title: Site-specific cancer risk in the Baltic cohort of Chernobyl cleanup workers, 1986-2007.
abstract: OBJECTIVE
  To assess site-specific cancer risk in the Baltic cohort of Chernobyl cleanup workers, 1986-2007.
  
  
  METHODS
  The Baltic cohort includes 17,040 men from Estonia, Latvia and Lithuania who participated in the environmental cleanup after the accident at the Chernobyl Nuclear Power Station in 1986-1991 and who were followed up for cancer incidence until the end of 2007. Cancer cases diagnosed in the cohort and in the male population of each country were identified from the respective national cancer registers. The proportional incidence ratio (PIR) with 95% confidence interval (CI) was used to estimate the site-specific cancer risk in the cohort. For comparison and as it was possible, the site-specific standardised incidence ratio (SIR) was calculated for the Estonian sub-cohort, which was not feasible for the other countries.
  
  
  RESULTS
  Overall, 756 cancer cases were reported during 1986-2007. A higher proportion of thyroid cancers in relation to the male population was found (PIR=2.76; 95%CI 1.63-4.36), especially among those who started their mission shortly after the accident, in April-May 1986 (PIR=6.38; 95%CI 2.34-13.89). Also, an excess of oesophageal cancers was noted (PIR=1.52; 95% CI 1.06-2.11). No increased PIRs for leukaemia or radiation-related cancer sites combined were observed. PIRs and SIRs for the Estonian sub-cohort demonstrated the same site-specific cancer risk pattern.
  
  
  CONCLUSIONS
  Consistent evidence of an increase in radiation-related cancers in the Baltic cohort was not observed with the possible exception of thyroid cancer, where conclusions are hampered by known medical examination including thyroid screening among cleanup workers.
authors.affiliation: Department of Epidemiology and Biostatistics, National Institute for Health Development, Tallinn, Estonia. kaja.rahu@tai.ee
authors.forename: Kaja
authors.initials: K
authors.lastname: Rahu
authors.forename: Timo
authors.initials: T
authors.lastname: Hakulinen
authors.forename: Giedre
authors.initials: G
authors.lastname: Smailyte
authors.forename: Aivars
authors.initials: A
authors.lastname: Stengrevics
authors.forename: Anssi
authors.initials: A
authors.lastname: Auvinen
authors.forename: Peter D
authors.initials: PD
authors.lastname: Inskip
authors.forename: John D
authors.initials: JD
authors.lastname: Boice
authors.forename: Mati
authors.initials: M
authors.lastname: Rahu
mesh_terms: D000328:Adult; D001454:Baltic States / Q000453:epidemiology; D047852:Chernobyl Nuclear Accident; D004938:Esophageal Neoplasms / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007938:Leukemia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D055848:Nuclear Power Plants; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D011829:Radiation Dosage; D011834:Radiation Monitoring; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult
keywords: Chernobyl nuclear accident; Estonia; Incidence; Latvia; Lithuania; Neoplasms; Radiation effects