title: Relationship between radiation exposure and risk of second primary cancers among atomic bomb survivors.
abstract: Radiation exposure is related to risk of numerous types of cancer, but relatively little is known about its effect on risk of multiple primary cancers. Using follow-up data through 2002 from 77,752 Japanese atomic bomb survivors, we identified 14,048 participants diagnosed with a first primary cancer, of whom 1,088 were diagnosed with a second primary cancer. Relationships between radiation exposure and risks of first and second primary cancers were quantified using Poisson regression. There was a similar linear dose-response relationship between radiation exposure and risks of both first and second primary solid tumors [excess relative risk (ERR)/Gy = 0.65; 95% confidence interval (CI), 0.57-0.74 and ERR/Gy = 0.56; 95% CI, 0.33-0.80, respectively] and risk of both first and second primary leukemias (ERR/Gy = 2.65; 95% CI, 1.78-3.78 and ERR/Gy = 3.65; 95% CI, 0.96-10.70, respectively). Background incidence rates were higher for second solid cancers, compared with first solid cancers, until about age 70 years for men and 80 years for women (P < 0.0001), but radiation-related ERRs did not differ between first and second primary solid cancers (P = 0.70). Radiation dose was most strongly related to risk of solid tumors that are radiation-sensitive including second primary lung, colon, female breast, thyroid, and bladder cancers. Radiation exposure confers equally high relative risks of second primary cancers as first primary cancers. Radiation is a potent carcinogen and those with substantial exposures who are diagnosed with a first primary cancer should be carefully screened for second primary cancers, particularly for cancers that are radiation-sensitive.
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Departments of Epidemiology and Biostatistics, University of Washington, Seattle, WA 98109-1024, USA. cili@fhcrc.org
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Li
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nishi
authors.forename: Jean A
authors.initials: JA
authors.lastname: McDougall
authors.forename: Erin O
authors.initials: EO
authors.lastname: Semmens
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sugiyama
authors.forename: Midori
authors.initials: M
authors.lastname: Soda
authors.forename: Ritsu
authors.initials: R
authors.lastname: Sakata
authors.forename: Mikiko
authors.initials: M
authors.lastname: Hayashi
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Kasagi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Suyama
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Mabuchi
authors.forename: Scott
authors.initials: S
authors.lastname: Davis
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kodama
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Kopecky
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology / Q000209:etiology*; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000209:etiology*; D009689:Nuclear Warfare; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D017741:Survivors