Caregiver experiences of hospice dementia care: a systematic review and meta-ethnography

OBJECTIVES

Hospices are regarded as gold standard providers of end-of-life care. The term hospice, however, is broadly used, and can describe a type of care offered in a variety of health care services (e.g. nursing homes). It thus becomes complex for families to decide between services. We aimed to review the evidence around the experience of family carers of people with dementia accessing in-patient hospice settings for end-of-life care.

METHOD

We registered the review protocol on PROSPERO. We used PerSPE(C)TiF to systematically organise our search strategy. The evidence was reviewed across six databases: PubMed, EMBASE, PsycINFO, ASSIA, ISI Web, and CINAHL. We used meta-ethnography as per the eMERGe guidance for data interpretation.

RESULTS

Four studies were included. Two third-order constructs were generated through meta-ethnography: expectations of care and barriers to quality of care. We found that carers had expectations of care, and these could change over time. If discussion was not held with hospice staff early on, the carers could experience reduced care quality due to unmatched expectations. Unmatched expectations acted as barriers to care and these were found in terms of carers not feeling adequately supported, and/or having the person discharged from hospice, which would entail increased care responsibility for carers.

CONCLUSION

In view of an increase in new dementia cases over time and with hospice services being under pressure, integrating palliative care services within community-based models of care is key to reducing the risk of having inadequate and under resourced services for people with dementia.

Experiences of hospice dementia care: A qualitative study of bereaved carers and hospice clinicians

BACKGROUND

Nearly 50 million people worldwide have dementia and the increasing numbers requiring end-of-life and palliative care, has led to national efforts to define standards of care for this patient group. Little research, however, has been done to date about the experience of hospice care for people with dementia accessing these services. This study explores the views of hospice dementia care for bereaved carers of people with dementia and hospice clinicians.

METHODS

We used purposive sampling for participant recruitment. Semi-structured qualitative interviews were conducted with bereaved carers and hospice clinical staff. Interviews were audio recorded and the transcriptions were analysed through thematic analysis. A total of 12 participants were interviewed from one service in the Northwest region in the UK. All were female and white British.

RESULTS

Participants described their experience of hospice dementia care in three main themes: Pre-access to service, roles and responsibility within hospice care, ease and difficulty of last period of end-of-life care.

CONCLUSION

Rapid response teams delivering hospice home care could represent a better option to inpatient care and may be preferred by patients. This type of service, however, may require joined-up care with other community services, and this type of care needs to be considered and planned. Future studies should evaluate this type of community care.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Whole-genome sequencing of chronic lymphocytic leukemia identifies subgroups with distinct biological and clinical features

The value of genome-wide over targeted driver analyses for predicting clinical outcomes of cancer patients is debated. Here, we report the whole-genome sequencing of 485 chronic lymphocytic leukemia patients enrolled in clinical trials as part of the United Kingdom's 100,000 Genomes Project. We identify an extended catalog of recurrent coding and noncoding genetic mutations that represents a source for future studies and provide the most complete high-resolution map of structural variants, copy number changes and global genome features including telomere length, mutational signatures and genomic complexity. We demonstrate the relationship of these features with clinical outcome and show that integration of 186 distinct recurrent genomic alterations defines five genomic subgroups that associate with response to therapy, refining conventional outcome prediction. While requiring independent validation, our findings highlight the potential of whole-genome sequencing to inform future risk stratification in chronic lymphocytic leukemia.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

779 IMPROVING USE OF COORDINATE MY CARE USING A QUALITY IMPROVEMENT APPROACH FOR MEDICAL PATIENTS ADMITTED TO BARNET HOSPITAL

Introduction

Coordinate My Care (CMC) is a digital care plan for communicating person-centred urgent and advance care planning. We recognised that it was not being consistently accessed on admission, nor updated on discharge, leading to a risk of ignoring patient wishes and previously clinician-agreed care plans. We used a quality improvement approach to increase use of CMC.

Method

We gathered baseline data on the number of users utilising their account, and explored current practice and barriers. A driver diagram was developed, a Steering Group met regularly, and interventions were tested using Plan, Do, Study, Act. Interventions began in January 2021, including electronic circulation of a guide to gain access to CMC, posters about CMC, departmental teaching, and drop-in training. A Core Group of clinicians repeatedly surveyed 12 medical ward areas and offered on-the-spot troubleshooting. To mitigate effects of staff turnover, we developed e-classroom training for new starters.

Results

53 people attended departmental teaching and drop-ins. The number of users utilising their account each month showed a steady increase, rising from 25 to 42 users. Monthly views of CMC records are increasing, with 167 in May 2021 compared to an average of 105 in the 5 months prior to the project. We have still to examine patient feedback.

Conclusion

Use of CMC is becoming more established. Future actions will concentrate on training (including in the emergency department and during junior doctor changeover), helping clinicians hold conversations, and establishing mentoring. Recording Advance Care Planning on CMC is a final step in a complex process of identifying that a patient may be in the last year of their life, starting conversations and taking actions. It follows that varied and sustained actions are needed to improve this, in order to realise the benefits of person-centred planning for our patients and those caring for them.

Using DNA testing for the precise, definite, and low-cost diagnosis of sickle cell disease and other Haemoglobinopathies: findings from Tanzania

Background

Sickle cell disease (SCD) is an important cause of under-five mortality. Tanzania is the 5th country in the world with the highest births prevalence of SCD individuals. Significant advances in the neonatal diagnosis of SCD using rapid point-of-care testing have been made. However genetic confirmation is still required for positive cases, in uncertain cases, in multiply transfused patients, to resolve compound heterozygosity (Hb S/ β⁰ Thal or Hb S/ β⁺ thal) not uncommon in the coastal regions of East Africa and increasingly also for pre-marital counselling and potentially for future curative approaches such as gene therapy. The currently available DNA tests are prohibitively expensive. Here, we describe an easy-to-use, affordable and accurate β-globin sequencing approach that can be easily integrated within existing NBS for SCD and other haemoglobinopathies especially in Low- and Middle-income Countries.

Aim

To evaluate an affordable DNA technology for the diagnosis of Sickle cell disease and other haemoglobinopathies in a resource-limited setting.

Methods

Laboratory-based validation study was conducted by Muhimbili University of Health and Allied Sciences and the University of Oxford involving sequencing of the entire β -haemoglobin locus using the Oxford Nanopore MinION platform. A total number of 36 Dried blood spots and whole blood samples were subjected to conventional protein-based methods (isoelectric focusing, HPLC), and/or sequenced by the Sanger method as comparators.

Results

Sequencing results for SCD using the MinION were 100% concordant with those from the Sanger method. In addition, the long-read DNA sequencing method enabled the resolution of cases with unusual phenotypes which make up 1% of all children in Tanzania. The cost is £11/ sample for consumables, which is cheaper compared to other sequencing platforms.

Conclusions

This is the first report of a comprehensive single DNA assay as a definitive diagnostic test for SCD and other haemoglobinopathies. The test is fast, precise, accurate and affordable.

TET2 Drives 5hmc Marking of GATA6 and Epigenetically Defines Pancreatic Ductal Adenocarcinoma Transcriptional Subtypes

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDAC) is characterized by advanced disease stage at presentation, aggressive disease biology, and resistance to therapy, resulting in an extremely poor 5-year survival rate of <10%. PDAC is classified into transcriptional subtypes with distinct survival characteristics, although how these arise is not known. Epigenetic deregulation, rather than genetics, has been proposed to underpin progression, but exactly why is unclear and is hindered by the technical limitations of analyzing clinical samples.

METHODS

We performed genome-wide epigenetic mapping of DNA modifications 5-methylcytosine and 5-hydroxymethylcytosine (5hmc) using oxidative bisulfite sequencing from formalin-embedded sections. We identified overlap with transcriptional signatures in formalin-fixed, paraffin-embedded tissue from resected patients, via bioinformatics using iCluster and mutational profiling and confirmed them in vivo.

RESULTS

We found that aggressive squamous-like PDAC subtypes result from epigenetic inactivation of loci, including GATA6, which promote differentiated classical pancreatic subtypes. We showed that squamous-like PDAC transcriptional subtypes are associated with greater loss of 5hmc due to reduced expression of the 5-methylcytosine hydroxylase TET2. Furthermore, we found that SMAD4 directly supports TET2 levels in classical pancreatic tumors, and loss of SMAD4 expression was associated with reduced 5hmc, GATA6, and squamous-like tumors. Importantly, enhancing TET2 stability using metformin and vitamin C/ascorbic acid restores 5hmc and GATA6 levels, reverting squamous-like tumor phenotypes and WNT-dependence in vitro and in vivo.

CONCLUSIONS

We identified epigenetic deregulation of pancreatic differentiation as an underpinning event behind the emergence of transcriptomic subtypes in PDAC. Our data showed that restoring epigenetic control increases biomarkers of classical pancreatic tumors that are associated with improved therapeutic responses and survival.

1083 Nightmares Are Negatively Associated With Immediate Memory And Visuospatial Performance In Individuals With Ptsd

Introduction

Disturbing dreams and nightmares are common in individuals with post-traumatic stress disorder (PTSD). At present, little research has investigated the associations between nightmares and cognition in these individuals. However, a robust body of research has shown memory and attention impairments among those with PTSD. The present study sought to investigate the potential relationships between cognitive performance and nightmares in this population.

Methods

Seventy-five individuals (49 female; Mage=31.8, SDage=8.8) were administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the PTSD Checklist for the DSM-5 (PCL-5), the Insomnia Severity Index (ISI), the Functional Outcomes of Sleep Questionnaire (FOSQ), the Clinician-Administered PTSD Scale (CAPS), and the Disturbing Dreams and Nightmares Index (DDNSI). Five linear regressions were conducted with index scores on the RBANS subscales (immediate memory, visuospatial/constructional, language, attention, and delayed memory) as the dependent variables and PCL-5, ISI, FOSQ, CAPS symptom class subscales (intrusion, avoidance, cognition, and arousal), and DDNSI scores entered stepwise.

Results

A linear regression revealed that nightmares predicted 15% of the variance in RBANS immediate memory scores (R2 change=.152, β=-.390, p=.003). A second linear regression revealed that nightmares predicted 9.6% of the variance in RBANS visual memory scores (R2 change=.096, β=-.310, p=.019). No other independent variables added to either model. None of the independent variables predicted any variance in language, attention, or delayed memory scores.

Conclusion

Our analysis revealed a unique contribution of nightmares to immediate memory and visuospatial performance in individuals with PTSD. This finding was not better explained by variation in PTSD severity or sleep. Because sleep and dreams are implicated in memory consolidation, one explanation for our finding is that highly distressing trauma-related dreams (i.e. nightmares) may lack the same memory-improving qualities as ordinary dreams. Additionally, given that immediate memory and visuospatial functioning utilize working memory, perhaps nightmares and deficits in working memory share similar mechanisms.

Support

W81XWH-14-1-0570

1076 Self-referential Language In Trauma Narratives Predicts Shorter Sleep Duration In Women With Ptsd

Introduction

The use of self-referential language, defined as first-person singular pronouns (e.g. I, me, my), in trauma narratives has been found to predict post-traumatic stress disorder (PTSD) severity. Additionally, taking a self-immersed perspective correlates with higher blood pressure reactivity than a self-distanced perspective. Given this relationship between self-immersed perspectives and physiological processes, we investigated the relationship between self-referential language and sleep in people with PTSD, as dysfunctional sleep is a major treatment target in this disorder.

Methods

Seventy-five participants (49 females; Mage=31.8, SDage=8.8) meeting DSM-5 criteria for PTSD were administered the PTSD Checklist for the DSM-5 (PCL-5) and the Pittsburg Sleep Quality Index (PSQI). Sleep duration was assessed with the PSQI. Participants provided typed descriptions of their traumatic event, which were then analyzed using the Linguistic Inquiry and Word Count 2015 software to count instances of first-person singular pronouns (“I” words). Linear regression, with PCL-5 scores and “I” words entered stepwise, was used to predict scores on the PSQI sleep duration subscale. Use of “I” words between the sexes was also compared.

Results

For females but not males, PTSD severity significantly predicted sleep duration (R2=.207, p=.001). Additionally, the number of “I” words in the trauma narratives predicted an additional 8% of the variance in sleep duration for females (R2 change=.083, β=.288, p=.029) but not males. Females used significantly more self-referential language in their narratives (M=11.84, SD=8.42) compared to males (M=5.25, SD=6.10, p=.001).

Conclusion

After controlling for PTSD severity, self-referential language in trauma narratives significantly predicted shorter sleep duration in females. While speculative, this finding suggests that treatment approaches for PTSD may benefit from a focus on targeting self-referential processes to improve sleep and PTSD in females but not males. As dysfunctional sleep is a hallmark of PTSD, further investigation into this relationship may illuminate a new treatment avenue for this disorder.

Support

W81XWH-14-1-0570

0081 Habitual Sleep Duration is Negatively Correlated with Emotional Reactivity within the Rostral Anterior Cingulate Cortex in Individuals with PTSD

Introduction

Sleep difficulties, such as insomnia, are highly prevalent in individuals with Post-Traumatic Stress Disorder (PTSD). However, sleep deprivation can also increase emotional reactivity to positive (as well as negative) stimuli. While the effects of sleep loss on emotional perception healthy individuals has been documented, it remains unclear how lack of sleep in individuals with PTSD may affect their emotional reactivity to positive stimuli. We hypothesized that lower habitual sleep duration would be associated with greater functional brain activation changes in response to subliminally presented happy faces in brain areas of the reward network, such as the rostral anterior cingulate cortex (rACC).

Methods

Thirty-nine individuals with DSM-5 confirmed PTSD were administered the Pittsburgh Sleep Quality Index (PSQI) as a measure of their average nightly sleep duration over the past month. Participants then underwent fMRI imagining while viewing subliminal presentations of faces displaying happiness, using a backward masked facial affect paradigm to minimize conscious awareness of the expressed emotion. Brain activation to masked happy expressions was regressed against sleep duration in SPM12.

Results

There was a negative correlation between habitual sleep duration and activation within the rACC in response to the masked happy faces (x=14,y=40,z=0; k=102, pFWE-corr= 0.008).

Conclusion

Individuals with PTSD who average less sleep at night showed greater emotional reactivity, as indexed by greater functional brain activation changes within an area of the reward network, than individuals who obtained more sleep per night. Future research involving actual sleep duration manipulation will be necessary to determine whether this finding reflects the well-known antidepressant effect of sleep deprivation or a form of greater emotional expression error monitoring among traumatized patients when lacking sleep. Regardless, these findings suggest that insufficient sleep could affect unconsciously perceived emotion in faces and potentially affect social and emotional responses among individuals with PTSD.

Support

US Army Medical Research and Materiel Command: W81XWH-14-1-0570

Optimising Radium 223 Therapy for Metastatic Castration-Resistant Prostate Cancer -5-year Real-World Outcome: Focusing on Treatment Sequence and Quality of Life

AIMS

Real-world evidence of radium 223 (Ra-223) for the treatment of men with metastatic castration-resistant prostate cancer is emerging. In this prospective single-centre service evaluation, we report for the first time in the UK, real-world quality of life (QoL) and survival outcomes, including the sequencing impact, in 228 treated patients. We aim to share our 5-year experience on how to optimise Ra-223 treatment.

MATERIALS AND METHODS

Patients who received Ra-223 therapy between 2014 and 2018 at the Northern Centre for Cancer Care, Newcastle upon Tyne, UK were included in this evaluation. Demographics, clinical characteristics, blood parameters, treatment sequencing and QoL data using abbreviated Functional Assessment of Cancer Therapy-Prostate questionnaires were prospectively collected and analysed.

RESULTS

In total, 228 patients were included; median age 72 years (51-87). The medium overall survival was 11.1 months. Overall survival in post-chemotherapy and chemotherapy-naïve patients was 8.1 and 12.3 months, respectively (P = 0.02, hazard ratio 1.52, 95% confidence interval 1.06-2.17); in pre-enzalutamide and post-enzalutamide patients was 11.3 and 10.4 months, respectively (P = 0.65, hazard ratio 0.92, 95% confidence interval 0.63-1.33); in pre-abiraterone and prednisolone and post-abiraterone and prednisolone patients was 11.8 and 10.5 months, respectively (P = 0.08, hazard ratio 0.74, 95% confidence interval 0.51-1.06); in this latter group, the fracture rate was 24% (15/63). QoL post Ra-223 (n = 101 evaluated) showed that pain scores improved in 54%, there was no change in 17% and pain scores worsened in 30% of treated patients. Overall QoL scores showed a similar trend. QoL was not significantly associated with overall survival.

CONCLUSIONS

Ra-223 palliates pain and improves disease-related QoL in most patients in the real-world setting. Our survival outcome is comparable with other real-world studies. Chemotherapy-naïve patients seemed to have better survival than those who received prior chemotherapy. No significant survival differences were observed between pre- and post-abiraterone and prednisolone or enzalutamide patients. The fracture rate in the post-abiraterone and prednisolone group seemed to be high. Bone health evaluation and protection should be incorporated as standard of care.

The AirTight Protocol for Mixed Criticality Wireless CPS

This article describes the motivation, design, analysis, and configuration of the criticality-aware multi-hop wireless communication protocol AirTight. Wireless communication has become a crucial part of the infrastructure of many cyber-physical applications. Many of these applications are real-time and also mixed-criticality, in that they have components/subsystems with different consequences of failure. Wireless communication is inevitably subject to levels of external interference. In this article, we represent this interference using a criticality-aware fault model; for each level of temporal interference in the fault model, we guarantee the timing behaviour of the protocol (i.e., we guarantee that packet deadlines are satisfied for certain levels of criticality). Although a new protocol, AirTight is built upon existing standards such as IEEE 802.15.4. A prototype implementation and protocol-accurate simulator have been produced. This article develops a series of schedulability analysis techniques for single-channel and multichannel wireless Cyber-Physical Systems (CPS). Heuristics are specified and evaluated as the starting point of design space exploration. Genetic algorithms are then defined and evaluated to assess their performance in developing schedule tables incorporating multichannel allocations in these systems.

Abstract PR02: Loss of TET2 activity results in epigenetic instability and drives PDAC molecular subtypes

Background: mRNA datasets have defined two molecular subtypes of pancreatic ductal adenocarcinoma (PDAC), classical and squamous, with distinct clinical characteristics and raising the possibility of subtype specific therapies (Collisson et al., 2019). The aggressive squamous subtype is characterized by poorer patient survival and loss of endodermal differentiation markers GATA6 and PDX1, but neither PDAC subtypes nor metastasis can be explained by genetic mutations alone (Reiter et al., 2018). Conversely, widespread epigenetic reprogramming is associated with progression to more aggressive phenotypes (McDonald et al., 2017), suggesting that aggressive molecular subtype is likely to be epigenetically driven. The role of DNA 5’methylcytosine (5’mc) in PDAC has been previously unclear due to an inability to distinguish this mark from the reciprocal activation mark DNA 5’hydroxymethylcytosine (5’hmC), mediated by Ten-eleven-translocation (TET) enzymes. Moreover, 5’hmc is dynamically regulated during pancreatic differentiation, but a role during PDAC initiation or progression has not been previously addressed.

Methods: PDAC patients who underwent surgical resection at the Churchill Hospital, Oxford (n=146) had FFPE tumor tissue mutation comprehensively profiled by illumina hotspot array (300X), mRNA microarray, and the first epigenetic separation of 5’mc and 5’hmc on FFPE via oxidative bisulphite sequencing (oxBS) and illumina EPIC arrays. iCluster was used to highlight epigenetic PDAC subtypes and compare to existing TCGA datasets. Orthotopic models were employed to test whether the Squamous subtype is defined by 5’hmc loss and if this can be converted to the classical subtype in vivo.

Results: Compared to healthy tissue, PDAC tumors demonstrate loss of 5’hmC at genes critical for pancreatic development and associated with PDAC progression, including MAPK signaling and TP53 targets. 5’hmC was preferentially lost in aggressive molecular subtypes (squamous) compared to the classical subtypes and was associated with SMAD4 mutations and reduced TET2. Overexpression of TET2 in squamous tumor cells restored 5’hmc and the expression of classical associated genes (e.g., GATA6 and PDX1), suggesting that 5’hmC is a master epigenetic regulator of PDAC molecular subtypes. Notably, we find TET2 stability is regulated by glucose levels, implying the widespread hypoglycemia seen in PDAC patients may contribute to progression of aggressive subtypes through loss of 5’hmC. Concomitantly, as metformin and vitamin C independently enhance endogenous TET2 activity, we find that this combination acts synergistically on squamous tumors to increase 5’hmC and expression of a classical-subtype phenotype, suggesting subtype switching is achievable in vitro and in vivo.

Conclusion: These results identify 5’hmC as a regulator of molecular subtype that can be targeted in vivo using well-tolerated drugs.

This abstract is also being presented as Poster A39.

Citation Format: Michael Eyres, Simone Lanfredini, Frances Willenbrock, Asmita Thapa, Andrew Blake, Adam Burns, Ahmad Sabbagh, Aswin Abraham, Timothy Maughan, Zahir Soonawalla, Anna Schuh, Somnath Mukhergee, Eric O'Neill. Loss of TET2 activity results in epigenetic instability and drives PDAC molecular subtypes [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr PR02.

Simultaneous Determination of Chlorothalonil and Hexachlorobenzene in Technical and Formulated Materials by Capillary Gas Chromatography: Collaborative Study

A collaborative study was conducted for the capillary gas chromatographic (GC) method for the simultaneous determination of the fungicide chlorothalonil (CTL) and the accompanying impurity, hexachlorobenzene (HCB), in technical and formulated materials. The method calls for the dissolution of technical and dry formulations of CTL and HCB from the aqueous flowable formulation. The 10 participating laboratories were asked to analyze the samples by adhering to the method as closely as their instrumentation and data systems allowed, and to note any deviations from the method. Collaborators were asked to prepare the standards and samples, set up the capillary GC systems, analyze the samples, and calculate the results. CTL produced reproducibility relative standard deviations (RSDR) of 0.4–2.5 (active ingredient concentrations ranged from approximately 52 to 98% by weight). HCB produced RSDR values of 5.2–22% (HCB concentrations were 0.02–0.04% by weight). The method was adopted First Action by AOAC INTERNATIONAL.

Relation between facial fractures and socioeconomic deprivation in the north east of England

Patients with a low socioeconomic status suffer disproportionately from trauma, and have a high incidence of mandibular fractures. To explore how deprivation affects the incidence of facial fractures in the north east of England, we reviewed 1096 patients who were admitted to the oral and maxillofacial surgical (OMFS) unit at Sunderland Royal Hospital for treatment of a facial fracture between December 2013 and December 2017. Levels of socioeconomic deprivation, which were obtained from postcodes and the UK Government Open Data Communities database, were compared with a random sample of deprivation data from the catchment area of our hospital. Patients with nasal and mandibular fractures were more likely to be socioeconomically deprived than those in the catchment area of our hospital (p = 0.006 and p < 0.001, respectively), but this was not the case in those with malar/maxillary or orbital floor fractures (p = 0.184 and p = 0.641, respectively). The incidence of fractures that were caused by assault was not associated with increased socioeconomic deprivation (p = 0.241). Patients of low socioeconomic status were more likely to have been under the influence of a substance when the injury occurred (p = 0.014). There is a strong association between socioeconomic deprivation and facial fractures. OMFS departments should therefore be as accessible as possible to patients from more disadvantaged backgrounds, given their greater risk of injury.

The Light Chain IgLV3-21 Defines a New Poor Prognostic Subgroup in Chronic Lymphocytic Leukemia: Results of a Multicenter Study

Purpose: Unmutated (UM) immunoglobulin heavy chain variable region (IgHV) status or IgHV3-21 gene usage is associated with poor prognosis in chronic lymphocytic leukemia (CLL) patients. Interestingly, IgHV3-21 is often co-expressed with light chain IgLV3-21, which is potentially able to trigger cell-autonomous BCR-mediated signaling. However, this light chain has never been characterized independently of the heavy chain IgHV3-21.Experimental Design: We performed total RNA sequencing in 32 patients and investigated IgLV3-21 prognostic impact in terms of treatment-free survival (TFS) and overall survival (OS) in 3 other independent cohorts for a total of 813 patients. IgLV3-21 presence was tested by real-time PCR and confirmed by Sanger sequencing.Results: Using total RNA sequencing to characterize 32 patients with high-risk CLL, we found a high frequency (28%) of IgLV3-21 rearrangements. Gene set enrichment analysis revealed that these patients express higher levels of genes responsible for ribosome biogenesis and translation initiation (P < 0.0001) as well as MYC target genes (P = 0.0003). Patients with IgLV3-21 rearrangements displayed a significantly shorter TFS and OS (P < 0.05), particularly those with IgHV mutation. In each of the three independent validation cohorts, we showed that IgLV3-21 rearrangements-similar to UM IgHV status-conferred poor prognosis compared with mutated IgHV (P < 0.0001). Importantly, we confirmed by multivariate analysis that this was independent of IgHV mutational status or subset #2 stereotyped receptor (P < 0.0001).Conclusions: We have demonstrated for the first time that a light chain can affect CLL prognosis and that IgLV3-21 light chain usage defines a new subgroup of CLL patients with poor prognosis. Clin Cancer Res; 24(20); 5048-57. ©2018 AACR.