ORCID Profile
0000-0003-0496-6710
Current Organisations
University of Manchester
,
Salford Royal NHS Foundation Trust
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Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2015
DOI: 10.1038/AJG.2015.151
Publisher: Georg Thieme Verlag KG
Date: 30-06-2015
Abstract: Mucosal neoplasia arising in Barrett's esophagus can be successfully treated with endoscopic mucosal resection (EMR) followed by radiofrequency ablation (RFA). The aim of the study was to compare clinical outcomes of patients with high grade dysplasia (HGD) or intramucosal cancer (IMC) at baseline from the United Kingdom RFA registry. Prior to RFA, visible lesions and nodularity were removed entirely by EMR. Thereafter, patients underwent RFA every 3 months until all visible Barrett's mucosa was ablated or cancer developed (end points). Biopsies were taken at 12 months or when end points were reached. A total of 515 patients, 384 with HGD and 131 with IMC, completed treatment. Prior to RFA, EMR was performed for visible lesions more frequently in the IMC cohort than in HGD patients (77 % vs. 47 % P < 0.0001). The 12-month complete response for dysplasia and intestinal metaplasia were almost identical in the two cohorts (HGD 88 % and 76 %, respectively IMC 87 % and 75 %, respectively P = 0.7). Progression to invasive cancer was not significantly different at 12 months (HGD 1.8 %, IMC 3.8 % P = 0.19). A trend towards slightly worse medium-term durability may be emerging in IMC patients (P = 0.08). In IMC, EMR followed by RFA was definitely associated with superior durability compared with RFA alone (P = 0.01). The Registry reports on endoscopic therapy for Barrett's neoplasia, representing real-life outcomes. Patients with IMC were more likely to have visible lesions requiring initial EMR than those with HGD, and may carry a higher risk of cancer progression in the medium term. The data consolidate the approach to ensuring that these patients undergo thorough endoscopic work-up, including EMR prior to RFA when necessary.
Publisher: Springer Science and Business Media LLC
Date: 05-09-2016
DOI: 10.1038/NG.3659
Publisher: BMJ
Date: 24-02-2018
DOI: 10.1136/GUTJNL-2017-315414
Abstract: These are updated guidelines which supersede the original version published in 2004. This work has been endorsed by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG) under the auspices of the oesophageal section of the BSG. The original guidelines have undergone extensive revision by the 16 members of the Guideline Development Group with representation from in iduals across all relevant disciplines, including the Heartburn Cancer UK charity, a nursing representative and a patient representative. The methodological rigour and transparency of the guideline development processes were appraised using the revised Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. Dilatation of the oesophagus is a relatively high-risk intervention, and is required by an increasing range of disease states. Moreover, there is scarcity of evidence in the literature to guide clinicians on how to safely perform this procedure. These guidelines deal specifically with the dilatation procedure using balloon or bougie devices as a primary treatment strategy for non-malignant narrowing of the oesophagus. The use of stents is outside the remit of this paper however, for cases of dilatation failure, alternative techniques—including stents—will be listed. The guideline is ided into the following subheadings: (1) patient preparation (2) the dilatation procedure (3) aftercare and (4) disease-specific considerations. A systematic literature search was performed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool was used to evaluate the quality of evidence and decide on the strength of recommendations made.
Publisher: Oxford University Press (OUP)
Date: 02-05-2022
Abstract: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic.
Publisher: Springer Science and Business Media LLC
Date: 05-02-2020
DOI: 10.1038/S41586-020-1969-6
Abstract: Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale 1–3 . Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution in acral melanoma, for ex le, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter 4 identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation 5,6 analyses timings and patterns of tumour evolution 7 describes the erse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity 8,9 and evaluates a range of more-specialized features of cancer genomes 8,10–18 .
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2015
DOI: 10.1038/AJG.2015.55
Publisher: Elsevier BV
Date: 05-2020
Publisher: Springer Science and Business Media LLC
Date: 21-09-2020
DOI: 10.1038/S41467-020-18151-Y
Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA s les, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological ergences between two reproducible somatic variant detection efforts.
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 02-2015
Publisher: BMJ
Date: 28-10-2013
DOI: 10.1136/GUTJNL-2013-305372
Abstract: These guidelines provide a practical and evidence-based resource for the management of patients with Barrett's oesophagus and related early neoplasia. The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument was followed to provide a methodological strategy for the guideline development. A systematic review of the literature was performed for English language articles published up until December 2012 in order to address controversial issues in Barrett's oesophagus including definition, screening and diagnosis, surveillance, pathological grading for dysplasia, management of dysplasia, and early cancer including training requirements. The rigour and quality of the studies was evaluated using the SIGN checklist system. Recommendations on each topic were scored by each author using a five-tier system (A+, strong agreement, to D+, strongly disagree). Statements that failed to reach substantial agreement among authors, defined as >80% agreement (A or A+), were revisited and modified until substantial agreement (>80%) was reached. In formulating these guidelines, we took into consideration benefits and risks for the population and national health system, as well as patient perspectives. For the first time, we have suggested stratification of patients according to their estimated cancer risk based on clinical and histopathological criteria. In order to improve communication between clinicians, we recommend the use of minimum datasets for reporting endoscopic and pathological findings. We advocate endoscopic therapy for high-grade dysplasia and early cancer, which should be performed in high-volume centres. We hope that these guidelines will standardise and improve management for patients with Barrett's oesophagus and related neoplasia.
Publisher: Elsevier BV
Date: 09-2018
Publisher: BMJ
Date: 18-03-2019
Publisher: Springer Science and Business Media LLC
Date: 30-11-2020
DOI: 10.1038/S41467-020-20128-W
Abstract: Correction to this paper has been published: 0.1038/s41467-020-20128-w
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 20-10-2015
DOI: 10.1002/HEP.28017
Abstract: The biochemical response to ursodeoxycholic acid (UDCA)—so‐called “treatment response”—strongly predicts long‐term outcome in primary biliary cholangitis (PBC). Several long‐term prognostic models based solely on the treatment response have been developed that are widely used to risk stratify PBC patients and guide their management. However, they do not take other prognostic variables into account, such as the stage of the liver disease. We sought to improve existing long‐term prognostic models of PBC using data from the UK‐PBC Research Cohort. We performed Cox's proportional hazards regression analysis of erse explanatory variables in a derivation cohort of 1,916 UDCA‐treated participants. We used nonautomatic backward selection to derive the best‐fitting Cox model, from which we derived a multivariable fractional polynomial model. We combined linear predictors and baseline survivor functions in equations to score the risk of a liver transplant or liver‐related death occurring within 5, 10, or 15 years. We validated these risk scores in an independent cohort of 1,249 UDCA‐treated participants. The best‐fitting model consisted of the baseline albumin and platelet count, as well as the bilirubin, transaminases, and alkaline phosphatase, after 12 months of UDCA. In the validation cohort, the 5‐, 10‐, and 15‐year risk scores were highly accurate (areas under the curve: .90). Conclusions : The prognosis of PBC patients can be accurately evaluated using the UK‐PBC risk scores. They may be used to identify high‐risk patients for closer monitoring and second‐line therapies, as well as low‐risk patients who could potentially be followed up in primary care. (H epatology 2016 :930–950)
Publisher: Georg Thieme Verlag KG
Date: 28-12-2015
Publisher: Cold Spring Harbor Laboratory
Date: 08-04-2019
Abstract: Esophageal adenocarcinoma (EAC) is one of the most frequent causes of cancer death, and yet compared to other common cancers, we know relatively little about the molecular composition of this tumor type. To further our understanding of this cancer, we have used open chromatin profiling to decipher the transcriptional regulatory networks that are operational in EAC. We have uncovered a transcription factor network that is usually found in primitive intestinal cells during embryonic development, centered on HNF4A and GATA6. These transcription factors work together to control the EAC transcriptome. We show that this network is activated in Barrett's esophagus, the putative precursor state to EAC, thereby providing novel molecular evidence in support of stepwise malignant transition. Furthermore, we show that HNF4A alone is sufficient to drive chromatin opening and activation of a Barrett's-like chromatin signature when expressed in normal human epithelial cells. Collectively, these data provide a new way to categorize EAC at a genome scale and implicate HNF4A activation as a potential pivotal event in its malignant transition from healthy cells.
Publisher: Springer Science and Business Media LLC
Date: 28-08-2020
DOI: 10.1038/S41467-020-17359-2
Abstract: Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research.
Publisher: BMJ
Date: 04-2006
Publisher: Springer Science and Business Media LLC
Date: 20-07-2015
DOI: 10.1038/NG.3357
Publisher: Cold Spring Harbor Laboratory
Date: 28-07-2018
DOI: 10.1101/373068
Abstract: Oesophageal adenocarcinoma (OAC) is one of the most frequent causes of cancer deaths and yet compared to other common cancers, we know relatively little about the molecular composition of this tumour type. To further our understanding of this cancer we have used open chromatin profiling to decipher the transcriptional regulatory networks that are operational in OAC. We have uncovered a transcription factor network that is usually found in primitive intestinal cells during embryonic development, centred on HNF4A and GATA6. These transcription factors work together to control the OAC transcriptome. Importantly, we show that this network is activated in Barrett’s oesophagus, the putative precursor state to OAC thereby providing novel molecular evidence in support of stepwise malignant transition. Furthermore, we show that HNF4A alone, is sufficient to drive chromatin opening and activation of a Barrett’s-like chromatin signature when expressed in normal human epithelial cells. Collectively, these data provide a new way to categorise OAC at a genome scale and implicate HNF4A activation as a potential pivotal event in regulating its malignant transition from healthy cells.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Yeng Ang.