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Dive into the research topics where Michael O'Rorke is active.

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Featured researches published by Michael O'Rorke.


Oral Oncology | 2012

Human papillomavirus related head and neck cancer survival: a systematic review and meta-analysis.

Michael O'Rorke; M V Ellison; Liam Murray; Michael Moran; Jacqueline James; Lesley A. Anderson

Human Papillomavirus (HPV) related oropharyngeal squamous cell carcinomas (OPSCCs) are reported to have improved prognosis and survival in comparison to other head and neck squamous cell cancers (HNSCCs). This systematic review and meta-analysis examines survival differences in HPV-positive HNSCC and OPSCC subtypes including tonsillar carcinoma in studies not previously investigated. Four electronic databases were searched from their inception till April 2011. A random effects meta-analysis was used to pool study estimates evaluating disease-specific (death from HNSCC), overall (all-cause mortality), progression-free and disease-free (recurrence free) survival outcomes in HPV-positive vs. HPV-negative HNSCCs. All statistical tests were two-sided. Forty-two studies were included. Patients with HPV-positive HNSCC had a 54% better overall survival compared to HPV-negative patients HR 0.46 (95% CI 0.37-0.57); the pooled HR for tonsillar cancer and OPSCC was 0.50 (95% CI 0.33-0.77) and HR 0.47 (95% CI 0.35-0.62) respectively. The pooled HR for disease specific survival was 0.28 (95% CI 0.19-0.40); similar effect sizes were found irrespective of the adjustment for confounders, HPV detection methods or study location. Both progression-free survival and disease-free survival were significantly improved in HPV-positive HNSCCs. HPV-positive HNSCCs and OPSCCs patients have a significantly lower disease specific mortality and are less likely to experience progression or recurrence of their cancer than HPV-negative patients; findings which have connotations for treatment selection in these patients.


International Journal of Cancer | 2010

Can physical activity modulate pancreatic cancer risk? a systematic review and meta-analysis.

Michael O'Rorke; Marie Cantwell; Christopher Cardwell; Helen G. Mulholland; Liam J. Murray

Numerous epidemiological studies have examined the association between physical activity and pancreatic cancer; however, findings from individual cohorts have largely not corroborated a protective effect. Among other plausible mechanisms, physical activity may reduce abdominal fat depots inducing metabolic improvements in glucose tolerance and insulin sensitivity, thereby potentially attenuating pancreatic cancer risk. We performed a systematic review to examine associations between physical activity and pancreatic cancer. Six electronic databases were searched from their inception through July 2009, including MEDLINE and EMBASE, seeking observational studies examining any physical activity measure with pancreatic cancer incidence/mortality as an outcome. A random effects model was used to pool individual effect estimates evaluating highest vs. lowest categories of activity. Twenty‐eight studies were included. Pooled estimates indicated a reduction in pancreatic cancer risk with higher levels of total (five prospective studies, RR: 0.72, 95% CI: 0.52–0.99) and occupational activity (four prospective studies, RR: 0.75, 95% CI: 0.59–0.96). Nonsignificant inverse associations were seen between risks and recreational and transport physical activity. When examining exercise intensity, moderate activity appeared more protective (RR: 0.79, 95% CI: 0.52–1.20) than vigorous activity (RR: 0.97, 95% CI: 0.85–1.11), but results were not statistically significant and the former activity variable incorporated marked heterogeneity. Despite indications of an inverse relationship with higher levels of work and total activity, there was little evidence of such associations with recreational and other activity exposures.


American Journal of Hematology | 2014

How common are myeloproliferative neoplasms? A systematic review and meta-analysis.

Glen Titmarsh; Andrew S Duncombe; Mary Frances McMullin; Michael O'Rorke; Ruben A. Mesa; Frank de Vocht; Sarah Horan; Lin Fritschi; Mike Clarke; Lesley A. Anderson

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of diseases including polycythemia vera (PV), essential thrombocythemia (ET), and primary(idiopathic) myelofibrosis (PMF). In this systematic review, we provide a comprehensive report on the incidence and prevalence of MPNs across the globe. Electronic databases (PubMed, EMBASE, MEDLINE, and Web of Science) were searched from their inception to August 2012 for articles reporting MPN incidence or prevalence rates. A random effects meta‐analysis was undertaken to produce combined incidence rates for PV, ET, and PMF. Both heterogeneity and small study bias were assessed. Thirty‐four studies were included. Reported annual incidence rates ranged from 0.01 to 2.61, 0.21 to 2.27, and 0.22 to 0.99 per 100,000 for PV, ET, and PMF, respectively. The combined annual incidence rates for PV, ET, and PMF were 0.84, 1.03, and 0.47 per 100,000. There was high heterogeneity across disease entities (I2 97.1–99.8%) and evidence of publication bias for ET and PMF (Egger test, P = 0.007 and P ≤ 0.001, respectively).The pooled incidence reflects the rarity of MPNs. The calculated pooled incidence rates do not reflect MPN incidence across the globe due to the high unexplained heterogeneity. Improved, widespread registration of MPNs would provide better information for global comparison of the incidence and prevalence of MPNs. Am. J. Hematol. 89:581–587, 2014.


Cancer Epidemiology, Biomarkers & Prevention | 2014

Prior Autoimmune Disease and Risk of Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma: A Systematic Review

Charlene McShane; Liam Murray; Ola Landgren; Michael O'Rorke; Neha Korde; Andrew T. Kunzmann; Mohammad Roshidi Ismail; Lesley A. Anderson

Background: Several observational studies have investigated autoimmune disease and subsequent risk of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma. Findings have been largely inconsistent and hindered by the rarity and heterogeneity of the autoimmune disorders investigated. A systematic review of the literature was undertaken to evaluate the strength of the evidence linking prior autoimmune disease and risk of MGUS/multiple myeloma. Methods: A broad search strategy using key terms for MGUS, multiple myeloma, and 50 autoimmune diseases was used to search four electronic databases (PubMed, Medline, Embase, and Web of Science) from inception through November 2011. Results: A total of 52 studies met the inclusion criteria, of which 32 were suitably comparable to perform a meta-analysis. “Any autoimmune disorder” was associated with an increased risk of both MGUS [n = 760 patients; pooled relative risk (RR) 1.42; 95% confidence interval (CI), 1.14–1.75] and multiple myeloma (n>2,530 patients; RR 1.13, 95% CI, 1.04–1.22). This risk was disease dependent with only pernicious anemia showing an increased risk of both MGUS (RR 1.67; 95% CI, 1.21–2.31) and multiple myeloma (RR 1.50; 95% CI, 1.25–1.80). Conclusions: Our findings, based on the largest number of autoimmune disorders and patients with MGUS/multiple myeloma reported to date, suggest that autoimmune diseases and/or their treatment may be important in the etiology of MGUS/multiple myeloma. The strong associations observed for pernicious anemia suggest that anemia seen in plasma cell dyscrasias may be of autoimmune origin. Impact: Underlying mechanisms of autoimmune diseases, general immune dysfunction, and/or treatment of autoimmune diseases may be important in the pathogenesis of MGUS/multiple myeloma. Cancer Epidemiol Biomarkers Prev; 23(2); 332–42. ©2014 AACR.


International Journal of Cancer | 2012

Toenail trace element status and risk of Barrett's oesophagus and oesophageal adenocarcinoma. Results from the FINBAR study

Michael O'Rorke; Marie Cantwell; Christian C. Abnet; and John D. Brockman; Liam J. Murray

Trace elements have been cited as both inhibitory and causative agents of cancer but importantly exposure to them is potentially modifiable. Our study aimed to examine toenail trace element status and risk of Barretts oesophagus (BO) and oesophageal adenocarcinoma (OAC). Toenail clippings from each hallux were obtained from 638 participants of the FINBAR (Factors Influencing the Barretts Adenocarcinoma Relationship) study comprising 221 healthy controls, 98 reflux oesophagitis, 182 BO and 137 OAC cases. The concentrations of eight toenail trace elements were determined using instrumental neutron activation analysis. Using multivariable adjusted logistic regression analysis, odds ratios (OR) and 95% confidence intervals (CIs) were calculated within tertiles of trace element concentrations. A twofold increased risk of BO was observed, but not OAC, among individuals in the highest tertile of toenail zinc status OR 2.21 (95% CI, 1.11–4.40). A higher toenail selenium status was not associated with risk of OAC OR 0.94 (95% CI, 0.44–2.04) or BO OR 0.89 (95% CI, 0.37–2.12). A borderline significant increased risk of BO was detected with a higher toenail cobalt concentration, OR 1.97 (95% CI, 1.01–3.85). No association was found between toenail levels of chromium, cerium, mercury and OAC or BO risk. This is the first case–control study to investigate a variety of trace elements in relation to OAC and BO risk. Despite antioxidant and proapoptotic properties, no associations were found with selenium. Higher concentrations of toenail zinc and cobalt were associated with an increased BO risk, but not OAC. These findings need confirmation in prospective analysis.


Journal of Medical Virology | 2013

Prevalence of human papillomavirus in women attending cervical screening in the UK and Ireland: New data from northern Ireland and a systematic review and meta-analysis

Lesley A. Anderson; Michael O'Rorke; Jackie Jamison; Robbie Wilson; Anna Gavin

There is substantial international variation in human papillomavirus (HPV) prevalence; this study details the first report from Northern Ireland and additionally provides a systematic review and meta‐analysis pooling the prevalence of high‐risk (HR‐HPV) subtypes among women with normal cytology in the UK and Ireland. Between February and December 2009, routine liquid based cytology (LBC) samples were collected for HPV detection (Roche Cobas® 4800 [PCR]) among unselected women attending for cervical cytology testing. Four electronic databases, including MEDLINE, were then searched from their inception till April 2011. A random effects meta‐analysis was used to calculate a pooled HR‐HPV prevalence and associated 95% confidence intervals (CI). 5,712 women, mean age 39 years (±SD 11.9 years; range 20–64 years), were included in the analysis, of which 5,068 (88.7%), 417 (7.3%) and 72 (1.3%) had normal, low, and high‐grade cytological findings, respectively. Crude HR‐HPV prevalence was 13.2% (95% CI, 12.7–13.7) among women with normal cytology and increased with cytological grade. In meta‐analysis the pooled HR‐HPV prevalence among those with normal cytology was 0.12 (95% CIs, 0.10–0.14; 21 studies) with the highest prevalence in younger women. HPV 16 and HPV 18 specific estimates were 0.03 (95% CI, 0.02–0.05) and 0.01 (95% CI, 0.01–0.02), respectively. The findings of this Northern Ireland study and meta‐analysis verify the prevalent nature of HPV infection among younger women. Reporting of the type‐specific prevalence of HPV infection is relevant for evaluating the impact of future HPV immunization initiatives, particularly against HR‐HPV types other than HPV 16 and 18. J. Med. Virol. 85:295–308, 2013.


Gut | 2017

Reduced risk of pancreatic cancer associated with asthma and nasal allergies.

Paulina Gomez-Rubio; Jan-Paul Zock; Marta Rava; Mirari Marquez; Linda Sharp; Manuel Hidalgo; Alfredo Carrato; Lucas Ilzarbe; Christoph W. Michalski; Xavier Molero; Antoni Farré; José Perea; William Greenhalf; Michael O'Rorke; Adonina Tardón; Thomas M. Gress; Víctor Manuel Barberá; Tatjana Crnogorac-Jurcevic; Enrique Dominguez-Munoz; Luís Muñoz-Bellvís; Cristina Alvarez-Urturi; Joaquim Balcells; Luis Barneo; Eithne Costello; Carmen Guillén-Ponce; Jörg Kleeff; Bo Kong; Rita T. Lawlor; Matthias Löhr; Josefina Mora

Objective Studies indicate an inverse association between ductal adenocarcinoma of the pancreas (PDAC) and nasal allergies. However, controversial findings are reported for the association with asthma. Understanding PDAC risk factors will help us to implement appropriate strategies to prevent, treat and diagnose this cancer. This study assessed and characterised the association between PDAC and asthma and corroborated existing reports regarding the association between allergies and PDAC risk. Design Information about asthma and allergies was collated from 1297 PDAC cases and 1024 controls included in the PanGenEU case–control study. Associations between PDAC and atopic diseases were studied using multilevel logistic regression analysis. Meta-analyses of association studies on these diseases and PDAC risk were performed applying random-effects model. Results Asthma was associated with lower risk of PDAC (OR 0.64, 95% CI 0.47 to 0.88), particularly long-standing asthma (>=17 years, OR 0.39, 95% CI 0.24 to 0.65). Meta-analysis of 10 case–control studies sustained our results (metaOR 0.73, 95% CI 0.59 to 0.89). Nasal allergies and related symptoms were associated with lower risk of PDAC (OR 0.66, 95% CI 0.52 to 0.83 and OR 0.59, 95% CI 0.46 to 0.77, respectively). These results were supported by a meta-analysis of nasal allergy studies (metaOR 0.6, 95% CI 0.5 to 0.72). Skin allergies were not associated with PDAC risk. Conclusions This study shows a consistent inverse association between PDAC and asthma and nasal allergies, supporting the notion that atopic diseases are associated with reduced cancer risk. These results point to the involvement of immune and/or inflammatory factors that may either foster or restrain pancreas carcinogenesis warranting further research to understand the molecular mechanisms driving this association.


Cancer Epidemiology | 2013

Non-steroidal anti-inflammatory drug use and cervical cancer risk: A case-control study using the Clinical Practice Research Datalink

Jessica Wilson; Michael O'Rorke; Janine A. Cooper; L J Murray; Carmel Hughes; Gerard Gormley; Lesley A. Anderson

PURPOSE Non-steroidal anti-inflammatory drugs (NSAIDs) have many anticarcinogenic properties via the inhibition of cyclooxygenase 2 (COX-2). Only one study, a cohort study examining risk of all cancers, investigated their role in cervical cancer with inconsistent findings between non-aspirin NSAIDs and aspirin. The aim of this study was to further investigate NSAID/aspirin use and cervical cancer risk. METHODS Using the United Kingdom Clinical Practice Research Datalink, 724 women diagnosed with cervical cancer between 1 January, 1995 and December 2010 were compared to 3479 women (without cervical cancer) matched on year of birth and general practice. Conditional logistic regression analysis adjusted for smoking, sexually transmitted infections, HRT and contraceptive use, was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for cervical cancer risk among users of any oral NSAIDs, non-aspirin NSAIDs and aspirin, as assessed from primary care prescribing data. RESULTS Excluding the year prior to diagnosis, there was no association in adjusted analyses between ever vs. never use of an NSAID (OR 0.92, 95% CI 0.77-1.09), non-aspirin NSAID (OR 0.95, 95% CI 0.80-1.13) or low-dose aspirin (OR 1.07, 0.80-1.44) and cervical cancer risk. In analysis of daily defined doses, there was no association with cervical cancer risk comparing the highest users to non-users of NSAIDs (OR 0.98, 95% CI 0.69-1.39) or non-aspirin NSAIDs (OR 1.00, 95% CI 0.70-1.43) or low-dose aspirin (OR 1.04, 95% CI 0.59-1.81). CONCLUSION This large historical cohort study found no evidence of an association between non-aspirin NSAID or aspirin use and cervical cancer risk.


Journal of Medical Virology | 2016

HPV prevalence and type-distribution in cervical cancer and premalignant lesions of the cervix: A population-based study from Northern Ireland

Lesley A. Anderson; Michael O'Rorke; Robbie Wilson; Jackie Jamison; Anna Gavin

Assessment of Human papillomavirus (HPV) prevalence and genotype distribution is important for monitoring the impact of prophylactic HPV vaccination. This study aimed to demonstrate the HPV genotypes predominating in pre‐malignant and cervical cancers in Northern Ireland (NI) before the vaccination campaign has effect. Formalin fixed paraffin embedded tissue blocks from 2,303 women aged 16–93 years throughout NI were collated between April 2011 and February 2013. HPV DNA was amplified by PCR and HPV genotyping undertaken using the Roche® linear array detection kit. In total, 1,241 out of 1,830 eligible samples (68.0%) tested positive for HPV, with the majority of these [1,181/1,830 (64.5%)] having high‐risk (HR) HPV infection; 37.4% were positive for HPV‐16 (n = 684) and 5.1% for HPV‐18 (n = 93). HPV type‐specific prevalence was 48.1%, 65.9%, 81.3%, 92.2%, and 64.3% among cervical intraepithelial neoplasias (CIN) Grades I–III, squamous cell carcinomas (SCC) and adenocarcinoma (AC) cases, respectively. Most SCC cases (81.3%) had only one HPV genotype detected and almost a third (32.0%) of all cervical pathologies were HPV negative including 51.9% of CIN I (n = 283), 34.1% CIN II (n = 145), 18.7% of CIN III (n = 146), 7.8% of SCC (n = 5), and 35.7% of AC (n = 5) cases. This study provides important baseline data for monitoring the effect of HPV vaccination in NI and for comparison with other UK regions. The coverage of other HR‐HPV genotypes apart from 16 and 18, including HPV‐45, 31, 39, and 52, and the potential for cross protection, should be considered when considering future polyvalent vaccines. J. Med. Virol. 88:1262–1270, 2016.


Breast Cancer Research | 2016

Propranolol and survival from breast cancer: a pooled analysis of European breast cancer cohorts

Christopher Cardwell; Anton Pottegård; Evelien Vaes; Hans Garmo; Liam Murray; Chris Brown; Pauline A. J. Vissers; Michael O'Rorke; Kala Visvanathan; Deirdre Cronin-Fenton; Harlinde De Schutter; Mats Lambe; Des G. Powe; Myrthe P. P. van Herk-Sukel; Anna Gavin; Søren Friis; Linda Sharp; Kathleen Bennett

BackgroundPreclinical studies have demonstrated that propranolol inhibits several pathways involved in breast cancer progression and metastasis. We investigated whether breast cancer patients who used propranolol, or other non-selective beta-blockers, had reduced breast cancer-specific or all-cause mortality in eight European cohorts.MethodsIncident breast cancer patients were identified from eight cancer registries and compiled through the European Cancer Pharmacoepidemiology Network. Propranolol and non-selective beta-blocker use was ascertained for each patient. Breast cancer-specific and all-cause mortality were available for five and eight cohorts, respectively. Cox regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CIs) for cancer-specific and all-cause mortality by propranolol and non-selective beta-blocker use. HRs were pooled across cohorts using meta-analysis techniques. Dose–response analyses by number of prescriptions were also performed. Analyses were repeated investigating propranolol use before cancer diagnosis.ResultsThe combined study population included 55,252 and 133,251 breast cancer patients in the analysis of breast cancer-specific and all-cause mortality respectively. Overall, there was no association between propranolol use after diagnosis of breast cancer and breast cancer-specific or all-cause mortality (fully adjusted HR = 0.94, 95% CI, 0.77, 1.16 and HR = 1.09, 95% CI, 0.93, 1.28, respectively). There was little evidence of a dose–response relationship. There was also no association between propranolol use before breast cancer diagnosis and breast cancer-specific or all-cause mortality (fully adjusted HR = 1.03, 95% CI, 0.86, 1.22 and HR = 1.02, 95% CI, 0.94, 1.10, respectively). Similar null associations were observed for non-selective beta-blockers.ConclusionsIn this large pooled analysis of breast cancer patients, use of propranolol or non-selective beta-blockers was not associated with improved survival.

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Liam Murray

Queen's University Belfast

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Anna Gavin

Queen's University Belfast

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Marie Cantwell

Queen's University Belfast

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Andrew S Duncombe

University Hospital Southampton NHS Foundation Trust

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Glen Titmarsh

Queen's University Belfast

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Jackie Jamison

Northern Health and Social Care Trust

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Liam J. Murray

Queen's University Belfast

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