Locoregional delivery of IL-13Rα2-targeting CAR-T cells in recurrent high-grade glioma: a phase 1 trial

Chimeric antigen receptor T cell (CAR-T) therapy is an emerging strategy to improve treatment outcomes for recurrent high-grade glioma, a cancer that responds poorly to current therapies. Here we report a completed phase I trial evaluating IL-13Rα2-targeted CAR-T cells in 65 patients with recurrent high-grade glioma, the majority being recurrent glioblastoma (rGBM). Primary objectives were safety and feasibility, maximum tolerated dose/maximum feasible dose and a recommended phase 2 dose plan. Secondary objectives included overall survival, disease response, cytokine dynamics and tumor immune contexture biomarkers. This trial evolved to evaluate three routes of locoregional T cell administration (intratumoral (ICT), intraventricular (ICV) and dual ICT/ICV) and two manufacturing platforms, culminating in arm 5, which utilized dual ICT/ICV delivery and an optimized manufacturing process. Locoregional CAR-T cell administration was feasible and well tolerated, and as there were no dose-limiting toxicities across all arms, a maximum tolerated dose was not determined. Probable treatment-related grade 3+ toxicities were one grade 3 encephalopathy and one grade 3 ataxia. A clinical maximum feasible dose of 200 × 106 CAR-T cells per infusion cycle was achieved for arm 5; however, other arms either did not test or achieve this dose due to manufacturing feasibility. A recommended phase 2 dose will be refined in future studies based on data from this trial. Stable disease or better was achieved in 50% (29/58) of patients, with two partial responses, one complete response and a second complete response after additional CAR-T cycles off protocol. For rGBM, median overall survival for all patients was 7.7 months and for arm 5 was 10.2 months. Central nervous system increases in inflammatory cytokines, including IFNγ, CXCL9 and CXCL10, were associated with CAR-T cell administration and bioactivity. Pretreatment intratumoral CD3 T cell levels were positively associated with survival. These findings demonstrate that locoregional IL-13Rα2-targeted CAR-T therapy is safe with promising clinical activity in a subset of patients. ClinicalTrials.gov Identifier: NCT02208362 .

Protecting workers in the temporary staffing industry

BACKGROUND

Workers hired through temporary staffing companies have a high rate of severe and fatal injuries despite the legally mandated, shared responsibility of the temporary staffing company and the host company to assure safe work.

AIMS

The aim of this study was to elucidate the perspective of temporary staffing personnel on approaches to mitigating injury risk among the workers they hire.

METHODS

Based on a conceptual model representing the interplay between work and health, we conducted a 'brainstorm' of temporary staffing personnel regarding perceived barriers to protecting temporary workers. A content/context analysis used standard qualitative methods, and the findings were triangulated with notes taken during the discussion.

RESULTS

Temporary staffing employers describe loss of control of the working conditions once workers are placed at host/client companies. Further, they describe a contentious relationship between temporary staffing and host companies, where it is difficult to hold host companies to account. Other barriers to providing temporary workers with a safe work environment include the temp companies' lack of knowledge of site-specific hazards, the poor quality of onsite Occupational Safety and Health training, and ignoring Occupational Safety and Health Administration (OSHA) requirements.

CONCLUSIONS

The perspective of temporary staffing companies should be considered to address the lack of cooperation and shifted responsibility described in this study. Policy and practice changes could include requiring contract language, implementing communication about safety, either sharing workers' compensation purchase or removing exclusive remedy protections from hosts, and prescribing safety training, such as an OSHA 10-h programme. Suggested interventions need further study.

RAGE ablation attenuates glioma progression and enhances tumor immune responses by suppressing galectin-3 expression

BACKGROUND

Malignant gliomas consist of heterogeneous cellular components that have adopted multiple overlapping escape mechanisms that overcome both targeted and immune-based therapies. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that is activated by diverse proinflammatory ligands present in the tumor microenvironment. Activation of RAGE by its ligands stimulates multiple signaling pathways that are important in tumor growth and invasion. However, treatment strategies that only target the interaction of RAGE with its ligands are ineffective as cancer therapies due to the abundance and diversity of exogenous RAGE ligands in gliomas.

METHODS

As an alternative approach to RAGE ligand inhibition, we evaluated the genetic ablation of RAGE on the tumorigenicity of 2 syngeneic murine glioma models. RAGE expression was inhibited in the GL261 and K-Luc gliomas by shRNA and CRSPR/Cas9 techniques prior to intracranial implantation. Tumor growth, invasion, and inflammatory responses were examined by histology, survival, Nanostring, and flow cytometry.

RESULTS

Intracellular RAGE ablation abrogated glioma growth and invasion by suppressing AKT and ERK1/2 activities and by downregulating MMP9 expression. Interestingly, RAGE inhibition in both glioma models enhanced tumor inflammatory responses by downregulating the expression of galectin-3 and potentiated immunotherapy responses to immune checkpoint blockade.

CONCLUSIONS

We demonstrated that intracellular RAGE ablation suppresses multiple cellular pathways that are important in glioma progression, invasion, and immune escape. These findings strongly support the development of RAGE ablation as a treatment strategy for malignant gliomas.

Prognostic value of minimal residual disease among patients with classical Hodgkin lymphoma undergoing autologous stem cell transplantation

Improved biomarkers are needed to guide patient selection for autologous stem cell transplantation (ASCT) and post-ASCT maintenance therapies in relapsed/refractory classical Hodgkin lymphoma (cHL). To assess the prognostic value of minimal residual disease (MRD) using immunoglobulin-based high-throughput sequencing (Ig-HTS), we analyzed pre- and post-ASCT peripheral blood and pre-ASCT apheresis stem cell (ASC) samples in 36 cHL patients. A tumor clonotype was detected in only 12 patients (33%). Among these patients, MRD within plasma samples was closely associated with impending relapse. All patients (n = 3) with detectable MRD in any post-ASCT plasma sample relapsed (100% specificity), and MRD was not detected in any patients in remission. MRD testing from cellular specimens (peripheral blood mononuclear cell or ASC samples) was not associated with relapse. In this small cohort, plasma-based MRD testing appeared to be a promising biomarker in cHL, but given low clonotype detection rates with Ig-HTS, alternative MRD approaches should be investigated.

NIMG-85. RADIOMIC FEATURES PREDICTIVE OF RESPONSE IN HGG-TARGETING CAR-T THERAPY

SIGNIFICANCE

Radiomics may improve precision medicine in CAR-T (Chimeric Antigen Receptor T Cell) therapy patient selection.

BACKGROUND

High-Grade Glioma (HGG) is a heterogenous primary CNS neoplasm with a high recurrence rate and poor outcomes. Many studies are exploring CAR T cells to combat HGG. Radiomic models have shown value in identifying biomarkers predictive of tumor genetics, response, and patient prognosis. In this study, we explore radiomic features derived from four clinical sequences and volumes of edema and enhancing tumor to predict treatment response to the first three doses of CAR-T therapy.

METHODS

In this IRB-approved phase 1 clinical trial (IRB 13384), patients underwent surgical resection of the tumor and received CAR-T cell therapy. Of the 82 patients accrued, 59 (20 females, median age = 49) completed three cycles of therapy and had 3T field strength MRI scans with minimal imaging artifacts. T1 weighted pre-contrast, T1 weighted post-contrast, T2 weighted, and T2 FLuid Attenuated Inversion Recovery sequences were used to generate 3D and 2D radiomics features. In total 28,541 radiomic features were generated per patient using the images prior to CAR-T administration. Each patient’s response to treatment after three cycles was determined to be either stable disease (29 patients) or progression. The radiomic feature set dimensionality was reduced using Maximum Relevance Minimum Redundancy. 10-fold cross-validation XGBoost was used to determine radiomic features predictive of treatment response with a randomized grid search for hyperparameter tuning.

RESULTS

Six radiomic features (four shape-based), had high SHapley Additive exPlanations (SHAP)-based importance feature predictive of RANO response with an AUC >0.73.

CONCLUSION

Despite the limited study size, such imaging-based radiomic models can serve as a potential basis for optimizing clinical trial design through more precise patient screening and providing potential predictive imaging biomarkers of whether a patient will respond to CAR-T cell therapy in HGGs.

IMMU-08. RAGE ABLATION ATTENUATES GLIOMA PROGRESSION AND ENHANCES TUMOR IMMUNE RESPONSES BY SUPPRESSING GALECTIN-3 EXPRESSION

INTRODUCTION

Malignant gliomas consist of heterogenous cellular components that have adopted multiple overlapping escape mechanisms that overcome both targeted and immune-based therapies. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that is activated by diverse proinflammatory ligands present in the tumor microenvironment (TME). Activation of RAGE by its ligands stimulates multiple signaling pathways that are important in tumor growth, invasion, and immune escape.

OBJECTIVE

We aimed to demonstrate that blockade of RAGE expression may tackle resistance pathways by inhibiting GBM progression, invasion, and immune evasion.

METHODS

We evaluated genetic ablation of RAGE on the tumorigenicity of two syngeneic murine glioma models. RAGE expression was inhibited in the GL261 and K-Luc gliomas by shRNA and CRSPR/Cas9 techniques prior to intracranial implantation. Tumor growth, invasion, and inflammatory responses were examined by immunohistochemistry, qPCR, ELISA, western blotting, NanoString, flow cytometry, and in vivo survival analysis.

RESULTS

Intracellular RAGE ablation abrogated glioma growth and invasion by suppressing AKT and ERK1/2 activities and by downregulating MMP9 expression. Interestingly, RAGE inhibition also enhanced tumor inflammatory responses by downregulating the expression of galectin-3, rendered the immunotherapy resistant K-Luc gliomas responsive to immune checkpoint blockade therapy, and significantly increased survival.

CONCLUSION

This study is the first to link RAGE expression with galactin-3 as an immune modulator in glioblastoma and revealed that the effect of glioma RAGE expression on TME was mediated through downregulation of Gal-3 and subsequent polarization of Tumor-associated macrophages. The therapeutic significance of RAGE downregulation was demonstrated by sensitizing a highly invasive and immune-resistant glioma model to immune checkpoint blockade and strongly supports the development of RAGE ablation as a complementary treatment strategy for malignant gliomas.

Phase 1 study of PSCA-targeted chimeric antigen receptor (CAR) T cell therapy for metastatic castration-resistant prostate cancer (mCRPC)

91

Background: Chimeric antigen receptor (CAR)-engineered T cell therapies are being pursued for the treatment of mCRPC. Prostate Stem Cell Antigen (PSCA) is highly expressed on the surface membrane in mCRPC and with limited expression on normal tissues. We undertook a phase 1, first-in-human study of a PSCA-targeted 4-1BB-co-stimulated CAR T cell therapy in mCRPC. Methods: CAR T cells were manufactured at City of Hope’s cGMP facility. The trial followed the Target equivalence range design with an equivalence range of.20-.35 and too toxic level of 0.51 following participants in cohorts of 3. The plan was to begin at a dose of 100 million (M) without lymphodepletion (LD) chemotherapy consisting of fludarabine and cyclophosphamide, then add LD to 100M prior to dose escalation to maximum 600M. Patients (pts) were required to have disease progression after at least 1 androgen receptor targeted therapy but there was no limit on prior chemotherapy or other treatments. Primary objective is to define the dose limiting toxicity (DLT) and recommended phase 2 dose as well as to describe preliminary bioactivity and efficacy. Correlative studies include MRI for target bone lesion response, CAR T cell persistence, circulating tumor cells, and serum cytokines. Results: 12 pts have been treated to date, median age 68 (42-72). Three pts were treated at the 100M dose with no DLTs. In the 100M plus LD dose level there 2 pts experienced DLT of grade 3 cystitis non-infective and fatigue. The protocol was amended to reduce the LD dose to 300 mg/m2 cyclophosphamide D1-3 and intensify monitoring with early intervention for cystitis. No DLT occurred in 3 pts treated in the modified LD 100M cohort. Cytokine release syndrome (CRS), DLTs and best response by RECIST are presented by dose level in the table. PSA declines (one >90%) were seen as well as radiographic improvement, though RECIST response was limited to stable disease (SD) by concurrent bone metastases. Correlative studies indicated bioactivity of PSCA-CAR T cells. Conclusions: PSCA-CAR T cell therapy is feasible in pts with mCRPC with DLT of cystitis, and shows preliminary anti-tumor effect at a dose of 100M plus LD. Dose escalation to 300M may proceed. Clinical trial information: NCT03873805. [Table: see text]

Core needle biopsy causing a pseudoaneurysm in the breast

Core needle biopsy (CNB) is the first-choice method of sampling suspicious, focal breast lesions for histological analysis. Here we present the case of a 65-year-old woman who was recalled for evaluation of the left breast following a screening mammogram. An ultrasound-guided biopsy was performed using a disposable core biopsy needle and 3 weeks later a magnetic resonance imaging scan showed a distended vessel with adjacent sac measuring 17 × 15mm². A Doppler ultrasound scan confirmed pseudoaneurysm. A review of the literature was made on breast pseudoaneurysm following CNB, and over the past 20 years there were few other reports. Pseudoaneurysms in the breast are a rare but serious complication of CNBs. They may spontaneously thrombose, but often require intervention, so it is essential that clinicians are aware of the risk.

Current update on vaginal malignancies

Primary vaginal cancers are rare and account for 1-3% of all gynecologic malignancies. There are several histological subtypes that affect a wide range of the population. Imaging plays an important role in the diagnosis, staging, and treatment planning of vaginal cancers. This article reviews the relevant anatomy, clinical findings, imaging characteristics, and recent advances in the management of vaginal malignancies.

1136 Cochlear Implant Outcomes in Patients with Otosclerosis: A Systematic Review

Introduction

In otosclerosis, spongiotic bone replaces normal bone in the ossicular chain. Focal deposits may also be found within the cochlea leading to sensorineural hearing loss refractory to conventional treatment. Cochlear implantation can play an important role in the management of otosclerosis in these patients. Our study objective is to establish hearing outcomes following cochlear implantation in patients with otosclerosis.

Method

Systematic review and narrative synthesis. Databases searched: Medline, PubMed, Embase, Web of Science, Cochrane Collection and ClinicalTrials.gov. No limits placed on language or year of publication. Review conducted in accordance with the PRISMA statement.

Results

Searches identified 68 studies meeting the inclusion criteria and reporting outcomes in a minimum of 481 patients with at least 516 implants. The methodological quality of included studies was modest, predominantly consisting of case reports and non-controlled case series with small numbers of patients. Significant heterogeneity existed in terms of outcomes and methods of reporting, which precluded a meta-analysis. Access to good rehabilitation support is essential to achieving the good hearing outcomes and Patient Reported Outcome Measures that can be expected by 12 months post-implantation in most cases. There was significant association between the radiological severity of otosclerosis and an increase in surgical and post-operative complications. Post-operative facial nerve stimulation can occur and may require deactivation of electrodes and subsequent hearing detriment.

Conclusions

Hearing outcomes are typically good, but patients should be counselled on associated surgical complications which may compromise hearing. Modern diagnostic techniques may help to identify potentially difficult cases to aid operative planning and patient counselling.

A phase 1 study to evaluate chimeric antigen receptor (CAR) T cells incorporating a chlorotoxin tumor-targeting domain for patients with MMP2+ Recurrent or progressive glioblastoma (NCT04214392)

TPS2662

Background: Glioblastoma (GBM) is the most common and most aggressive primary brain tumor. Around 294,900 new cases are diagnosed globally with 241,000 deaths each year. The 5-year survival is only 5%. Median overall survival from first recurrence is only 5-8 months. There is no established standard of care for recurrent GBM. City of Hope (COH) has developed and optimized a CAR T cell therapy utilizing the chlorotoxin peptide (CLTX) as the CAR’s tumor recognition domain against GBM. CLTX-CAR T cells specifically and broadly target GBM through recognition of a receptor complex including membrane-bound matrix metalloprotease 2 (MMP-2). CLTX-CAR T cells do not exhibit off-tumor recognition of normal human or murine cells and tissues in preclinical models. In in vitro studies, COH evaluated patient-derived brain tumor (PBT) cell lines for CLTX binding and expression of IL13Rα2, HER2 and EGFR, three targets of CAR T cell trials for GBMs. Strong CLTX binding to tumor cells was observed in of the majority of primary GBM lines, independent of these other antigens. In preclinical studies using in vivo mouse models, a single intratumoral (ICT) injection of CLTX-CAR T cells (1×106 CAR+ T cells) exhibited robust anti-tumor activity against ffLuc+ PBT106 tumors orthotopically-engrafted in NSG mice. Overall, when compared to mice treated with mock-transduced Tn/mem (no CAR) T cells, the CLTX(EQ)28ζ/CD19t+ T cells reduced tumor burden and significantly increased survival. Taken together, these preclinical findings support the potential safety and efficacy of CLTX-CAR T cells, and provide the rationale for clinical testing of this therapy. As cellular heterogeneity intrinsic to GBM likely contributes to resistance to therapy and limited response rates, CLTX-CAR T cells may provide greater tumor eradication in a higher proportion of patients with GBM. Methods: This study is a phase 1, single center, safety and maximum tolerated dose (MTD) finding study of CLTX-CAR T cells for subjects with MMP2+ recurrent or progressive GBM. A safety lead-in of 3−6 participants receiving CLTX-CAR T cells by ICT delivery will be completed first. Subsequently, subjects would receive cells administered through both ICT and intraventricular (ICV catheters) (i.e. dual delivery) in two dose schedules. Subjects will be evaluated for safety and tolerability, and may continue to receive treatment until disease progression. Time to progression, overall survival, and disease response by Response Assessment in Neuro-Oncology (RANO) criteria, will be evaluated and descriptively compared to historical data. The study is actively enrolling patients. Clinical trial information: NCT04214392.

Explainable prediction of survival using clinical, molecular, and radiomic profiles in recurrent high-grade glioma patients treated with CAR T-cell therapy

104

Background: High-grade glioma (HGG) is an aggressive heterogeneous primary CNS neoplasm with high recurrence rate and poor survival. Multiple ongoing clinical trials are leveraging targeted molecular and immunologic therapeutics (e.g., pembrolizumab, Chimeric Antigen Receptor [CAR] T-cell therapy) in effort to improve survival. Explainable predictive models have shown value in identifying biomarkers predictive of treatment response as well as informing prognosis. In this study, we developed an explainable machine learning model leveraging clinical, molecular and radiomic (imaging) features to predict overall survival in patients suffering from HGG treated with CAR T-cell therapy. Methods: In this IRB-approved phase 1 clinical trial, 60 patients (39 males, median age = 49) suffering from HGG underwent surgical resection and CAR T-cell therapy1. All patients underwent baseline MRI scans prior to both surgical resection and CAR T-cell administration in the resection cavity. Using contrast-enhanced T1-weighted MRIs, we segmented the enhancing tumor (ET) and generated radiomic features. For predictive modeling, we incorporated the following features: Age, gender, race, ethnicity, histology, tumor grade (WHO), IL-13 receptor alpha 2 (IL-13Rα2) expression (H score), unifocal or multifocal lesions, tumor location (lobe), shape-based radiomics (tumor volume, surface area, and sphericity). We utilized gradient-boosted tree models to classify whether survival is above or below 180 days with two-loop nested cross-validation. For the inner validation loop, we optimized the model with hyper-parameter tuning. For the outer validation loop, we tested the optimal model on the hold-out data and the predictions were used as survival scores (0 – 1). Larger scores imply better predicted survival. For prediction explanations, we adopted the Shapley additive explanation (SHAP) framework. Results: The outer validation loop Area Under the Receiver Operating Characteristic Curve and Area under the Precision-Recall Curve were 0.76 and 0.81, respectively. Among the top five most important features calculated from SHAP; patients with larger tumor surface area, tumor volume and age have reduced survival scores while patients with larger IL-13Rα2 and tumor sphericity have increased survival scores. We stratified the patients into two distinct prognostic sub-groups (30 patients each group) using the survival scores obtained from the outer loop, with a log-rank test p < 0.01. Conclusions: In patients with HGG treated with CAR T-cell therapy, we found that tumor surface area/volume and age are inversely related to survival while increased IL-13Rα2 expression and tumor sphericity were positive predictor of survival. Our model can potentially be used to optimize clinical trial enrollment through more precise patient screening and treatment planning.

Radiomic features of renal cell carcinoma primary and metastatic sites as predictors of TERT and BAP1 mutations

282

Background: TERT and BAP1 mutations are associated with poor clinical outcome in patients (pts) with metastatic renal cell carcinoma (mRCC) (Dizman et al JITC 2020; Joseph et al J Urol 2016). In this study we explore radiogenomics as a non-invasive method to identify these alterations. Methods: Pts with mRCC who had genomic testing in the course of routine clinical care were included in the current analysis. Pts were assessed with the GEM Extra assay, a CAP-accredited, CLIA-certified test encompassing paired tumor-normal whole exome sequencing (WES) and tumor whole transcriptome sequencing (TGen; Phoenix, AZ). Pts underwent CT imaging; radiomic analysis was performed on the segmented metastatic and primary lesions. Features were independently correlated with TERT and BAP1 mutation status to generate Pearson correlation values (PCVs). Results: 92 pts (65:27 M: F) were included in the analysis; of these, the majority of pts (84%) had clear cell histology. Alterations in the TERT gene were seen in 12 pts. In these pts 1,325 radiomic features of the primary tissue were examined and 251 features correlated with a PCV ≥ |0.2|. Of these, 42 features were correlated with a PCV ≥ |0.3|. Highest correlation with TERT mutation was seen with Gray Level Cooccurrence Matrix (GLCM) and First Order Features (FOF). 9 pts had BAP1 mutation with 5 detected in primary tumor and 4 in metastatic sites. Analysis of primary tumor imaging yielded no significant associations between radiomic features and BAP1 mutation. However, out of approximately 1,500 radiomic features noted in metastatic sites, 111 features correlated with BAP1 mutation with a PCV ≥ 0.2. Of these, 15 features correlated with a PCV ≥ 0.3. The radiomic features with the highest correlation with BAP1mt were Gray Level Dependence Matrix (GLDM) and GLCM. Conclusions: By identifying a correlation between radiomic features of TERT mutation in primary tumors and BAP1 mutation in metastatic sites, our work may ultimately yield a non-invasive method of discerning mutational status in patents with mRCC. Efforts are ongoing to validate our findings within The Cancer Imaging Archive.

Role of theranostics in thoracic oncology

Theranostics is a re-emerging field of medicine that aims to create targeted agents that can be used for diagnostic and/or therapeutic indications. In the past, theranostics has been used to treat neoplasms, such as thyroid cancer and neuroblastomas. More recently, theranostics has seen a resurgence with advent of new therapeutic antibodies and small molecules which can be transformed into Theranostic agents through radioconjugating with a radioactive isotope. Positron emitting radioisotopes can be used for diagnostic purposes while alpha- and beta-emitting radioisotopes can be used for therapy. The technique of radiolabeling an existing therapeutic agent (small molecule or antibody) leverages the existing qualities of that drug, and potentiates therapeutic effect by conjugating it with a cytotoxic-energy bearing radioisotope (e.g., 131-iodine, 177-lutetium). Theranostics have been used for a few decades now, starting with 131-iodine for therapy of autoimmune thyroiditis (Graves’ disease, Hashimoto’s thyroiditis) as well as for thyroid cancer. Additionally, 131-iodine-meta-iodobenzylguanidine (131-I-MIBG) initially had been used for gastroenteropancreatic neuroendocrine (carcinoid) tumors. However, recently clinical trials have start enrolling patients to evaluate efficacy of 131-I-MIBG in patients with small cell carcinoma of the lung. In the era of precision medicine and personalized targeted therapeutics, Theranostics can play a key pivotal in improving diagnostic and therapeutic specificity by increasing potency of these targeted small molecules and antibodies with radioisotopes. In this review, we will review various clinically relevant Theranostics agent and their utility in thoracic disorders, notably within oncology.

Thoracic imaging finding of rheumatic diseases

In the era of Precision Medicine, diagnostic imaging plays a key role in initial diagnosis and treatment response assessment in thoracic manifestation of various rheumatic disorders; resulting in increased dependency on imaging for treatment planning. Chest radiographs serve as a good initial screening tool for assessment of emergent and urgent thoracic conditions, e.g., pneumothorax, pulmonary edema, consolidation and pleural effusions. Cross-sectional imaging techniques, e.g., computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) are most commonly utilized to evaluate more detailed pulmonary and mediastinal manifestations of rheumatic conditions. Magnetic resonance imaging (MRI) and ultrasound are most commonly used in cardiovascular, neural and musculoskeletal structures. This review article aims to highly key common thoracic imaging findings of rheumatic disorders, highlighting imaging test of choice for the particular disorder.

Role of cardiac nuclear stress perfusion exam after computed tomographic coronary angiogram for evaluation of obstructive coronary artery disease in patients with chest pain

Background

Clinical workup for chest pain varies among institutions. Acute coronary syndrome (ACS) is the primary diagnosis to rule out in the differential diagnosis, due to its associated mortality and morbidity. Although studies have demonstrated efficacy of coronary computed tomographic angiography (CCTA) in diagnosis obstructive coronary artery disease (CAD), there is limited evidence in the clinical value of performing cardiac nuclear stress perfusion imaging [myocardial perfusion imaging (MPI)] exam in patients with chest pain after undergoing CCTA. We aim to evaluate clinical value of follow-up nuclear cardiac MPI in patients with chest pain who have undergone recent CCTA.

Methods

A total of 1,000 patients were evaluated in this IRB approved retrospective study who presented with symptoms of ACS. Patients who had elevated troponin or abnormal electrocardiogram (ECG) findings at initial presentation or prior to cardiac nuclear MPI were excluded from the study. All patients who underwent 64- or 320-detector row ECG-gated CCTA as well as a follow-up nuclear MPI. Patients who had diagnostics studies limited by artifact [e.g., suboptimal intravenous (IV) contrast bolus in CCTA, motion artifact on CCTA or MPI, etc.] were excluded.

Results

One hundred patients met the inclusion criteria. Patient demographics include average age 64.3 [32–89] years, 59 male, 41 females. Ninety-five/100 patients had at least one vessel with 50–70% coronary artery diameter stenosis measured on CCTA. There were no focal perfusion abnormalities identified on cardiac nuclear MPI in patients with less than 70% stenosis diagnosed on CCTA. Five percent of patients were identified with coronary arterial narrowing greater than 70% on CCTA and all 5 of these patients have evidence of abnormal cardiac nuclear stress test (perfusion abnormalities, chest pain, abnormal ECG).

Conclusions

In low-to-intermediate risk patients with chest pain and evidence of non-critical coronary artery stenosis (i.e., less than 70% stenosis) diagnosed on CCTA, a follow-up cardiac nuclear perfusion imaging is of limited value.

Artificial intelligence-guided image acquisition on patients with implanted electrophysiological devices: results from a pivotal prospective multi-center clinical trial

Background

A novel, recently FDA-authorized software uses deep learning (DL) to provide prescriptive transthoracic echocardiography (TTE) guidance, allowing novices to acquire standard TTE views. The DL model was trained by &gt;5,000,000 observations of the impact of probe motion on image orientation/quality. This study evaluated whether novice-acquired TTE images guided by this software were of diagnostic quality in patients with and without implanted electrophysiological (EP) devices, focusing on RV size and function, which were thought to be sensitive to EP devices. Some aspects of the study have previously been presented.

Methods

240 patients (61±16 years old, 58% male, 33% BMI &gt;30 kg/m2, 91% with cardiac pathology) were recruited. 8 nurses without echo experience each acquired 10 view TTEs in 30 patients guided by the software. 235 of the patients were also scanned by a trained sonographer without assistance from the software. 5 Level 3 echocardiographers independently assessed the diagnostic quality of the TTEs acquired by the nurses and sonographers to evaluate the effect of EP devices on DL software performance.

Results

Nurses using the AI-guided acquisition software acquired TTEs of sufficient quality to make qualitative assessments of right ventricular (RV) size and function in greater than 80% of cases for patients with and without implanted EP devices (Table). There was no significant difference between nurse- and sonographer-acquired scans.

Conclusion

These results indicate that new DL software can guide novices to obtain TTEs that enable qualitative assessment of RV size even in the presence of implanted EP devices. The results of the comparison to sonographer-acquired exams indicate the software performance is robust to presence of pacemaker/ICD leads visible in the images (Figure).

Nurse-acquired TTE with visible ICD lead

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Caption Health, Inc.

Radiogenomics of lung cancer

Machine learning (ML) and artificial intelligence (AI) are aiding in improving sensitivity and specificity of diagnostic imaging. The rapid adoption of these advanced ML algorithms is transforming imaging analysis; taking us from noninvasive detection of pathology to noninvasive precise diagnosis of the pathology by identifying whether detected abnormality is a secondary to infection, inflammation and/or neoplasm. This is led to the emergence of “Radiobiogenomics”; referring to the concept of identifying biologic (genomic, proteomic) alterations in the detected lesion. Radiobiogenomic involves image segmentation, feature extraction, and ML model to predict underlying tumor genotype and clinical outcomes. Lung cancer is the most common cause of cancer related death worldwide. There are several histologic subtypes of lung cancer, e.g., small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) (adenocarcinoma, squamous cell carcinoma). These variable histologic subtypes not only appear different at microscopic level, but these also differ at genetic and transcription level. This intrinsic heterogeneity reveals itself as different morphologic appearances on diagnostic imaging, such as CT, PET/CT and MRI. Traditional evaluation of imaging findings of lung cancer is limited to morphologic characteristics, such as lesion size, margins, density. Radiomics takes image analysis a step further by looking at imaging phenotype with higher order statistics in efforts to quantify intralesional heterogeneity. This heterogeneity, in turn, can be potentially used to extract intralesional genomic and proteomic data. This review aims to highlight novel concepts in ML and AI and their potential applications in identifying radiobiogenomics of lung cancer.

Thyroid cancer diagnosis in the era of precision imaging

Thyroid cancer affects 1.3% of the population with increasing rates of incidence over the last decade (approximately 2% per year). Although the overall prognosis is good in the differentiated subtypes, there has been a slow but steady increase in rate of deaths associated with thyroid cancer (approximately 0.7% per year over the last decade). Thyroid cancer is usually detected when: (I) patients feel a lump in the neck; (II) a routine clinical exam is performed; (III) an incidental thyroid nodule is identified on diagnostic imaging (e.g., CT neck or chest, carotid ultrasound, PET scan acquired for non-thyroid pathology). Identification of suspicious thyroid nodules results in further diagnostic work-up including laboratory assessment, further imaging, and biopsy. Accurate diagnosis is required for clinical staging and optimal patient treatment design. In this review, we aim to discuss utility of various imaging modalities and their role in thyroid cancer diagnosis and management. Additionally, we aim to highlight emerging diagnostic techniques that aim to improve diagnostic specificity and accuracy in thyroid cancer, thus paving way for precision medicine.

Molecular Biomarkers in Multiple Sclerosis and Its Related Disorders: A Critical Review

Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system (CNS) which can lead to severe disability. Several diseases can mimic the clinical manifestations of MS. This can often lead to a prolonged period that involves numerous tests and investigations before a definitive diagnosis is reached. As well as the possibility of misdiagnosis. Molecular biomarkers can play a unique role in this regard. Molecular biomarkers offer a unique view into the CNS disorders. They help us understand the pathophysiology of disease as well as guiding our diagnostic, therapeutic, and prognostic approaches in CNS disorders. This review highlights the most prominent molecular biomarkers found in the literature with respect to MS and its related disorders. Based on numerous recent clinical and experimental studies, we demonstrate that several molecular biomarkers could very well aid us in differentiating MS from its related disorders. The implications of this work will hopefully serve clinicians and researchers alike, who regularly deal with MS and its related disorders.

Abstract 1525: Upregulation of genes linked to epithelial-mesenchymal transition in anaplastic thyroid cancer

Introduction: Epithelial-mesenchymal transition (EMT) plays a major role in invasion, migration, and drug resistance in cancer. There are several signaling pathways associated with EMT, including PI3K/Akt and NFΚB. EMT is present in several cancer types, especially in the recurrent and metastatic setting. Anaplastic thyroid cancer (ATC) accounts for 2% of thyroid cancers and are notoriously aggressive. Clinically, these patients have poor survival rates and are resistant to standard of care therapies. ATC can arise de novo from follicular thyroid cells or in association with papillary thyroid carcinoma (PTC). Therefore, we investigated the differences in gene signature and cancer pathway expression in these histological subtypes, and their potential association with genes upregulated in EMT.

Methods: De novo ATC and mixed ATC/PTC cases (N=12) from 1998 to 2018 with viable formalin-fixed paraffin-embedded (FFPE) tissue were identified and selected. 8 cases exhibited both PTC and ATC components while the rest (N=4) were pure ATC cases, as confirmed by a pathologist. In the 4 mixed ATC/PTC histology group specimen, 3 were identified by a pathologist to contain greater than 80% ATC involvement while the fourth was characterized as 40% ATC and 60% PTC. The NanoString PanCancer Pathway panel, which contains 770 genes from 13 signaling pathways, was performed with the extracted tumor RNA to evaluate and compare the gene signatures of the pure ATC versus mixed ATC/PTC cases.

Results: Majority of patients (N=11, 92%) developed metastatic disease, a common feature of ATC, and are currently deceased (N=10, 83%). Using Nanostring panel on the patient specimen, we identified differential expression of genes and cancer pathways in the mixed ATC/PTC cohort in comparison to the pure ATC cohort. 28 genes, strongly associated with cancer pathways including MAPK, cell cycle-apoptosis, driver genes, and RAS, were significantly upregulated with at least two-fold change in the mixed ATC/PTC histology group in comparison to the pure ATC histology group (p&lt;0.01). Three genes strongly linked with EMT demonstrated increased expression. MMP3 was the most upregulated gene in the mixed ATC/PTC histology group, with a 41.4 linear fold change (p=0.001), and has been shown to induce EMT in various cancers. Two other EMT-related genes, TNF and PIK3CG, were similarly significantly expressed in the mixed ATC/PTC versus the pure ATC histology group (p&lt;0.005).

Conclusion: Our results demonstrate a significant difference in the expression of cancer-related genes between the mixed ATC/PTC and the pure ATC histology groups. Our findings also suggest a correlation between mixed ATC/PTC histology cases and genes associated with EMT.

Citation Format: Rebecca R. Pharaon, Hannah J. Young, Kimberley-Jane C. Bonjoc, Feras Ally, Holly Yin, Robert Kang, Thomas Gernon, Ammar Chaudhry, Ellie Maghami. Upregulation of genes linked to epithelial-mesenchymal transition in anaplastic thyroid cancer [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 1525.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Role of AXL in metastatic melanoma and impact of TP-0903 as a novel therapeutic option for melanoma brain metastasis

e22021

Background: Melanoma brain metastases (MBM) are common with a median overall survival of 4-5 months. Although immunotherapies have improved clinical outcomes and have doubled overall survival in MBM, there is a high incidence rate of relapse caused by drug resistance. AXL, a receptor tyrosine kinase (RTK), is associated with drug resistance and metastasis in many cancers. The activation of AXL via trans-phosphorylation regulates multiple signaling pathways that induce tumor survival, metastasis, drug resistance, and epithelial-to-mesenchymal transition (EMT). In MBM, AXL is upregulated and associated with disease progression, promoting cell invasion and migration. This suggests that targeting AXL can be a novel strategy to overcome treatment-related resistance in MBM. TP-0903, an investigational small molecule inhibitor of AXL, has shown efficacy in reversing the mesenchymal phenotype and re-sensitizing resistant cancer cells to targeted therapies in heme malignancies, pancreatic, and breast cancer. We aim to investigate the efficacy of TP-0903 in MBM. Methods: The Cancer Genome Atlas (TCGA) data was utilized to investigate the signaling pathways downstream of AXL that are upregulated in advanced melanoma. Nine signaling molecules including AKT1, mTOR, and PAK4 were analyzed to identify any correlation between gene expression levels and overall survival. Four metastatic melanoma cell lines were used to evaluate the effect of TP-0903 on cell viability and active AXL downregulation was assessed in vitro through MTS cell viability assays and Immunoblotting. Wound closure assays were executed to understand the functional consequences of AXL downregulation. Results: In all nine genes, high expression levels confer poor survival probability. Cell viability assays of four malignant melanoma cell lines showed that TP-0903 treatment resulted in IC50 values ranging from 32 – 692 nM. Western blot analysis indicated that TP-0903 reduced the levels of phosphorylated AXL in malignant melanoma cell lines. In addition, increasing TP-0903 concentrations reduced the rate of cell migration in these malignant melanoma cell lines. Conclusions: AXL plays a role in EMT, treatment resistance, and metastasis in MBM, resulting in poor survival. Our findings suggest TP-0903 is effective in reducing cell migration, inhibit metastasis, and can be a potential therapeutic option in MBM.

Differential immune pathways in classic and mixed variants of anaplastic thyroid cancer

e18579

Background: Patients with anaplastic thyroid cancer (ATC) have poor outcomes due to treatment resistance with an estimated 5-year survival rate of 7%. Although “classic” ATC can arise de novo from follicular thyroid cells, it can also arise in association with papillary thyroid carcinoma (PTC), as a “mixed” histology. The immunologic and molecular differences between these histological subtypes have not been well-characterized. We aimed to investigate the differences in immune signatures in these histological subtypes to assess immune pathway differences in the classic ATC and mixed ATC/PTC tumor microenvironment. Methods: Classic ATC and mixed ATC/PTC cases (N = 12) from 1998 to 2018 with viable formalin-fixed paraffin-embedded (FFPE) tissue were identified and selected by a board-certified pathologist. 4 samples exhibited both PTC and ATC components while 8 were classic ATC cases, as confirmed by a pathologist. In the 4 mixed ATC/PTC histology specimens, 3 were identified to contain greater than 80% ATC involvement while the fourth was characterized as 40% ATC and 60% PTC. The NanoString Immune Profiling panel contains more than 770 genes. It was performed with extracted RNA to evaluate and compare the gene expression of classic ATC versus mixed ATC/PTC. Results: Majority of patients (N = 11) developed metastatic disease, a common feature of ATC, and are currently deceased (N = 10). The NanoString panel identified several differentially expressed immune pathways in the mixed ATC/PTC in comparison to the classic ATC group. There is upregulation of CD3 (p < 0.01) and CD8 (p < 0.01) transcripts in the mixed ATC/PTC group, but not CD4 transcripts (p > 0.05). Additionally, we found that genes associated with B cell and T cell function were significantly upregulated in the mixed ATC group, including CD27 (p < 0.01), CD28 (p < 0.05), BTLA (p < 0.01), CTLA4 (p < 0.01), LAG3 (p < 0.05), and TIGIT(p < 0.01). We did not observe any significant differences in the expression of PD1 (p > 0.05) or MR1 (p > 0.05) between classic ATC and mixed ATC variants. Conclusions: Our study demonstrates a significant difference in the immune landscape between classic and mixed variants of ATC. Our results indicate there may be an increase in immune cell infiltration and tumor inflammation in the mixed ATC variant, which suggests patients with the mixed ATC variant may show a positive response to immunotherapy.

Quantitative imaging biomarkers of CNS lymphoma and its correlation with genotypic markers

e14520

Background: Central nervous system (CNS) lymphoma can be divided into primary CNS lymphoma (PCNS) versus secondary involvement of the CNS in systemic lymphoma. Traditionally radiology-pathology correlation is needed to accurately stage these entities, but the invasive nature of intracranial biopsies can add to patient morbidity. As such, there is an unmet need for noninvasive imaging biomarkers of CNS lymphoma. We aim to assess whether quantitative imaging analysis can characterize improve diagnostic specific and identify underlying genomic alterations in CNS lymphoma. Methods: 42 cases of CNS lymphoma (26 males, 16 females) were reviewed. Inclusion criteria required MRI (1.5Tesla or 3.0Tesla) of the brain and time-concordant histopathologic evaluation (i.e. MRI obtained within 72 hours of histologic evaluation) confirming diagnosis of CNS lymphoma. 19 patients met the inclusion criteria: 16 patients with large B-cell and 3 patients with T-cell lymphoma. All diagnoses were confirmed by evaluating biopsies through morphological and immunohistochemical analysis. MRI studies included T1-weighted pre- and post-contrast images, T2-weighted images and diffusion weighted images. Quantitative analysis included 3D-volumetric and textural analysis. Results: In B-cell lymphoma, mean patient age was 57 (22-91) while in T-cell lymphoma mean age of diagnosis was 43 (20-59). On MRI, all cases of CNS lymphoma (B- and T-cell) demonstrated enhancement. All T-cell lymphoma lesions were intra-axial and demonstrated homogeneous enhancement. Meanwhile, B-cell lymphomas demonstrated variable pattern of enhancement (homogenous; reticulonodular; subcortical U-fiber; peripheral). 80% (4/5) patients tested for MYC alterations demonstrated peripheral enhancement. 70% (7/10) tested for BCL2 expression demonstrated homogenous enhancement; while BCL2 & MYC dual-expression was noted in the remaining 30% (3/10) with MRI showing peripheral enhancement. All CNS lymphomas demonstrated restricted diffusion with variable ADC range: 292-980. 84.2% (16/19) of the cases were intra-axial while 15.2 (3/19) were extra-axial (all of which were B-cell lymphoma). Conclusions: Our study shows all lymphomas enhance and demonstrate variable degree of restricted diffusion. Patients with Myc-alterations or dual-expression of BCL2-MYC showed peripheral enhancement, while isolated BCL2 expressed tumors showed homogeneous enhancement.

A phase I study to evaluate PSCA-targeting chimeric antigen receptor (CAR)-T cells for patients with PSCA+ metastatic castration-resistant prostate cancer (mCRPC)

TPS250

Background: Although treatment options have improved, mCRPC remains highly lethal. Immunotherapy holds potential for durable remissions but not yet in mCRPC. CAR-T cell therapy has yielded cure for patients with refractory hematologic malignancies, and shows promise in solid tumors. Identifying and targeting the optimal antigen will be key to successful translation in solid tumors. Prostate stem cell antigen (PSCA) is highly expressed on prostate cancer cells, especially metastatic foci, and has limited expression on normal tissues. City of Hope has developed a second-generation PSCA CAR-T cell therapy containing an intracellular 4-1BB co-stimulatory domain (PSCA-BBζ) for first-in-human testing in men with mCRPC refractory to standard therapy (NCT03873805). Methods: The toxicity equivalence range (TEQR) design of Blanchard and Longmate will be used to evaluate select doses of PSCA-BBζ cells and determine the maximum tolerated dose (MTD). Doses include Cohort 1 = 100 million (M) CAR-T x 1 alone; Cohort 1b = 100M CAR-T x1 after lymphodepletion; Cohort 2 = 300M after lymphodepletion; Cohort 3 = 600M after lymphodepletion. 12 subjects will be accrued at the MTD. Eligibility: mCRPC treated with either abiraterone, enzalutamide or both; prior chemotherapy and/or radium223 allowed but not mandated. Tumor tissue, primary or metastatic, must stain positive for PSCA by IHC (Abcam 15168) and biopsy is repeated 28 days post infusion. Endpoints: Primary: all toxicities and dose-limiting toxicities defined as grade 3+ toxicity with attribution of possibly related or above, except CRS grade 3 resolved to < grade 2 within 72 hours or grade 3 encephalopathy resolved to baseline within 28 days. Secondary: persistence/expansion of CAR-T, response (soft tissue by RECIST, bone by PCWG3 criteria). Correlative studies include blood (immunophenotyping, cytokines, circulating tumor cell enumeration and PSCA expression), MRI (enhancement/diffusion changes in target lesions) and metastatic core biopsies (PSCA expression and local immune phenotype changes). Progress: 4 subjects have successfully manufactured PSCA-BBζ T cells; 1 completed treatment. Clinical trial information: NCT03873805.

547 Point-of-care cardiac assessment using machine learning to guide image acquisition

Funding Acknowledgements

Bay Labs, Inc; San Francisco, CA

Background/Introduction: When used by experienced examiners, the utility of point-of-care (POC) ultrasound for assessing cardiac anatomy and function has been well established. However, in some clinical circumstances (Primary Care offices, Intensive Care Unit, some Emergency Rooms, or in remote settings) in which a rapid assessment of cardiac anatomy and dynamics can facilitate patient care, an examiner experienced at POC scanning may not be immediately available.

Purpose

To help novice users acquire clinically useful standard cardiac views using novel machine learning (ML) software.

Methods

We used an investigational device that employs ML software to provide real-time adaptive guidance of transducer position and orientation to help novice users acquire tomographic views of the heart. We tested the utility of this approach when 4 nurses with no prior training in sonography performed POC studies on 16 subjects (10 healthy, 6 with cardiac abnormalities; 9 men; body mass index normal in 6, overweight in 6, and obese in 4 subjects). Each nurse underwent didactic training and 4 hours of supervised practice using the ML program. Each nurse scanned each study subject using a scanner equipped with ML software to acquire 10 digital two-dimensional image clips, including: parasternal long axis, short axis at the aortic valve, mitral valve, and mid-left ventricle (LV), apical 2-, 4-, and 5-chamber, subcostal 4-chamber, and longitudinal views of the inferior vena cava (IVC). All video clips (n = 640) were later reviewed independently by 5 level 3-trained cardiologists who were blinded to subject, scanner, and each other"s assessments. The expert readers reviewed each set of 10 clips to determine if the following variables could be assessed qualitatively: LV size and function; right ventricular (RV) size and function; aortic, mitral and tricuspid valves; pericardial effusion; left atrial size; IVC size.

Results

The majority of expert readers concurred, independently, that the sets of images acquired by nurses using ML guidance allowed qualitative assessment of LV size and function in 98%, pericardial effusion in 98%, RV size and function in 92%, and aortic and mitral valve anatomy and dynamics in 94-97% of cases. Qualitative assessment of LA size was feasible in 95%. Images of the IVC were judged as adequate for assessment in 58%.

Conclusion

This preliminary study suggests the potential value of novel ML software by demonstrating that nurses with limited training can acquire tomographic images useful for qualitative assessment of the cardiac chambers and valves in more than 90% of the subjects examined. This approach might be useful when timely POC cardiac assessment is indicated in settings where an experienced examiner is not available. Further refinements in the guiding software are needed to improve the success rate of IVC imaging, since IVC size can be a useful indicator of volume status.

Abstract P5-11-10: Biomarkers associated with resistance or response to CDK4/6 treatment in patients with metastatic hormone-receptive positive breast cancer

Background:

CDK4/6 inhibitor (CDKi) drugs are the current standard of care for treatment of first and second-line hormone-receptor positive/HER2 negative (HR+/HER2-) metastatic breast cancers. Numerous research efforts have commenced to understand biomarkers of response and resistance. To date, no biomarker of response has been identified. Treatment induced RB1 mutations were noted as mechanism of resistance to palbociclib and fulvestrant in about 5% of patients treated on PALOMA3 trials, whereas PI3K and ESR1 mutations emerged as potential resistance to the anti-hormonal backbone1. Additionally, FGFR1 amplification has been suggested as a resistance pathway to fulvestrant and ribociclib2. A better understanding of the molecular landscape of CDK4/6 treatment is needed. Utilizing next-gen sequencing (NGS), chromogenic in situ hybridization (CISH) and immunohistochemistry (IHC) data from HR+/HER2- patients treated at the University of Tennessee West Cancer Center, we attempted to retrospectively identify a molecular signature of resistance or response as measured by PFS.

Methods:

We analyzed 115 breast cancer patients who received CDKi treatment and 30 matched controls not exposed to CDKi and underwent comprehensive molecular profiling (Caris Life Sciences, Phoenix, AZ). A Cox proportional hazards model was built using genetic test as predictors and progression free survival (PFS) time as response. Only alterations with known pathogenic potential were considered aberrant. The R package glmnet was used to perform regularized lasso regression for feature selection on the entire data set. Important features were then used to construct Kaplan-Meier curves and perform a log-rank test for difference in PFS times.

Results:

Here we report the analysis for 2 known pathogenic biomarkers, ESR1 and TP53 based on PFS for patients who test positive versus negative. The median PFS for all patients was 234 days. Patients who harbored ESR1 mutations had reduced PFS of 180 days compared to 237 days. Patients who had P53 mutations had shorter PFS of 201 days compared to 240 days. When both groups with positive mutations were combined, the median PFS was 191 days compared to 276 days for patients without either ESR1 or P53 mutation with a p-value of 0.011. Further analysis using 4 way Kaplan Meier Curves for controls versus treated, altered versus non-altered genes, or PDL-1 expression is ongoing and will be presented at the conference.

Conclusion:

This data further support, in a real world model, the poor predictive value of ESR1 and P53 mutations on clinical outcome. Because no testing data was used, additional validation will be necessary to confirm the findings from this analysis.

References:

1. Nicholas C. Turner, Ben O'Leary, Ros Cutts, Massimo Cristofanilliet al, Genetic landscape of resistance to CDK4/6 inhibition in circulating tumor DNA (ctDNA) analysis of the PALOMA3 trial of palbociclib and fulvestrant versus placebo and fulvestrant. J Clin Oncol 36, 2018 (suppl; abstr 1001).

2. Luigi Formisano, Yao Lu, Carlos Arteaga et al. Gain of function kinase library identifies FGFR1 amplification as a mechanism of resistance to antiestrogen and CDK4/6 inhibitor in ER+ breast cancer. SABCS 2017 abstract GS6-05.

Citation Format: Mullins JN, Chaudhry A, Ryder J, Valasareddy P, Jain A, Ranganath H, Hare F, Vidal GA. Biomarkers associated with resistance or response to CDK4/6 treatment in patients with metastatic hormone-receptive positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-11-10.

Detection of the Stellate and Thoracic Sympathetic Chain Ganglia with High-Resolution 3D-CISS MR Imaging

BACKGROUND AND PURPOSE

Despite the importance of the sympathetic nervous system in homeostasis and its putative role in various disease states, little is known regarding our ability to image the sympathetic chain and sympathetic chain ganglia, perhaps owing to their small size. In this retrospective study, we sought to evaluate the normal anatomy of the sympathetic chain ganglia and assess the detectability of the sympathetic chain and sympathetic chain ganglia on high-resolution 3D-CISS images.

MATERIALS AND METHODS

This study included 29 patients who underwent 3D-CISS MR imaging of the thoracic spine for reasons unrelated to abnormalities of the sympathetic nervous system. Patients with a prior spinal operation or visible spinal pathology were excluded. The sympathetic chain ganglia were evaluated using noncontrast 3D-CISS MR imaging. Statistical analyses included t tests and measures of central tendency. The Cohen κ statistic was calculated to evaluate interrater reliability.

RESULTS

The stellate ganglion and thoracic chain ganglia were identified in all subjects except at the T10-T11 and T11-T12 levels. The stellate ganglion was found inferomedial to the subclavian artery and anterior and inferior to the transverse process of C7 in all subjects. Thoracic sympathetic chain ganglia were identified ventral to the costovertebral junction in all subjects from T2 to T10. There was strong interobserver agreement for the detection of the sympathetic chain ganglia with κ > 0.80. The size, shape, and location of these structures corresponded with gross anatomic and surgical observations.

CONCLUSIONS

The thoracic sympathetic chain ganglia can be identified on precontrast 3D-CISS MR imaging. This technique may aid in the initial evaluation of stellate ganglion and/or sympathetic chain ganglia size and signal change for comparison in future studies.