Single pulmonary nanopolystyrene exposure in late-stage pregnancy dysregulates maternal and fetal cardiovascular function

Large-scale production and waste of plastic materials have resulted in widespread environmental contamination by the breakdown product of bulk plastic materials to micro- and nanoplastics (MNPs). The small size of these particles enables their suspension in the air, making pulmonary exposure inevitable. Previous work has demonstrated that xenobiotic pulmonary exposure to nanoparticles during gestation leads to maternal vascular impairments, as well as cardiovascular dysfunction within the fetus. Few studies have assessed the toxicological consequences of maternal nanoplastic (NP) exposure; therefore, the objective of this study was to assess maternal and fetal health after a single maternal pulmonary exposure to polystyrene NP in late gestation. We hypothesized that this acute exposure would impair maternal and fetal cardiovascular function. Pregnant rats were exposed to nanopolystyrene on gestational day 19 via intratracheal instillation. 24 h later, maternal and fetal health outcomes were evaluated. Cardiovascular function was assessed in dams using vascular myography ex vivo and in fetuses in vivo function was measured via ultrasound. Both fetal and placental weight were reduced after maternal exposure to nanopolystyrene. Increased heart weight and vascular dysfunction in the aorta were evident in exposed dams. Maternal exposure led to vascular dysfunction in the radial artery of the uterus, a resistance vessel that controls blood flow to the fetoplacental compartment. Function of the fetal heart, fetal aorta, and umbilical artery after gestational exposure was dysregulated. Taken together, these data suggest that exposure to NPs negatively impacts maternal and fetal health, highlighting the concern of MNPs exposure on pregnancy and fetal development.

Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU): Trial Satisfaction and Attitudes towards Future Clinical Trials

BACKGROUND

Clinical trial satisfaction is increasingly important for future trial designs and is associated with treatment adherence and willingness to enroll in future research studies or to recommend trial participation. In this post-trial survey, we examined participant satisfaction and attitudes toward future clinical trials in the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU).

METHODS

We developed an anonymous, participant satisfaction survey tailored to participants enrolled in the DIAN-TU-001 double-blind clinical trial of solanezumab or gantenerumab and requested that all study sites share the survey with their trial participants. A total of 194 participants enrolled in the trial at 24 study sites. We utilized regression analysis to explore the link between participants' clinical trial experiences, their satisfaction, and their willingness to participate in upcoming trials.

RESULTS

Survey responses were received over a sixteen-month window during 2020-2021 from 58 participants representing 15 study sites. Notably, 96.5% of the survey respondents expressed high levels of satisfaction with the trial, 91.4% would recommend trial participation, and 96.5% were willing to enroll again. Age, gender, and education did not influence satisfaction levels. Participants reported enhanced medical care (70.7%) and pride in contributing to the DIAN-TU trial (84.5%). Satisfaction with personnel and procedures was high (98.3%). Respondents had a mean age of 48.7 years, with most being from North America and Western Europe, matching the trial's demographic distribution. Participants' decisions to learn their genetic status increased during the trial, and most participants endorsed considering future trial participation regardless of the DIAN-TU-001 trial outcome.

CONCLUSION

Results suggest that DIAN-TU-001 participants who responded to the survey exhibited high motivation to participate in research, overall satisfaction with the clinical trial, and willingness to participate in research in the future, despite a long trial duration of 4-7 years with detailed annual clinical, cognitive, PET, MRI, and lumbar puncture assessments. Implementation of features that alleviate barriers and challenges to trial participation is like to have a high impact on trial satisfaction and reduce participant burden.

Comparison of imputation methods for missing production data of dairy cattle

Nowadays, vast amounts of data representing feed intake, growth, and environmental impact of individual animals are being recorded in on-farm settings. Despite their apparent use, data collected in real-world applications often have missing values in one or several variables, due to reasons including human error, machine error, or sampling frequency misalignment across multiple variables. Since incomplete datasets are less valuable for downstream data analysis, it is important to address the missing value problem properly. One option may be to reduce the dataset to a subset that contains only complete data, but considerable data may be lost via this process. The current study aimed to compare imputation methods for the estimation of missing values in a raw dataset of dairy cattle including 454 553 records collected from 629 cows between 2009 and 2020. The dataset was subjected to a cleaning process that reduced its size to 437 075 observations corresponding to 512 cows. Missing values were present in four variables: concentrate DM intake (CDMI, missing percentage = 2.30%), forage DM intake (FDMI, 8.05%), milk yield (MY, 15.12%), and BW (64.33%). After removing all missing values, the resulting dataset (n = 129 353) was randomly sampled five times to create five independent subsets that exhibit the same missing data percentages as the cleaned dataset. Four univariate and nine multivariate imputation methods (eight machine learning methods and the MissForest method) were applied and evaluated on the five repeats, and average imputation performance was reported for each repeat. The results showed that Random Forest was overall the best imputation method for this type of data and had a lower mean squared prediction error and higher concordance correlation coefficient than the other imputation methods for all imputed variables. Random Forest performed particularly well for imputing CDMI, MY, and BW, compared to imputing FDMI.

Nanoparticles at the maternal-fetal interface

The increasing production of intentional and unintentional nanoparticles (NPs) has led to their accumulation in the environment as air and ground pollution. The heterogeneity of these particles primarily relies on the NP physicochemical properties (i.e., chemical composition, size, shape, surface chemistry, etc.). Pregnancy represents a vulnerable life stage for both the woman and the developing fetus. The ubiquitous nature of these NPs creates a concern for developmental fetal exposures. At the maternal-fetal interface lies the placenta, a temporary endocrine organ that facilitates nutrient and waste exchange as well as communication between maternal and fetal tissues. Recent evidence in human and animal models identifies that gestational exposure to NPs results in placental translocation leading to local effects and endocrine disruption. Currently, the mechanisms underlying placental translocation and cellular uptake of NPs in the placenta are poorly understood. The purpose of this review is to assess the current understanding of the physiochemical factors influencing NP translocation, cellular uptake, and endocrine disruption at the maternal-fetal interface within the available literature.

Effectiveness and Toxicity of Five Fraction Prone Accelerated Partial Breast Irradiation

PURPOSE/OBJECTIVE(S)

Accelerated partial breast irradiation (APBI) after breast conserving therapy (BCT) is increasingly used to treat women with early stage breast cancer. Our institution was an early adopter of 5-fraction ABPI and delivers APBI primarily to patients in the prone position. This study reports long term oncologic and cosmetic outcome in a large cohort of women treated with 5-fraction external beam APBI.

MATERIALS/METHODS

We included patients receiving APBI 600 cGy × 5 fx delivered every other day or every day between 2010 and 2022. Late toxicities and clinician and patient rated cosmesis were evaluated for patients with > 6 month follow up. Univariate and multivariate logistic regression models were used to identify clinical and dosimetric factors associated with development of acute and late toxicities, clinician and patient rated cosmesis. All statistical tests were two-sided, and the null hypothesis was rejected for p<0.05. Kaplan Meier methodology was used to calculate overall survival (OS), disease-free survival (DFS) and locoregional recurrence-free survival (LR-RFS).

RESULTS

Four hundred and forty-two patients received APBI either daily (56%) or every other day (44%). Most of the patients (92%) were treated in the prone position. Average mean heart dose was 23 cGy for left-sided and 11 cGy for right-sided breast cancers. Ipsilateral lung V30% ≤ 30%. At a median follow up of 48 months (range: 5.96 - 155 months), 12 (2.7%) patients developed a local recurrence, 14 (3.2%) patients developed a contralateral breast primary, 10 patients (2.3%) developed a distant metastasis and one patient (0.2%) developed a local recurrence followed by a distant metastasis 1 month later. Out of 258 patients with > 6 month follow up, rates of late grade 1-2 telangiectasia, fibrosis, edema, atrophy and hyperpigmentation were 4%, 18%, 1%, 19% and 7% respectively. There was only one late grade 3 event in a patient who developed significant breast atrophy. The rate of good-excellent physician and patient rated cosmesis was 95% and 89% respectively (N = 256 at median follow up of 80 months). On multivariate logistic regression, patients who did not receive any adjuvant endocrine or chemotherapy were at increased risk of developing a local recurrence. Patients with PR negative disease were at increased risk of distant metastasis. Patient who experienced any grade of acute dermatitis during treatment were at increased risk of any high grade (grade ≥ 2) late adverse event and worse physician rated cosmesis. Daily or every other day treatment did not correlate with worse toxicity or clinical outcomes. Plastic surgery involvement, LVI, EIC, lobular histology, and ER negativity did not correlate with an increased risk of recurrence. Five-year LR-RFS, DFS and OS were 98%, 92.5% and 98.6% respectively.

CONCLUSION

Five- fraction APBI delivered primarily in the prone position either daily or every other day was effective with low rates of local recurrence, minimal toxicity and excellent cosmetic scores at long term follow up.

Laparoscopy uptake for paediatric appendicectomy: a comparison of general surgeons versus specialist paediatric surgeons in England from 1997 to 2015

INTRODUCTION

Laparoscopy is used in as many as 95% of adult appendicectomies. There is level I evidence showing that it reduces wound infection, postoperative ileus and length of inpatient stay in children compared with the open approach. The aim of this study was to report the uptake of laparoscopy for paediatric appendicectomy in England and to determine whether this was similar for general surgeons (GS) and specialist paediatric surgeons (SPS).

METHODS

Hospital Episode Statistics data were obtained for all children aged <16 years who had an OPCS 4.6 code for emergency appendicectomy from 1997 to 2015 (18 years). Data are analysed to compare rate of laparoscopic vs open procedures for GS and SPS over time and to investigate factors associated with the use of laparoscopy.

RESULTS

There were 196,987 appendicectomies and where specialty was available, 133,709 (79%) cases were undertaken by GS and 35,141 (21%) by SPS. The rate of cases undertaken with laparoscopy for both specialties combined increased from 0.8% in 1998 to 50% in 2014 (p<0.0001). In 2014, this rate was 41% for GS compared with 71% for SPS (p<0.0001). Female gender (odds ratio (OR)=1.84, 95% confidence interval (CI) 1.80-1.90), increasing age (OR=1.18, 95% CI 1.18-1.19 per year) and treatment by SPS (OR=3.71, 95% CI 3.60-3.82) were all factors positively associated with use of laparoscopy in multivariate analysis.

CONCLUSIONS

There has been a vast increase in the proportion of appendicectomies undertaken laparoscopically in children. Despite adjusting for patient factors, laparoscopy was used significantly less by GS when compared with SPS. This difference is most apparent in younger children.

The consequences of hyperphagia in people with Prader-Willi Syndrome: A systematic review of studies of morbidity and mortality

Prader-Willi Syndrome (PWS) is a multi-system genetically determined neurodevelopmental disorder and the commonest cause of syndromal obesity. The development of hyperphagia in early childhood is part of the phenotype arising as a result of an impaired neural response to food intake and the inability to regulate food intake in line with energy needs. Severe obesity develops if access to food is not controlled. In this review we evaluate the evidence for increased morbidity and mortality in PWS in order to establish the extent to which it is directly related to the obesity; a consequence of the eating behaviour itself independent of obesity; or associated with other characteristics of the syndrome. Medline, Cochrane, PsychINFO, CINAHL, Web of Science and Scopus databases were used to systematically identify published material on PWS and hyperphagia and syndrome-related morbidity and mortality. One hundred and ten key papers were selected. Data on 500 people with PWS indicated that the average age of death was 21 years and obesity was, as expected, a significant factor. However, the behaviour of hyperphagia itself, independent of obesity, was also important, associated with choking, gastric rupture, and/or respiratory illness. Other syndrome-related factors increased the risk for, and seriousness of, co-morbid illness or accidents. We conclude that improving life-expectancy largely depends on managing the immediate non-obesity and obesity-related consequences of the hyperphagia, through improved support. The development of new treatments that significantly reduce the drive to eat are likely to decrease morbidity and mortality improving quality of life and life expectancy.

A position statement and practical guide to the use of particulate filtering facepiece respirators (N95, FFP2, or equivalent) for South African health workers exposed to respiratory pathogens including Mycobacterium tuberculosis and SARS-CoV-2

SUMMARY

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is transmitted mainly by aerosol in particles <10 µm that can remain suspended for hours before being inhaled. Because particulate filtering facepiece respirators ('respirators'; e.g. N95 masks) are more effective than surgical masks against bio-aerosols, many international organisations now recommend that health workers (HWs) wear a respirator when caring for individuals who may have COVID-19. In South Africa (SA), however, surgical masks are still recommended for the routine care of individuals with possible or confirmed COVID-19, with respirators reserved for so-called aerosol-generating procedures. In contrast, SA guidelines do recommend respirators for routine care of individuals with possible or confirmed tuberculosis (TB), which is also transmitted via aerosol. In health facilities in SA, distinguishing between TB and COVID-19 is challenging without examination and investigation, both of which may expose HWs to potentially infectious individuals. Symptom-based triage has limited utility in defining risk. Indeed, significant proportions of individuals with COVID-19 and/or pulmonary TB may not have symptoms and/or test negative. The prevalence of undiagnosed respiratory disease is therefore likely significant in many general clinical areas (e.g. waiting areas). Moreover, a proportion of HWs are HIV-positive and are at increased risk of severe COVID-19 and death.

RECOMMENDATIONS

Sustained improvements in infection prevention and control (IPC) require reorganisation of systems to prioritise HW and patient safety. While this will take time, it is unacceptable to leave HWs exposed until such changes are made. We propose that the SA health system adopts a target of 'zero harm', aiming to eliminate transmission of respiratory pathogens to all individuals in every healthcare setting. Accordingly, we recommend: the use of respirators by all staff (clinical and non-clinical) during activities that involve contact or sharing air in indoor spaces with individuals who: (i) have not yet been clinically evaluated; or (ii) are thought or known to have TB and/or COVID-19 or other potentially harmful respiratory infections;the use of respirators that meet national and international manufacturing standards;evaluation of all respirators, at the least, by qualitative fit testing; andthe use of respirators as part of a 'package of care' in line with international IPC recommendations. We recognise that this will be challenging, not least due to global and national shortages of personal protective equipment (PPE). SA national policy around respiratory protective equipment enables a robust framework for manufacture and quality control and has been supported by local manufacturers and the Department of Trade, Industry and Competition. Respirator manufacturers should explore adaptations to improve comfort and reduce barriers to communication. Structural changes are needed urgently to improve the safety of health facilities: persistent advocacy and research around potential systems change remain essential.

505 Failed Femoral Nail with Significant Operative Technical Difficulty: A Practical Solution to Achieve Metalwork Extraction Using Conical Screw Remover

Introduction

There is a greater risk of delayed healing and revision surgery in atypical femoral fractures (AFFs). Although non-union in reamed intra-medullary (IM) nailing is relatively uncommon, it can lead to fracture of the nail and present a considerable challenge to the treating surgeon.

Case Report

We present a case of AFF treated with IM nail fixation. Metalwork failure of the nail prompted removal of distal locking screws and plating of the fracture site at 8 months. Failure of the plate-bone interface 3 months later led to further revision surgery to remove the broken metalwork. We focus on the significant operative difficulty encountered during removal of the failed IM metalwork and provide a novel practical solution to overcome this particular challenge - insertion of a conical cannulated screw remover under fluoroscopy guidance to create an interference fit with the distal segment of the broken nail.

Discussion

This case is an example of significant and unexpected intra-operative technical difficulty, requiring improvisation and teamwork to manage. We introduce an accessible and uncomplicated alternative to the existing techniques for removal of a broken femoral nail and in doing so hope to benefit peers and colleagues should they encounter similar difficulties in the future.

The journey of tumor-infiltrating lymphocytes as a biomarker in breast cancer: clinical utility in an era of checkpoint inhibition

In 2014, we described a method to quantify percentage of tumor-infiltrating lymphocytes (TILs) on hematoxylin and eosin-stained slides of breast cancer samples using light microscopy that could be performed easily by pathologists with no extra stains. The aim of detailing the method was to facilitate independent research groups replicating our prognostic findings using TIL quantity in early-stage breast cancers. A global working group of breast pathologists was convened to standardize, test reproducibility, and refine the method. A website was also established which allowed free training (www.tilsinbreastcancer.org). As a result of this work, TIL data have been collected in over 20 000 primary breast cancer samples worldwide and the robust associations with better prognoses in triple-negative breast cancer (TNBC) and HER2+ BC have been confirmed. This has resulted in the inclusion of the TIL biomarker in several international breast cancer guidelines as well as in national criteria for routine pathology reporting. TIL therefore represents the first biological prognostic biomarker for early-stage TNBCs, and here its prognostic effect is linear, with values of 30%-50% being suggested as suitable for use in potential chemotherapy de-escalation studies. The efficacy of immune checkpoint-targeted agents in breast cancer now provides direct evidence that host immune responses can modify tumor growth in some patients. With the recent granting of accelerated approvals for the first PD-1/PD-L1 targeting agents in early and advanced TNBC, our focus has now moved to investigating the clinical utility of TIL in the setting of immune checkpoint agents, with or without PD-L1 protein assessment. Emerging data suggest that TIL quantity can help clinicians identify patients with breast cancer who benefit most from PD-1/PD-L1 inhibition. In patients with advanced TNBC and HER2+ disease a TIL cut-off of 5% or 10%, with PD-L1 expression can define 'immune-enriched' tumors and currently seems to have the most clinical relevance in this context.

Management of perianal abscesses in infants without general anaesthesia: a systematic review of the literature

Perianal abscesses are a common surgical presentation in infants. Historically, general anaesthesia (GA) has been used to facilitate incision and drainage, with or without exploration for a fistula-in-ano (FIA). This review aims to assess outcomes following management of perianal abscesses without GA in infants less than 24 months old. We aim to identify the success of management without GA. Using PRISMA guidelines, studies were identified from MEDLINE, EMBASE and PubMed. Studies including infants less than 24 months with perianal abscesses managed without GA were reviewed. The primary outcome was the number of patients requiring GA following initial management without GA. Secondary outcomes included rates of recurrent perianal abscesses, rates of progression to FIA and time to cure. Nine studies, involving 1049 infants less than 24 months old met inclusion criteria. A total of 1039 (99.0%) were males. Study design consisted of one prospective case series of 18 patients, and eight retrospective cohort studies. There were no randomized control trials. A total of 1037 (98.9%) patients were initially managed without GA. Of these, 59 (5.6%) were documented to subsequently require a general anaesthetic. Treatment modalities included antibiotics, regular baths, needle aspiration, incision and drainage under local anaesthesia, hainosankyuto and fibroblast growth factor. A total of 790 (75.3%) healed primarily without further intervention. A total of 243 (23.2%) were documented to have a recurrence or progression to FIA. All patients who required a subsequent general anaesthetic had progressed to FIA. Despite the lack of well-designed prospective studies, existing evidence supports management of perianal abscesses without initial GA in infants, with more than 75% healing completely. Further research aimed at standardizing care and confirming the safety and efficacy of initial non-operative management are warranted, and may potentially reduce the number of unnecessary initial and subsequent clinical interventions.

Maternal exposure to organophosphate flame retardants alters locomotor and anxiety-like behavior in male and female adult offspring

Endocrine disrupting chemicals (EDCs) are chemicals found in our environment that interrupt typical endocrine function. Some flame retardants (FRs) are EDCs as shown in their interaction with steroid and nuclear receptors. Humans are consistently exposed to flame retardants as they are used in everyday items such as plastics, clothing, toys, and electronics. Polybrominated diphenyl ethers were used as the major FR until 2004, when they were replaced by organophosphate flame retardants (OPFRs). Previous research in rodent models utilizing a commercial flame retardant mixture containing OPFRs reported alterations in anxiety-like behavior in the elevated plus maze (EPM) for rodents perinatally exposed to OPFRs. In the present study we utilize wild-type mice maternally exposed (gestational day 7 to postnatal day 14) to either an OPFR mixture of tris(1,3-dichloro-2-propyl), triphenyl phosphate, and tricresyl phosphate or a sesame seed oil vehicle. These mice were evaluated for anxiety-like behavior in adulthood on the open field test (OFT) and the light/dark box (LDB) as well as the EPM. Outcomes from the OFT and LDB indicate that males and females maternally exposed to OPFRs exhibit altered locomotor activity. Results of the EPM were sex-specific as we did not observe an effect in females; however, effects in males differed depending on exposure condition. Males maternally exposed to OPFRs exhibited an anxiolytic-like phenotype in contrast to their vehicle counterparts. This effect in perinatally OPFR-exposed males was not due to alterations in locomotor activity. Our research illustrates that there are sex- and exposure-dependent effects of perinatal OPFR exposure on adult locomotor and anxiety-like behaviors in a mouse model.

Pembrolizumab monotherapy for previously treated metastatic triple-negative breast cancer: cohort A of the phase II KEYNOTE-086 study

BACKGROUND

Treatment options for previously treated metastatic triple-negative breast cancer (mTNBC) are limited. In cohort A of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as second or later line of treatment for patients with mTNBC.

PATIENTS AND METHODS

Eligible patients had centrally confirmed mTNBC, ≥1 systemic therapy for metastatic disease, prior treatment with anthracycline and taxane in any disease setting, and progression on or after the most recent therapy. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. Primary end points were objective response rate in the total and PD-L1-positive populations, and safety. Secondary end points included duration of response, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), progression-free survival, and overall survival.

RESULTS

All enrolled patients (N = 170) were women, 61.8% had PD-L1-positive tumors, and 43.5% had received ≥3 previous lines of therapy for metastatic disease. ORR (95% CI) was 5.3% (2.7-9.9) in the total and 5.7% (2.4-12.2) in the PD-L1-positive populations. Disease control rate (95% CI) was 7.6% (4.4-12.7) and 9.5% (5.1-16.8), respectively. Median duration of response was not reached in the total (range, 1.2+-21.5+) and in the PD-L1-positive (range, 6.3-21.5+) populations. Median PFS was 2.0 months (95% CI, 1.9-2.0), and the 6-month rate was 14.9%. Median OS was 9.0 months (95% CI, 7.6-11.2), and the 6-month rate was 69.1%. Treatment-related adverse events occurred in 103 (60.6%) patients, including 22 (12.9%) with grade 3 or 4 AEs. There were no deaths due to AEs.

CONCLUSIONS

Pembrolizumab monotherapy demonstrated durable antitumor activity in a subset of patients with previously treated mTNBC and had a manageable safety profile.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02447003.

R-spondin 2 mediates neutrophil egress into the alveolar space through increased lung permeability

Objective

R-spondin 2 (RSPO2) is required for lung morphogenesis, activates Wnt signaling, and is upregulated in idiopathic lung fibrosis. Our objective was to investigate whether RSPO2 is similarly important in homeostasis of the adult lung. While investigating the characteristics of bronchoalveolar lavage in RSPO2-deficient (RSPO2^−/−) mice, we observed unexpected changes in neutrophil homeostasis and vascular permeability when compared to control (RSPO2^+/+) mice at baseline. Here we quantify these observations to explore how tonic RSPO2 expression impacts lung homeostasis.

Results

Quantitative PCR (qPCR) analysis demonstrated significantly elevated myeloperoxidase (MPO) expression in bronchoalveolar lavage fluid (BALF) cells from RSPO2^−/− mice. Likewise, immunocytochemical (ICC) analysis demonstrated significantly more MPO+ cells in BALF from RSPO2^−/− mice compared to controls, confirming the increase of infiltrated neutrophils. We then assessed lung permeability/barrier disruption via Fluorescein Isothiocyanate (FITC)-dextran instillation and found a significantly higher dextran concentration in the plasma of RSPO2^−/− mice compared to identically treated RSPO2^+/+ mice. These data demonstrate that RSPO2 may be crucial for blood-gas barrier integrity and can limit neutrophil migration from circulation into alveolar spaces associated with increased lung permeability and/or barrier disruption. This study indicates that additional research is needed to evaluate RSPO2 in scenarios characterized by pulmonary edema or neutrophilia.

Scar wars

BACKGROUND

Burn scars are common in the paediatric population. When involving the face, it diminishes quality of life. Ablative fractional laser (AFL) therapy is becoming the preferred choice for established scars due to its greater potential depth for thermal injury (4 mm), which leads to photothermolysis with subsequent neocollagenesis and collagen fibre realignment and remodelling. Combined with small z-plasties and topical steroids, it has been proven to: flatten and decrease the volume of scars, increase pliability and decrease pruritus and erythema. The purpose of the case series was to determine the clinical significance of a single session of AFL therapy, combined with small z-plasties and topical steroids on facial scars post burn injury.

METHOD

Four cases of paediatric facial scarring post burns were selected to undergo a single treatment of AFL therapy, accompanied by small z-plasties and topical steroids. Modified Vancouver Scar Scores (MVSS) pre- and postoperatively at 3 and 6 months were evaluated.

RESULTS

Improvement of all components of the MVSS was achieved after 6 months, with major improvement in scar pliability and symptomatology. The mean MVSS improved from 14 (range 12-16) preoperatively to 5 and 5.5 respectively at 3 and 6 months postoperatively. Non-parametric analysis with Friedman Two-Way ANOVA by Rank showed a statistical significance between the pre- and postoperative MVSS (p = 0.024).

CONCLUSION

AFL should form an integral part of the burn scar armamentarium.

Therapeutic landscape of metaplastic breast cancer

Metaplastic breast carcinomas (MPBC) are rare, aggressive and relatively chemorefractory tumors with a high unmet need. While most are "triple negative" and lack expression of estrogen, progesterone and HER2 receptors, MPBC are associated with worse outcomes compared to conventional triple negative invasive tumors. MPBCs are genetically heterogeneous and harbor somatic mutations, most frequently in TP53, PIK3CA and PTEN, with emerging studies suggesting a role for novel targeted therapies. These tumors have also been associated with overexpression of PD-L1 and tumor-infiltrating lymphocytes suggesting an endogenous immune response and therefore a rationale for treatment with immunotherapies. Here, we focus on therapeutic options for this difficult to treat breast cancer subtype and encourage physicians to consider targeted therapies/immunotherapies as part of ongoing clinical trials.

Abstract ES9-2: Updates on immunotherapy for TNBC

Immunotherapeutic strategies have revolutionized the treatment of cancer. Immune checkpoint blockade (ICB) agents such as inhibitors of programmed cell death receptor-1 (PD-1) and programmed cell death ligand-1 (PD-L1) have been FDA-approved for the treatment of various tumors.

While breast cancers have previously been considered immunologically quiescent compared with other tumor types, recent investigations underscore the immunogenicity of some breast tumors. Triple negative breast cancers (TNBCs) in particular, have the highest rates of tumor-infiltrating lymphocytes (TILs) compared with other subtypes at diagnosis. TILs are indicative of a pre-existing anti-tumor immune response which carries a better prognosis in patients with early TNBC, at least in part due to a better response to conventional cancer therapies. It has been demonstrated that TILs correlate with pathologic complete response (pCR) after neoadjuvant chemotherapy (Denkert et al, Lancet Oncol 2018). The survival benefit associated with TIL in early TNBC is remarkable with a 10% increase in TIL correlating with a 19% reduction in risk of death in trials of adjuvant chemotherapy (Adams et al, J Clin Oncol 2014). These advances ignited the studies of ICB in TNBC with the goal to harness the anti-tumor immune response to improve patient outcomes.

Initial Phase I/II trials in metastatic TNBC showed proof of principle that durable responses could be achieved with ICB monotherapy, but also highlighted the need to develop rational combinations. ICB agents address one important step by which the T-cell response can be blunted, counteracting PD-L1 expressed in the tumor microenvironment in an effort to avoid immune destruction. However, as depicted in the Cancer Immunity Cycle, which manages the delicate balance between the recognition of nonself and the prevention of autoimmunity (Chen et al, Immunity 2013), there are multiple steps required for an effective immune response. Released tumor antigens must be presented in the context of major histocompatibility complexes (MHC) on activated antigen presenting cells to prime an efficient T cell response. Activated T cells must then traffic to the tumor site, infiltrate into the tumor, recognize, and kill tumor cells. Different therapeutic strategies including chemotherapy and radiotherapy are currently being studied as combination partners due to their potential of inducing an immunogenic cell death (Galluzzi et al, Nat Rev Immunol 2017).

Recently the first positive phase 3 chemo-immunotherapy study was reported in metastatic TNBC (Schmid et al, ESMO 2018). Impassion130, a global, randomized, double-blind trial of nab-paclitaxel with or without atezolizumab in front-line metastatic TNBC, met its co-primary progression-free survival (PFS) endpoint in the intent-to-treat as well as the PD-L1+ population, with clinically meaningful overall survival (OS) benefit seen at interim OS analysis in PD-L1+ patients. Additional phase 3 trials of ICB in TNBC are ongoing in the adjuvant, neoadjuvant and metastatic setting.

Citation Format: Adams S. Updates on immunotherapy for TNBC [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 ES9-2.

    

Abstract P6-18-31: PROCLAIM-CX-072: Monotherapy for advanced triple negative breast cancer with skin metastases in a phase 1-2 trial of the PD-L1 probody therapeutic CX-072

Background: Probody™ therapeutics are novel, fully recombinant antibody prodrugs designed to remain relatively inactive in healthy tissue and to be specifically activated by proteases in the tumor microenvironment. In this way, Probody therapeutics may broaden the therapeutic window for effective but potentially toxic anticancer agents. CX-072 is a Probody therapeutic directed against programmed death-ligand 1 (PD-L1) for the treatment of cancer patients. In a first-in-human, open-label, multicenter, dose-escalation, 3+3 design, phase 1-2 study, PROCLAIM-CX-072 (PRObody CLinical Assessment In Man) (NCT03013491), 22 patients were enrolled in the phase 1 dose escalation portion. Twenty patients were evaluable per RECIST v1.1. Three patients had confirmed partial response (15%), including a 39-year-old woman with stage IV triple negative breast cancer (TNBC) treated with 10 mg/kg CX-072 monotherapy whose disease had progressed on one previous line of chemotherapy for metastatic disease. Metastatic sites included extensive nodal disease and skin/chest wall lesions. The tumor was negative for PD-L1 expression, was microsatellite stable, and had a low tumor mutational burden (4 mutations/megabase). Positive results from the phase 1 study suggest that additional exploration of treatment with CX-072 monotherapy in the TNBC patient population is warranted.

Dose expansion trial design: The phase 2 dose expansion part of the PROCLAIM-CX-072 study will include enrollment of TNBC patients with skin metastases. Key inclusion criteria for patients in the TNBC cohort are as follows: naive to immunotherapy (PD-1/PD-L1 and CTLA-4 inhibitors), approved immune checkpoint inhibitor agents not available, histologically confirmed triple negative (estrogen receptor–, progesterone receptor–, and human epidermal growth factor receptor-2–negative cancer per ASCO-CAP guidelines), previously treated with 1 to 3 systemic chemotherapy regimens, and locally advanced and recurrent skin or subcutaneous metastases not suitable for surgical resection or radiotherapy. Patients will receive doses of 10 mg/kg CX-072 intravenously every 2 weeks. Efficacy will be evaluated using RECIST v1.1 and immune-related RECIST criteria. Safety and tolerability will be assessed based on the incidence and severity of adverse events (categorized by NCI CTCAE criteria, v4.03) and relationship to study drug. Other analyses will include pharmacokinetics, incidence of anti-drug antibodies against CX-072, exploratory analysis for immune response, and CX-072 activation in the tumor.

PROBODY is a trademark of CytomX Therapeutics, Inc.

Citation Format: Adams S, Hamilton E, Ott PA, Cho D, Kalinsky K, LoRusso P, Will M, Huels V, Benson B, Murias C, Arkenau H-T. PROCLAIM-CX-072: Monotherapy for advanced triple negative breast cancer with skin metastases in a phase 1-2 trial of the PD-L1 probody therapeutic CX-072 [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 P6-18-31.

Prognostic implications of residual disease tumor-infiltrating lymphocytes and residual cancer burden in triple-negative breast cancer patients after neoadjuvant chemotherapy

BACKGROUND

For primary triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NAC), higher pretreatment tumor-infiltrating lymphocytes (TILs) correlates with increased pathologic complete response (pCR) rates, and improved survival. We evaluated the added prognostic value of residual disease (RD) TILs to residual cancer burden (RCB) in predicting survival post-NAC.

PATIENTS AND METHODS

We combined four TNBC NAC patient cohorts who did not achieve pCR. RD TILs were investigated for associations with recurrence-free survival (RFS), and overall survival (OS) using Cox models with stromal TILs as a continuous variable (per 10% increment). The likelihood ratio test was used to evaluate added prognostic value of RD TILs.

RESULTS

A total of 375 RD TNBC samples were evaluable for TILs and RCB. The median age was 50 years, with 62% receiving anthracycline/taxane chemotherapy. The RCB class after NAC was 11%, 50%, and 39% for I, II, and III, respectively. The median RD TIL level was 20% (IQR 10-40). There was a positive correlation between RD TIL levels and CD8+ T-cell density (ρ = 0.41). TIL levels were significantly lower with increasing post-NAC tumor (P = 0.005), nodal stage (P = 0.032), but did not differ by RCB class (P = 0.84). Higher RD TILs were significantly associated with improved RFS (HR: 0.86; 95% CI 0.79-0.92; P < 0.001), and improved OS (HR: 0.87; 95% CI 0.80-0.94; P < 0.001), and remained significant predictors in multivariate analysis (RFS P = 0.032; OS P = 0.038 for OS). RD TILs added significant prognostic value to multivariate models including RCB class (P < 0.001 for RFS; P = 0.021 for OS). The positive prognostic effect of RD TILs significantly differed by RCB class for RFS (PInt=0.003) and OS (PInt=0.008) with a greater magnitude of positive effect observed for RCB class II than class III.

CONCLUSIONS

TIL levels in TNBC RD are significantly associated with improved RFS and OS and add further prognostic information to RCB class, particularly in RCB class II.

Computational analysis and identification of battery materials

Crystallography is a powerful descriptor of the atomic structure of solid-state matter and can be applied to analyse the phenomena present in functional materials. Especially for ion diffusion – one of the main processes found in electrochemical energy storage materials – crystallography can describe and evaluate the elementary steps for the hopping of mobile species from one crystallographic site to another. By translating this knowledge into parameters and search for similar numbers in other materials, promising compounds for future energy storage materials can be identified. Large crystal structure databases like the ICSD, CSD, and PCD have accumulated millions of measured crystal structures and thus represent valuable sources for future data mining and big-data approaches. In this work we want to present, on the one hand, crystallographic approaches based on geometric and crystal-chemical descriptors that can be easily applied to very large databases. On the other hand, we want to show methodologies based onab initioand electronic modelling which can simulate the structure features more realistically, incorporating also dynamic processes. Their theoretical background, applicability, and selected examples are presented.

Weaning practices in phenylketonuria vary between health professionals in Europe

Background

In phenylketonuria (PKU), weaning is considered more challenging when compared to feeding healthy infants. The primary aim of weaning is to gradually replace natural protein from breast milk or standard infant formula with solids containing equivalent phenylalanine (Phe). In addition, a Phe-free second stage L-amino acid supplement is usually recommended from around 6 months to replace Phe-free infant formula. Our aim was to assess different weaning approaches used by health professionals across Europe.

Methods

A cross sectional questionnaire (survey monkey®) composed of 31 multiple and single choice questions was sent to European colleagues caring for inherited metabolic disorders (IMD). Centres were grouped into geographical regions for analysis.

Results

Weaning started at 17–26 weeks in 85% (n = 81/95) of centres, >26 weeks in 12% (n = 11/95) and < 17 weeks in 3% (n = 3/95). Infant's showing an interest in solid foods, and their age, were important determinant factors influencing weaning commencement. 51% (n = 48/95) of centres introduced Phe containing foods at 17–26 weeks and 48% (n = 46/95) at >26 weeks. First solids were mainly low Phe vegetables (59%, n = 56/95) and fruit (34%, n = 32/95).

A Phe exchange system to allocate dietary Phe was used by 52% (n = 49/95) of centres predominantly from Northern and Southern Europe and 48% (n = 46/95) calculated most Phe containing food sources (all centres in Eastern Europe and the majority from Germany and Austria). Some centres used a combination of both methods.

A second stage Phe-free L-amino acid supplement containing a higher protein equivalent was introduced by 41% (n = 39/95) of centres at infant age 26–36 weeks (mainly from Germany, Austria, Northern and Eastern Europe) and 37% (n = 35/95) at infant age > 1y mainly from Southern Europe. 53% (n = 50/95) of centres recommended a second stage Phe-free L-amino acid supplement in a spoonable or semi-solid form.

Conclusions

Weaning strategies vary throughout European PKU centres. There is evidence to suggest that different infant weaning strategies may influence longer term adherence to the PKU diet or acceptance of Phe-free L-amino acid supplements; rendering prospective long-term studies important. It is essential to identify an effective weaning strategy that reduces caregiver burden but is associated with acceptable dietary adherence and optimal infant feeding development.

A comparison of methodologies: sibling identification using a relational versus a graph-based approach

IntroductionThe detection of siblings is an important pre-requisite for many research problems, yet is traditionally difficult or time-consuming owing to the way linked data is conventionally stored. We compare the methodology and results for an identification of siblings by SANT DataLink using a legacy relational approach and a graph-based approach. Objectives and ApproachAn existing project involving the identification of sibling clusters using relational techniques was replicated using the same core data in SANT DataLink’s Next Generation Linkage Managment System (NGLMS) which is graph-based. Data is stored in the NGLMS using richer relationships than just 'is W% similar to' or 'is part of group N'. Birth data was separated into children and parents and explicit child/parent relationships recorded. When coupled with electoral roll data using probabilistic and deterministic linkage, sibling structure can be identified by performing network traversal via parents, e.g. crecord—[MOTHER]⟶mrecord—[IS_SIMILAR_TO]⟶mrecord*⟵[MOTHER]—crecord* i.e. find the mother, find that mother’s cluster, find all children related to that cluster. The resulting records are siblings. ResultsA graph-based approach enabled the methology of 'finding siblings' to be more clearly described and communicated by mirroring genealogical structures natively within in the data. Comparable results were achieved in a shorter time with less manual effort using the same underlying data. Generating sibling clusters from the graph-based data required less manual intervention and review as explicit PARENT/CHILD relationships were stored in the data and able to be quickly traversed to assemble familial units and thus siblings. A focus on automated linkage quality rather than manual review was facilitated by the approach. Anomalous structures requiring detailed review, such as multiple fathers and mothers of a single child, were trivially identifiable and so manual effort was focussed on actions where a higher return in terms of end-product quality could be achieved. Conclusion/ImplicationsStoring data in a representation which more closely resembles the the underlying real-world situation allows greater fidelity with respect to data modeling. This in turn, enables the asking of richer questions and makes the answering of such questions much easier.

Early feeding practices in infants with phenylketonuria across Europe

Background

In infants with phenylketonuria (PKU), dietary management is based on lowering and titrating phenylalanine (Phe) intake from breast milk or standard infant formula in combination with a Phe-free infant formula in order to maintain blood Phe levels within target range. Professionals use different methods to feed infants with PKU and our survey aimed to document practices across Europe.

Methods

We sent a cross sectional, survey monkey® questionnaire to European health professionals working in IMD. It contained 31 open and multiple-choice questions. The results were analysed according to different geographical regions.

Results

Ninety-five centres from 21 countries responded. Over 60% of centres commenced diet in infants by age 10 days, with 58% of centres implementing newborn screening by day 3 post birth. At diagnosis, infant hospital admission occurred in 61% of metabolic centres, mainly in Eastern, Western and Southern Europe. Breastfeeding fell sharply following diagnosis with only 30% of women still breast feeding at 6 months.

53% of centres gave pre-measured Phe-free infant formula before each breast feed and 23% alternated breast feeds with Phe-free infant formula. With standard infant formula feeds, measured amounts were followed by Phe-free infant formula to satiety in 37% of centres (n = 35/95), whereas 44% (n = 42/95) advised mixing both formulas together. Weaning commenced between 17 and 26 weeks in 85% centres, ≥26 weeks in 12% and < 17 weeks in 3%.

Discussion

This is the largest European survey completed on PKU infant feeding practices. It is evident that practices varied widely across Europe, and the practicalities of infant feeding in PKU received little focus in the PKU European Guidelines (2017). There are few reports comparing different feeding techniques with blood Phe control, Phe fluctuations and growth. Controlled prospective studies are necessary to assess how different infant feeding practices may influence longer term feeding development.

Scalp as a donor site in children: Is it really the best option?

BACKGROUND

Since 2003 we have used the scalp as a donor site for split skin grafts (SSGs) in major burns when there was a shortage of conventional donor areas. However, we seen a high incidence of complications, contrary to international experience.

OBJECTIVE

The aim of this study was to analyze the results and complications related to the scalp as a donor site and to determine whether there is an association between our specific patient population and the complications encountered.

METHODS

A retrospective review of our scalp donor site outcomes over a 12-year period was conducted. The cohort included 25 patients, 15 of black African descent, nine of mixed race and one Caucasian. The various hair types were identified based on ethnicity and classified into eight types. Most of our patients had hair types VI-VIII. None of these patients had scalp burns and all received standard burn treatment. The SSGs were taken with an electric dermatome with a standard micrometric setting of 0.2mm. Complications were categorized into short- or long-term, with a mean follow-up time of 1.59years.

RESULTS

The mean age of the 25 children was 5.7years. Nineteen sustained flame burns and 6 sustained hot water burns, with a mean total body surface area of 44.9%. A total of 43 scalp procurements were performed in the 25 patients studied. The group of 15 black African patients (hair types VI-VIII) had a total of 22 procurements, the nine patients of mixed race (hair types III-V) had 18 procurements and the single Caucasian patient (hair types II-III) had two procurements. The median healing time was 15days, 11.8days and 8.5days, respectively, per group. Significant complications were encountered, including folliculitis 44%, non-healing wounds 52%, alopecia 16% and visible, hypopigmented scars 3%. One patient had a hypertrophic scar and no hair transfers to the recipient areas were observed. The various hair types correlated with the complications encountered. Five children, with an average burn size of 65.2% (range: 40-85%) died of sepsis. Due to the small sample size, the only statistically significant findings were related to the total body surface area of the burn and the number of times skin was harvested from the scalp, with a p-value of 0.005. The p-values for the healing times related to the first, second and third croppings, were p=0.022, p=0.00032 and p<0.001 respectively.

CONCLUSION

Our study suggests that in pediatric patients of black African descent (hair types VI-VIII) the scalp is not an ideal donor area, due to the unacceptably high incidence of complications. Hence, every precaution should be taken when it becomes necessary to harvest donor skin from the scalp.

Abstract P3-05-03: Metaplastic breast cancers: Genomic profile, mutational burden and TILs

Background: Metaplastic breast cancers (MPBC) are rare, typically triple negative aggressive tumors composed of both, adenocarcinoma and metaplastic elements. Recent evidence that TNBC and MPBC can respond vigorously to immune checkpoint inhibitor therapy (Adams et al, ASCO 2017 and npj Breast Cancer 2017) has prompted the following comprehensive genomic profiling (CGP) and histopathologic assessment of tumor infiltrating lymphocytes (TIL) designed to uncover potential biomarkers of immunotherapy response for MPBC, including mutational burden, Microsatellite Instability (MSI) status and gene amplification of 9p21.4 (or CD274, which includes the PD-L1 locus).

Methods: 12,214 locally aggressive, relapsed and metastatic breast malignancies (mBM) were subjected to CGP using DNA extracted from 40 µm of FFPE sections and adaptor ligation-based libraries to a mean coverage depth &gt;650X for up to 315 cancer-related genes. The results were analyzed for all classes of genomic alterations (GA) including base substitutions, insertions and deletions, select rearrangements, and copy number changes. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA. MSI status was determined by an algorithm based on the sequencing results. TIL were assessed on archived H&E tumor sections and enumerated per guidelines established by the TIL Working Group (Salgado, Ann Oncol 2015) in a subset of MPBC with the highest TMB and compared with low TMBC cases.

Results: 165 of mBM cases were MPBC (1.4%) and are included in this study. All patients were female with a median age of 60 (range 24-86). 165 of the MPBC cases (100%) harbored a wide variety of GA involving more than 100 individual genes. The most common GA were identified in TP53 (65%), followed by PIK3CA (37%). No cases of MSI hi status (0/103) and only one case with amplification of 9p21.4 (1/165, 0.6%) were observed. Most MPBC had a low mutational burden, with a median TMB of 2.7 mutations/Mb (range 0-39.6). Only 11/165 tumors (6.7%) were found to have a TMB over 10 mutations/Mb, including 3 cases (1.8%) with TMB &gt;20. Tumor sections were available for TIL review from 9/11 cases with highest TMB, as well as 11 control cases with lowest TMB. TIL were more frequently observed in high versus low TMB MPBC, with median TIL percentage of 40 and 20 (range 10-80 and range 10-60), respectively, although this difference was not statistically significant (Wilcoxon rank-sum test, p=0.15).

Conclusions: Genomic profiling in the largest cohort of MPBC reported to date confirms that MPBC is enriched for TP53 and PIK3CA mutations and many tumors harbor targetable GA. The frequently observed tumoral PD-L1 expression in MPBC is not based on gene amplification as amplification of 9p21.4 is rare. Most tumors had a low mutation burden, and no significant association of TIL with TMB was observed, suggesting additional processes underlying MPBC immunogenicity.

Citation Format: Taff J, Suh J, Singh B, Denkert C, Troxel AB, Ross JS, Adams S. Metaplastic breast cancers: Genomic profile, mutational burden and TILs [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-03.