Infection Rates of an Intraoral Versus Extraoral Approach to Mandibular Fracture Repairs are Equal: A Systematic Review and Meta-Analysis

PURPOSE

This study investigates whether the intraoral approach to mandibular open reduction and internal fixation, through exposure to the oral cavity's microbiome, results in higher infection rates compared to the extraoral approach, thus addressing a critical public health concern, potentially offering an opportunity to reduce health-care costs, and aiming to guide effective clinical practice.

METHODS

In this systematic review with meta-analyses, a review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. A comprehensive literature search was conducted using Embase and PubMed for articles published between 1989 and 2023. Inclusion criteria targeted studies on open reduction and internal fixation mandibular fractures comparing intraoral and extraoral approaches and reporting infection rates. Exclusion criteria eliminated non-English articles, case reports, and studies with insufficient approach-specific data. The primary outcome was the postoperative infection rate, with surgical approach as the predictor. Covariates such as age, sex, diabetes, and smoking status were included when reported. Data were analyzed using R software, employing random-effects models due to anticipated heterogeneity (I2 statistics).

RESULTS

From 61 studies, 11 provided direct comparisons involving 1,317 patients-937 intraoral and 380 extraoral. Infection rates were 5.9% for intraoral and 10% for extraoral approaches. Pooled relative risk was 0.94 [95% confidence interval, 0.63, 1.39], suggesting no significant risk difference. Prevalence of infections was estimated at 9% for intraoral and 6.1% for extraoral procedures, with significant heterogeneity (I2 = 84% for intraoral and 56% for extraoral).

CONCLUSION

Our meta-analysis found no significant difference in infection rates between the two approaches. There is opportunity to expand on reporting complication rates comparing the various approaches to mandibular fixation. Until these data are presented, surgeon preference may dictate the operative approach to expose the mandible for reduction and fixation.

Oncoplastic breast-conserving surgery (OBCS) vs. mastectomy with reconstruction: a comparison of outcomes in an underserved population

Background

Oncoplastic breast-conserving surgery (OBCS) has demonstrated superior cosmetic outcomes to traditional breast-conserving surgery (BCS) while maintaining oncologic safety. While prior studies have compared OBCS to mastectomy, there is a scarcity of literature on the impact of social determinants of health on outcomes. Furthermore, although traditionally tumors larger than 5 cm and multifocal disease were treated with mastectomy, the literature has now shown OBCS to be safe in treating such disease. As a result, patients with large or multifocal tumors could be eligible for both mastectomy and OBCS, which prompts the need for comparison between the two. Thus, the aim of our study was to compare OBCS and mastectomy with reconstruction using BREAST-Q and oncologic outcome measures, as well as stratify these outcomes based on race, ethnicity, and body mass index (BMI).

Methods

A retrospective chart review was performed for 57 patients treated with OBCS and 204 patients treated with mastectomy with reconstruction from 2015 to 2021. Variables including age, race, ethnicity, BMI, insurance status, surgery type, pathology, recurrence, and complications were recorded. Patient-reported outcomes (PROs) were recorded using BREAST-Q pre- and post-operatively.

Results

Despite having a higher BMI (P<0.001), OBCS yielded higher "satisfaction with breast" and "satisfaction with outcome" than mastectomy (P=0.02 and P=0.02, respectively). When stratified by race, there were no statistical differences in the PROs between the two surgeries for Hispanic nor African American patients. OBCS had a significantly lower rate of infection and fewer additional surgeries than mastectomy (P=0.004 and P<0.001, respectively). There were no differences in positive margin rate or recurrence rate between the groups.

Conclusions

In our study, OBCS yielded better PROs than mastectomy while maintaining oncologic safety and resulting in fewer surgeries and complications. These excellent outcomes in a majority non-Caucasian cohort support the utilization of OBCS for underserved, minority populations. Larger studies evaluating PROs in diverse and uninsured groups are needed to reinforce these conclusions.

Antibiotic Prescribing Patterns for Respiratory Tract Illnesses Following the Conclusion of an Education and Feedback Intervention in Primary Care

BACKGROUND

A study previously conducted in primary care practices found that implementation of an educational session and peer comparison feedback was associated with reduced antibiotic prescribing for respiratory tract diagnoses (RTDs). Here, we assess the long-term effects of this intervention on antibiotic prescribing following cessation of feedback.

METHODS

RTD encounters were grouped into tiers based on antibiotic prescribing appropriateness: tier 1, almost always indicated; tier 2, possibly indicated; and tier 3, rarely indicated. A χ2 test was used to compare prescribing between 3 time periods: pre-intervention, intervention, and post-intervention (14 months following cessation of feedback). A mixed-effects multivariable logistic regression analysis was performed to assess the association between period and prescribing.

RESULTS

We analyzed 260 900 RTD encounters from 29 practices. Antibiotic prescribing was more frequent in the post-intervention period than in the intervention period (28.9% vs 23.0%, P < .001) but remained lower than the 35.2% pre-intervention rate (P < .001). In multivariable analysis, the odds of prescribing were higher in the post-intervention period than the intervention period for tier 2 (odds ratio [OR], 1.19; 95% confidence interval [CI]: 1.10-1.30; P < .05) and tier 3 (OR, 1.20; 95% CI: 1.12-1.30) indications but was lower compared to the pre-intervention period for each tier (OR, 0.66; 95% CI: 0.59-0.73 tier 2; OR, 0.68; 95% CI: 0.61-0.75 tier 3).

CONCLUSIONS

The intervention effects appeared to last beyond the intervention period. However, without ongoing provider feedback, there was a trend toward increased prescribing. Future studies are needed to determine optimal strategies to sustain intervention effects.

Electroconvulsive Therapy in Patients With Cerebral Aneurysms

ABSTRACT

Subarachnoid hemorrhage due to cerebral aneurysm rupture is a devastating event with a high mortality and significant morbidity. The safety of patients undergoing electroconvulsive therapy (ECT) in the presence of an aneurysm is not clear and is a cause of anxiety for both health care workers and patients. The present article collated the available evidence related to ECT in the presence of an aneurysm and found that there were no case reports where ECT directly led to the rupture of an aneurysm, although 1 case reported a rupture of an aneurysm between sessions of ECT. The epidemiology of cerebral aneurysms is discussed, as are key clinical considerations related to the care of patients with aneurysms who require ECT.

Balancing growth amidst salt stress - lifestyle perspectives from the extremophyte model Schrenkiella parvula

Schrenkiella parvula, a leading extremophyte model in Brassicaceae, can grow and complete its lifecycle under multiple environmental stresses, including high salinity. Yet, the key physiological and structural traits underlying its stress-adapted lifestyle are unknown along with trade-offs when surviving salt stress at the expense of growth and reproduction. We aimed to identify the influential adaptive trait responses that lead to stress-resilient and uncompromised growth across developmental stages when treated with salt at levels known to inhibit growth in Arabidopsis and most crops. Its resilient growth was promoted by traits that synergistically allowed primary root growth in seedlings, the expansion of xylem vessels across the root-shoot continuum, and a high capacity to maintain tissue water levels by developing thicker succulent leaves while enabling photosynthesis during salt stress. A successful transition from vegetative to reproductive phase was initiated by salt-induced early flowering, resulting in viable seeds. Self-fertilization in salt-induced early flowering was dependent upon filament elongation in flowers otherwise aborted in the absence of salt during comparable plant ages. The maintenance of leaf water status promoting growth, and early flowering to ensure reproductive success in a changing environment, were among the most influential traits that contributed to the extremophytic lifestyle of S. parvula.

Comparison of preoperative versus postoperative treatment dosimetry plans of single-fraction stereotactic radiosurgery for surgically resected brain metastases

OBJECTIVE

Stereotactic radiosurgery (SRS) for operative brain metastasis (BrM) is usually administered 1 to 6 weeks after resection. Preoperative versus postoperative timing of SRS delivery related to surgery remains a critical question, as a pattern of failure is the development of leptomeningeal disease (LMD) in as many as 35% of patients who undergo postoperative SRS or the occurrence of radiation necrosis. As they await level I clinical data from ongoing trials, the authors aimed to bridge the gap by comparing postoperative with simulated preoperative single-fraction SRS dosimetry plans for patients with surgically resected BrM.

METHODS

The authors queried their institutional database to retrospectively identify patients who underwent postoperative Gamma Knife SRS (GKSRS) after resection of BrM between January 2014 and January 2021. Exclusion criteria were prior radiation delivered to the lesion, age < 18 years, and prior diagnosis of LMD. Once identified, a simulated preoperative SRS plan was designed to treat the unresected BrM and compared with the standard postoperative treatment delivered to the resection cavity per Radiation Therapy Oncology Group (RTOG) 90-05 guidelines. Numerous comparisons between preoperative and postoperative GKSRS treatment parameters were then made using paired statistical analyses.

RESULTS

The authors' cohort included 45 patients with a median age of 59 years who were treated with GKSRS after resection of a BrM. Primary cancer origins included colorectal cancer (27%), non-small cell lung cancer (22%), breast cancer (11%), melanoma (11%), and others (29%). The mean tumor and cavity volumes were 15.06 cm3 and 12.61 cm3, respectively. In a paired comparison, there was no significant difference in the planned treatment volumes between the two groups. When the authors compared the volume of surrounding brain that received 12 Gy or more (V12Gy), an important predictor of radiation necrosis, 64% of patient plans in the postoperative SRS group (29/45, p = 0.008) recorded greater V12 volumes. Preoperative plans were more conformal (p < 0.001) and exhibited sharper dose drop-off at the lesion margins (p = 0.0018) when compared with postoperative plans.

CONCLUSIONS

Comparison of simulated preoperative and delivered postoperative SRS plans administered to the BrM or resection cavity suggested that preoperative SRS allows for more highly conformal lesional coverage and sharper dose drop-off compared with postoperative plans. Furthermore, V12Gy was lower in the presurgical GKSRS plans, which may account for the decreased incidence of radiation necrosis seen in prior retrospective studies.

Comparative Outcomes of Malar Implants Versus Fat Transfer to Cheeks Among Transfeminine Individuals Undergoing Malar Augmentation

BACKGROUND

Malar augmentation is a key procedure sought out by transfeminine individuals seeking to feminize their facial appearance. Different surgical techniques have been described in the literature including fat transfer to the cheeks and malar implant placement. Because of the paucity of information in the literature, there is no consensus on best practices for this procedure. The objective of our study is to determine the effectiveness and safety of malar implants as compared with fat transfer to the cheeks in transfeminine individuals.

METHODS

We examined all patients with the diagnosis of gender dysphoria that were referred to the senior author seeking consultation for feminizing facial procedures between June 2017 and August 2022. Patients who underwent fat transfer to the cheeks or malar implant placement were included in our study. We reviewed the electronic medical record of each patient, and we retrieved and analyzed data regarding demographics, medical and surgical history, operative dictations, clinic notes, and postoperative follow-up. Univariate analysis was used to assess for differences in postoperative complications between these 2 groups.

RESULTS

We identified 231 patients underwent feminizing facial gender affirming surgery, with 152 patients receiving malar augmentation through malar implants or fat grafting. One hundred twenty-nine patients (84.9%) underwent malar implant placement and 23 (15.1%) underwent fat grafting to the cheeks. The mean follow-up time was 3.6 ± 2.7 months. Patient satisfaction was greater in the malar implant group (126/129, 97.7%) compared with the fat transfer group (20/23, 87%, P < 0.045). Two patients who received implants (1.8%) experienced postoperative complications. No patient undergoing fat transfer experiences similar adverse outcomes. Nevertheless, the difference was not statistically significant (P = 1.00).

CONCLUSIONS

Our findings support the contention that malar implants are a safe alternative for malar augmentation among transfeminine individuals. While autologous fat transfer to the cheek is an indispensable option in patients requiring minor malar enhancement, malar implants offer a more permanent option with a better aesthetic outcome in patients requiring major malar enhancement. To minimize postoperative complications, surgeons should emphasize patient compliance with postoperative directions.

Ensuring privacy protection in the era of big laparoscopic video data: development and validation of an inside outside discrimination algorithm (IODA)

BACKGROUND

Laparoscopic videos are increasingly being used for surgical artificial intelligence (AI) and big data analysis. The purpose of this study was to ensure data privacy in video recordings of laparoscopic surgery by censoring extraabdominal parts. An inside-outside-discrimination algorithm (IODA) was developed to ensure privacy protection while maximizing the remaining video data.

METHODS

IODAs neural network architecture was based on a pretrained AlexNet augmented with a long-short-term-memory. The data set for algorithm training and testing contained a total of 100 laparoscopic surgery videos of 23 different operations with a total video length of 207 h (124 min ± 100 min per video) resulting in 18,507,217 frames (185,965 ± 149,718 frames per video). Each video frame was tagged either as abdominal cavity, trocar, operation site, outside for cleaning, or translucent trocar. For algorithm testing, a stratified fivefold cross-validation was used.

RESULTS

The distribution of annotated classes were abdominal cavity 81.39%, trocar 1.39%, outside operation site 16.07%, outside for cleaning 1.08%, and translucent trocar 0.07%. Algorithm training on binary or all five classes showed similar excellent results for classifying outside frames with a mean F1-score of 0.96 ± 0.01 and 0.97 ± 0.01, sensitivity of 0.97 ± 0.02 and 0.0.97 ± 0.01, and a false positive rate of 0.99 ± 0.01 and 0.99 ± 0.01, respectively.

CONCLUSION

IODA is able to discriminate between inside and outside with a high certainty. In particular, only a few outside frames are misclassified as inside and therefore at risk for privacy breach. The anonymized videos can be used for multi-centric development of surgical AI, quality management or educational purposes. In contrast to expensive commercial solutions, IODA is made open source and can be improved by the scientific community.

Cholinergic Antagonists and Behavioral Disturbances in Neurodegenerative Diseases

Cholinergic antagonists interfere with synaptic transmission in the central nervous system and are involved in pathological processes in patients with neurocognitive disorders (NCD), such as behavioral and psychological symptoms of dementia (BPSD). In this commentary, we will briefly review the current knowledge on the impact of cholinergic burden on BPSD in persons with NCD, including the main pathophysiological mechanisms. Given the lack of clear consensus regarding symptomatic management of BPSD, special attention must be paid to this preventable, iatrogenic condition in patients with NCD, and de-prescription of cholinergic antagonists should be considered in patients with BPSD.

Technical Feasibility of Whole-eye Vascular Composite Allotransplantation: A Systematic Review

There are over 43 million individuals in the world who are blind. As retinal ganglion cells are incapable of regeneration, treatment modalities for this condition are limited. Since first incepted in 1885, whole-eye transplantation (WET) has been proposed as the ultimate cure for blindness. As the field evolves, different aspects of the surgery have been individually explored, including allograft viability, retinal survival, and optic nerve regeneration. Due to the paucity in the WET literature, we aimed to systematically review proposed WET surgical techniques to assess surgical feasibility. Additionally, we hope to identify barriers to future clinical application and potential ethical concerns that could be raised with surgery.

Methods

We conducted a systematic review of PubMed, Embase, Cochrane Library, and Scopus from inception to June 10, 2022, to identify articles pertaining to WET. Data collection included model organisms studied, surgical techniques utilized, and postoperative functional outcomes.

Results

Our results yielded 33 articles, including 14 mammalian and 19 cold-blooded models. In studies performing microvascular anastomosis in mammals, 96% of allografts survived after surgery. With nervous coaptation, 82.9% of retinas had positive electroretinogram signals after surgery, indicating functional retinal cells after transplantation. Results on optic nerve function were inconclusive. Ocular-motor functionality was rarely addressed.

Conclusions

Regarding allograft survival, WET appears feasible with no complications to the recipient recorded in previous literature. Functional restoration is potentially achievable with a demonstrated positive retinal survival in live models. Nevertheless, the potential of optic nerve regeneration remains undetermined.

Modifiable factors associated with pediatric asthma readmissions: a multi-center linked cohort study

OBJECTIVES

To (a) identify rates of hospital readmission and emergency department (ED) re-presentation for asthma within a 12-month period, (b) estimate the effects of modifiable hospital, general practitioner (GP) and home environmental factors on hospital readmission, ED re-presentations and rescue oral corticosteroid use.

METHODS

We recruited 767 children aged 3-18 years who were admitted to 3 hospitals in Victoria, Australia between 2017 and 2018 with a validated diagnosis of asthma on chart review. Primary outcome was hospital readmission with asthma within 12 months of index admission. Secondary outcomes were ED re-presentation for asthma and rescue oral corticosteroid use. All outcomes were identified through linked administrative datasets. Their caregivers and 277 nominated GPs completed study surveys regarding the home environment and their usual asthma management practices respectively.

RESULTS

Within 12 months of an index admission for asthma 263 (34.3%) participants were readmitted to a hospital for asthma, with participants between the ages of 3-5 years accounting for 69.2% of those readmitted. The estimated effect of GP reported guideline discordant care on the odds of readmission was OR 1.57, 95% CI 1.00-2.47, p = 0.05. None of the hospital or home environmental factors appeared to be associated with hospital readmissions.

CONCLUSIONS

Hospital readmissions among Australian children with asthma are increasing, and linked datasets are important for objectively identifying the health services burden of asthma. They also confirm the important role of the GP in the management of pediatric asthma.

1654. Analysis of Prescribing Patterns for Respiratory Tract Illnesses Following the Conclusion of an Education and Feedback Intervention

Background

We previously conducted a study in primary care practices assessing the impact of an educational session paired with peer comparison feedback on antibiotic prescribing, demonstrating a reduction in overall prescribing for respiratory tract diseases (RTDs). However, the lasting effects of this intervention on antibiotic prescribing patterns without ongoing feedback are unknown.

Methods

To study the long-term effects of this feedback on antibiotic prescribing, we analyzed prescribing trends for 14 months after the initial study. We collected encounter-level data, including patient and provider information, ICD-10 codes, and antibiotics prescribed. RTDs were grouped into tiers based on prescribing appropriateness: tier 1 (almost always indicated), tier 2 (may be indicated), and tier 3 (rarely indicated). A χ² test was used to compare proportions of antibiotic prescribing between three time periods: pre-intervention, intervention, and post-intervention (following cessation of provider feedback). A mixed-effects multivariable logistic regression analysis was performed to assess the association between the period and antibiotic prescribing.

Results

We analyzed 260,900 encounters (127,324 pre-intervention, 58,431 during the intervention, and 75,145 post-intervention) from 28 practices, with patient, provider and practice characteristics in Table 1. Rates of antibiotic prescribing for RTD visits were higher in the post-intervention period than the intervention period (28.9% vs 23.0%, p< 0.001), but remained lower than the 35.2% pre-intervention rate (Figure 1, p< 0.001). In multivariable analyses, the odds of receiving a prescription was higher in the post-intervention compared to the intervention period for tier 2 (OR 1.19, 95% CI 1.10–1.30, p< 0.05) and tier 3 (OR 1.20, 95% CI 1.12–1.30) indications, but was still lower when compared to the pre-intervention period for each tier (OR 0.66, 95% CI 0.59–0.73 for tier 2; OR 0.68, 95% CI 0.61–0.75 for tier 3) (Table 2).

Table 1 includes patient, provider, and encounter level demographics.

Table 2 includes the results of the multivariable analysis.

Figure 1 is a graph of proportion of encounters with an antibiotic prescribed over time. The time period associated with the intervention is highlighted and graphs are separated by tier of appropriateness of antibiotic prescribing associated with the encounter.

Conclusion

The effects of this targeted educational and feedback program last beyond the intervention period, but without ongoing provider feedback there is a trend toward increased prescribing. Future studies are needed to determine optimal strategies to maintain the efficacy of this intervention.

Disclosures

Kathleen Degnan, MD, Gilead: Grant/Research Support Michael Z. David, MD PhD, Contrafect: Grant/Research Support|GSK: Advisor/Consultant|Johnson and Johnson: Advisor/Consultant.

Australian hospital paediatricians and nurses' perspectives and practices for influenza vaccine delivery in children with medical comorbidities

INTRODUCTION

Influenza vaccination of children with medical comorbidities is critical due their increased risks for severe influenza disease. In Australia, hospitals are an avenue for influenza vaccine delivery to children with comorbidities but are not always effectively utilised. Qualitative enquiry sought to ascertainment the barriers and enablers for influenza vaccination recommendation, delivery, and recording of these children at Australian hospitals.

METHODS

Semi-structured interviews and discussion group sessions were conducted with paediatricians and nurses at four tertiary paediatric specialist hospitals and two general community hospitals in three Australian states. Transcripts from interviews and group sessions were inductively analysed for themes. The Capability, Opportunity, Motivation, and Behaviour (COM-B) model was used to explore the elements of each theme and identify potential interventions to increase influenza vaccination recommendation and delivery behaviours by providers.

RESULTS

Fifteen discussion sessions with 28 paediatricians and 26 nurses, and nine in-depth interviews (five paediatricians and four nurses) were conducted. Two central thematic domains were identified: 1. The interaction between hospital staff and parents/patients for influenza vaccine recommendation, and 2. Vaccination delivery and recording in the hospital environment. Six themes across these domains emerged detailing the importance of dedicated immunisation services, hospital leadership, paediatricians' vaccine recommendation role, the impact of comorbidities, vaccination recording, and cocooning vaccinations. Supportive hospital leadership, engaged providers, and dedicated immunisation services were identified as essential for influenza vaccination of children with comorbidities in Australian hospital.

CONCLUSION

Recommendation of influenza vaccination for Australian children with comorbidities is impacted by the beliefs of paediatricians and the perceived impact of influenza disease on children's comorbidities. Dedicated immunisation services and supportive hospital leadership were drivers for influenza vaccine delivery at hospitals. Future interventions targeting hospital-based influenza vaccine delivery for children with comorbidities should take a rounded approach targeting providers' attitudes, the hospital environment and leadership support.

CTIM-29. PHASE 2 STUDY OF A NOVEL IMMUNOTHERAPY SL-701 IN ADULTS WITH RECURRENT GBM: IDENTIFICATION OF TREATMENT-INDUCED CD8+CD107A+ CD57+ PD-1- MEMORY T-CELLS THAT ARE ASSOCIATED WITH INCREASED SURVIVAL

Recurrent glioblastoma (GBM) is an aggressive disease with poor survival and limited treatment options. SL-701 is a novel immunotherapy comprised of synthetic peptides designed to elicit an anti-tumor immune response against GBM antigens IL-13Rα2, ephrinA2, and survivin. Here we describe an 18-color flow cytometry analysis from stage 2 of a Ph2 clinical trial of SL-701+poly-ICLC+bevacizumab (NCT02078648), in which 12-month overall survival (OS) was 50%. Of the 27 patients in stage 2, 24 (89%) developed heterogeneous T-cell responses against 1, 2, or 3 of the SL-701 CD8 peptides. Magnitude and kinetics of peptide responses were variable among these patients with no clear relationship to OS. Therefore, a phenotypic analysis of the T-cell response in all 27 patients was conducted using terraFlow, a unique data analysis approach utilizing machine learning to identify T-cell phenotypes associated with clinical response from all possible combinations of markers. In total, 10,184 unique SL-701 induced phenotypes were measured, including 223 phenotypes (P &lt; 0.05) and 16 core phenotypes that uniquely represent differences between patients with OS above or below 12 months (P &lt; 0.05). 50% of the core phenotypes were CD8+ CD57+ CD107a+ PD-1- SL-701-specific T-cells, which are highly-differentiated memory T-cells primed for cytotoxicity. The frequency of the CD57+ core phenotypes (8%-18%) was enhanced 1.6- to 2.3-fold in patients with an OS &gt; 12 months (P &lt; 0.05). Similarly, 2 core phenotypes identified cytotoxic CD4+ and CD8+ T cells, which were enhanced 1.9- and 2.5-fold in patients with an OS &gt;12 months. The final 6 core phenotypes identified activated CD4+ CD154+ SL-701-specific T-cells (5%-19%) that were enhanced 0.3- to 0.5-fold in patients with an OS &lt; 12 months (P &lt; 0.05), suggesting helper T-cell responses in the absence of cytotoxic T-cell responses are associated with an OS &lt; 12 months. Deep sequencing of SL-701-specific T-cells using whole transcriptome-based molecular cytometry is planned.

QOL-20. PATTERNS AND PREDICTORS OF ANXIETY AND DEPRESSION SYMPTOM TRAJECTORIES IN PATIENTS DIAGNOSED WITH PRIMARY BRAIN TUMORS

BACKGROUND

Patients diagnosed with primary brain tumors (pPBTs) exhibit high psychological distress. This study assessed how symptoms of anxiety and depression change over time in pPBTs and identified factors that may predict patients’ symptom trajectories.

METHODS

Ninety-nine adult pPBTs completed psychosocial assessments at routine neuro-oncology clinical appointments over 6 to 18 months, with a minimum 8-week interval between assessments. Symptoms of anxiety and depression were assessed with the PROMIS Anxiety and Depression Short-Forms. The prevalence and incidence of patients with clinically elevated anxiety and depression symptoms throughout follow-up were examined, along with the prevalence of patients that experienced clinically meaningful changes in symptoms between follow-ups. Linear mixed-effects models evaluated changes in symptoms over time at the group level and latent class growth analysis (LCGA) evaluated changes in symptoms over time at the individual level.

RESULTS

At baseline, 51.5% and 32.3% of patients exhibited clinically elevated levels of anxiety and depression, respectively. Of patients with any follow-up data (N = 74), 54.1% and 50% experienced clinically meaningful increases in anxiety and depression scores, respectively. The incidence of moderate to severe anxiety and depression was 15.6% and 8.3%, respectively. There was no significant change in symptoms over time at the group level, but better physical, functional, and brain-cancer well-being predicted significantly lower anxiety and depression symptoms (p&lt; .001). Results from LCGA showcased 5-unique subgroups of patients with distinct anxiety and depression symptom trajectories.

CONCLUSION

pPBTs commonly experience elevated anxiety and depression. Symptoms of anxiety and depression change in clinically meaningful manners throughout the disease, even in the absence of significant group-level time effects. Routine screening for elevated symptoms is needed to capture clinically meaningful changes in symptoms and identify factors affecting symptoms to intervene.

CTIM-27. AUTOLOGOUS TUMOR LYSATE-LOADED DENDRITIC CELL VACCINATION IMPROVES SURVIVAL IN PATIENTS WITH NEWLY DIAGNOSED AND RECURRENT GLIOBLASTOMA: SURVIVAL RESULTS FROM A PHASE 3 TRIAL

BACKGROUND

Standard of care (SOC) and patient survival in glioblastoma have changed little in the past 17 years. We evaluated in a phase 3 trial whether adding an autologous tumor lysate-loaded dendritic cell vaccine (murcidencel) to SOC extends survival. Patients and

METHODS

Newly diagnosed glioblastoma patients were randomized 2:1 to either murcidencel or placebo. Under a crossover design, all patients could receive murcidencel following tumor recurrence. All parties remained blinded regarding treatments before recurrence. Patients thus received murcidencel at new diagnosis (nGBM) or at recurrence (rGBM) following crossover from placebo. The primary and secondary endpoints compare overall survival (OS) with contemporaneous, matched external controls. Four sets of analyses were conducted to ensure rigorous matching of the controls, reduce biases, and confirm the robustness of the results.

RESULTS

331 patients were enrolled. With the crossover, 89% received murcidencel. Median OS (mOS) for nGBM patients (n = 232) was 19.3 months from randomization (22.4 months from surgery) with murcidencel vs. 16.5 months from randomization in the controls (HR = 0.80, p = 0.002). Survival at 48 months from randomization was 15.7% vs. 9.9%, and at 60 months was 13% vs. 5.7%. For rGBM (n = 64), mOS was 13.2 months from relapse vs. 7.8 months in the controls (HR = 0.58, p &lt; 0.001). Survival at 24 months post-recurrence was 20.7% vs. 9.6%, and at 30 months post-recurrence was 11.1% vs 5.1%. In nGBM patients with methylated MGMT (n = 90), mOS was 30.2 months from randomization (33 months from surgery) with murcidencel vs. 21.3 months from randomization in the controls (HR = 0.74, p = 0.027). The treatment was well tolerated, with only 5 serious adverse events deemed at least possibly related to the vaccine.

CONCLUSION

Clinically meaningful and statistically significant survival extension was seen in both nGBM and rGBM patients treated with murcidencel and SOC compared with contemporaneous, matched external controls who received SOC alone.

CTIM-05. FINAL RESULTS OF 2-THE-TOP: A PILOT PHASE 2 STUDY OF TTFIELDS (OPTUNE) PLUS PEMBROLIZUMAB PLUS MAINTENANCE TEMOZOLOMIDE (TMZ) IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA (NDGBM)

INTRODUCTION

TTFields induce anti-tumor immunity via type-1 interferon (T1IFN) pathways of the STING and AIM2 inflammasomes. Thus, TTFields may synergize with immune checkpoint inhibitors to prolong survival in GBM.

METHODS

We enrolled 26 ndGBM patients in a pilot phase 2 study combining TTFields, pembrolizumab and maintenance TMZ. Primary endpoints were PFS versus case-matched controls of TTFields plus TMZ in the EF-14 study and immune signatures by multiomics of PBMCs and tumors. Secondary endpoints included toxicity and OS.

RESULTS

The median age was 60.5 years. Fourteen (54%) had biopsy only or partial resection. Nineteen (73%) had unmethylated MGMT and 3 (11.5%) had an IDH mutation. As of 2/16/22, 7 (27%) were progression-free and 14 (54%) were alive with median follow-up of 16.8 months. Median PFS was 12.1 months versus 7.9 months in a case-matched control cohort of 26 patients (HR = 0.456; 95% CI: 0.222-0.937; P = 0.015). Twelve-month PFS was 52.4% (95% CI: 31.4-69.6%) versus 20.4% (95% CI: 5.5-41.7%) in controls; P = 0.012. Six of 15 (40%) patients with measurable disease achieved partial or complete response. Median OS was 25.2 months versus 15.9 months in controls (HR = 0.382; 95% CI: 0.168-0.861; P = 0.078). Two-year OS was 57.8% (95% CI: 33.7-75.9%) versus 19.2% (95% CI: 7.0-36.0%) in controls; P = 0.002. In a Cox regression analysis adjusting for key prognostic factors, P-value reached 0.033 for PFS and 0.020 for OS. Molecular analyses confirmed robust T cell activation via the T1IFN trajectory, which highly correlated with TCRαβ clonal expansion (Spearman coefficient = -0.8; P = 0.014), and defined a T cell-based gene signature of TTFields effects. The most common serious adverse events were thromboses, seizures, and metabolic disturbances in 4 (15%), 3 (11.5%), and 2 (8%) patients, respectively.

CONCLUSIONS

The triple combination demonstrated acceptable toxicity and promising efficacy in ndGBM. Survival and molecular data will be updated.

EXTH-57. IDENTIFICATION OF NOVEL IMMUNE CHECKPOINT MOLECULE IN GLIOMA, LAIR1

BACKGROUND

In recent years, emerging evidence indicates that tumor-associated myeloid cells (TAMCs) affect cancer progression. But the molecular mechanisms and signaling pathways involved in the TAMCs’ interaction with extracellular matrix (ECM) and tumor stroma are incompletely understood. Checkpoint inhibition therapy targets immune inhibitory receptors, such as CTLA-4 and PD-1, which have become a major weapon in fighting cancer. These antibodies demonstrate apparent advantages such as being easy to use, broad applicability, and durable clinical response. Leukocyte-Associated Immunoglobulin-like Receptor 1 (LAIR1), also called CD305, a collagen-binding immunoreceptor tyrosine-based inhibition motifs (ITIM)-bearing inhibitory receptor, was identified to present on almost all immune cell populations and overexpressed in cancers of human patients. However, LAIR1’s role and regulation in solid cancers are poorly defined.

OBJECTIVE

To identify LAIR1 as a new class of immune checkpoints in cancers that impacts TAMCs-associated tumor immunity. Further functional investigation warrants understanding the crosstalk between LAIR1-related immune checkpoint blocking agent(s), immune micro-environment, and its underlying mechanisms for targeted therapy development.

METHODS

Murine GBM cell line KR158-Luciferase cell line was used to set up the mouse model. Tumor-bearing mice were administered the Anti-LAIR1 blockade and IgG, followed by IVIS imaging for tumor growth and survival were recorded. The presentation and phenotype of immune cell populations in tumors and spleens were measured through scRNA-Seq.

RESULTS

GBM is one of these tumors that overexpress LAIR1 based on the TCGA analysis. LAIR1 molecules express highly on macrophages, monocytes, DCs, and activated T cells, not on the naive T cells. We found that LAIR1 blockade enhanced survival in preclinical GBM models. LAIR1 blockade reduced the presentation and function of TAMCs in tumors. What's more, LAIR1 blockade provided a synergetic antitumor effect with CD70 CAR T cells.

CONCLUSION

This study suggests that we identified a novel immune checkpoint molecule, LAIR1, which can limit tumor progression.

Diagnostic performance of MRI perfusion and spectroscopy for brainstem glioma grading

OBJECTIVE

This study investigated the roles of dynamic susceptibility contrast (DSC) perfusion and multivoxel magnetic resonance spectroscopy (MRS) in grading brainstem glioma (BSG).

PATIENTS AND METHODS

Our retrospective study comprised 12 patients, including 6 with pathology verified low-grade BSGs and 6 with high-grade BSGs. We examined differences in age, relative cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and the metabolite ratios of choline (Cho)/N-acetyl aspartate (NAA) and Cho/creatine (Cr) between these two groups using the Mann-Whitney U test and Chi-square test. Receiver operating characteristic (ROC) curve analysis was used to establish cutoff values and assess their usefulness in grading BSG.

RESULTS

The Cho/NAA metabolite ratio had the strongest preoperative predictive performance for identifying the correct histological grade among BSGs, with an area under the ROC curve (AUC) value of 0.944 (cutoff: 3.88, sensitivity [Se]: 83.3%; specificity [Sp]: 100%), followed by the Cho/Cr ratio (cutoff: 3.08; AUC: 0.917; Se: 83.3%; Sp: 100%), rCBF (cutoff: 3.56, AUC: 0.917; Se: 83.3%; Sp: 100%), rCBV (cutoff: 3.16, AUC: 0.889; Se: 100%; Sp: 66.7%), and age (cutoff: 9.5 years, AUC: 0.889; Se: 100%; Sp: 83.3%).

CONCLUSIONS

rCBF and rCBV values comparing solid tumors with the normal brain parenchyma and the metabolite ratios for Cho/NAA and Cho/Cre may serve as useful indices for establishing BSG grading and provide important information when determining treatment planning and prognosis in patients with BSG.

Processed electroencephalography: impact of patient age and surgical position on intraoperative processed electroencephalogram monitoring of burst-suppression

We previously reported that processed EEG underestimated the amount of burst suppression compared to off-line visual analysis. We performed a follow-up study to evaluate the reasons for the discordance. Forty-five patients were monitored intraoperatively with processed EEG. A computer algorithm was used to convert the SedLine® (machine)-generated burst suppression ratio into a raw duration of burst suppression. The reference standard was a precise off-line measurement by two neurologists. We measured other potential variables that may affect machine accuracy such as age, surgery position, and EEG artifacts. Overall, the median duration of bust suppression for all study subjects was 15.4 min (Inter-quartile Range [IQR] = 1.0-20.1) for the machine vs. 16.1 min (IQR = 0.3-19.7) for the neurologists' assessment; the 95% limits of agreement fall within - 4.86 to 5.04 s for individual 30-s epochs. EEG artifacts did not affect the concordance between the two methods. For patients in prone surgical position, the machine estimates had significantly lower overall sensitivity (0.86 vs. 0.97; p = 0.038) and significantly wider limits of agreement ([- 4.24, 3.82] seconds vs. [- 1.36, 1.13] seconds, p = 0.001) than patients in supine position. Machine readings for younger patients (age < 65 years) had higher sensitivity (0.96 vs 0.92; p = 0.021) and specificity (0.99 vs 0.88; p = 0.007) for older patients. The duration of burst suppression estimated by the machine generally had good agreement compared with neurologists' estimation using a more precise off-line measurement. Factors that affected the concordance included patient age and position during surgery, but not EEG artifacts.

Gate-Tunable Magnetism and Giant Magnetoresistance in Suspended Rhombohedral-Stacked Few-Layer Graphene

Conventionally, magnetism arises from the strong exchange interaction among the magnetic moments of d- or f-shell electrons. It can also emerge in perfect lattices from nonmagnetic elements, such as that exemplified by the Stoner criterion. Here we report tunable magnetism in suspended rhombohedral-stacked few-layer graphene (r-FLG) devices with flat bands. At small doping levels (n ∼ 10¹¹ cm^-2), we observe prominent conductance hysteresis and giant magnetoconductance that exceeds 1000% as a function of magnetic fields. Both phenomena are tunable by density and temperature and disappear at n > 10¹² cm^-2 or T > 5 K. These results are confirmed by first-principles calculations, which indicate the formation of a half-metallic state in doped r-FLG, in which the magnetization is tunable by electric field. Our combined experimental and theoretical work demonstrate that magnetism and spin polarization, arising from the strong electronic interactions in flat bands, emerge in a system composed entirely of carbon atoms.

Randomized comparison between perineural dexamethasone and combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block

BACKGROUND

This randomized trial compared perineural dexamethasone with combined perineural dexamethasone-dexmedetomidine for ultrasound-guided infraclavicular block. We hypothesized that the combination of perineural adjuvants would result in a longer motor block.

METHODS

Fifty patients undergoing upper limb surgery with ultrasound-guided infraclavicular block (using 35 mL of lidocaine 1%-bupivacaine 0.25% with epinephrine 5 µg/mL) were randomly allocated to receive perineural dexamethasone (2 mg) or combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg). After the performance of the block, a blinded observer assessed the success rate (defined as a minimal sensorimotor composite score of 14 out of 16 points at 30 min), the onset time (defined as the time required to reach a minimal composite score of 14 points) as well as the incidence of surgical anesthesia (defined as the ability to complete surgery without local infiltration, supplemental blocks, intravenous opioids or general anesthesia).Postoperatively, the blinded observer contacted patients with successful blocks to inquire about the duration of motor block, sensory block and postoperative analgesia.

RESULTS

No intergroup differences were observed in terms of success rate, onset time and surgical anesthesia. Compared with dexamethasone alone, combined dexamethasone-dexmedetomidine provided longer durations of motor block (21.5 (2.7) vs 17.0 (3.9) hours; p<0.001; 95% CI 2.6 to 6.4), sensory block (21.6 (3.6) vs 17.2 (3.6) hours; p<0.001; 95% CI 2.2 to 6.5), and postoperative analgesia (25.5 (9.4) vs 23.5 (5.6) hours; p=0.038; 95% CI 1.0 to 7.7).

CONCLUSION

Compared with perineural dexamethasone (2 mg) alone, combined perineural dexamethasone (2 mg)-dexmedetomidine (50 µg) results in longer durations of sensorimotor block and analgesia. Further studies are required to determine the optimal dosing combination for dexamethasone-dexmedetomidine.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT04875039.

POS1405 LESS THAN 50% FEMALES WITH CHRONIC RHEUMATIC INFLAMMATORY DISEASES CONTINUE A DMARD DURING PREGNANCY: A DESCRIPTIVE ANALYSIS OF THE NATIONAL FRENCH SOCIAL SECURITY DATABASE

Background

Treatment of patients with chronic rheumatic inflammatory diseases (CRID) during pregnancy has changed in the last decade, namely due to the availability of new DMARDs labelled to be used during pregnancy.

Objectives

To describe the anti-rheumatic drug use during pregnancy in women with CRID (i.e. rheumatoid arthritis (RA) or spondyloarthritis (SpA)) in France over the past decade.

Methods

This is a retrospective cohort study within the French Healthcare database (SNDS), which covers 98% of the French population. Adult women were included if they had RA or SpA according to CIM-10 codes, had started a singleton pregnancy between 2008 and 2017 (index date), and were continuously covered by this health insurance from 1-year before pregnancy onset to 1-year after end of the pregnancy or death (whichever comes first). The treatment exposures of interest were: NSAIDs, oral corticosteroids, csDMARD (methotrexate, leflunomide, sulfasalazine, azathioprine, hydroxychloroquine), biologics (anti-TNF, rituximab, abatacept, tocilizumab, ustekinumab, anakinra). Exposure during pregnancy was defined as at least one drug reimbursement from the 6 months before the last menstrual period (LMP) to the end of pregnancy period.

Results

Among the 35,737 adult women with a CIRD (40.7% with RA and 59.3% with SpA) who had a past history of DMARD reimbursement, 11,274 (41.7%) started a singleton pregnancy during the study period. In total, during preconception and pregnancy, 4,773 (42.3%) women were not delivered any DMARD nor corticosteroids, 769 (6.8%) were delivered corticosteroids alone, 3,639 (32.2%) a csDMARD alone and 2,862 (25.4%) a biologic (among whom 33.1% associated a csDMARD). Biologics delivered during pregnancy were mainly anti-TNFs (92.1%).

Exposure to NSAIDs was more frequent during the first trimester (30% patients) of pregnancy but occurred all along the pregnancy (6% and 2% in the second and third trimesters, respectively). Conversely, exposure to oral corticosteroids was stable during the pregnancy (33% to 27%); however, more than half of the prescriptions corresponded to doses higher than 10mg. Exposure to DMARDs including bDMARDs during pregnancy was more frequent during the first trimester, compared to the rest of the pregnancy (see graph).

Conclusion

Overall, less than 50% of women with a CRID who received a DMARD prior to the pregnancy continued to retrieve such treatment during pregnancy, and overall less than 20% were delivered biologics during pregnancy. Whether the withdrawal of DMARDs led to unfavorable maternal and pregnancy outcomes needs to be evaluated.

Acknowledgements

This study was conducted thanks to a grant from the French Ministry of Health - Programme Hospitalier de Recherche Clinique

Disclosure of Interests

Anna Moltó Consultant of: UCB, Abbvie, Lilly, Pfizer, BMS, MSD, Novartis, Biogen, Janssen, Grant/research support from: UCB, Aya Ajrouche: None declared, Diep Tran: None declared, Barbara Roux: None declared, Nathalie Costedoat-Chalumeau Grant/research support from: UCB, Elisabeth Elefant: None declared, Vassilis Tsatsaris: None declared, Jeanne Fresson: None declared, Brigitte Bader-Meunier: None declared, Bruno Fautrel: None declared, Florence Tubach: None declared

AB1391 19% PATIENTS WITH CHRONIC RHEUMATIC INFLAMMATORY DISEASES PRESENT AN UNFAVORABLE PREGNANCY OUTCOME: A DESCRIPTIVE ANALYSIS OF THE NATIONAL FRENCH SOCIAL SECURITY DATABASE

Background

patients with chronic rheumatic inflammatory diseases (CRID, i.e. rheumatoid arthritis (RA) or spondyloarthritis (SpA)) have been reported to have poorer pregnancy outcomes than the general population.

Objectives

to describe the pregnancy outcomes of singleton in patients with CRID in France in the past decade.

Methods

this is an analysis of the French Health Insurance claims database (SNDS), which represents 87% of the French population) from 2008 to 2016. To be included in the analysis patients had to be identified as RA or SpA according to existing diagnostic algorithms, to have at least one pregnancy declaration in the database, and to have continuous health insurance from 1-year before pregnancy onset to 1-year after end of the pregnancy or until death (if death occured before the 1-year-period after the end of pregnancy) to be included. Only the first singleton pregnancy occurring during the study period was included in this analysis. Both maternal and pregnancy outcomes were considered. Outcomes were identified either by ICM-10 codes or hospital discharge summaries discharge between 2008-2016.

Results

Among the 35 737 identified adult females with a CRID diagnosis (40.7% with RA and 59.3% with SpA), 27 722 (78%) had a pregnancy during the study period. 11 274 (42%) had received at least one DMARD prior to the pregnancy and were included in the analysis. Among them, only 4025 (36%) were exposed to DMARDs during pregnancy.

Mean (SD) age of females at the start of the pregnancy was 32 (5) years, and mean (SD) disease duration was 4 (4) years. Pregnancy ended before 13 WG in 21% and after 37 WG in 70% cases. Live-birth represented the most frequent pregnancy outcome (76.9%), and overall 34.7% patients presented at least one unfavorable outcome (see Table 1).

Table 1.Unfavourable outcomeN(%)Pregnancy outcomesMiscarriage (<22WG)579 (5.3%)Abortion91 (0.8%)Stillbirth48 (0.4%)Preterm delivery (>= 22WG and <37 WG)779 (7.1%)Low weight at birth (<3th percentile)287 (2.6%)Perinatal mortality (22WG to 6 days of life)2 (0%)Maternal outcomesSevere maternal infection*211 (1.9%)Newborn outcomesHospitalisation in neonatal intensive care > 48h in full-term newborns (after 37 WG)95 (0.8%)Neonatal mortality (27 first days of life)2 (0%)Severe infection * during first year603 (5.3%)

Conclusion

More than 75% pregnancies in patients with CRID resulted in a live-birth. Prevalence of miscarriage was surprisingly low, probably related to under-coding. Maternal and infant outcomes seemed comparable to general population. Whether medications had an impact on such outcomes is currently under evaluation.

Disclosure of Interests

None declared

Gaps in Patient Education on Safe Handling and Disposal of Oral Chemotherapy Drugs: A Pilot Prospective Cohort Survey Study

Background

Oral anticancer chemotherapy (OC) has been misperceived as being safer than intravenous chemotherapy, leading to its increased risk of improper handling and disposal. This survey study assessed the knowledge, practices and attitudes of pharmacists and patients regarding OC handling and disposal, gaps in knowledge and barriers to patient education.

Methods

Surveys were developed based on literature review and pilot study validation results. Patients completed a 33-item paper or electronic survey whereas pharmacists completed a 38-item electronic survey. Descriptive statistics and Fisher's exact test computed using the R Project were used for analyses.

Results

Pharmacist group (16/25, 62.5%) and patient group (14/29, 48.3%) believed that the oral route is safer than IV. Average overall correct response rates for pharmacist and patient groups were 78.3% and 61.9%, respectively. Significant gaps in knowledge between groups were observed in three sections (p < 0.05). Common barriers to providing patient education were insufficient training (70.8%) and insufficient time (50%).

Conclusion

Pharmacist and patient knowledge, awareness and practices of OC safe handling and disposal are suboptimal. Areas of knowledge gaps and barriers to patient education were identified. Enhanced supports are needed to empower pharmacists to assume an active role in patient education on safe handling and disposal of OC.

Outcomes of transjugular liver biopsies for liver transplant recipients with bicaval and piggyback hepatic vein anastomoses

BACKGROUND

Liver transplant hepatic venous anastomoses are usually created using "bicaval" or "piggyback" techniques, which may result in unfavorable angulation between the inferior vena cava and hepatic veins, and makes hepatic vein catheterization and tissue sampling during transjugular liver biopsy (TLB) technically challenging.

PURPOSE

To compare the technical successes and complications of TLBs for recipients of liver transplants with bicaval and piggyback hepatic vein anastomoses.

MATERIAL AND METHODS

Information on type of hepatic vein surgical anastomosis was available for 190 adult patients in whom 306 consecutive TLBs were performed during 2009-2017: 158 with bicaval and 148 with piggyback anastomoses. The primary outcome of procedural success was defined as obtaining a tissue sample sufficient to make a pathologic diagnosis.

RESULTS

A technical success rate of 97% with adequate liver tissue for diagnosis was similar between the anastomotic groups (P = 0.50). TLB was unsuccessful in 3% of patients with piggyback anastomoses due to unfavorable hepatic venous anatomy whereas biopsy was successful in all patients with bicaval anastomoses (P = 0.02). Fluoroscopy times were not significantly different (12.1 vs. 13.9 min, P = 0.08). Rates of major complication were similar between the two groups (3% vs. 3%, P > 0.99).

CONCLUSION

TLB is safe and effective for liver transplant patients regardless of the type of hepatic vein anastomosis. While failure to catheterize or advance the stiffened biopsy cannula into the hepatic vein is more likely to occur in patients with piggyback anastomoses, this is a rare occurrence.

IMMU-35. INDUCTION OF ANTI-TUMOR IMMUNITY BY TUMOR TREATING FIELDS (TTFIELDS) IN GLIOBLASTOMA

INTRODUCTION

The novel approved GBM treatment TTFields employs alternating, intermediate-frequency (200kHz) electric fields to disrupt mitotic macromolecules leading to chromosome mis-segregation and apoptosis. Emerging evidence indicates that TTFields may also induce inflammation; however, the mechanism and whether this can be harnessed as cancer immunotherapy remain unclear.

METHODS

Multiple GBM cell lines were treated with TTFields using Inovitro, an in vitro TTFields system and integrity of the nuclear envelope and content and activation of key DNA sensor inflammatory pathways analyzed by immunostaining, expression profiling, and protein assays. In a syngeneic orthotopic murine model, TTFields-treated GBM cells were used to provide an in-situ vaccination platform. For validation, we performed bulk and single-cell RNAseq of PBMCs from 12 newly diagnosed GBM patients treated with TTFields.

RESULTS

TTFields induce focal disruption of the nuclear envelope, leading to cytosolic release of large micronuclei clusters that recruit and intensely activate the 2 major DNA sensors – cGAS and AIM2, and their cognate inflammasomes, thereby releasing pro-inflammatory cytokines and type-1 interferons (T1IFNs) that promote development and maturation of DCs and cytotoxic T cells. In murine model, TTFields-treated GBM cells induce anti-tumor memory immunity both intratumorally and systemically, producing a cure rate of 40% and partial immunity in an additional 25% in a STING- and AIM2-dependent manner. In patients with newly diagnosed GBM patients, we sequenced a total of 193,760 PBMCs and detected robust post-TTFields activation of adaptive immunity via the T1IFN trajectory anchored by plasmacytoid DCs, which was strongly correlated with the TCRαβ clonal expansion index observed in 11 of 12 patients (Spearman coefficient r=-0.8, P=0.014). Importantly, we also defined a T cell-based gene signature predictive of TTFields effects on T cell activation and TCRαβ clonal expansion.

CONCLUSION

Collectively, these studies define a novel strategy using TTFields to improve immunotherapy in GBM and potentially other solid tumors.

DDRE-13. PROSTAGLANDIN E RECEPTOR 3 (PTGER3) REGULATES RESISTANCE TO TUMOR TREATING FIELDS (TTFields) IN GLIOBLASTOMA CELLS

INTRODUCTION

TTFields, a novel approved therapy for GBM, employ alternating intermediate-frequency electric fields to disrupt mitotic macromolecules leading to chromosome mis-segregation and apoptosis. The addition of TTFields significantly improves survival. However, most patients eventually develop resistance to TTFields through an unknown mechanism.

METHODS

Multiple human GBM cell lines were treated with TTFields continuously using Inovitro, an in vitro TTFields system, until cells with relative resistance to killing by TTFields emerged. Temporal gene expression profiles were analyzed using NETZEN, an innovative deep-learning and gene network-based ranking computational algorithm, to identify resistance pathways, followed by experimental validation.

RESULTS

PTGER3, a Gαi-protein-coupled cell surface receptor, is the top ranked master regulator in the predicted resistance program, which is upregulated in GBM cells within 24 hrs of exposure to TTFields and further reinforced as resistance sets in. Forced expression of PTGER3 in sensitive GBM cells confers relative resistance to TTFields, while PTGER3 depletion in resistant cells re-sensitizes them to TTFields. Most importantly, pharmacological inhibition of PTGER3 using either aspirin to reduce prostaglandin E production or PTGER3-specific inhibitors effectively prevent resistance from developing. Mechanistically, PTGER3 is rapidly translocated from the plasma membrane to the nucleus after TTFields exposure, where it interacts with ZNF488, a stemness transcription factor tightly linked to PTGER3 in our predicted network to initiate and maintain the resistance program. Indeed, TTFields resistance is associated with a transition to glioma stem cells (GSCs) as determined by increased neurosphere formation and orthotopic tumorigenesis in immunocompromised mice, and PTGER3 inhibition alone reverses the GSC transition leading to improved tumor control and survival.

CONCLUSIONS

PTGER3 is at the apex of a novel pathway that indispensably regulates TTFields resistance through a unique mechanism involving the physical nuclear translocation of this 7-transmembrane receptor. PTGER3 and its pathway are thus potential therapeutic targets to enhance therapeutic efficacy of TTFields.

PATH-30. RAPID AND LOW-COST LIQUID BIOPSY-BASED METHOD FOR SCREENING AND MONITORING OF GBM BY MASTER REGULATORY GENE MARKERS IN GBM STEM-LIKE CELLS

BACKGROUND

Current liquid-based cancer screening relies on massive deep NGS to detect rare cancer-derived genetic materials - a costly method fraught with high false-negative and false-positive rates. We aim to develop a non-NGS-centered, AI-directed liquid-based detection of GBM stem-like cells (GSCs).

METHODS

Utilizing a robust AI suite, NETZEN, we defined a common master regulatory gene network (MRGN) of the GBM state in GSCs. Since master regulators (MRs) in MRGN are developmentally restricted, their chromosomal loci are accessible in GSCs but not in normal cells. Downstream factors in MRGN are massively overexpressed in GSCs compared to normal cells. Thus, we measured the following in PBMCs from healthy controls spiked with known quantities of GSCs and patients with GBM: 1) accessibility of MR genes using transposase/transposons carrying unique barcodes to be inserted into the MR’s predetermined accessible locations, and 2) expression of downstream factors using nested qRT-PCR.

RESULTS

We characterized 10 MRs in GSCs with ≥1 promoter region that is hypomethylated and accessible (by ATACseq) in GBM/GSCs per GSE70175-92460 (19 samples) and GSE67633-96088 (14 samples), or hypermethylated and inaccessible in lymphocytes/PBMCs per GSE98837 (6) and GSE74912 (13). Using barcoded transposons, we specifically disrupted 4 MR’s accessible foci only in GSCs, not in PBMCs. We also identified 50 downstream factors with the top 20 having 3 to 5-orders-of-magnitude higher mean expression in GSCs compared to PBMCs (GSE79362-86884, 451 samples). Currently our method has a detection limit of 0.2-1 GSC per 106 PBMCs. Using the first iteration, we detected MRGN of the GBM state in blood samples of 14 of 14 GBM patients before resection, compared to none of 15 healthy donors.

CONCLUSIONS

Chromosomal accessibility and signal amplification in MRGN of GSCs provide powerful substrates for a non-NGS, low-cost, liquid-based GBM detection system with high sensitivity and specificity. Further testing and optimization are ongoing.

IMMU-46. ARTIFICIAL INTELLIGENCE-DIRECTED, GENE THERAPY-BASED TRANSDIFFERENTIATION OF GLIOBLASTOMA TO FUNCTIONAL DENDRITIC CELLS AS NOVEL CANCER IMMUNOTHERAPY

BACKGROUND

Despite recent advances in tumor immunotherapy in solid tumors, success in GBM remains elusive, likely due to its poor immunogenicity and CNS barriers limiting immune cell trafficking. Here we describe a novel approach of stimulating glioma-specific immunity by transdifferentiating GBM cells in situ to induced dendritic cells (iDCs).

METHODS

We applied NETZEN, an integrated deep-learning and gene network-based ranking computational platform and identified cell fate determinants (CFDs) to convert GBM cells to DCs. CFDs were delivered using a viral vector. Transdifferentiation was assessed by immunophenotyping and iDCs functionally validated by their ability to prime naive T cells.

RESULTS

A four CFDs subnetwork anchored by PU.1 was sufficient to transdifferentiate mouse GBM cells to CD45+MHCII+ cells with high co-stimulatory CD80 expression and to induce nearly 98% of GBM cells to express 100-fold higher levels of MHCI. Consistent with a new identity of antigen-presenting cells (APC), the induced immune cells are growth arrested, exhibit 3-fold higher phagocytic activity and upregulate the canonical antigen processing and presenting machineries by 10-40 folds, resulting in 40-fold greater efficiency at processing ovalbumin and presenting SIINFEKL on MHCI compared to native GBM cells. Importantly, SIINFEKL-loaded iAPCs are capable of activating naive OTII-CD4+ and OTI-CD8+ T cells, indicating that they are DC-like. In addition, iDCs efficiently present tumor cell-intrinsic antigens and elicit &gt;20-fold higher activation and cytotoxicity in tumor-specific T cells compared to native GBM cells. Lastly, intratumoral GBM-DC transdifferentiation in a syngeneic orthotopic GBM model produces a robust memory T cell response in deep cervical draining lymph nodes compared to control animals.

CONCLUSIONS

Our results comfirm that GBM-derived iDCs acquire functions similar to native DCs, and thus, lay the foundation for a novel therapeutic approach in which poorly immunogenic tumors like GBM may be forced to generate their own immunity from within through cell fate transdifferentiation.

CTIM-16. PHASE 2 STUDY OF PEMBROLIZUMAB PLUS TTFields PLUS TEMOZOLOMIDE IN PATIENTS WITH NEWLY DIAGNOSED glioblastoma (2-THE-TOP)

INTRODUCTION

Emerging data indicate that TTFields, the new anti-mitotic treatment for GBM, stimulate immunity via the type-1 interferon (T1IFN) pathway of STING and AIM2 inflammasomes. Thus, we hypothesize that TTFields synergize with immune checkpoint inhibitors to induce anti-tumor immunity in GBM.

METHODS

We conduct a phase 2 study combining pembrolizumab, TTFields and maintenance TMZ in 25 patients with newly diagnosed GBM (ndGBM). To distinguish immune effects of TTFields from pembrolizumab, TTFields is started at cycle 1 of TMZ and pembrolizumab (200mg Q3Wks) at cycle 2. The primary endpoint is PFS vs. the historical control of TTFields plus TMZ (JAMA/318:2306-2316). Secondary endpoints include toxicity, immune signature of TTFields vs. pembrolizumab by single-cell RNAseq of PBMCs, and OS.

RESULTS

As of 05/24/2021, 25 patients with a median age of 61 years were enrolled. Eight (32%) and 4 (16%) had biopsy only and partial resection, respectively. Eighteen (72%) had unmethylated MGMT and 3 (12%) had an IDH mutation. The median follow-up was 14.7 months. Twelve (48%) were progression-free, and 15 (60%) were alive. Of 19 patients with follow-up &gt;=9 months, the median PFS was &gt;=11.2 months vs. 6.7 months in the control. Six (24%) patients with measureable tumors achieved partial to complete response. The most common serious adverse events were thrombosis, seizure, and metabolic disturbances in 4 (16%), 3 (12%), and 2 (8%) patients, respectively. We sequenced 193,760 PBMCs in 12 patients before pembrolizumab and detected robust post-TTFields T cell activation in 11 of 12 patients via the T1IFN trajectory with a strong correlation with the TCRab clonal expansion Simpson index (Spearman coefficient r=-0.8, P=0.014). Importantly, we defined a T cell-based gene signature of TTFields effects on TCRab clonal expansion.

CONCLUSION

The triple combination is well tolerated and shows early evidence of efficacy in ndGBM patients. Survival and molecular data will be updated.

CTIM-11. PHASE 2 STUDY OF SL-701, A NOVEL IMMUNOTHERAPY, IN ADULTS WITH RECURRENT GBM: A HIGH PARAMETER FLOW CYTOMETRY ANALYSIS OF CD8+ T CELLS AND POTENTIAL IMPLICATIONS FOR PATIENT ENRICHMENT STRATEGIES

Treatment of glioblastoma (GBM) remains a critical challenge and unmet medical need due to limited treatment options. SL-701 is a novel immunotherapy comprised of synthetic peptides designed to elicit a target-specific anti-tumor immune response against the GBM antigens IL-13Rα2, ephrinA2, and survivin. A multicenter, 2-stage, phase 2 clinical trial (NCT02078648) that evaluated the safety and efficacy of SL-701 in 74 adults with recurrent GBM was previously reported. This report describes preliminary data to suggest a correlation of immunocompetence to clinical outcome. In stage 2 (SL-701 + bevacizumab + poly-ICLC) the overall survival at 12 months was 50%. Two of 28 patients enrolled in stage 2 achieved CR (duration of response: 7.8 and 8.8 months) and 2 achieved PR (duration of response: 7.9 and 8.8 months). In a preliminary analysis to assess CD8+ T-cell responses, long-term survivors were comprised largely of subjects with an SL-701-induced target-specific CD8+ T-cell response, indicating a potential correlation of immunocompetence to clinical outcome. By week 24, SL-701-induced target-specific CD8+ T cells expressing IFNg were detected in 8 of 27 patients (30%) who had sufficient samples, with co-expression of PD-1, TIM3, and LAG3 detected in 4 patients. To further understand the T-cell response to SL-701, deep sequencing of target-specific CD8+ T cells using whole transcriptome-based molecular cytometry and high parameter (25+ color) flow cytometry is currently underway and updated data will be reported.

CTIM-26. PHASE I/II STUDY OF THE COMBINATION OF PEMBROLIZUMAB (MK-3475) AND LASER INTERSTITIAL THERMAL THERAPY (LITT) IN RECURRENT GLIOBLASTOMA

BACKGROUND

The blood brain barrier (BBB) remains a potential barrier to central nervous system (CNS) penetration of novel immunotherapies in recurrent glioblastoma (rGBM). Laser interstitial thermal therapy (LITT) was recently demonstrated to induce BBB disruption. When combined with anti-PD1 blockade, LITT may therefore potentiate host T-cell mediated cytotoxicity. This phase I/II study aims to evaluate the safety and efficacy of combining LITT and the PD-1 inhibitor pembrolizumab for rGBM.

METHODS

Phase I treated eligible bevacizumab-naïve high grade glioma patients with LITT and the anti-PD1 inhibitor pembrolizumab at 3 dose levels (100, 150, and 200 mg IV Q3W; 3 patients at each level), while phase II was restricted to rGBM patients only with the recommended phase II dose (RP2D) of pembrolizumab. Phase II was initially designed to randomize rGBM to either pembrolizumab or pembrolizumab+LITT but was later amended to receive only pembrolizumab+LITT after 16 patients were randomized (10 pembrolizumab+LITT arm, 6 pembrolizumab-alone arm). Progression-free survival (PFS) and overall survival (OS) were evaluated using the Kaplan Meier method, and adverse events (AE) documented.

RESULTS

Phase I enrolled 9 patients (7 rGBM and 2 anaplastic astrocytomas, 33% IDH-mut, 44% MGMTp-methylated) with no dose limiting toxicities (DLT), prompting selection of 200mg Q3W as the RP2D. Phase II interim analysis included 34 rGBM patients (9% IDH-mut, 50% MGMTp-methylated; 6 receiving pembrolizumab alone and 28 pembrolizumab+LITT) plus two Phase I rGBM patients who received RP2D. On per-protocol analysis, pembrolizumab+LITT cohort had improved PFS (median PFS 10.5 months vs 2.1 months) and OS (median OS 11.4 months vs 5.2 months) than pembrolizumab alone. A single treatment-related grade 3 AE was noted (respiratory infection). CONCLUSION: LITT may be safely combined with pembrolizumab for rGBM with promising clinical outcomes on interim analysis. Enrollment for Phase II, correlative studies, and continued AE documentation are ongoing.

Clinical Trial ID

NCT02311582.

EXTH-51. DEVELOPMENT OF A NOVEL GENE THERAPY APPROACH TARGETING GLIOBLASTOMA FOLLOWING ARTIFICIAL INTELLIGENCE (AI)-DIRECTED IDENTIFICATION OF THE GBM STATE

BACKGROUND

Profound heterogeneity has severely hampered therapeutic advancements in GBM. Remarkably, however, GBM exhibits broad clinical and histopathologic overlaps suggesting the presence of a common state. The GBM state embodies network restructuring forced by founding mutations and perpetuated in subclones of GBM stem-like cells (GSCs). Successful targeting of the GBM state promises to circumvent the heterogeneity.

METHODS

To decipher the GBM state, we applied NETZEN, an AI suite integrating a deep neural network with gene network-based ranking, to first generate the reference GBM gene network from TCGA’s entire GBM RNAseq collection, and then identify the altered master regulatory gene subnetwork in GBM using a dataset containing &gt;30 diverse patient-derived GSC lines and their paired differentiated cells, 6 astrocyte and 3 neuronal precursor cell lines. To develop a gene therapy against the GBM state, we screened a rAAV capsid library through GBM patient-derived xenografts (PDX) to identify variants with specific tropism for GBM cells that can deliver targeting constructs intratumorally.

RESULTS

We discovered a putative GBM state anchored by developmentally restricted master regulators. To validate its critical role, we deconstructed it using shRNA in a panel of PDX and uniformly observed improved tumor control and survival compared to controls (p&lt; 0.05 in all lines). More notably, when the core GBM state was forcibly reconstructed in astrocytes, transformation into GSC-like cells occurred, as measured by single-cell analysis, neurosphere formation, and most importantly, development of lethal infiltrating brain tumors in 15/15 mice. Finally, selected novel rAAV capsids with 10-40-fold higher specificity for GBM cells were utilized in a shRNA-based rAAV platform to target key master regulators of the validated GBM state.

CONCLUSIONS

The GBM state is established by a developmental master regulator subnetwork permitting the creation of a first-of-its-kind, heterogeneity-agnostic GBM therapy. This AI-directed R&D program can be expanded to target other tumors.

Utilizing the Microbiota and Machine Learning Algorithms To Assess Risk of Salmonella Contamination in Poultry Rinsate

ABSTRACT

Traditional microbiological testing methods are slow, and many molecular-based techniques rely on culture-based enrichment to overcome low limits of detection. Recent advancements in sequencing technologies may make it possible to utilize machine learning to identify patterns in microbiome data to potentially predict the presence or absence of pathogens. In this study, 299 poultry rinsate samples from various points in the processing chain were analyzed to determine if microbiota could inform about a sample's risk for containing Salmonella. Samples were culture confirmed as Salmonella positive or negative following modified U.S. Department of Agriculture Microbiological Laboratory Guidebook protocols. The culture confirmation result was used as a reference to compare with 16S sequencing data. Prechill samples tested positive (71 of 82) at a higher frequency than postchill samples (30 of 217) and contained greater microbial diversity. Due to the larger sample size, postchill samples were analyzed more thoroughly. Analysis of variance identified a significant effect of chilling on the number of genera (P < 0.001), but analysis of similarities failed to provide evidence for microbial dissimilarity between pre- and postchill samples (P = 0.001, R = 0.443). Various machine learning models were trained by using postchill samples to predict if a sample contained Salmonella on the basis of the samples' microbiota preenrichment. The optimal model was a random forest-based model with a performance as follows: accuracy (88%), sensitivity (85%), and specificity (90%). Although the algorithms described in this article are prototypes, these risk-based algorithms demonstrate the potential and need for further studies to provide insight alongside diagnostic tests. Combining risk-based information with diagnostic tools can help poultry processors make informed decisions to help identify and prevent the spread of Salmonella. These data add to the growing body of literature exploring novel ways to utilize microbiome data for predictive food safety.

HIGHLIGHTS

Real-world Safety of Bevacizumab with First-line Combination Chemotherapy in Patients with Metastatic Colorectal Cancer: Population-based Retrospective Cohort Studies in Three Canadian Provinces

AIMS

To examine the real-world safety of adding bevacizumab to first-line irinotecan-based chemotherapy for patients with metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS

Patients diagnosed with CRC in three Canadian provinces (Ontario, Saskatchewan and British Columbia) who received publicly funded bevacizumab and/or irinotecan from 2000 to 2016 were identified from cancer registries. Propensity score 1:1 matching (PSM) and inverse probability of treatment weighting (IPTW) were performed to contemporaneous and historical controls, adjusting for baseline demographic and clinical characteristics. Safety end points evaluated during first-line treatment plus 30 days included mortality within 30 days and all-cause-, chemotherapy- and bevacizumab-related hospitalisations. Chemotherapy- and bevacizumab-related visits were defined as hospitalisations for specific conditions commonly associated with chemotherapy (e.g. infections) or bevacizumab (e.g. arteriovenous thromboembolism) using most responsible diagnosis codes. In PSM and IPTW-weighted cohorts, we assessed event frequencies using odds ratios from logistic regressions and event rate ratios using negative binomial regression models. The results from each province and comparison were pooled using random-effects meta-analysis.

RESULTS

We identified 16 250 mCRC patients who received first-line irinotecan-based treatment. In PSM cohorts, bevacizumab was associated with fewer deaths within 30 days of treatment compared with contemporaneous (pooled odds ratio = 0.62; 95% confidence interval 0.50-0.75) and historical controls (pooled odds ratio = 0.73; 95% confidence interval 0.58-0.93). Hospitalisations were more frequent among patients treated with bevacizumab compared with historical controls but similar to contemporaneous controls. As patients receiving bevacizumab were exposed to a longer average treatment duration, across their full treatment duration, patients receiving bevacizumab had significantly lower rates of hospitalisations (contemporaneous pooled rate ratio = 0.56; 95% confidence interval 0.47-0.67; historical pooled rate ratio = 0.73; 95% confidence interval 0.56-0.95). Similar trends were observed for chemotherapy- and bevacizumab-related hospitalisations and in IPTW-weighted cohorts.

DISCUSSION

We did not observe any increase in rates of hospitalisation or death within 30 days of treatment among mCRC patients treated with bevacizumab plus chemotherapy versus chemotherapy alone; these findings should be interpreted with caution due to the risk of residual confounding.

Real-World Cost-Effectiveness of Bevacizumab With First-Line Combination Chemotherapy in Patients With Metastatic Colorectal Cancer: Population-Based Retrospective Cohort Studies in Three Canadian Provinces

Background. Real-world evidence can be a valuable tool when clinical trial data are incomplete or uncertain. Bevacizumab was adopted as first-line therapy for metastatic colorectal cancer (mCRC) based on significant survival improvements in initial clinical trials; however, survival benefit diminished in subsequent analyses. Consequently, there is uncertainty surrounding the cost-effectiveness of bevacizumab therapy achieved in practice. Objective. To assess real-world cost-effectiveness of first-line bevacizumab with irinotecan-based chemotherapy versus irinotecan-based chemotherapy alone for mCRC in British Columbia (BC), Saskatchewan, and Ontario, Canada. Methods. Using provincial cancer registries and linked administrative databases, we identified mCRC patients who initiated publicly funded irinotecan-based chemotherapy, with or without bevacizumab, in 2000 to 2015. We compared bevacizumab-treated patients to historical controls (treated before bevacizumab funding) and contemporaneous controls (receiving chemotherapy without bevacizumab), using inverse-probability-of-treatment weighting with propensity scores to balance baseline covariates. We calculated incremental cost-effectiveness ratios (ICER) using 5-year cost and survival adjusted for censoring, with bootstrapping to characterize uncertainty. We also conducted one-way sensitivity analysis for key drivers of cost-effectiveness. Results. The cohorts included 12,112 (Ontario), 1,161 (Saskatchewan), and 2,977 (BC) patients. Bevacizumab significantly increased treatment costs, with mean ICERs between $78,000 and $84,000/LYG (life-year gained) in the contemporaneous comparisons and $75,000 and $101,000/LYG in the historical comparisons. Reducing the cost of bevacizumab by 50% brought ICERs in all comparisons below $61,000/LYG. Limitations. Residual confounding in observational data may bias results, while the use of original list prices overestimates current bevacizumab cost. Conclusion. The addition of bevacizumab to irinotecan-based chemotherapy extended survival for mCRC patients but at significant cost. At original list prices bevacizumab can only be considered cost-effective with certainty at a willingness-to-pay threshold over $100,000/LYG, but price reductions or discounts have a significant impact on cost-effectiveness.

A Bayesian adaptive randomized phase II multicenter trial of bevacizumab with or without vorinostat in adults with recurrent glioblastoma

BACKGROUND

Bevacizumab has promising activity against recurrent glioblastoma (GBM). However, acquired resistance to this agent results in tumor recurrence. We hypothesized that vorinostat, a histone deacetylase (HDAC) inhibitor with anti-angiogenic effects, would prevent acquired resistance to bevacizumab.

METHODS

This multicenter phase II trial used a Bayesian adaptive design to randomize patients with recurrent GBM to bevacizumab alone or bevacizumab plus vorinostat with the primary endpoint of progression-free survival (PFS) and secondary endpoints of overall survival (OS) and clinical outcomes assessment (MD Anderson Symptom Inventory Brain Tumor module [MDASI-BT]). Eligible patients were adults (≥18 y) with histologically confirmed GBM recurrent after prior radiation therapy, with adequate organ function, KPS ≥60, and no prior bevacizumab or HDAC inhibitors.

RESULTS

Ninety patients (bevacizumab + vorinostat: 49, bevacizumab: 41) were enrolled, of whom 74 were evaluable for PFS (bevacizumab + vorinostat: 44, bevacizumab: 30). Median PFS (3.7 vs 3.9 mo, P = 0.94, hazard ratio [HR] 0.63 [95% CI: 0.38, 1.06, P = 0.08]), median OS (7.8 vs 9.3 mo, P = 0.64, HR 0.93 [95% CI: 0.5, 1.6, P = 0.79]) and clinical benefit were similar between the 2 arms. Toxicity (grade ≥3) in 85 evaluable patients included hypertension (n = 37), neurological changes (n = 2), anorexia (n = 2), infections (n = 9), wound dehiscence (n = 2), deep vein thrombosis/pulmonary embolism (n = 2), and colonic perforation (n = 1).

CONCLUSIONS

Bevacizumab combined with vorinostat did not yield improvement in PFS or OS or clinical benefit compared with bevacizumab alone or a clinical benefit in adults with recurrent GBM. This trial is the first to test a Bayesian adaptive design with adaptive randomization and Bayesian continuous monitoring in patients with primary brain tumor and demonstrates the feasibility of using complex Bayesian adaptive design in a multicenter setting.

Prevalence Study of PD-L1 SP142 Assay in Metastatic Triple-negative Breast Cancer

Metastatic triple-negative breast cancer (mTNBC) is the most aggressive breast cancer subtype. Programmed death ligand 1 (PD-L1) on immune cells (IC) using the VENTANA SP142 assay is linked to improved clinical outcome in atezolizumab plus nab-paclitaxel-treated patients with mTNBC in the IMpassion130 study. The goal of the current study was to evaluate prevalence of VENTANA SP142 PD-L1 assay by anatomic location in 670 histologically confirmed TNBC cases from subjects with metastatic disease screened for the phase 1 study PCD4989g (NCT01375842). PD-L1 immunohistochemistry was centrally tested on tumor cells (TC) and on tumor infiltrating IC, following manufacturer's instructions. At a 1% cutoff, tumor PD-L1 was more prevalent in IC than TC: 46% were PD-L1 IC+/TC-, 3% were PD-L1 IC-/TC+, and 10% were PD-L1 IC+/TC+. PD-L1 IC and TC immunostaining correlated with CD274 RNA expression, as assessed by fluidigm. Analyses of anatomic locations suggest that prevalence of PD-L1 IC+ was highest in lymph nodes (65.0%), lowest in liver metastases (26.9%), while breast tissue was intermediate (57.1%). Matched paired samples from the same subject collected synchronously or asynchronously showed a PD-L1 IC status agreement of 80% (8/10) and 75% (15/20), respectively. Our results suggest that the anatomic location of metastases and time of collection may influence the detection of PD-L1.

Segmental Cardiac Radiation Dose Determines Magnitude of Regional Cardiac Dysfunction

Background

Subclinical left ventricular dysfunction detected by 2‐dimensional global longitudinal strain post breast radiotherapy has been described in patients with breast cancer. We hypothesized that left ventricular dysfunction postradiotherapy may be site specific, based on differential segmental radiotherapy dose received.

Methods and Results

Transthoracic echocardiograms were performed at baseline, 6 weeks, and 12 months postradiotherapy on 61 chemotherapy‐naïve women with left‐sided breast cancer undergoing tangential breast radiotherapy. Radiation received within basal, mid, and apical regions for the 6 left ventricular walls was quantified from the radiotherapy treatment planning system. Anterior, anteroseptal, and anterolateral walls received the highest radiation doses, while inferolateral and inferior walls received the lowest. There was a progressive increase in the radiation dose received from basal to apical regions. At 6 weeks, the most significant percentage deterioration in strain was seen in the apical region, with greatest reductions in the anterior wall followed by the anteroseptal and anterolateral walls, with a similar pattern persisting at 12 months. There was a within‐patient dose–response association between the segment‐specific percentage deterioration in strain at 6 weeks and 12 months and the radiation dose received.

Conclusions

Radiotherapy for left‐sided breast cancer causes differential segmental dysfunction, with myocardial segments that receive the highest radiation dose demonstrating greatest strain impairment. Percentage deterioration in strain observed 6 weeks postradiotherapy persisted at 12 months and demonstrated a dose–response relationship with radiotherapy dose received. Radiotherapy‐induced subclinical cardiac dysfunction is of importance because it could be additive to chemotherapy‐related cardiotoxicity in patients with breast cancer. Long‐term outcomes in patients with asymptomatic strain reduction require further investigation.

COVD-17. TUMOR TREATING FIELDS FOR GLIOBLASTOMA THERAPY DURING THE COVID-19 PANDEMIC: EXPERT CONSENSUS ON USE AND EXPERIENCE

BACKGROUND

The COVID-19 pandemic has placed excessive strain on health care systems and this is especially evident in treatment decision-making for cancer patients. Glioblastoma (GBM) patients are among the most vulnerable due to increased incidence in the elderly (median age 64 years, peak between 75–84 years) and the short survival time. A virtual meeting was convened on May 9, 2020 with a panel of international neuro-oncology experts with hands-on experience using Tumor Treating Fields (TTFields). The objective was to assess the risk-to-benefit and to provide guidance for using TTFields in GBM during the COVID-19 pandemic.

PANEL DISCUSSION

Topics discussed included support and delivery of TTFields during the COVID-19 pandemic, concomitant use of TTFields with chemotherapy, and any potential impact of TTFields on the immune system in an intrinsically immunosuppressed GBM population. Special consideration was given to TTFields’ use in elderly patients and in combination with radiotherapy regimens (standard versus hypo-fractionated). Finally, we discussed the need to better capture COVID-19 positive brain tumor patients to analyze longitudinal outcomes and subtle changes in treatment decision-making during the pandemic.

EXPERT CONSENSUS

TTFields is a portable home-use device which can be managed via telemedicine and safely used in GBM patients during the COVID-19 pandemic. TTFields has no known immunosuppressive effects and is a reliable treatment modality with a relatively favorable side-effect profile. This is important during a crisis where other treatment methods might be limited, especially for elderly patients and patients with multiple co-morbidities. It is too early to estimate the full impact of COVID-19 on the global healthcare system and on patient outcomes and strongly recommended the need to collaborate with existing cancer COVID-19 registries (i.e. CCC19, ESMO-CoCARE, etc.) to follow CNS tumor patients. These efforts would have implications in assessing lessons-learned from this crisis and future guideline development.