combining immunotherapy with hormonal agents.[Table: see text]

A Universal Standard for the Validation of Blood Pressure Measuring Devices: Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Collaboration Statement

In the past 30 years, several organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on Blood Pressure (BP) Monitoring, and the International Organization for Standardization (ISO), have developed protocols for clinical validation of BP measuring devices. However, it is recognized that science, as well as patients, consumers, and manufacturers, would be best served if all BP measuring devices were assessed for accuracy according to an agreed single validation protocol that had global acceptance. Therefore, an international initiative was taken by the AAMI, ESH, and ISO experts who agreed to develop a universal standard for device validation. This statement presents the key aspects of a validation procedure, which were agreed by the AAMI, ESH, and ISO representatives as the basis for a single universal validation protocol. As soon as the AAMI/ESH/ISO standard is fully developed, this will be regarded as the single universal standard and will replace all other previous standards/protocols.

Robotic salvage retroperitoneal and pelvic lymph node dissection for 'node-only' recurrent prostate cancer: technique and initial series

OBJECTIVES

To describe the technique of robot-assisted high-extended salvage retroperitoneal and pelvic lymphadenectomy (sRPLND+PLND) for 'node-only' recurrent prostate cancer.

PATIENTS AND METHODS

In all, 10 patients underwent robot-assisted sRPLND+PLND (09/2015-03/2016) for 'node-only' recurrent prostate cancer, as identified by 11 C-acetate positron emission tomography/computed tomography imaging. Our anatomical template extends from bilateral renal artery/vein cranially up to Cloquet's node caudally, completely excising lymphatic-fatty tissue from aorto-caval and iliac vascular trees; RPLND precedes PLND. Meticulous node-mapping assessed nodes at four prospectively assigned anatomical zones.

RESULTS

The median operative time was 4.8 h, estimated blood loss 100 mL and hospital stay 1 day. No patient had an intraoperative complication, open conversion or blood transfusion. Three patients had spontaneously resolving Clavien-Dindo grade II postoperative complications. The mean (range) number of nodes excised per patient was 83 (41-132) and mean (range) number of positive nodes per patient was 23 (0-109). Seven patients (70%) had positive nodes on final pathology. Node-positive rates per anatomical level I, II, III and IV were 28%, 32%, 33% and 33%, respectively. In patients with positive nodes, the median PSA level had decreased by 83% at the 2-month follow-up.

CONCLUSION

The initial series of robot-assisted sRPLND+PLND is presented, wherein we duplicate open surgery with superior nodal counts and decreased morbidity. Robot-assisted technical details for an anatomical LND template up to the renal vessels are presented. Longer follow-up is necessary to assess oncological outcomes.

Abstract 1717: Orthogonal identification of circulating tumor cells (CTCs) using single cell low pass whole-genome sequencing (WGS) and copy-number alteration (CNA) analysis

Introduction: Presence of circulating tumor cells has prognostic value in multiple malignancies, and molecular analysis of CTCs is currently ongoing in numerous clinical trials. Most CTC enrichment methods rely on standard epithelial and leukocyte markers (CK+CD45-), so recovered cells are assumed to be of epithelial origin but never shown to be bona fide tumor cells. Conversely, atypical cells lacking the characteristic marker profile may not be analyzed, even though they may represent important tumor subpopulations. Here we evaluate a rapid, non-exhaustive, and cost-effective first-pass genomic analysis of individual candidate CTCs. This approach allows efficient upfront CNA-based confirmation that a given cell is of tumor origin, while leaving abundant DNA for deeper subsequent analysis in cells of interest.

Methods: Whole peripheral blood of metastatic prostate cancer patients was enriched for CTCs using the CellSearch® system (Janssen Diagnostics) under an IRB-approved protocol, and 5 samples with &gt;5 CTCs were selected for further study. Next, the DEPArray™ v2 system (Menarini Silicon Biosystems) was used to identify and isolate single CTCs (CK+CD45-DAPI+) and paired white blood cells (WBCs; CK-CD45+DAPI+) from the enriched samples. In addition, cells negative for both cytokeratin and CD45 but with characteristic malignant morphology (large with high nuclear-cytoplasmic ratio) were isolated. Recovered single cells were whole-genome amplified with Ampli1™ WGA and quality controlled by Ampli1 QC. Ampli1 LowPass kit was then used to prepare NGS libraries for absolute CNA profiling by low-pass WGS.

Results: Thirty-three single CTCs (CK+CD45-DAPI+) and 30 WBCs (CK-CD45+DAPI+), as well as 47 putative CTCs with non-conventional phenotype (CK-CD45-DAPI+) were isolated. Single-cell WGA products with high Genome-Integrity Index (QC score ≥3) were prioritized for CNA analysis. Ampli1 LowPass data demonstrated copy number gains/losses confirming tumor origin of the CK+ cells, while WBCs showed a normal profile. In addition, a portion of the cells having non-conventional phenotype also demonstrated copy number alterations consistent with tumor origin.

Discussion: We demonstrate a WGA and low-pass WGS approach on single CTCs sorted from enriched peripheral blood, which offers a dual benefit: i) it allows rapid, non-exhaustive upfront identification of bona fide tumor cells for further study, and ii) it reveals genetic similarities and diversities (vis a vis copy number alteration) across CTCs of classical as well as non-conventional phenotypes, which may better represent clonal diversity. In a clinical setting, this molecular approach may be more effective for reliably identifying and characterizing heterogeneous CTCs, yielding profiles that more accurately reflect disease evolution and inform treatment strategies.

Citation Format: Gareth Morrison, Valeria Sero, Yucheng Xu, Jacek Pinski, Sue Ingles, David Quinn, Claudio Forcato, Genny Buson, Chiu-Ho Webb, Kyle Horvath, Aditi Khurana, Gianni Medoro, Suman Verma, Matthew Moore, Philip Cotter, Nicolò Manaresi, Farideh Bischoff, Amir Goldkorn. Orthogonal identification of circulating tumor cells (CTCs) using single cell low pass whole-genome sequencing (WGS) and copy-number alteration (CNA) analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1717. doi:10.1158/1538-7445.AM2017-1717

Formation and size distribution of self-assembled vesicles

When detergents and phospholipid membranes are dispersed in aqueous solutions, they tend to self-assemble into vesicles of various shapes and sizes by virtue of their hydrophobic and hydrophilic segments. A clearer understanding of such vesiculation processes holds promise for better elucidation of human physiology and disease, and paves the way to improved diagnostics, drug development, and drug delivery. Here we present a detailed analysis of the energetics and thermodynamics of vesiculation by recourse to nonlinear elasticity, taking into account large deformation that may arise during the vesiculation process. The effects of membrane size, spontaneous curvature, and membrane stiffness on vesiculation and vesicle size distribution were investigated, and the critical size for vesicle formation was determined and found to compare favorably with available experimental evidence. Our analysis also showed that the critical membrane size for spontaneous vesiculation was correlated with membrane thickness, and further illustrated how the combined effects of membrane thickness and physical properties influenced the size, shape, and distribution of vesicles. These findings shed light on the formation of physiological extracellular vesicles, such as exosomes. The findings also suggest pathways for manipulating the size, shape, distribution, and physical properties of synthetic vesicles, with potential applications in vesicle physiology, the pathobiology of cancer and other diseases, diagnostics using in vivo liquid biopsy, and drug delivery methods.