title: Ionizing radiation exposure and the development of soft-tissue sarcomas in atomic-bomb survivors.
abstract: BACKGROUND
  Very high levels of ionizing radiation exposure have been associated with the development of soft-tissue sarcoma. The effects of lower levels of ionizing radiation on sarcoma development are unknown. This study addressed the role of low to moderately high levels of ionizing radiation exposure in the development of soft-tissue sarcoma.
  
  
  METHODS
  Based on the Life Span Study cohort of Japanese atomic-bomb survivors, 80,180 individuals were prospectively assessed for the development of primary soft-tissue sarcoma. Colon dose in gray (Gy), the excess relative risk, and the excess absolute rate per Gy absorbed ionizing radiation dose were assessed. Subject demographic, age-specific, and survival parameters were evaluated.
  
  
  RESULTS
  One hundred and four soft-tissue sarcomas were identified (mean colon dose = 0.18 Gy), associated with a 39% five-year survival rate. Mean ages at the time of the bombings and sarcoma diagnosis were 26.8 and 63.6 years, respectively. A linear dose-response model with an excess relative risk of 1.01 per Gy (95% confidence interval [CI]: 0.13 to 2.46; p = 0.019) and an excess absolute risk per Gy of 4.3 per 100,000 persons per year (95% CI: 1.1 to 8.9; p = 0.001) were noted in the development of soft-tissue sarcoma.
  
  
  CONCLUSIONS
  This is one of the largest and longest studies (fifty-six years from the time of exposure to the time of follow-up) to assess ionizing radiation effects on the development of soft-tissue sarcoma. This is the first study to suggest that lower levels of ionizing radiation may be associated with the development of soft-tissue sarcoma, with exposure of 1 Gy doubling the risk of soft-tissue sarcoma development (linear dose-response). The five-year survival rate of patients with soft-tissue sarcoma in this population was much lower than that reported elsewhere.
authors: Radiation Effects Research Foundation, Hiroshima and Nagasaki, Japan. dsamartzis@msn.com
authors: Dino
authors: D
authors: Samartzis
authors: Nobuo
authors: N
authors: Nishi
authors: John
authors: J
authors: Cologne
authors: Sachiyo
authors: S
authors: Funamoto
authors: Mikiko
authors: M
authors: Hayashi
authors: Kazunori
authors: K
authors: Kodama
authors: Edward F
authors: EF
authors: Miles
authors: Akihiko
authors: A
authors: Suyama
authors: Midori
authors: M
authors: Soda
authors: Fumiyoshi
authors: F
authors: Kasagi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D009689:Nuclear Warfare; D054043:Nuclear Weapons; D011446:Prospective Studies; D012509:Sarcoma / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012983:Soft Tissue Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D015996:Survival Rate; D017741:Survivors