title: Childhood leukemia and lymphoma: time trends and factors affecting survival in five Southern and Eastern European Cancer Registries.
abstract: OBJECTIVE
  Within Europe, incidence and mortality rates of childhood leukemia and lymphoma are rather heterogeneous. The present study comprising data from five Southern and Eastern European Cancer Registries aims to compare time trends and examine whether sociodemographic variables, clinical parameters, and proxies of efficient care affect survival.
  
  
  METHODS
  Data spanning 1996-2010 were obtained for a total of 3,041 newly diagnosed childhood leukemia and 1,183 lymphoma cases reported by the Greek Nationwide Registry for Childhood Hematological Malignancies, Bulgarian National Cancer Registry, Moscow Region and Turkey (Antalya and Izmir) Cancer Registries. Poisson modeling for the evaluation of time trends and multivariate Cox regression analysis for the assessment of prognostic factors were performed.
  
  
  RESULTS
  The incidence of leukemia was increasing in all cases, with Bulgaria and Greece presenting statistically significant annual changes (+3.5, and +1.7 %, respectively), followed by marginally increasing trends in Izmir and Moscow; by contrast, there was a remarkable, statistically significant, decreasing mortality trend for leukemia. Rates for lymphoma remained flat. Greece experienced almost twofold better survival rates for both leukemia and lymphoma, probably due to its higher socioeconomic status during the study period. Overall, patients with leukemia living in rural areas had a 28 % lower prognosis (RR: 1.28, 95 % CI 1.03-1.59), pointing to effects of remoteness, when the most privileged country (Greece) was excluded from the analysis.
  
  
  CONCLUSIONS
  The favorable mortality trends highlight the progress in Southern-Eastern European countries along their trajectory to converge with Northern-Western EU counterpart states. Socioeconomic status may act as a multipotent factor underlying the study findings.
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Athens University Medical School, 75 M. Asias Str. Goudi, 115 27, Athens, Greece. epetrid@med.uoa.gr
authors.forename: Eleni Th
authors.initials: ET
authors.lastname: Petridou
authors.forename: Nadya
authors.initials: N
authors.lastname: Dimitrova
authors.forename: Sultan
authors.initials: S
authors.lastname: Eser
authors.forename: Denis
authors.initials: D
authors.lastname: Kachanov
authors.forename: Hulya
authors.initials: H
authors.lastname: Karakilinc
authors.forename: Svetlana
authors.initials: S
authors.lastname: Varfolomeeva
authors.forename: Maria
authors.initials: M
authors.lastname: Belechri
authors.forename: Margarita
authors.initials: M
authors.lastname: Baka
authors.forename: Maria
authors.initials: M
authors.lastname: Moschovi
authors.forename: Sofia
authors.initials: S
authors.lastname: Polychronopoulou
authors.forename: Fani
authors.initials: F
authors.lastname: Athanasiadou-Piperopoulou
authors.forename: Ioanna
authors.initials: I
authors.lastname: Fragandrea
authors.forename: Eftichia
authors.initials: E
authors.lastname: Stiakaki
authors.forename: Apostolos
authors.initials: A
authors.lastname: Pourtsidis
authors.forename: Christodoulos
authors.initials: C
authors.lastname: Stefanadis
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Coebergh
authors.forename: Theodoros N
authors.initials: TN
authors.lastname: Sergentanis
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005060:Europe / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007938:Leukemia / Q000453:epidemiology / Q000401:mortality*; D008223:Lymphoma / Q000453:epidemiology / Q000401:mortality*; D012042:Registries; D012923:Social Class; D016019:Survival Analysis