title: Risk of myelodysplastic syndromes in people exposed to ionizing radiation: a retrospective cohort study of Nagasaki atomic bomb survivors.
abstract: OBJECTIVE
  The risk of myelodysplastic syndromes (MDS) has not been fully investigated among people exposed to ionizing radiation. We investigate MDS risk and radiation dose-response in Japanese atomic bomb survivors.
  
  
  METHODS
  We conducted a retrospective cohort study by using two databases of Nagasaki atomic bomb survivors: 64,026 people with known exposure distance in the database of Nagasaki University Atomic-Bomb Disease Institute (ABDI) and 22,245 people with estimated radiation dose in the Radiation Effects Research Foundation Life Span Study (LSS). Patients with MDS diagnosed from 1985 to 2004 were identified by record linkage between the cohorts and the Nagasaki Prefecture Cancer Registry. Cox and Poisson regression models were used to estimate relationships between exposure distance or dose and MDS risk.
  
  
  RESULTS
  There were 151 patients with MDS in the ABDI cohort and 47 patients with MDS in the LSS cohort. MDS rate increased inversely with exposure distance, with an excess relative risk (ERR) decay per km of 1.2 (95% CI, 0.4 to 3.0; P < .001) for ABDI. MDS risk also showed a significant linear response to exposure dose level (P < .001) with an ERR per Gy of 4.3 (95% CI, 1.6 to 9.5; P < .001). After adjustment for sex, attained age, and birth year, the MDS risk was significantly greater in those exposed when young.
  
  
  CONCLUSIONS
  A significant linear radiation dose-response for MDS exists in atomic bomb survivors 40 to 60 years after radiation exposure. Clinicians should perform careful long-term follow-up of irradiated people to detect MDS as early as possible.
authors.affiliation: Department of Hematology and Molecular Medicine, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. masakoiwng@gmail.com
authors.forename: Masako
authors.initials: M
authors.lastname: Iwanaga
authors.forename: Wan-Ling
authors.initials: WL
authors.lastname: Hsu
authors.forename: Midori
authors.initials: M
authors.lastname: Soda
authors.forename: Yumi
authors.initials: Y
authors.lastname: Takasaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tawara
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Joh
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Amenomori
authors.forename: Masaomi
authors.initials: M
authors.lastname: Yamamura
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Takashi
authors.initials: T
authors.lastname: Koba
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Matsuo
authors.forename: Dale L
authors.initials: DL
authors.lastname: Preston
authors.forename: Akihiko
authors.initials: A
authors.lastname: Suyama
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kodama
authors.forename: Masao
authors.initials: M
authors.lastname: Tomonaga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D019992:Databases as Topic; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007223:Infant; D007564:Japan; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000209:etiology*; D054043:Nuclear Weapons; D016016:Proportional Hazards Models; D011832:Radiation Injuries / Q000209:etiology*; D012042:Registries; D012111:Residence Characteristics; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017741:Survivors / Q000706:statistics & numerical data*; D013997:Time Factors; D055815:Young Adult