The Effects of Preoperative Botulinum Toxin A Injection on Abdominal Wall Reconstruction

BACKGROUND

Fascial closure significantly reduces postoperative complications and hernia recurrence after abdominal wall reconstruction (AWR), but can be challenging in massive ventral hernias.

METHODS

A prospective single-institution cohort study was performed to examine the effects of preoperative injection of botulinum toxin A (BTA) in patients undergoing AWR for midline or flank hernias.

RESULTS

A total of 108 patients underwent BTA injection with average 243 units, mean 32.5 days before AWR, without complications. Comorbidities included diabetes (31%), history of smoking (27%), and obesity (mean body mass index 30.5 ± 7.7). Hernias were recurrent in 57%, massive (mean defect width 15.3 ± 5.5 cm; hernia sac volume 2154 ± 3251 cm³) and had significant loss of domain (mean 46% visceral volume outside abdominal cavity). Contamination was present in 38% of patients. Fascial closure was achieved in 91%, with 57% requiring component separation techniques (CSTs). Subxiphoidal hernias needed a form of CST in 88% compared with 50% for hernia not extending subxiphoidal (P < 0.001). Mesh augmentation was used in 98%. Postoperative complications occurred in 40%: 19% surgical site occurrences, 12% surgical site infections, and 7% respiratory failure requiring intubation, 2% mesh infection and no fascial dehiscence. Recurrence was identified in seven patients after mean 14 months of follow-up. Patients undergoing AWR with CST had more surgical site occurrences (29 versus 7%, p0.003) and respiratory failures (18 versus 0%, P = 0.002) than patients who did not require CST.

CONCLUSIONS

In patients with massive ventral hernias, the use of preoperative BTA injections for AWR is safe and is associated with high fascial closure rates and excellent recurrence rates.

[Management of emergency department inflows during the COVID-19 outbreak in the CHU of Liege : efficiency of an advanced triage center]

In March 2020, the COVID-19 pandemic started to spread among the Belgian territory. Our university hospital was confronted to the very need of specific reorganizations guided by the implementation of the Hospital Emergency Plan.This article aims to describe the experience of the University Hospital of Liège (CHU Liège) during the COVID-19 outbreak and demonstrates the efficiency of advanced triage centers to regulate hospital admissions from the emergency department (ED).

METHODS

since the beginning of March 2020, the CHU of Liège has implemented specific advanced triage centers to manage patients with SARS-CoV-2 suspected symptoms. The first center was organized inside the hospital but the need of outside structures led to the creation of two centers by the end of March. From March 2 to May 3, data from the different visits at the COVID-19 centers were collected (numbers of admissions, rationale for coming, work up and outcome).

RESULTS

during the study period, 3,094 patients were admitted to the specific COVID-19 centers of the CHU Liège. This represents 3,431 visits among which 337 were classified as readmission visits. The sensitivity and specificity of the triage centers to determine the need for hospitalization were, respectively, estimated at 87,9 % and 93,4 %.

CONCLUSION

our experience tends to demonstrate the role of specific COVID-19 triage centers located very close to the EDs aimed at managing COVID-19 suspected patients in order to actually determine their need for subsequent hospitalization.

Immune evasion in renal cell carcinoma: biology, clinical translation, future directions

Targeted therapies and immune checkpoint inhibitors have advanced the treatment landscape of Renal Cell Carcinoma (RCC) over the last decade. While checkpoint inhibitors have demonstrated survival benefit and are currently approved in the front-line and second-line settings, primary and secondary resistance is common. A comprehensive understanding of the mechanisms of immune evasion in RCC is therefore critical to the development of effective combination treatment strategies. This article reviews the current understanding of the different, yet coordinated, mechanisms adopted by RCC cells to evade immune killing; summarizes various aspects of clinical translation thus far, including the currently registered RCC clinical trials exploring agents in combination with checkpoint inhibitors; and provides perspectives on the current landscape and future directions for the field.

Canopy position affects photosynthesis and anatomy in mature Eucalyptus trees in elevated CO2

Leaves are exposed to different light conditions according to their canopy position, resulting in structural and anatomical differences with consequences for carbon uptake. While these structure-function relationships have been thoroughly explored in dense forest canopies, such gradients may be diminished in open canopies, and they are often ignored in ecosystem models. We tested within-canopy differences in photosynthetic properties and structural traits in leaves in a mature Eucalyptus tereticornis canopy exposed to long-term elevated CO2 for up to three years. We explored these traits in relation to anatomical variation and diffusive processes for CO2 (i.e., stomatal conductance, gs and mesophyll conductance, gm) in both upper and lower portions of the canopy receiving ambient and elevated CO2. While shade resulted in 13% lower leaf mass per area ratio (MA) in lower versus upper canopy leaves, there was no relationship between leaf Nmass and canopy gap fraction. Both maximum carboxylation capacity (Vcmax) and maximum electron transport (Jmax) were ~ 18% lower in shaded leaves and were also reduced by ~ 22% with leaf aging. In mature leaves, we found no canopy differences for gm or gs, despite anatomical differences in MA, leaf thickness and mean mesophyll thickness between canopy positions. There was a positive relationship between net photosynthesis and gm or gs in mature leaves. Mesophyll conductance was negatively correlated with mean parenchyma length, suggesting that long palisade cells may contribute to a longer CO2 diffusional pathway and more resistance to CO2 transfer to chloroplasts. Few other relationships between gm and anatomical variables were found in mature leaves, which may be due to the open crown of Eucalyptus. Consideration of shade effects and leaf-age dependent responses to photosynthetic capacity and mesophyll conductance are critical to improve canopy photosynthesis models and will improve understanding of long-term responses to elevated CO2 in tree canopies.

1166 Investigating Social Workers’ Sleep Health Knowledge: Opportunities to Promote Sleep Health Among Underserved Populations

Introduction

Social workers are often front-line psychosocial providers working with underserved populations, many of whom struggle with sleep. They are uniquely positioned to promote sleep health among individuals experiencing health inequities. However, U.S. accredited social work programs do not require sleep health training. We used both quantitative and qualitative methodologies to investigate social work students’: a) sleep health knowledge; b) self-reported sleep quality; c) prior sleep health education; and d) client discussions about sleep, in order to inform the development of a sleep health training for social work students.

Methods

Twenty-five social work students were recruited via a listserv email sent at a Florida university. Participants were asked to complete the Sleep Beliefs Scale (SBS) and the Pittsburgh Sleep Quality Index (PSQI) and then to participate in a one-hour long focus group (3 groups with 6-11 students/group) conducted by experienced qualitative researchers.

Results

Mean age was 27.0±11.5 yrs, 92.0% were female, and 48.0% were non-Hispanic white, 28.0% African American, 16.0% Hispanic, 8.0% other. Only 28.0% indicated that they had ever discussed sleep with clients. Knowledge of healthy sleep behaviors (assessed via the SBS) was moderate on a 0-20 scale (13.88, S.D.= 2.7). Participants had an average PSQI score of 8.8 (SD.=4.0), reported sleeping an average of 6.0 hours (SD=1.6), and mean sleep efficiency of 87.0% (SD=12.0). Themes from focus group data highlight students’ lack of exposure to sleep health training and a dearth of sleep discussions in clinical practice.

Conclusion

Though social work students acknowledged the importance of sleep health promotion, they reported feeling ill-equipped to promote healthy sleep practices due to lack of sleep education. Sleep health training could allow social workers to confidently promote healthy sleep practices among their clients, recognize when appropriate to refer clients for evaluation for sleep disorders, and improve social workers’ own sleep health. An online educational program was subsequently created by study investigators to meet these aims.

Support

American Academy of Sleep Medicine Foundation

1168 Preliminary Impact of a Sleep Health Educational Module for Social Work Students

Introduction

Social workers are well-positioned to promote healthy sleep behaviors among underserved populations; however sleep health training is rarely integrated into social work curriculums. To address this gap, our interdisciplinary team developed a 2-hour online sleep health educational module for social work students. The module was grounded in best e-learning pedagogical principles, and based on qualitative formative research. We tested the initial impact and acceptability of the module.

Methods

We recruited 32 social work students at a Florida University via a departmental listserve. Pre- to post-intervention changes in the Sleep Beliefs Scale (SBS) and the Sleep Practices and Attitudes Questionnaire (SPAQ) were assessed using Wilcoxon Signed-Rank tests. We conducted qualitative research to assess intervention acceptability,and to inform future iterations of the program.

Results

Mean age was 29.5±11.6 yrs, 100% were female, and primarily Non-Hispanic White (41.9%), followed by African American/Black (35.5%), and Hispanic/Latino (22.6%). Results showed pre/post intervention improvements in both the Sleep Beliefs Scale (14.7±2.2 vs.16.9±2.6 [p=.002]; higher score=higher knowledge) and SPAQ (2.1±0.6 to 1.5±0.6 [p=.001]; lower score=higher importance of sleep) indicating improvements in knowledge surrounding healthy sleep behaviors and the importance of sleep for overall health (respectively). Qualitative data supports the intervention’s acceptability and utility. When asked what participants liked best about the module, responses included: “I was educated and am better prepared to offer some insight to my clients and staff”; “..they offer resources we can use for ourselves and our clients;” and “easy to navigage, and full of useful information.” Suggestions for improvement included shortening the module’s length.

Conclusion

Assessment of an online sleep health educational module indicates a promising impact on sleep health knowledge. A larger study is planned to more definitively evaluate the module’s impact and acceptability among social work students.

Support

American Academy of Sleep Medicine Foundation

0750 Nocturnal Sleep Stability and Cerebrospinal Fluid Orexin-A Levels: Sleep and Wake Bouts

Introduction

The orexin (ORX)/hypocretin system stabilizes sleep-wake regulation by sustaining long periods of wakefulness in humans and animals. We aimed to evaluate the relationships between cerebrospinal fluid (CSF) ORX levels and markers of nocturnal sleep stability assessed by polysomnography (PSG) in humans.

Methods

Nocturnal PSG data and CSF ORX levels of 300 drug-free subjects (55% men, 29.9±15.5 years old, mean ORX levels 155.1±153.7 pg/mL) with a complaint of hypersomnolence were collected in the National Reference Center for Narcolepsy, France. Several markers of nocturnal sleep stability were analyzed: wake (WB), sleep bouts (SB), and sleep/wake transitions. Groups were categorized according to ORX levels: two categories (≤110, &gt;110 pg/mL, the current established threshold of ORX-deficiency), and tertiles (≤26,]26;254], &gt;254 pg/mL); and were compared using logistic regression models. Results were adjusted for age, gender and body mass index.

Results

ORX-deficient subjects had more WB, SB, and sleep-wake transitions than the others. The WB duration was longer and the SB duration shorter in ORX-deficient category. The proportion of the shortest WB (30 sec) was lower in the ORX-deficient category whereas the proportion of WB above 1 min 30 sec was higher. The proportion of SB ≤ 14min was higher among ORX-deficient patients, with opposite results for longer SB. Subsequent analyses performed in the population categorized according to tertiles of CSF ORX-A confirmed all these findings, with a strong dose-response effect of ORX levels in post-hoc comparisons. All results remained highly significant in adjusted statistical models.

Conclusion

This study provides a strong evidence of the direct effect of ORX on nocturnal sleep stabilization in humans. WB and SB are reliable markers of nighttime sleep stability, strongly correlated to CSF ORX-A levels in a dose dependent way. These PSG biomarkers are promising to be applied in clinical and research settings.

Support

none

Genomic profiling of prostate cancer at a diverse academic center

64

Background: According to recent reports, ~1 in 4 patients with metastatic prostate cancer may harbor alterations in DNA damage repair (DDR) genes. Clinical trial data demonstrates that prostate cancer patients with DDR mutations may respond to poly-ADP ribose polymerase (PARP) inhibitors. Less is known about the mutational profile in minority patients with prostate cancer. We sought to determine the genomic profile of prostate cancer in an ethnically diverse patient population at a single center. Methods: We performed a retrospective review of men with prostate cancer at the Montefiore-Einstein Cancer Center who had next generation sequencing (NGS) with FoundationOne solid tumor testing between 2/2016 - 8/2019. Individual chart review was used to obtain clinical and demographic data including self-reported race/ethnicity. Results: NGS was attempted on archival tissue from 95 patients and results were obtained for 85. Among patients with results, the self-reported race/ethnicity was: Hispanic (H) 37.6%, Non-Hispanic Black (NHB) 52.9%, Non-Hispanic White (NHW) 4.7%, and Other (O) 4.7%. At the time of tissue sampling, 61 patients had metastatic disease and 10 were castration-resistant. 63 samples were from the prostate, 7 from bone, 7 from lymph node, 3 from liver and 5 from other soft tissue sites. The most commonly altered genes included: TP53 (26%), TMPRSS2-ERG fusion (23%), and PTEN (17%). Alterations in the androgen receptor were identified in 5 samples (all with CRPC). 32.8% had alterations in DDR genes including BRCA2 9 (10.6%), ATM 7 (8.2%), ATR 4 (4.7%), BRIP1 2 (2.3%), CDK12 3 (3.5%), FANCA 2 (2.3%), and PALB2 1 (1.2%). Alterations in mismatch repair genes (MSH2, MLH1, MSH6, PMS2) were present in 4 (4.7%) patients (3 of these were MSI-H). In samples where tumor mutational burden (TMB) was reported, 4 (4.7%) were TMB-high (3 MSI-H and 1 with POLE mutation). Conclusions: DDR gene mutations are common in this primarily minority population. As DDR mutations become more common in the CRPC setting, our data may underestimate the frequency of DDR mutations as only 10 patients had CRPC at the time of tissue sampling. Minority men, like all men, with prostate cancer should be considered for genomic analysis as results are likely to guide therapeutic decisions.

The use of melatonin in adult psychiatric disorders: Expert recommendations by the French institute of medical research on sleep (SFRMS)

Melatonin is a hormone secreted by the pineal gland at night. This hormone has many physiological functions, the main one being to synchronise individuals' biological rhythms. Exogenous melatonin has the same chronobiotic action, even at small doses (0.125mg). In addition, a sleep-inducing (soporific) action appears to occur in a dose-effect relationship, i.e. as the dose increases. In psychiatric disorders, these two effects could have interesting applications in clinical practice. The French institute of medical research on sleep (SFRMS) appointed a group of experts to conduct a consensus conference to study the indications of melatonin and the conditions of its prescription. An account of the conclusions on adult psychiatric disorders (presented orally at the Congress on Sleep in Marseille, 23 November 2017) is given here. Exogenous melatonin proves to be useful among patients with a stabilized psychiatric disorder or in remission, to prevent relapse in case of associated complaints of insomnia, poor quality sleep or delayed sleep phase syndrome. During acute phases, melatonin could be used as an adjuvant treatment when there are insomnia symptoms, in mood disorders (bipolar disorder, major depressive disorder, seasonal affective disorder), in attention deficit hyperactivity disorder (ADHD), in peri-surgical anxiety and in schizophrenia. In somatoform disorders, melatonin is a possible treatment for painful symptoms in fibromyalgia, irritable bowel syndrome, functional dyspeptic syndrome and temporomandibular joint dysfunction.

Practical considerations for the evaluation and management of Attention Deficit Hyperactivity Disorder (ADHD) in adults

Attention deficit with or without hyperactivity disorder (ADHD) is one of the most frequent neuropsychiatric disorders, and affects 2-4% of adults. In contrast with many European countries, the identification and management of adult ADHD remains underdeveloped in France, and a subject of controversy. This review provides a practical update on current knowledge about ADHD in adults for French-speaking professionals who have to detect or manage adult patients with ADHD. ADHD is classified as a neurodevelopmental disorder in the recent update of the international diagnostic classification. While symptoms and impairment due to ADHD are frequently severe during childhood, they often evolve as children grow older, with frequent persistent disabilities in adulthood. In adulthood, the clinical presentation, as in childhood, involves the symptom triad of inattention, hyperactivity and impulsivity. However, differences are noted: hyperactivity is more often internalized, symptoms of inattention may be masked by anxiety symptoms or obsessive-like compensation strategies. ADHD is often diagnosed during childhood, but it is not rare for the diagnosis to be made later. Failure to recognise symptoms resulting in misdiagnosis, or alternatively well-developed compensation factors could be two underlying reasons for the long delay until diagnosis. Other symptoms, such as emotional deregulation or executive function-related symptoms are also usually observed in adults. In addition, in adults, ADHD is often associated with other psychiatric disorders (in 80% of cases); this makes the diagnosis even more difficult. These disorders encompass a broad spectrum, from mood disorders (unipolar or bipolar), to anxiety disorders, and other neurodevelopmental disorders and personality disorders, especially borderline and antisocial personality disorder. Substance-use disorders are very common, either as a consequence of impulsivity and emotional dysregulation or as an attempt at self-treatment. Sleep disorders, especially restless leg syndrome and hypersomnolence, could share common pathophysiological mechanisms with ADHD. ADHD and comorbidity-related symptoms are responsible for serious functional impairment, in various domains, leading to academic, social, vocational, and familial consequences. The impact on other psychiatric disorders as an aggravating factor should also be considered. The considerable disability and the poorer quality of life among adults with ADHD warrant optimal evaluation and management. The diagnostic procedure for ADHD among adults should be systematic. Once the positive diagnosis is made, the evaluation enables characterisation of the levels of severity and impairment at individual level. A full examination should also assess medical conditions associated with ADHD, to provide personalized care. In recent years, a growing number of assessment tools have been translated and validated in French providing a wide range of structured interviews and standardized self-report questionnaires for the evaluation of core and associated ADHD symptoms, comorbidities and functional impairment. The treatment of ADHD in adults is multimodal, and aims to relieve the symptoms, limit the burden of the disease, and manage comorbidities. The most relevant and validated psychological approaches are psycho-education, cognitive-behavioural therapy and "third wave therapies" with a specific focus on emotional regulation. Cognitive remediation and neurofeedback are promising strategies still under evaluation. Medications, especially psychostimulants, are effective for alleviating ADHD symptoms with a large effect size. Their safety and tolerance are satisfactory, although their long-term clinical benefit is still under discussion. In France, methylphenidate is the only stimulant available for the treatment of ADHD. Unfortunately, there is no authorization for its use among adults except in continuation after adolescence. Hence the prescription, which is subject to the regulations on narcotics, is off-label in France. This article aims to provide practical considerations for the management of ADHD and associated disorders in adults, in this particular French context.

Interhospital Sepsis Code in Catalonia (Spain): Territorial model for initial care of patients with sepsis

Sepsis is a syndromic entity with high prevalence and mortality. The management of sepsis is standardized and exhibits time-dependent efficiency. However, the management of patients with sepsis is complex. The heterogeneity of the forms of presentation can make it difficult to detect and manage such cases, in the same way as differences in training, professional competences or the availability of health resources. The Advisory Commission for Patient Care with Sepsis (CAAPAS), comprising 7 scientific societies, the Emergency Medical System (SEM) and the Catalan Health Service (CatSalut), have developed the Interhospital Sepsis Code (CSI) in Catalonia (Spain). The general objective of the CSI is to increase awareness, promote early detection and facilitate initial care and interhospital coordination to attend septic patients in a homogeneous manner throughout Catalonia.

Is There a Role for pH Impedance Monitoring in Identifying Eosinophilic Esophagitis in Children with Esophageal Atresia?

OBJECTIVES

To evaluate clinical, endoscopic, and pH-impedance measures in a cohort of children with esophageal atresia and concomitant eosinophilic esophagitis (EoE) and compared it with disease-matched controls, to identify predictive factors for the development of EoE and esophageal stricture.

STUDY DESIGN

We reviewed 63 patients with esophageal atresia assessed for refractory upper gastrointestinal symptoms between January 2015 and September 2017 at 2 tertiary referral centers. All patients underwent upper gastrointestinal endoscopy and pH-impedance monitoring. Based on esophageal histology, patients were classified as (1) esophageal atresia without evidence of esophagitis; (2) esophageal atresia with evidence of esophagitis (including esophageal eosinophilia not meeting the criteria for EoE); (3) esophageal atresia with concomitant EoE. Age and sex matched patients with gastroesophageal reflux disease were used as disease controls.

RESULTS

The presence of atopy and peripheral eosinophilia at baseline were significantly associated with EoE (P < .05). Although there was a tendency toward an increased number of strictures in patients with esophageal atresia-EoE, this did not reach statistical significance (P = .06). Higher esophageal acid exposure time and lower baseline impedance values were significantly associated with eosinophilic infiltration (P < .05 and P < .01, respectively). Using logistic regression analysis, the presence of mucosal eosinophilia was the most predictive factor for stricture formation (P < .05).

CONCLUSIONS

A history of atopy and the presence of peripheral eosinophilia in patients with esophageal atresia are predictive factors for the development of EoE, which in turn is a predictive factor for stricture occurrence. Higher esophageal acid exposure time and lower baseline impedance are associated with esophageal eosinophilic infiltration, suggesting their value in selecting which patients with esophageal atresia should undergo endoscopic examination.

Regulation of PGLYRP1 and TREM-1 during Progression and Resolution of Gingival Inflammation

INTRODUCTION

The triggering receptor expressed on myeloid cells 1 (TREM-1) signaling pathway is stimulated by bacteria and, together with its putative ligand peptidoglycan recognition protein 1 (PGLYRP1), propagates proinflammatory responses.

OBJECTIVES

We aimed to evaluate the TREM-1/PGLYRP1/interleukin (IL)-1β regulation in response to biofilm accumulation and removal in an experimental human gingivitis model.

METHODS

The study (n = 42 participants, mean age: 23.8 ± 3.7 y) comprised a recruitment step (day -14) followed by experimentally induced biofilm formation (induction [I] phase, day 0 to +21) and a 2-wk resolution (R) phase (day +21 to +35). Plaque was recorded by the Modified Quigley and Hein Plaque Index (TQHPI), while records of gingival inflammation were based on the Modified Gingival Index (MGI). Unstimulated whole saliva supernatants (n = 210, 5 time points) were tested for TREM-1, PGLYRP1, and IL-1β by enzyme-linked immunosorbent assay.

RESULTS

During the I-phase, concentrations of all analytes showed a tendency for downregulation at day +7 compared to day 0. TREM-1 (P = 0.019) and PGLYRP1 (P = 0.007) increased significantly between day +7 and day +21. Although all analyte levels decreased during the R-phase, the difference was not significant except TREM-1 being at borderline significance (P = 0.058). Moreover, TREM-1, PGLYRP1, and IL-1β showed significant positive correlations (P < 0.0001) with each other. The study participants were grouped into "fast" and "slow" responders based on clinical gingival inflammation scores. At each time point, fast responders showed significantly higher concentrations of TREM-1 (P < 0.025), PGLYRP1 (P < 0.007), and IL-1β (P < 0.025) compared to slow responders. Mixed-effects multilevel regression analyses revealed that PGLYRP1 (P = 0.047) and IL-1β (P = 0.005) showed a significant positive association with the MGI scores.

CONCLUSION

The study demonstrated that TREM-1 and PGLYRP1 are regulated in response to biofilm accumulation and removal, and fast responders demonstrated higher levels of these analytes compared to slow responders.

KNOWLEDGE TRANSFER STATEMENT

The results of this study demonstrated the suitability of salivary TREM-1 and PGLYRP1 to reflect biofilm accumulation and removal and PGLYRP1 to monitor the progression and resolution of inflammation in gingivitis-susceptible individuals (fast responders). Combined with conventional risk factors, the molecular toolbox proposed here should be further validated in future studies to confirm whether it can be used for population-based monitoring and prevention of gingivitis.

It's About Everything: Validation and Optimization of 96-Well Tray Flow Cytometry Crossmatch

Flow cytometric crossmatch (FCXM) is widely used in many centers as part of pretransplant risk assessment to detect donor-specific anti-HLA antibodies. The limited number of crossmatches that can be performed during on-call work-up for deceased donors within reasonable time remains the main obstacle to accommodating the majority of highly sensitized listed patients to be tested by the standard tube FCXM method. This limitation often directs the organs to nonsensitized patients and deprives highly sensitized patients who could be compatible if their sera were included in the crossmatch test. The goal of this study is to optimize a 96-well tray FCXM protocol that allows more sera to be crossmatched without prolonging the overall procedural time while maintaining quality and sensitivity of the assay. The new method was validated against use of the standard tube method and included total of 63 crossmatches performed simultaneously by both methods using 20 donors' cells with patients' sera, pooled positive controls tested on different dilutions, and commercial negative control. In the new protocol we modify various assay parameters including tube platform, incubation time, amount of reagent antibody cocktail, and cell volumes. An overall concordance of 98% was achieved with the protocols with slight improvement in sensitivity (2 negative B-cell reactions converted to positive in presence of weak donor-specific antibodies and mild T-cell reactivity could be picked up at 1:80 diluted positive control by the tray method only). The median channel fluorescence values of the 2 methods were essentially equivalent for both T and B crossmatches (r² of 0.98 and 0.97, respectively). In conclusion, 96-well tray assay has the potential to increase the probability of highly sensitized patients receiving transplants by allowing increased number of crossmatches to be performed with significant reduction in turnaround time and assay cost. Furthermore, the enhanced sensitivity of the assay will provide more accurate information about sensitization status and strength of donor-specific antibodies to treating physicians, allowing them to choose the best therapeutic option and to provide better patient care.

Abstract P6-17-07: Gene signatures and subtype changes during HER2 dual blockade in PAM50 HER2-enriched HER2-positive breast cancer

Background: HER2-positive (HER2+) breast cancer (BC) is composed of 4 molecular subtypes: Luminal A and B, HER2-enriched (HER2-E) and Basal-like. Among them, the HER2-E is highly sensitive to anti-HER2 treatment. However, ˜60% of HER2-E tumors do not achieve a pathological complete response (pCR) following neoadjuvant dual HER2 blockade without chemotherapy. Here, we aimed to better understand the molecular changes of the HER2-E subtype during anti-HER2 treatment.

Methods: Gene expression was evaluated in 101 patients with HER2-E tumors from the PAMELA neoadjuvant phase II trial (Lancet Oncol 2017). Briefly, women with HER2+ BC were treated with lapatinib and trastuzumab (and hormonal therapy if hormone receptor [HR]-positive) for 18 weeks. The median time between the last dose of treatment and surgery was 35 days (range=213; interquartile range=16). Expression of the PAM50 genes and 6 PAM50 signatures (Luminal A, Luminal B, HER2-E, Basal-like, normal-like and the PAM50 proliferation score) were determined using the nCounter platform at baseline (n=101), after 2 weeks of treatment (n=96) and in residual tumors (non-pCR) at surgery (n=57). Same analyses were done in 2 HER2+/HER2-E cell line models (BT474 [HR+] and SKBR3 [HR-]) following in vitro treatment with trastuzumab in combination with lapatinib. Biological changes between 2 time-points were determined by paired t-tests with a false discovery rate (FDR) &lt;5%.

Results: After 2 weeks of treatment, 85.7% and 94.6% of the 56 genes/signatures were found differentially expressed (FDR&lt;5%) in HER2-E/HR+ (n=35) and HER2-E/HR- (n=61) tumors, respectively. The two gene lists were highly correlated (correlation coefficient=0.93). Overall, a significant relative increase in Luminal A and normal-like signature scores, and a relative decrease in proliferation, HER2-E and Luminal B signature scores, were observed between baseline and week 2. Interestingly, a PAM50 subtype switch to Luminal A was observed in 31.6% and 4.8% of HER2-E/HR+ and HER2-E/HR- tumors. In BT474 and SKBR3, all genes/signatures were also found differentially expressed (FDR&lt;5%) following 72h of dual HER2 blockade. The in vitro findings recapitulated the in vivo findings in 80-86% of the genes/signatures. Similar to tumors, a switch to a Luminal A subtype following dual HER2 blockade was observed in BT474 but not in SKBR3. Finally, 92.9% of the 56 genes/signatures were found differentially expressed (FDR&lt;5%) in residual tumors at surgery compared to week 2. Contrary to the findings in the first 2 weeks of treatment, a general rebound effect in gene expression was observed between week 2 and surgery. Similarly, a rebound effect was observed in 60% of the genes/signatures in BT474 after removing anti-HER2 therapy for 72h, leading to a subtype switch from Luminal A back to HER2-E.

Conclusions: Dual HER2 blockade in the HER2-E subtype induces large biological changes that lead to a more low-proliferative Luminal A phenotype both in tumors and in vitro models, especially in HER2-E/HR+ disease. These phenotypic changes are reversible upon stopping anti-HER2 treatment. This finding supports the use of maintenance anti-HER2 treatment +/- endocrine therapy (if HR+) in advanced HER2+ BC.

Citation Format: Brasó-Maristany F, Griguolo G, Llombart-Cussac A, Pascual T, Paré L, Bermejo B, Oliveira M, Morales S, Martinez N, Vidal M, Pernas S, Lopez R, Muñoz M, Galvan P, Garau I, Manso L, Alarcón J, Martínez E, Villagrasa P, Cortés J, Prat A. Gene signatures and subtype changes during HER2 dual blockade in PAM50 HER2-enriched HER2-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 P6-17-07.

Abstract P6-17-08: Dynamics of tumor-infiltrating lymphocytes (TILs) during neoadjuvant dual HER2 blockade in HER2-positive (HER2+) breast cancer in the absence of chemotherapy

Background: TILs in HER2+ breast cancer (BC) predict 1) prognosis in early setting, 2) complete pathological response (pCR) following neoadjuvant antiHER2-based therapy and 3) response to trastuzumab and pembrolizumab in the metastatic setting. However, less is known regarding changes in TILs during antiHER2-based treatment.

Methods: Stromal TILs where evaluated centrally using H/E slides in tumor samples from the PAMELA (NCT01973660) neoadjuvant phase II trial. Briefly, 151 women with HER2+ BC were treated with lapatinib and trastuzumab, and hormonal therapy if HR positive, for 18 weeks. TIL levels were determined at baseline (n=148), after 2 weeks of treatment (n=134) and at surgery (n=137). Expression of 560 genes, including immune-related genes (e.g. CD8A, CD4, PD1 and PDL1) was measured at the same timepoints (baseline n=151, 2-weeks n=144, surgery n=144) using the nCounter platform. Intrinsic subtyping at baseline was determined using the PAM50 gene expression predictor. Changes in TILs between 2 time-points were determined by paired t-tests. Correlation of TILs with gene expression was assessed by quantitative SAM analysis using a False Discovery Rate &lt;1%. All statistical tests were two-sided and considered significant when p&lt;0.05. All statistical analyses were carried out using the R software.

Results: Compared to baseline, a significant increase in TILs was observed at week 2 in HR- (p&lt;0.001) and HER2-enriched (HER2-E) tumors (p=0.001), but not in HR+ (p=0.133) and non-HER2-E tumors (p=0.067). Within HR- and HER2-E tumors, increase in TILs at week 2 from baseline was observed regardless of pathological response at surgery (pCR and HR- [p=0.008]; RD and HR- [p=0.037]; pCR and HER2-E [p=0.010]; RD and HER2-E [p=0.056]). Compared to week 2, a significant decrease in TILs at surgery was observed in HR- (p=0.002) and HER2-E (p=0.003) tumors, but not in HR+ (p=0.616) and non-HER2-E tumors (p=0.578). Within HR- and HER2-E tumors, a significant decrease in TILs between week 2 and surgery was observed in tumors achieving pCR (p=0.004 and p=0.005), while, in tumors not achieving pCR, no significant tendency was observed (26.4% and 33.0% of tumors showed an increase and a decrease of TILs between week 2 and surgery). Nonetheless, the vast majority of residual tumors (non-pCR) at surgery had TILs above ≥5%: 34.3% 5-10%, 21.0% 10-20%, 15.2% 20-40% and 11.4% ≥40%. Finally, TILs scoring was found highly enriched (FDR&lt;1%) for immune-related genes tracking activated CD8 T-cells (i.e. CD8A, CD3G, LAG3 and PD1). Expression of these immune genes consistently correlated with TIL levels across the 3 time-points.

Conclusions: In early HER2+ BC, a general increase in TILs is observed following 2 weeks of dual HER2 blockade. This observation is mostly observed in HR- and HER2-E subtype, but regardless of pathological response at surgery. After 2 weeks of treatment, TILs consistently decrease in patients achieving a pCR, whereas two main patterns of TILs expression are observed in patients with residual disease at surgery. Nonetheless, most residual tumors at surgery are inflamed (i.e. TILs ≥5%) and might be good candidates for clinical trials evaluating adjuvant immune checkpoint inhibitors.

Citation Format: Griguolo G, Holgado E, Cortés J, Fasani R, Pascual T, Paré L, Bermejo B, Oliveira M, Morales S, Martinez N, Vidal M, Pernas S, Lopez R, Muñoz M, Galvan P, Garau I, Manso L, Alarcón J, Martínez E, Villagrasa P, LLombart-Cussac A, Prat A, Nuciforo P. Dynamics of tumor-infiltrating lymphocytes (TILs) during neoadjuvant dual HER2 blockade in HER2-positive (HER2+) breast cancer in the absence of chemotherapy [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 P6-17-08.