Thomas P. Thomopoulos
National and Kapodistrian University of Athens
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Featured researches published by Thomas P. Thomopoulos.
European Journal of Cancer | 2015
Paraskevi Papathoma; Thomas P. Thomopoulos; Maria A. Karalexi; Anton Ryzhov; Anna Zborovskaya; Nadya Dimitrova; Snezana Zivkovic; Sultan Eser; Luís Antunes; Mario Sekerija; Tina Zagar; Joana Bastos; Anna Demetriou; Raluca Cozma; Daniela Coza; Evdoxia Bouka; Nick Dessypris; Maria Kantzanou; Prodromos Kanavidis; Helen Dana; Emmanuel Hatzipantelis; Maria Moschovi; Sophia Polychronopoulou; Apostolos Pourtsidis; Eftichia Stiakaki; Evgenia Papakonstantinou; Konstantinos Oikonomou; Spyros Sgouros; Antonios Vakis; Basilios Zountsas
AIM Following completion of the first 5-year nationwide childhood (0-14 years) registration in Greece, central nervous system (CNS) tumour incidence rates are compared with those of 12 registries operating in 10 Southern-Eastern European countries. METHODS All CNS tumours, as defined by the International Classification of Childhood Cancer (ICCC-3) and registered in any period between 1983 and 2014 were collected from the collaborating cancer registries. Data were evaluated using standard International Agency for Research on Cancer (IARC) criteria. Crude and age-adjusted incidence rates (AIR) by age/gender/diagnostic subgroup were calculated, whereas time trends were assessed through Poisson and Joinpoint regression models. RESULTS 6062 CNS tumours were retrieved with non-malignant CNS tumours recorded in eight registries; therefore, the analyses were performed on 5191 malignant tumours. Proportion of death certificate only cases was low and morphologic verification overall high; yet five registries presented >10% unspecified neoplasms. The male/female ratio was 1.3 and incidence decreased gradually with age, apart from Turkey and Ukraine. Overall AIR for malignant tumours was 23/10(6) children, with the highest rates noted in Croatia and Serbia. A statistically significant AIR increase was noted in Bulgaria, whereas significant decreases were noted in Belarus, Croatia, Cyprus and Serbia. Although astrocytomas were overall the most common subgroup (30%) followed by embryonal tumours (26%), the latter was the predominant subgroup in six registries. CONCLUSION Childhood cancer registration is expanding in Southern-Eastern Europe. The heterogeneity in registration practices and incidence patterns of CNS tumours necessitates further investigation aiming to provide clues in aetiology and direct investments into surveillance and early tumour detection.
Journal of Geriatric Psychiatry and Neurology | 2016
Marios K. Georgakis; Fotios C. Papadopoulos; Athanasios D. Protogerou; Ioanna Pagonari; Fani Sarigianni; Stylianos-Iason Biniaris-Georgallis; Eleni Ι. Kalogirou; Thomas P. Thomopoulos; Elisabeth Kapaki; Charalampos Papageorgiou; Socratis G. Papageorgiou; Dimitrios Tousoulis; Eleni Petridou
Objective: To investigate the association of cognitive impairment (COGI) and depression with all-cause mortality and cardiovascular-specific mortality among community-dwelling elderly individuals in rural Greece. Methods: Cognition and depressive symptomatology of 676 Velestino town residents aged ≥60 years were assessed using Mini-Mental State Examination (MMSE) and Geriatric Depression Scale (GDS), respectively. Eight-year all-cause mortality and cardiovascular mortality were explored by multivariate Cox regression models controlling for major confounders. Results: Two hundred and one patients died during follow-up. Cognitive impairment (MMSE ≤ 23) was independently associated with all-cause mortality (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.13-2.18) and cardiovascular mortality (HR: 1.57, 95%CI: 1.03-2.41). Moderate to severe depression (GDS > 10) was significantly associated only with a 51% increase in all-cause mortality. A male-specific association was noted for moderate to severe depression, whereas the effect of COGI was limited to females. Noteworthy, COGI and depression comorbidity, rather than their sole presence, increased all-cause mortality and cardiovascular mortality by 66% and 72%, respectively. The mortality effect of COGI was augmented among patients with depression and of depression among patients with COGI. Conclusion: COGI and depression, 2 entities often coexisting among elderly individuals, appear to increase all-cause mortality and cardiovascular mortality. Gender-specific modes may prevail but their comorbidity should be carefully assessed, as it seems to represent an independent index of increased frailty, which eventually shortens life expectancy.
The Lancet Haematology | 2016
Erin L. Marcotte; Thomas P. Thomopoulos; Claire Infante-Rivard; Jacqueline Clavel; Eleni Petridou; Joachim Schüz; Sameera Ezzat; John D. Dockerty; Catherine Metayer; Corrado Magnani; Michael E. Scheurer; Beth A. Mueller; Ana M. Mora; Catharina Wesseling; Alkistis Skalkidou; Wafaa M. Rashed; Stephen S. Francis; Roula Ajrouche; Friederike Erdmann; Laurent Orsi; Logan G. Spector
BACKGROUND Results from case-control studies have shown an increased risk of acute lymphoblastic leukaemia (ALL) in young children born by caesarean delivery, and prelabour caesarean delivery in particular; however, an association of method of delivery with childhood leukaemia subtypes has yet to be established. We therefore did a pooled analysis of data to investigate the association between childhood leukaemia and caesarean delivery. METHODS We pooled data from 13 case-control studies from the Childhood Leukemia International Consortium done in nine countries (Canada, Costa Rica, Egypt, France, Germany, Greece, Italy, New Zealand, and the USA) for births from 1970-2013. We analysed caesarean delivery overall and by indications that probably resulted in prelabour caesarean delivery or emergency caesarean delivery. We used multivariable logistic regression models, adjusted for childs birthweight, sex, age, ethnic origin, parental education, maternal age, and study, to estimate odds ratios (ORs) and 95% CIs for the risk of ALL and acute myeloid leukaemia (AML) in children aged 0-14 years at diagnosis. FINDINGS The studies provided data for 8780 ALL cases, 1332 AML cases, and 23 459 controls, of which the birth delivery method was known for 8655 (99%) ALL cases, 1292 (97%) AML cases, and 23 351 (>99%) controls. Indications for caesarean delivery were available in four studies (there were caesarean deliveries for 1061 of 4313 ALL cases, 138 of 664 AML cases, and 1401 of 5884 controls). The OR for all indications of caesarean delivery and ALL was 1·06 (95% CI 0·99-1·13), and was significant for prelabour caesarean delivery and ALL (1·23 [1·04-1·47]; p=0·018). Emergency caesarean delivery was not associated with ALL (OR 1·02 [95% CI 0·81-1·30]). AML was not associated with caesarean delivery (all indications OR 0·99 [95% CI 0·84-1·17]; prelabour caesarean delivery 0·83 [0·54-1·26]; and emergency caesarean delivery 1·05 [0·63-1·77]). INTERPRETATION Our results suggest an increased risk of childhood ALL after prelabour caesarean delivery. If this association is causal, maladaptive immune activation due to an absence of stress response before birth in children born by prelabour caesarean delivery could be considered as a potential mechanism. FUNDING National Cancer Institute.
European Journal of Cancer Prevention | 2016
Thomas P. Thomopoulos; Alkistis Skalkidou; Nick Dessypris; George P. Chrousos; Maria A. Karalexi; Theodoros G. Karavasilis; Margarita Baka; Emmanuel Hatzipantelis; Maria Kourti; Sophia Polychronopoulou; Vasiliki Sidi; Eftichia Stiakaki; Maria Moschovi; Dimitrios Loutradis; Eleni Petridou
The long-term impact of cesarean delivery (CD) on the health of the offspring is being explored methodically. We sought to investigate the effect of birth by (a) prelabor and (b) during-labor CD on the risk of early-onset (⩽3 years) acute lymphoblastic leukemia (ALL), specifically of its prevailing precursor B (B-ALL) subtype. A total of 1099 incident cases of ALL (957 B-ALL), 131 of acute myeloid leukemia (AML), and their 1 : 1 age-matched and sex-matched controls, derived from the Nationwide Registry for Childhood Hematological Malignancies (1996–2013), were analyzed using multivariate regression models. A null association was found between prelabor and/or during labor CD and either ALL (B-ALL) or AML in the 0–14 age range. By contrast, birth by CD increased significantly the risk of early-onset ALL [odds ratioCD (ORCD)=1.57, 95% confidence interval (CI): 1.10–2.24] mainly on account of prelabor CD (ORprelaborCD=1.66, 95% CI: 1.13–2.43). The respective figures were even higher for the early-onset precursor B-ALL (ORCD=1.66, 95% CI: 1.15–2.40 and ORprelaborCD=1.79, 95% CI: 1.21–2.66), whereas no association emerged for early-onset AML. Prelabor CD, which deprives exposure of the fetus/infant to the presumably beneficial effect of stress hormones released in both vaginal labor and during labor CD, was associated exclusively with an increased risk of early-onset ALL, particularly the precursor B-ALL subtype. If confirmed, these adverse long-term outcomes of CD may point to re-evaluation of prelabor CD practices and prompt scientific discussion on the best ways to simulate the effects of vaginal delivery, such as a precesarean induction of labor.
European Journal of Cancer | 2015
Maria A. Karalexi; Paraskevi Papathoma; Thomas P. Thomopoulos; Anton Ryzhov; Anna Zborovskaya; Nadya Dimitrova; Snezana Zivkovic; Sultan Eser; Luís Antunes; Mario Sekerija; Tina Zagar; Joana Bastos; Anna Demetriou; Domenic Agius; Raluca Cozma; Daniela Coza; Evdoxia Bouka; Nick Dessypris; Maria Belechri; Helen Dana; Emmanuel Hatzipantelis; Evgenia Papakonstantinou; Sophia Polychronopoulou; Apostolos Pourtsidis; Eftichia Stiakaki; Achilles Chatziioannou; Katerina Manolitsi; Georgios Orphanidis; Savvas Papadopoulos; Mathilda Papathanasiou
AIM Childhood central nervous system (CNS) tumour registration and control programs in Southern and Eastern Europe remain thin, despite the lethal nature of the disease. Mortality/survival data were assembled to estimate the burden of malignant CNS tumours, as well as the potential role of sociodemographic survival determinants across 14 cancer registries of this region. METHODS Average age-adjusted mortality rates were calculated, whereas time trends were quantified through Poisson and Joinpoint regressions. Kaplan-Meier curves were derived for the maximum and the more recent (10 and 5 year) registration periods. Multivariate Cox regression models were used to assess demographic and disease-related determinants. RESULTS Variations in mortality (8-16 per million) and survival (5-year: 35-69%) were substantial among the participating registries; in most registries mortality trend was stable, whereas Bulgaria, having the highest starting rate, experienced decreasing annual mortality (-2.4%, p=0.001). A steep decrease in survival rates was evident before the second year of follow-up. After controlling for diagnostic subgroup, age, gender and diagnostic year, Greece seemed to present higher survival compared with the other contributing registries, although the follow-up period was short. Irrespective of country, however, rural residence was found to impose substantial adverse repercussions on survival (hazard ratio (HR): 1.2, 95% confidence interval (CI): 1.1-1.4). CONCLUSION Cross-country mortality and survival variations possibly reflect suboptimal levels of health care delivery and cancer control in some regions of Southern and Eastern Europe, notwithstanding questionable death certification patterns or follow-up procedures. Continuous childhood cancer registration and linkage with clinical data are prerequisite for the reduction of survival inequalities across Europe.
European Journal of Cancer Prevention | 2017
Maria A. Karalexi; Nick Dessypris; Thomas P. Thomopoulos; Evangelos Ntouvelis; Maria Kantzanou; Andreas-Antonios Diamantaras; Maria Moschovi; Margarita Baka; Emmanuel Hatzipantelis; Maria Kourti; Sophia Polychronopoulou; Eftichia Stiakaki; Ana-M. Mora; Victor Wünsch-Filho; Claire Infante-Rivard; Dimitrios Loutradis; Eleni Petridou
Parental alcohol consumption before and during pregnancy has been linked to adverse outcomes in the offspring including leukemogenesis. We, therefore, aimed to systematically assess and quantitatively synthesize published data on the association of paternal consumption during preconception and maternal consumption during pregnancy with leukemia risk in childhood (0–14 years). Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched PubMed (until February 2016) and the reference lists of the relevant studies. Observational studies examining the association between parental alcohol consumption and childhood leukemia were considered eligible. Data extracted from 39 case–control studies (over 16 000 leukemia cases and 30 000 controls) were pooled and summary-effect estimates were calculated. Subgroup analyses were carried out by main acute leukemia type [lymphoblastic or myeloid), cytogenetics/genetic polymorphisms, and specific alcohol beverages. We found a statistically significant dose–response association of any level of maternal alcohol consumption compared with nondrinking during pregnancy exclusively with acute myeloid leukemia (AML) [odds ratio (OR)moderate consumption: 1.64, 95% confidence intervals (CIs): 1.23–2.17 and ORhigh consumption: 2.36, 95% CI: 1.60–3.49]. In contrast, no association of paternal preconception consumption with any leukemia type was noted. In beverage-specific analyses, only a positive association of maternal wine drinking with childhood AML was found, which was more pronounced in analyses including only studies on infant leukemia (ORwine: 2.12, 95% CI: 1.16–3.90). The largest ever meta-analysis shows a sizeable, statistically significant dose–response association of maternal alcohol consumption during index pregnancy with AML risk. Future research exploring the role of genetic polymorphisms is anticipated to shed light on the underlying pathophysiology.
Pediatric Blood & Cancer | 2016
Thomas P. Thomopoulos; Theodoros N. Sergentanis; Maria A. Karalexi; Eleni Petridou
To the Editor: We read with great interest the recent metaanalysis by Yan et al.[1] on the associations of maternal factors during pregnancy and the risk of childhood acute lymphoblastic leukemia (ALL). Yet, certain methodological shortcomings, overlooked in this meta-analysis, need to be addressed. Exclusion of overlapping studies, namely, studies that have been performed on the same population during time intervals overlapping each other, is a prerequisite in the quantitative synthesis of studies included in a meta-analysis, as to avoid introducing replicate datasets in the synthesized scientific evidence.[2] The authors stated that the issue of overlap was addressed by retaining only the largest or themost recent study; nevertheless, in the forest plots provided by Yan et al. several publications springing from the same population during coinciding time periods were included as independent studies. Most strikingly, in the forest plot for birth order (Fig. 2), the AusALL study, a case–control study conducted during 2003–2007[3] was represented by five studies [Bailey et al. (2011), Milne et al. (2009), Milne et al. (2010), Milne et al. (2012), and Milne et al. (2013)] along with twoGreek studies [Diamantaras et al. (2013) and Lariou et al. (2013)] reporting on the same study population of the Nationwide Registry of Childhood Hematological Malignancies (NARECHEM) during the period 1999–2003;[4] likewise, in both included Californian studies [Ma et al. (2005) and Oksuzyan et al. (2013)], the Californian Cancer Registrywas the source of cases and the study periods coincided.[5] Similarly, in the forest plot examining maternal age (Supplementary Fig. S2), six studies [(Bartley et al. (2005), Chang et al. (2006), Kwan et al. (2005), Kwan et al. (2009), Ma et al. (2005a), and Ma et al. (2005b)], overlapped completely with the study by Oksuzyan et al.,[5] three Greek studies [(Diamantaras et al. (2013), Lariou et al. (2013), and Petridou et al. (2005)] were based on overlapping populations during the same time period and five studies [Bailey et al. (2010), Bailey et al. (2011), Milne et al. (2009), Milne et al. (2013), and Reid et al. (2011)] were actually different publications of the Aus-ALL study for the period 2003– 2007.[3] Moreover, as studies published up to 2014 were included, it is indirectly inferred that the end of search date, not disclosed in the paper, was 2014. If this is indeed the case, multiple potentially eligible studies were not included; not even, a large US multicenter study by Johnson et al. comprising over 4,000 childhood ALL cases, [6] published back in 2009. In conclusion, repeated inclusion of the same study populations via multiple publications as well as non-identification of eligible studies during the search and selection of studies process, may have considerably distorted the pooled effect estimates in the recent meta-analysis addressing exposures, as maternal age, birth order, and maternal education in association with childhood ALL. An elaborate strategy employing snowball procedures seems required in this context, as the respective variables are often used in multivariate models, aiming to investigate other exposures.
Paediatric and Perinatal Epidemiology | 2015
Maria A. Karalexi; Alkistis Skalkidou; Thomas P. Thomopoulos; Maria Belechri; Stylianos-Iason Biniaris-Georgallis; Evdoxia Bouka; Margarita Baka; Emmanuel Hatzipantelis; Maria Kourti; Sophia Polychronopoulou; Vassiliki Sidi; Eftichia Stiakaki; Maria Moschovi; Nick Dessypris; E. Th. Petridou
BACKGROUND Despite the putative intrauterine origins of childhood (0-14 years) leukaemia, it is complex to assess the impact of perinatal factors on disease onset. Results on the association of maternal history of fetal loss (miscarriage/stillbirth) with specific disease subtypes in the subsequent offspring are in conflict. We sought to investigate whether miscarriage and stillbirth may have different impacts on the risk of acute lymphoblastic leukaemia (ALL) and of its main immunophenotypes (B-cell and T-cell ALL), as contrasted to acute myeloid leukaemia (AML). METHODS One thousand ninety-nine ALL incidents (957 B-ALL) and 131 AML cases along with 1:1 age and gender-matched controls derived from the Nationwide Registry for Childhood Hematological Malignancies and Brain Tumors (1996-2013) were studied. Multivariable regression models were used to assess the roles of previous miscarriage(s) and stillbirth(s) on ALL (overall, B-, T-ALL) and AML, controlling for potential confounders. RESULTS Statistically significant exposure and disease subtype-specific associations of previous miscarriage(s) exclusively with AML [odds ratio (OR) 1.67, 95% confidence interval (CI) 1.00, 2.81] and stillbirth(s) with ALL [OR 4.82, 95% CI 1.63, 14.24] and B-ALL particularly, emerged. CONCLUSION Differential pathophysiological pathways pertaining to genetic polymorphisms or cytogenetic aberrations are likely to create hostile environments leading either to fetal loss or the development of specific leukaemia subtypes in subsequent offspring, notably distinct associations of maternal miscarriage history confined to AML and stillbirth history confined to ALL (specifically B-ALL). If confirmed and further supported by studies revealing underlying mechanisms, these results may shed light on the divergent leukemogenesis processes.
Cancer Causes & Control | 2017
Maria A. Karalexi; Nick Dessypris; Alkistis Skalkidou; Stylianos-Iason Biniaris-Georgallis; Ε. Ι. Kalogirou; Thomas P. Thomopoulos; Eric Herlenius; Logan G. Spector; D. Loutradis; Georgios Chrousos; E. Th. Petridou
PurposeHistory of fetal loss including miscarriage and stillbirth has been inconsistently associated with childhood (0–14 years) leukemia in subsequent offspring. A quantitative synthesis of the inconclusive literature by leukemia subtype was therefore conducted.MethodsEligible studies (N = 32) were identified through the screening of over 3500 publications. Random-effects meta-analyses were conducted on the association of miscarriage/stillbirth history with overall (AL; 18,868 cases/35,685 controls), acute lymphoblastic (ALL; 16,150 cases/38,655 controls), and myeloid (AML; 3042 cases/32,997 controls) leukemia. Sensitivity and subgroup analyses by age and ALL subtype, as well as meta-regression were undertaken.ResultsFetal loss history was associated with increased AL risk [Odds Ratio (OR) 1.10, 95% Confidence Intervals (CI) 1.04–1.18]. The positive association was seen for ALL (OR 1.12, 95%CI 1.05–1.19) and for AML (OR 1.13, 95%CI 0.91–1.41); for the latter the OR increased in sensitivity analyses. Notably, stillbirth history was significantly linked to ALL risk (OR 1.33, 95%CI 1.02–1.74), but not AML. By contrast, the association of ALL and AML with previous miscarriage reached marginal significance. The association of miscarriage history was strongest in infant ALL (OR 2.34, 95%CI 1.19–4.60).ConclusionsIn this meta-analysis involving >50,000 children, we found noteworthy associations by indices of fetal loss, age at diagnosis, and leukemia type; namely, of stillbirth with ALL and miscarriage history with infant ALL. Elucidation of plausible underlying mechanisms may provide insight into leukemia pathogenesis and indicate monitoring interventions prior to and during pregnancy.
The Lancet Haematology | 2016
Erin L. Marcotte; Thomas P. Thomopoulos; Claire Infante-Rivard; Jacqueline Clavel; Eleni Petridou; Joachim Schüz; Sameera Ezzat; John D. Dockerty; Catherine Metayer; Corrado Magnani; Michael E. Scheurer; Beth A. Mueller; Ana M. Mora; Catharina Wesseling; Alkistis Skalkidou; Wafaa M. Rashed; Stephen S. Francis; Roula Ajrouche; Friederike Erdmann; Laurent Orsi; Logan G. Spector
BACKGROUND Results from case-control studies have shown an increased risk of acute lymphoblastic leukaemia (ALL) in young children born by caesarean delivery, and prelabour caesarean delivery in particular; however, an association of method of delivery with childhood leukaemia subtypes has yet to be established. We therefore did a pooled analysis of data to investigate the association between childhood leukaemia and caesarean delivery. METHODS We pooled data from 13 case-control studies from the Childhood Leukemia International Consortium done in nine countries (Canada, Costa Rica, Egypt, France, Germany, Greece, Italy, New Zealand, and the USA) for births from 1970-2013. We analysed caesarean delivery overall and by indications that probably resulted in prelabour caesarean delivery or emergency caesarean delivery. We used multivariable logistic regression models, adjusted for childs birthweight, sex, age, ethnic origin, parental education, maternal age, and study, to estimate odds ratios (ORs) and 95% CIs for the risk of ALL and acute myeloid leukaemia (AML) in children aged 0-14 years at diagnosis. FINDINGS The studies provided data for 8780 ALL cases, 1332 AML cases, and 23 459 controls, of which the birth delivery method was known for 8655 (99%) ALL cases, 1292 (97%) AML cases, and 23 351 (>99%) controls. Indications for caesarean delivery were available in four studies (there were caesarean deliveries for 1061 of 4313 ALL cases, 138 of 664 AML cases, and 1401 of 5884 controls). The OR for all indications of caesarean delivery and ALL was 1·06 (95% CI 0·99-1·13), and was significant for prelabour caesarean delivery and ALL (1·23 [1·04-1·47]; p=0·018). Emergency caesarean delivery was not associated with ALL (OR 1·02 [95% CI 0·81-1·30]). AML was not associated with caesarean delivery (all indications OR 0·99 [95% CI 0·84-1·17]; prelabour caesarean delivery 0·83 [0·54-1·26]; and emergency caesarean delivery 1·05 [0·63-1·77]). INTERPRETATION Our results suggest an increased risk of childhood ALL after prelabour caesarean delivery. If this association is causal, maladaptive immune activation due to an absence of stress response before birth in children born by prelabour caesarean delivery could be considered as a potential mechanism. FUNDING National Cancer Institute.